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1

Hamster oocyte penetration tests with oocytes frozen in propanediol: comparison with non-frozen oocytes.  

PubMed

Hamster oocytes were frozen using a 1,2-propanediol-sucrose procedure, which resulted in over 90% survival. After thawing and zona removal the oocytes were compared with non-frozen oocytes in a zona-free hamster egg test employing spermatozoa from human semen donors and suspected infertility patients. Similar data were obtained, indicating that propanediol-sucrose frozen hamster eggs may be used in place of fresh eggs for convenience and to avoid scheduling problems. PMID:2591850

Sachs, H H; Pink, M J; Gwatkin, R B

1989-09-01

2

Collection and cryopreservation of hamster oocytes and mouse embryos.  

PubMed

Embryos and oocytes were first successfully cryopreserved more than 30 years ago, when Whittingham et al. and Wilmut separately described that mouse embryos could be frozen and stored at -196 degrees C and, a few years later, Parkening et al. reported the birth of live offspring resulting from in vitro fertilization (IVF) of cryopreserved oocytes. Since then, the use of cryopreservation techniques has rapidly spread to become an essential component in the practice of human and animal assisted reproduction and in the conservation of animal genetic resources. Currently, there are two main methods used to cryopreserve oocytes and embryos: slow freezing and vitrification. A wide variety of approaches have been used to try to improve both techniques and millions of animals and thousands of children have been born from cryopreserved embryos. However, important shortcomings associated to cryopreservation still have to be overcome, since ice-crystal formation, solution effects and osmotic shock seem to cause several cryoinjuries in post-thawed oocytes and embryos. Slow freezing with programmable freezers has the advantage of using low concentrations of cryoprotectants, which are usually associated with chemical toxicity and osmotic shock, but their ability to avoid ice-crystal formation at low concentrations is limited. Slow freezing also induces supercooling effects that must be avoided using manual or automatic seeding. In the vitrification process, high concentrations of cryoprotectants inhibit the formation of ice-crystals and lead to the formation of a glasslike vitrified state in which water is solidified, but not expanded. However, due to the toxicity of cyroprotectants at the concentrations used, oocytes/embryos can only be exposed to the cryoprotectant solution for a very short period of time and in a minimum volume solution, before submerging the samples directly in liquid nitrogen. In the last decade, vitrification has become more popular because it is a very quick method in which no expensive equipment (programmable freezer) is required. However, slow freezing continues to be the most widely used method for oocyte/embryo cryopreservation. In this video-article we show, step-by-step, how to collect and slowly freeze hamster oocytes with high post-thaw survival rates. The same procedure can also be applied to successfully freeze and thaw mouse embryos at different stages of preimplantation development. PMID:19329926

Costa-Borges, Nuno; González, Sheyla; Ibáñez, Elena; Santaló, Josep

2009-01-01

3

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

4

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....

5

Hamsters  

NSDL National Science Digital Library

Scientists believe that most behaviors, from fighting to mating, are controlled by brain chemistry. In this Science Update, you'll hear how researchers are using hamsters to understand the roots of aggression.

Science Update;

2000-03-15

6

In vitro penetration of pig oocytes in a modified Tris-buffered medium: effect of BSA, caffeine and calcium  

Microsoft Academic Search

The effect of BSA, caffeine and calcium was studied on the penetration of pig oocytes by frozen-thawed spermatozoa in a modified Tris-buffered medium (mTBM) without added bicarbonate. Pig cumulus-oocyte complexes (COC) were cultured in BSA-free NCSU 23 medium containing porcine follicular fluid (10%), cysteine (0.1 mg\\/ml) and hormonal supplements (eCG and hCG: 10 IU\\/ml each) for 22 h. The COC

L. R. Abeydeera; B. N. Day

1997-01-01

7

Platelet activating factor improves the in vitro penetration of zona free hamster eggs by buffalo (Bubalus bubalis) spermatozoa.  

PubMed

Twelve buffalo bulls of Murrah breed, selected on the basis of their conception rates, were classified into low-, moderate- and high-fertility groups. Frozen semen was thawed and treated with 200 microM platelet activating factor (PAF) for 15 min at 37 degrees C and 5% CO2. In both treated and control (no PAF) semen samples (five replicates per bull), the following were assessed: motility, acrosome reaction (AR) evaluation (for 10 replicates of each bull), and zona-free hamster oocyte penetration test--to determine aspects of fertilization in vitro, viz., sperm attached per ovum (SA/O), fertilization percent (FP), fertilization index (FI), and polyspermic ova (PO). There was an effect of group (P < 0.01) on all parameters; all except motility were increased by PAF treatment. However, the group X treatment interaction was not significant for any parameter. The overall mean values of motility, AR, SA/O, FP, FI, and PO, for controls, treated spermatozoa and (net change) were: 42.89 +/- 0.85, 36.65 +/- 0.85, (-6.24); 28.94 +/- 0.46, 61.44 +/- 0.58, (32.50); 126 +/- 2, 145 +/- 2, (19); 74.21 +/- 1.59, 89.11 +/- 1.18, (14.90); 0.79 +/- 0.02, 1.10 +/- 0.03, (0.31) and 5.22 +/- 1.22, 21.69 +/- 1.88, (16.47)%, respectively. In conclusion, PAF significantly increased the AR and other aspects of fertilization, despite a small reduction in motility. PMID:15763101

Kumar, Subodh; Sharma, Arjava

2005-04-01

8

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...

9

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

10

Sperm attachment and penetration competence in the human oocyte: a possible aetiology of fertilization failure involving the organization of oolemmal lipid raft microdomains influenced by the ??m of subplasmalemmal mitochondria.  

PubMed

The roles of oolemmal lipid raft microdomains enriched in the ganglioside GM1 and the tetraspanin protein CD9 were investigated as causative agents in fertilization failure in human IVF where spermatozoa progress to the oolemma but fail to attach or, if attached, to penetrate. The findings show that specific configurations of GM1 lipid raft microdomains are consistent with attachment and penetration, while microdomains composed of CD9 lipid rafts, a protein known to be critical for penetration, do not appear to have a central role in the initial stages of attachment. The relative magnitude of the potential difference across the inner membrane (??m) in mitochondria localized to a stable subplasmalemmal domain appears to influence the organization of GM1 but not CD9 lipid raft microdomains in the corresponding oolemma. The findings present a novel view of how fertilization competence may be established in the human oocyte and a means by which certain fertilization failures that occur after conventional clinical IVF can be identified and explained in the unfortunate instance of fertilization arrest at the oolemma. PMID:24157131

Van Blerkom, Jonathan; Caltrider, Kyle

2013-12-01

11

Pyrazine derivatives in cigarette smoke inhibit hamster oviductal functioning  

Microsoft Academic Search

BACKGROUND: Our past studies have shown that cigarette smoke inhibits oviductal functioning in vivo and in vitro. The goals in this study were to identify pyrazine derivatives in cigarette smoke solutions that inhibit ciliary beat frequency, oocyte pickup rate, and infundibular smooth muscle contraction in the hamster oviduct and to determine their lowest observable adverse effect levels (LOAELs) using in

Karen Riveles; Ryan Roza; Janet Arey; Prue Talbot

2004-01-01

12

Evaluation of the effect of 17alphaOH-progesterone and 17beta-oestradiol on human sperm ability to fuse with oocytes: comparison and possible interference with the effect of progesterone.  

PubMed

The demonstration of a stimulatory effect of progesterone (P) on the sperm/oocyte fusion has provided the most relevant biological evidence of the effect of P on sperm functions involved in fertilization. Some evidence exists that 17alpha-hydroxyprogesterone (17alphaOH-P) and 17beta-oestradiol (17beta-E2), could also exert non-genomic effects on human spermatozoa and a role for 17beta-E2 as a possible physiological modulator of P action on spermatozoa has been suggested. This study aimed to determine the effect of the exposure of human spermatozoa to 17alphaOH-P and 17beta-E2 on sperm/oocyte fusion as well as the possible interference of 17beta-E2 with the effect of P. The effect of steroids on sperm/oocyte fusion was assessed by means of the hamster egg penetration test (HEPT). The exposure of capacitated sperm suspensions to scalar doses of 17alphaOH-P produced a significant enhancement of penetrations/oocytes with a dose/response effect. It was equal to 75.3% of that produced by equimolar doses of P. Conversely, 17beta-E2 (from 100 nM to 50 microM) did not produce any significant effect when added either before or after capacitation. Moreover, the sperm pre-incubation with 17beta-E2 did not interfere with the stimulatory effect of P. These results support a physiological role for 17OH-P in the process of fertilization, but not a role for 17beta-E2 as a possible physiological modulator of P action on spermatozoa. PMID:14636219

Francavilla, F; Romano, R; Pandolfi, C; Macerola, B; Santucci, R; Necozione, S; Francavilla, S

2003-12-01

13

Localization of fucosyl glycoconjugates in human oocytes following insemination for in vitro fertilization.  

PubMed

Human oocytes that failed to cleave after insemination were examined for the presence of fucosyl glycoconjugates in the perivitelline space by staining with Ulex europeaus lectin conjugated to fluorescein isothiocynate. Oocytes that formed two or three pronuclei following first insemination always exhibited positive lectin staining similar to that observed with in vitro fertilized mouse oocytes. Among those oocytes that failed to form any pronuclei after the first insemination attempt, only 5% contained lectin positive substances in the perivitelline space. Upon reinsemination, a higher percentage of those oocytes produced lectin-positive materials, although pronuclei were still absent. The appearance of fucosyl glycoconjugates in these oocytes might be the result of the release of cortical granules triggered by sperm penetration or, more likely, due to spontaneous granule discharge in senescent oocytes. PMID:2380620

Tam, P P; Loong, E P; Chiu, T T

1990-06-01

14

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, ...

15

Curiosity in the hamster  

Microsoft Academic Search

Running time for repeated alley runs by hamsters to end boxes containing (a) nothing, (b) a constant set of objects, or (c) a changing set of objects was in the order a > b > c: thus, novelty appeared reinforcing. Length of intersession interval (2, 24, 48 hr.) affected only Condition b: thus, \\

Gerald E. Schneider; Charles G. Gross

1965-01-01

16

Gait Disturbances in Dystrophic Hamsters  

PubMed Central

The delta-sarcoglycan-deficient hamster is an excellent model to study muscular dystrophy. Gait disturbances, important clinically, have not been described in this animal model. We applied ventral plane videography (DigiGait) to analyze gait in BIO TO-2 dystrophic and BIO F1B control hamsters walking on a transparent treadmill belt. Stride length was ?13% shorter (P < .05) in TO-2 hamsters at 9 months of age compared to F1B hamsters. Hindlimb propulsion duration, an indicator of muscle strength, was shorter in 9-month-old TO-2 (247 ± 8?ms) compared to F1B hamsters (272 ± 11?ms; P < .05). Braking duration, reflecting generation of ground reaction forces, was delayed in 9-month-old TO-2 (147 ± 6?ms) compared to F1B hamsters (126 ± 8?ms; P < .05). Hindpaw eversion, evidence of muscle weakness, was greater in 9-month-old TO-2 than in F1B hamsters (17.7 ± 1.2° versus 8.7 ± 1.6°; P < .05). Incline and decline walking aggravated gait disturbances in TO-2 hamsters at 3 months of age. Several gait deficits were apparent in TO-2 hamsters at 1 month of age. Quantitative gait analysis demonstrates that dystrophic TO-2 hamsters recapitulate functional aspects of human muscular dystrophy. Early detection of gait abnormalities in a convenient animal model may accelerate the development of therapies for muscular dystrophy. PMID:21318074

Hampton, Thomas G.; Kale, Ajit; Amende, Ivo; Tang, Wenlong; McCue, Scott; Bhagavan, Hemmi N.; VanDongen, Case G.

2011-01-01

17

Liquid penetrants  

NASA Technical Reports Server (NTRS)

Liquid-penetrant inspection is discussed for surface defects in solids. The principle advantages are considered to be its simplicity and economy. The techniques and penetrants are described along with the developers. Commercially available equipment is also described.

Pasley, R. L.

1973-01-01

18

Development block of golden hamster ICSI embryos is associated with decreased expression of HDAC1, HSPA1A and MYC.  

PubMed

We have investigated the mechanism for embryo development block in vitro and to improve the development rate of golden hamster embryos in vitro. Intracytoplasmic sperm injection (ICSI) technique was used to produce golden hamster ICSI embryos. The changes in the histone acetylation and the expression of histone deacetylase and related genes were analyzed by immunocytochemical staining and real-time PCR both in golden hamster in vivo embryos and in ICSI embryos. Aged oocytes significantly increased the oocyte spontaneous activation rate. In vitro cultured ICSI embryos suffered from severe development block in M199TE medium. Expression of histone deacetylase 1 (HDAC1) was significantly decreased in the nuclei of the arrested ICSI 2-cell embryos, and its nuclear and cytoplasmic expression pattern was also markedly altered. The acetylation level of H4K5, however, was not significantly changed between golden hamster in vivo embryos and ICSI embryos. HSPA1A and MYC, the marker genes for zygotic genome activation (ZGA), were transcriptionally decreased in arrested ICSI 2-cell embryos. Transcription of HDAC1 was also downregulated in these embryos, whereas the mRNA expression of the proapoptotic gene, BAX, was not changed. These results indicate that the golden hamster ICSI embryo development block during ZGA is associated with decreased nuclear expression and altered expression of HDAC1. HSPA1A, MYC, and HDAC1 mRNA levels, which decrease, resulting in ZGA failure. PMID:24890342

Pan, Xiaoyan; Kong, Delong; Liu, Limei; Gao, Fei; Zhang, Xueming; Tang, Bo; Li, Ziyi

2014-11-01

19

Oolemma receptors and oocyte activation.  

PubMed

At fertilization the sperm triggers a series of intracellular calcium oscillations that are pivotal to oocyte activation and development. Although the biological significance of the characteristic intracellular calcium (Ca(2+)(i)) oscillations is not fully understood, calcium ions are known to be involved in cortical granule release and in controlling cell cycle progression. Two different hypotheses attempt to explain how sperm initiate (Ca(2+)(i)) oscillations in mammalian oocytes. One hypothesis is that spermatozoa interact with a receptor located in the plasma membrane of the oocyte, which results in induction of pathways leading to activation. This receptor is coupled to a GTP-binding protein or to have tyrosine kinase activity and have the ability to induce activation of phospholipase C (PLC). In turn, PLC stimulates the hydrolysis of phosphatidyl inositol (4,5)-bisphosphate (PIP2) to produce diacylglycerol (DAG) and 1,4,5 inositol trisphosphate (IP3), a common Ca(2+) releasing compound. Most studies used to develop the mammalian model of oocyte activation have been performed in the mouse. There is a paucity of information from other mammalian models. The predominant mouse model of oocyte activation is that there is a soluble factor (PLC-zeta) delivered to the cytosol after fertilization that induces oocyte activation. However, as data in other mammals is collected, substantial evidence is beginning to support the existence of other more complex oocyte activation pathways in both murine and non-murine systems. Indeed, activation may involve redundant processes, each of which acting alone may be able to induce aspects of oocyte activation. Recent findings demonstrate the involvement of receptors that are known to associate in large, multimeric complexes. This fact leads one to speculate that the process of oocyte activation by the sperm cell is a highly complex and elaborate process that likely involves many more players than perhaps was initially expected. PMID:20397882

White, Kenneth L; Pate, Barry J; Sessions, Benjamin R

2010-10-01

20

Nanoliter droplet vitrification for oocyte cryopreservation  

PubMed Central

Aim Oocyte cryopreservation remains largely experimental, with live birth rates of only 2–4% per thawed oocyte. In this study, we present a nanoliter droplet technology for oocyte vitrification. Materials & methods An ejector-based droplet vitrification system was designed to continuously cryopreserve oocytes in nanoliter droplets. Oocyte survival rates, morphologies and parthenogenetic development after each vitrification step were assessed in comparison with fresh oocytes. Results Oocytes were retrieved after cryoprotectant agent loading/unloading, and nanoliter droplet encapsulation showed comparable survival rates to fresh oocytes after 24 h in culture. Also, oocytes recovered after vitrification/thawing showed similar morphologies to those of fresh oocytes. Additionally, the rate of oocyte parthenogenetic activation after nanoliter droplet encapsulation was comparable with that observed for fresh oocytes. This nanoliter droplet technology enables the vitrification of oocytes at higher cooling and warming rates using lower cryoprotectant agent levels (i.e., 1.4 M ethylene glycol, 1.1 M dimethyl sulfoxide and 1 M sucrose), thus making it a potential technology to improve oocyte cryopreservation outcomes. PMID:22188180

Zhang, Xiaohui; Khimji, Imran; Shao, Lei; Safaee, Hooman; Desai, Khanjan; Keles, Hasan Onur; Gurkan, Umut Atakan; Kayaalp, Emre; Nureddin, Aida; Anchan, Raymond M; Maas, Richard L; Demirci, Utkan

2011-01-01

21

Nuclear and Spindle Positioning during Oocyte Meiosis  

PubMed Central

Female meiosis is unique in that an asymmetrically positioned meiotic spindle expels chromosomes into tiny, non-developing polar bodies. The extrusion of chromosomes into polar bodies is always mediated by meiotic spindles that are attached to the oocyte cortex by one pole. The asymmetric, cortical positioning of the oocyte meiotic spindle preserves the volume and contents of the oocyte. Recent work in C. elegans and mouse has provided mechanistic details of spindle positioning in oocytes. PMID:20708397

Fabritius, Amy S.; Ellefson, Marina L.; McNally, Francis J.

2010-01-01

22

[Oocyte donation as in France].  

PubMed

Oocyte donation, initially proposed in agonadal women, saw indications expand to ovarian deficiencies and failures of in vitro fertilization (IVF), resulting in a significant increasing demand. The recruitment of oocyte donors is a critical issue for all countries that have allowed this practice. The French legislation, with the laws of bioethics, is clearly the most restrictive of European countries, imposing an absolute free gift from mother. The different solutions in the neighboring countries are analysed and in particular the interpretations made in respect of gratuity and compensation. Motivating donors (spontaneous, relational, or by reciprocity), but also motivating the medical teams can organize a program of oocyte donation in France. The authors present their results of three years experience, demonstrating that this system is possible in the current legislative framework. PMID:20022281

Le Lannou, D; Griveau, J-F; Veron, E; Jaffre, F; Jouve, G; Descheemaeker, V; Gueho, A; Morcel, K

2010-01-01

23

Recent Progress in Cryopreservation of Bovine Oocytes  

PubMed Central

Principle of oocyte cryoinjury is first overviewed and then research history of cryopreservation using bovine oocytes is summarized for the last two decades with a few special references to recent progresses. Various types of cryodevices have been developed to accelerate the cooling rate and applied to the oocytes from large domestic species enriched with cytoplasmic lipid droplets. Two recent approaches include the qualitative improvement of IVM oocytes prior to the vitrification and the short-term recovery culture of vitrified-warmed oocytes prior to the subsequent IVF. Supplementation of L-carnitine to IVM medium of bovine oocytes has been reported to reduce the amount of cytoplasmic lipid droplets and improve the cryotolerance of the oocytes, but it is still controversial whether the positive effect of L-carnitine is reproducible. Incidence of multiple aster formation, a possible cause for low developmental potential of vitrified-warmed bovine oocytes, was inhibited by a short-term culture of the postwarm oocytes in the presence of Rho-associated coiled-coil kinase (ROCK) inhibitor. Use of an antioxidant ?-tocopherol, instead of the ROCK inhibitor, also supported the revivability of the postwarm bovine oocytes. Further improvements of the vitrification procedure, combined with pre- and postvitrification chemical treatment, would overcome the high sensitivity of bovine oocytes to cryopreservation. PMID:24738063

Hochi, Shinichi

2014-01-01

24

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

25

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

26

Comparison of in-vitro outcomes from cryopreserved oocytes and sibling fresh oocytes.  

PubMed

In Italy, the restrictive IVF law generalizes the indication for oocyte freezing for surplus oocytes in 78.5% of in-vitro assisted reproductive cycles. With a view to understanding better what the prospects for intracytoplasmic sperm injection (ICSI) on frozen-thawed oocytes might be, the consequences of freeze-thaw procedures on fertilization, cleavage rates and embryo quality obtained from frozen-thawed oocytes were studied and compared with the results obtained from sibling fresh oocytes. Eleven IVF and 29 ICSI on 76 and 169 fresh oocytes were performed and the corresponding 40 ICSI on 221 sibling frozen-thawed oocytes. There was no difference in terms of fertilization rate between fresh and sibling frozen-thawed oocytes. The cleavage rate (98.0 and 94.4% with fresh oocytes in IVF and ICSI; 77.3% with frozen-thawed oocytes in ICSI; P < 0.001) and embryo quality (grade I embryos over total embryos: 36.7 and 22.2% with fresh oocytes in IVF and ICSI; 12.1% with frozen-thawed oocytes in ICSI; respectively P < 0.001 and P < 0.05) were statistically lower after oocyte cryopreservation. The significant decrease in meiotic spindle retrieval rate before freezing (62.4%) and after thawing procedures (43.4%; P < 0.001) suggests that cryoconservation induces irreversible damage to microtubule repolymerization. The consequences of oocyte cryopreservation procedures on embryo development are reviewed. PMID:16792849

Chamayou, S; Alecci, C; Ragolia, C; Storaci, G; Maglia, E; Russo, E; Guglielmino, A

2006-06-01

27

The Transcriptome of a Human Polar Body Accurately Reflects Its Sibling Oocyte*S  

E-print Network

created through in vitro fertilization (IVF). All oocytes that are retrieved and matured in culture applications. The clinical importance of healthy oocyte development is evidenced by the impressive pregnancy

Wessel, Gary M.

28

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

29

Oocyte control of metabolic cooperativity between oocytes and companion granulosa cells: energy metabolism  

Microsoft Academic Search

Intercellular communication between oocytes and granulosa cells is essential for normal follicular differentiation and oocyte development. Subtraction hybridization was used to identify genes more highly expressed in cumulus cells than in mural granulosa cells of mouse antral follicles. This screen identified six genes involved in glycolysis: Eno1, Pkm2, Tpi, Aldoa, Ldh1, and Pfkp. When oocytes were microsurgically removed from cumulus

Koji Sugiura; Frank L. Pendola; John J. Eppig

2005-01-01

30

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

31

In Vitro Fertilization and Development of Porcine Oocytes Matured in Follicular Fluid  

PubMed Central

Abstract This study was conducted to assess the fertilization and development of porcine oocytes matured in a solo follicular fluid (pFF) using different in vitro culture systems and insemination periods. Cumulus-oocyte complexes (COCs), follicular cells (FCs), and pFF were collected from the follicles of ovaries. The pFF was used as a maturation medium (MpFF) after supplementation with follicle stimulating hormone (FSH) and antibiotics. The COCs were matured in a 15 ml test tube containing 3.5 ml of MpFF with FCs (5.2 × 106 cells/ml; rotating culture system) or 2 ml of MpFF without FCs in a 35-mm petri dish (static culture system) for 44 to 48 h. After maturation culture, oocytes were co-incubated with frozen-thawed spermatozoa for 5 h and then cultured for 7 days. The total mean rates of sperm penetration, normal fertilization, male pronucleus (MPN) formation, cleavage, and development to the blastocyst stage of oocytes after insemination were significantly higher (P<0.01) in the rotating culture system than in the static culture system. In conclusion, compared with the static culture system, the rotating culture system is adequate for the production of developmentally competent porcine oocytes when MpFF is used as a maturation medium. PMID:23428620

AGUNG, Budiyanto; OTOI, Takeshige; FUCHIMOTO, Dai-ichiro; SENBON, Shoichiro; ONISHI, Akira; NAGAI, Takashi

2013-01-01

32

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

33

Calcium ion currents mediating oocyte maturation events  

Microsoft Academic Search

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

Elisabetta Tosti

2006-01-01

34

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...

35

Current trends and progress in clinical applications of oocyte cryopreservation  

PubMed Central

Purpose of review To delineate the current trends in the clinical application of oocyte cryopreservation. Recent findings Although the first live birth from oocyte cryopreservation was reported approximately three decades ago, significant improvement in the clinical application of oocyte cryopreservation took place only over the past decade. On the basis of the available evidence suggesting that success rates with donor oocyte vitrification are similar to that of IVF with fresh donor oocytes, the American Society of Reproductive Medicine has recently stated that oocyte cryopreservation should no longer be considered experimental for medical indications, outlying elective oocyte cryopreservation. Meanwhile, a few surveys on the attitudes toward oocyte cryopreservation revealed that elective use for the postponement of fertility is currently the most common indication for oocyte cryopreservation. Most recently, a randomized controlled trial revealed important evidence on the safety of nondonor oocyte cryopreservation, and confirmed that the clinical success of vitrification is comparable to that of IVF with fresh oocytes. Summary The evidence suggesting similar IVF success rates with both donor and nondonor cryopreserved oocytes compared with fresh oocytes will increase the utilization of elective oocyte cryopreservation. Appropriate counseling of women for oocyte cryopreservation requires the establishment of age-based clinical success rates with cryopreserved oocytes for various indications. PMID:23562954

Cil, Aylin P.; Seli, Emre

2013-01-01

36

ACOG: Committee Opinion No. 584: oocyte cryopreservation.  

PubMed

: In 2013, the American Society for Reproductive Medicine and the Society for Assisted Reproductive Technology published a joint document, Mature Oocyte Cryopreservation: A Guideline, which addresses advances in techniques to freeze human eggs that have resulted in significant recent improvements in pregnancy success. Based on the current state of evidence, modern procedures to cryopreserve oocytes should no longer be considered experimental. The American College of Obstetricians and Gynecologists' Committee on Gynecologic Practice endorses the joint document and encourages its use by Fellows. There are not yet sufficient data to recommend oocyte cryopreservation for the sole purpose of circumventing reproductive aging in healthy women. PMID:24463693

2014-01-01

37

Effects of alphafetoprotein on isolated mouse oocytes.  

PubMed

The supposition of an effect of alphafetoprotein (AFP) on female germinal cells is put forward. The spontaneous in vitro maturation of adult mouse oocytes is significantly inhibited when mouse AFP replaces albumin in culture medium. Furthermore, the very unusual degenerative appearance of the cells subjected to AFP seems to indicate that this meiotic inhibition is linked to a premature degeneration of the oocytes rather than to a blockage of the cells at an earlier stage of maturation. Accordingly AFP, perhaps through its ligands, may play a role in reducing the number of gonocytes during fetal and immediate post-natal life rather than in stopping oocyte meiosis at the diplotene stage. PMID:2432648

Lambert, J C; Seralini, G E; Stora, C; Vallette, G; Vranckx, R; Nunez, E A

1986-01-01

38

Metabolism of amino acids differs in the brains of Djungarian hamster (P. sungorus) and Roborovskii hamster (P. roborovskii).  

PubMed

Djungarian hamster (P. sungorus) and Roborovskii hamster (P. roborovskii) belong to the same genus of phodopus. Roborovskii hamster shows high locomotor activity and low level of dopamine (DA) in the brain. Administration of L-tyrosine, a precursor of DA, decreases locomotor activity in Roborovskii hamsters. However, the amino acid metabolism in relation to the hyperactivity is not yet well known. In the present study, L- and D-amino acid concentrations in the brain, liver, and plasma in Djungarian and Roborovskii hamsters were investigated during day and night times to explain the possible difference in hyperactivity between them. Most of the examined amino acids were higher in the night time when hamsters are active compared to those in day time. L- and D-tyrosine concentrations were higher in the liver of Roborovskii hamsters than in Djungarian hamsters. Furthermore, brain concentration of D-tyrosine was higher in the Roborovskii than in Djungarian hamsters, but no significant difference was observed for L-tyrosine concentrations between the two species. These results suggest that the conversion of L-tyrosine to D-tyrosine in the brain of Roborovskii hamster may be higher than in Djungarian hamster, which may cause low DA concentration and hyperactivity in Roborovskii hamster. On the other hand, L- and D-serine, which are known as sedative factors, were lower in Roborovskii hamsters than Djungarian hamster. These results suggest that species-specific regulation in amino acid metabolism may contribute to hyperactivity in Roborovskii hamsters. PMID:24936396

Ikeda, Hiromi; Kawase, Takahiro; Nagasawa, Mao; Chowdhury, Vishwajit Sur; Yasuo, Shinobu; Furuse, Mitsuhiro

2014-01-01

39

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

40

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

E-print Network

one of the major reasons for the failure to produce viable porcine embryos. This phenomenon has included modifying culture medium and number of spermatozoa inseminated in order to reduce the incidence in the microchannels has produced a higher incidence of monospermic penetration (p , 0.05) as compared to the oocytes

Beebe, David J.

41

Caspase 9 is constitutively activated in mouse oocytes and plays a key role in oocyte elimination during meiotic prophase progression  

PubMed Central

In many mammalian species, more than half of the initial oocyte population is eliminated by neonatal life, thus limiting the oocyte reserve for reproduction. The cause or mechanism of this major oocyte loss remains poorly understood. We examined the apoptotic pathway involved in oocyte elimination in wild-type mouse ovaries as well as in Msh5 ?/? ovaries, in which all oocytes were eliminated due to a lack of double strand break repair. Immunoblot and immunofluorescence staining showed that an initiator caspase 9 and an effector caspase 7 were constitutively activated in almost all oocytes in fetal ovaries regardless of their genotypes. In caspase 9 ?/? ovaries, the total number of oocytes remained high while that in wild-type ovaries steadily declined during ovarian development. Therefore, the activation of caspase 9 was required for but did not immediately lead to oocyte demise. We found that XIAP, an endogenous inhibitor of apoptosis, was also abundant in oocytes during meiotic prophase progression. On the other hand, a cleaved form of PARP1, a target of effector caspases, was localized to the nuclei of a limited number of oocytes, and the frequency of cleaved PARP1-positive oocyte nuclei increased significantly higher before all oocytes disappeared in Msh5 ?/? ovaries. We conclude that the mitochondrial apoptotic pathway mediated by caspase 9 is constitutively activated in oocytes and renders the elimination of oocytes with meiotic errors, which can be captured by the cleavage of PARP1. PMID:23384561

Ene, Adriana C.; Park, Stephanie; Edelmann, Winfried; Taketo, Teruko

2013-01-01

42

Precision-cut hamster liver slices as an ex vivo model to study amoebic liver abscess.  

PubMed

Entamoeba histolytica is the etiological agent of amoebiasis, the second cause of global morbidity and mortality due to parasitic diseases in humans. In approximately 1% of the cases, amoebas penetrate the intestinal mucosa and spread to other organs, producing extra-intestinal lesions, among which amoebic liver abscess (ALA) is the most common. To study ALA, in vivo and in vitro models are used. However, animal models may pose ethical issues, and are time-consuming and costly; and cell cultures represent isolated cellular lineages. The present study reports the infection of precision-cut hamster liver slices with Entamoeba histolytica trophozoites. The infection time-course, including tissue damage, parallels findings previously reported in the animal model. At the same time amoebic virulence factors were detected in the infected slices. This new model to study ALA is simple and reproducible, and employs less than 1/3 of the hamsters required for in vivo analyses. PMID:20412797

Carranza-Rosales, Pilar; Santiago-Mauricio, María Guadalupe; Guzmán-Delgado, Nancy Elena; Vargas-Villarreal, Javier; Lozano-Garza, Gerardo; Ventura-Juárez, Javier; Balderas-Rentería, Isaías; Morán-Martínez, Javier; Gandolfi, A Jay

2010-10-01

43

Proteomes of Animal Oocytes: What Can We Learn for Human Oocytes in the In Vitro Fertilization Programme?  

PubMed Central

Oocytes are crucial cells for mammalian reproduction, yet the molecular principles underlying oocyte development are only partially understood. Therefore, contemporary proteomic approaches have been used increasingly to provide new insights into oocyte quality and maturation in various species such as mouse, pig, and cow. Especially, animal studies have helped in elucidating the molecular status of oocytes during in vitro maturation and other procedures of assisted reproduction. The aim of this review is to summarize the literature on mammalian oocyte proteome and secretome research in the light of natural and assisted reproduction and on lessons to be learned for human oocytes, which have so far remained inaccessible for proteome analysis. PMID:24804254

Virant-Klun, Irma; Krijgsveld, Jeroen

2014-01-01

44

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

45

In vitro oocyte maturation and fertilization.  

PubMed

Complete functional oocyte maturation involves many complex processes that occur within preovulatory follicles and are initiated and sustained by the gonadotropins, steroid hormones and many recognized and unrecognized factors. The product of oocyte maturation is a mature egg that has complete nuclear, plasma membrane and cytoplasmic changes that enable normal fertilization and subsequent development to occur. In vitro maturation has been achieved with viability of resulting eggs demonstrated by their fertilization and successful gestational development. Higher proportions of in vitro matured eggs develop from hormonally supported cultures of whole follicles than from cultures of extrafollicular oocytes. In vivo fertilization has been more useful in these efforts than in vitro fertilization. Accomplishments toward understanding the physiological mechanisms involved in oocyte maturation are encouraging and with improvements anticipated for in vitro fertilization technology it should become possible to efficiently combine these procedures at some future date. Such an advancement would open many doors beyond the new technologies in animal breeding of today. Exploitation of in vitro oocyte maturation might remove the present technical limitations imposed on dissemination of genetic offerings of desirable females. PMID:3908431

Brackett, B G

1985-01-01

46

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...

47

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

48

British women's attitudes towards oocyte donation: Ethnic differences and altruism  

Microsoft Academic Search

ObjectiveThis study assessed the importance of altruism and willingness to donate oocytes in British Asian and Caucasian samples. The Theory of Planned Behaviour (TPB) was used to test the importance of attitudes towards oocyte donation, normative and control beliefs to attitudes to donate oocytes.

S. Purewal; O. B. A. van den Akker

2006-01-01

49

Oocyte triplet pairing for electrophysiological investigation of gap junctional coupling  

Microsoft Academic Search

Gap junctions formed by expressing connexin subunits in Xenopus oocytes provide a valuable tool for revealing the gating properties of intercellular gap junctions in electrically coupled cells. We describe a new method that consists of simultaneous triple recordings from 3 apposed oocytes expressing exogenous connexins. The advantages of this method are that in one single experiment, 1 oocyte serves as

Abdallah Hayar; Amanda Charlesworth; Edgar Garcia-Rill

2010-01-01

50

LINE-1 of evidence for fetal oocyte attrition by retrotransposon.  

PubMed

Fetal oocytes in mammals undergo extensive apoptosis during development. In this issue of Developmental Cell, Malki et al. (2014) provide insight into how and why such massive oocyte loss occurs through the demonstration that the expression level of LINE-1 retrotransposon defines the survival threshold and thus viability of fetal oocytes. PMID:24914555

Chuma, Shinichiro

2014-06-01

51

Development competence and relative transcript abundance of oocytes derived from small and medium follicles of prepubertal gilts.  

PubMed

The objective of this study was to examine the competence of mature oocytes aspirated from small follicles (SF, <2 mm in diameter) and medium follicles (MF, 3-6 mm) of abattoir-derived prepubertal gilt ovaries. Oocytes were selected by the presence of the first polar body (1pb) after IVM in a chemically defined medium, for sperm penetration, pronuclear formation, cleavage rate, and development to the blastocyst stage. Relative transcript abundance of genes associated with regulation of oocyte maturation (AURKA, AURKB, and MOS), fertilization (ZP3 and ZP4), maternal effect (NALP9 and HSF1), and anti-apoptosis (BCL2) were also examined in oocytes at germinal vesicle (GV) and metaphase-II (MII) stages. In SF, compared with MF, the maturation rate post-IVM was lower (P < 0.05), but there were no differences in sperm penetration rate (78.2% and 68.5% at 6 hours after insemination and 90.8% and 91.9% at 9 hours after insemination, P = 0.51 and P = 0.67, respectively), the percentage of oocytes that formed both female and male pronuclei (27.9% and 25.8% at 6 hours after insemination and 79.4% and 76.1% at 9 hours after insemination), or cleavage rate at 48 hours after insemination (85.9% and 89.7%, respectively, P = 0.46), whereas blastocyst formation rate was lower (P < 0.05) in oocytes from SF versus MF (14.7% and 31.0%). Transcript abundances decreased (P < 0.05) in all genes examined between the GV and MII stages, although only transcript abundance for MOS was lower (P < 0.05) in GV oocytes from SF versus MF. In conclusion, mature oocytes from SF and MF of prepubertal gilts with a visible 1pb had similar fertilizability in vitro and relative transcript abundance of nine genes. However, follicle size affected meiotic competence, early embryonic development to the blastocyst stage, and transcript abundance of the MOS gene. PMID:23987988

Kohata, Chiyuki; Izquierdo-Rico, María José; Romar, Raquel; Funahashi, Hiroaki

2013-12-01

52

Sperm and Oocyte Communication Mechanisms Controlling C. elegans Fertility  

PubMed Central

During sexual reproduction in many species, sperm and oocyte secrete diffusible signaling molecules to help orchestrate the biological symphony of fertilization. In the Caenorhabditis elegans gonad, bidirectional signaling between sperm and oocyte is important for guiding sperm to the fertilization site and inducing oocyte maturation. The molecular mechanisms that regulate sperm guidance and oocyte maturation are being delineated. Unexpectedly, these mechanisms are providing insight into human diseases, such as amyotrophic lateral sclerosis, spinal muscular atrophy, and cancer. Here we review sperm and oocyte communication in C. elegans and discuss relationships to human disorders. PMID:20034089

Han, Sung Min; Cottee, Pauline A.; Miller, Michael A.

2010-01-01

53

Mouse oocyte killing by neutrons: target considerations  

SciTech Connect

Highly radiosensitive primordial mouse oocytes, the principal cells at genetic risk in the female, have been studied using 0.43-MeV neutrons. Analysis of the survival curve (D/sub 37/ = 0.055 Gy) indicates that the diameter of the radiosensitive target (assumed spherical and of unit density) is larger than that of the nucleus but not of the oocyte, implicating a non-nuclear but sub-cellular target. This is consistent with results from /sup 3/H-thymidine incorporated in DNA. Our efforts to identify the extraordinarily radiosensitive lethality target in these primordial oocytes suggest it is the plasma membrane. Monte Carlo calculations for 0.43-MeV neutrons show that at the D/sub 37/ only a single proton recoil will traverse the plasma membrane, consistent with the observed exponential survival curve. A highly sensitive non-DNA target for mouse oocyte killing may importantly influence interpretations of genetic mutation data from mice and their use in estimating genetic risk in humans. 7 refs., 1 fig., 1 tab.

Straume, T.; Dobson, R.L.

1985-04-01

54

Sperm-induced calcium oscillations of human oocytes show distinct features in oocyte center and periphery.  

PubMed

Temporal and spatial characteristics of explosive periodic increases (spikes) of intracellular free Ca2+ concentration ([Ca2+]i) induced by sperm in human oocytes (Ca2+ oscillations) were analyzed by confocal laser scanning microscopy and compared to Ca2+ oscillations induced in oocytes by the thiol reagent thimerosal. During the steady-state period of sperm-induced Ca2+ oscillations, each individual [Ca2+]i spike invariably began from a focus in oocyte periphery and spread throughout the entire peripheral region before propagating to the central ooplasm. This peripheral Ca2+ wave was immediately followed by an explosive [Ca2+]i increase in the central ooplasm. However, this central [Ca2+]i rise only peaked when [Ca2+]i in the peripheral ooplasm was already on the decline. Moreover, the peak [Ca2+]i values were always considerably higher in the oocyte center than in the periphery. In contrast, thimerosal-induced Ca2+ oscillations did not show this particular form of propagation. These data show that sperm-induced Ca2+ oscillations have a unique pattern of spatial dynamics and suggest that the bulk of Ca2+ mobilized during each spike is released from stores that have a relatively high threshold for Ca(2+)-induced Ca2+ release (CICR). These stores are poorly developed, if not absent, in the oocyte cortex, and CICR from them is triggered by previous CICR from another type of store with a lower threshold that are preferentially located in the oocyte cortex and act as a detonator. PMID:7654379

Tesarik, J; Sousa, M; Mendoza, C

1995-06-01

55

Oocyte-secreted factors in oocyte maturation media enhance subsequent development of bovine cloned embryos.  

PubMed

Successful in vitro maturation (IVM) and oocyte quality both affect the subsequent development of cloned embryos derived from somatic-cell nuclear transfer (SCNT). Developmental competence is usually lower in oocytes matured in vitro compared with those that matured in vivo, possibly due to insufficient levels of oocyte-secreted factors (OSFs) and disrupted oocyte-cumulus communication. This study investigated the effects of OSFs secreted by denuded oocytes (DOs) during IVM on the subsequent developmental competence of cloned bovine embryos. Cumulus-oocyte complexes (COCs) from antral follicles of slaughtered-cow ovaries collected from an abattoir were divided into four groups: COCs co-cultured with and without DOs in maturation media used for SCNT, as well as COCs co-cultured with and without DOs in maturation media used for in vitro fertilization (IVF). Based on the developmental competence and embryo quality of bovine embryos generated from these four groups, we found that co-culturing the COCs with DOs enhanced the in vitro development of IVF and cloned bovine embryos, and potentially generated more high-quality cloned blastocysts that possessed locus-specific histone modifications at levels similar to in vitro-fertilized embryos. These results strongly suggest that co-culturing COCs with DOs enhances subsequent developmental competence of cloned bovine embryo. PMID:24420374

Su, Jianmin; Wang, Yongsheng; Zhang, Lei; Wang, Bo; Liu, Jun; Luo, Yan; Guo, Zekun; Quan, Fusheng; Zhang, Yong

2014-04-01

56

Oocyte maturation in human in vitro fertilisation programmes.  

PubMed

Oocyte immaturity represents a serious loss of efficiency in the in vitro fertilisation (IVF) treatment cycle since it is associated with a great list of detrimental effects mainly reflected in lower fertilisation and pregnancy rates. In stimulated cycles, oocyte maturation depends on stimulation protocol, ovarian response, time of human chorionic gonadotrophin (hCG) administration, hCG to oocyte retrieval interval, and/or time of in vitro culture period before insemination. The present review discusses the influence of these factors on human oocyte maturation and proposes several preventive and corrective measures. Due to the difficulty of ascertaining the grade of oocyte maturity based on morphological and physical properties of the oocyte-corona-cumulus complex (OCCC), fertilisation rate has been considered as an indirect index of nuclear and cytoplasmic maturation. The proportion of immature oocytes increases as the ovarian response to gonadotrophins increases. However, the detrimental effects of oocyte immaturity in high responders may be balanced by the higher number of oocytes retrieved per patient (and available embryos for transfer) and the selection of the best embryos for transfer. Oocyte immaturity might be prevented by delaying hCG injection and/or oocyte retrieval. Corrective strategies would involve in vitro or in vivo culture before insemination; addition of gonadotrophins or epidermal growth factor to the culture medium; and coculture with granulosa cells. PMID:1309118

Tarín, J J; Pellicer, A

1992-07-01

57

Selection of Ovine Oocytes by Brilliant Cresyl Blue Staining  

PubMed Central

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

58

Intraspecific sexual preferences of female hamsters  

Microsoft Academic Search

Studied the sexual preference behavior of 32 estrous females of 3 species of hamsters of the genus Mesocricetus by introducing individual females into an arena with a pair of males from 2 different species. When 1 male of the pair was a conspecific, females of all 3 species spent significantly more time investigating the conspecific male. When neither male was

Michael R. Murphy

1977-01-01

59

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

60

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

61

Mitochondrial DNA rearrangements in human oocytes and embryos.  

PubMed

Human mitochondrial DNA (mtDNA) rearrangements, including more than 150 deletions and insertions, accumulate with age and are responsible for certain neuromuscular diseases. Human oocytes, arrested for up to 50 years, may express certain mtDNA rearrangements possibly affecting function. Investigations have previously shown a single mtDNA rearrangement (dmtDNA(4977)) in human oocytes. Sequencing of other rearrangements and their correlation with maternal age have not been performed in human oocytes or embryos. Here we use a nested PCR strategy of long followed by short polymerase chain reaction (PCR) that amplifies two-thirds of the mitochondrial genome. mtDNA rearrangements were detected in 50.5% of the oocytes (n = 295) and 32.5% of the embryos (n = 197). This represents a significant difference in the percentage of mtDNA rearrangements between oocytes and embryos (P < 0.0001). Twenty-three novel mtDNA rearrangements with deletions, insertions and duplications were found. There was no significant age-related increase in the percentage of human oocytes or embryos that contained mtDNA rearrangements. Significant reductions in the number of oocytes containing mtDNA rearrangements occurred as oocyte development progressed from germinal vesicle to the mature metaphase II oocyte (P < 0.05). These findings are discussed as they relate to mitochondria, mtDNA, and ATP production in human oocytes and embryos. PMID:10508220

Barritt, J A; Brenner, C A; Cohen, J; Matt, D W

1999-10-01

62

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

63

SARCOMAS IN HAMSTERS AFTER INJECTION WITH ROUS CHICKEN TUMOR MATERIAL  

PubMed Central

Newborn hamsters were injected subcutaneously with a suspension of finely minced Rous chicken sarcoma (Schmidt-Ruppin strain). After an interval of about 2 weeks, progressively growing sarcomas developed at the site of injection in almost all animals. Also in adult hamsters inoculated intramuscularly with the same material sarcomas developed at the site of injection within 2 to 4 months. Secondary growths appeared on the peritoneal surface, in the retroperitoneal and mediastinal lymph nodes and in the lungs. The sarcomas usually had a pleomorphic appearance and showed a certain resemblance to rhabdomyosarcoma, but sometimes they had the character of spindle cell sarcomas of varying degree of maturity. Sarcomas were not only obtained in hamsters injected with cellular material from the Rous chicken sarcoma but were also seen in hamsters which were injected at birth or when 2 months' old with supernatant fluid obtained by repeated centrifugation of suspensions of homogenized chicken sarcoma, and presumed to be cell-free. The hamster sarcoma was transplanted to a newborn hamster and could then without difficulties be passed in series in hamsters. All attempts to transfer the sarcoma from hamster to hamster by means of cell-free material from the hamster sarcoma failed. On the other hand, material from the hamster sarcomas inoculated into chickens induced rapidly growing Rous sarcomas at the site of inoculation. This proved possible not only with material from the first but also from later passages of the tumor in hamsters. It is concluded that the strain of Rous virus used has the capacity to induce sarcomas not only in chickens but also in hamsters. PMID:13859724

Ahlstrom, C. G.; Forsby, Nils

1962-01-01

64

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

Microsoft Academic Search

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

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

2011-01-01

65

Embryo development after successful somatic cell nuclear transfer to in vitro matured human germinal vesicle oocytes  

Microsoft Academic Search

BACKGROUND: Somatic cell nuclear transfer (SCNT) involves the transfer of somatic cell nuclei into enucleated oocytes. Because human in vivo matured oocytes are scarcely available, we investigated whether in vitro matured (IVM) germinal vesicle (GV) oocytes could also support preimplantation development of human cloned embryos. METHODS: Three groups were used for SCNT: in vitro matured GV oocytes (IVM oocytes), 'in

B. Heindryckx; P. De Sutter; J. Gerris; M. Dhont; J. Van der Elst

2007-01-01

66

Calcium waves in the the maturing oocyte  

NASA Astrophysics Data System (ADS)

Calcium waves in oocytes are sustained by release of Ca2+ from the endoplasmic reticulum (ER) through clustered release channels. As the oocytes matures, a) the calcium waves slow down by about a factor of two, b) the overall duration of Ca2+ elevation grows substantially, and c) the cell is more susceptible to wave initiation. At the same time, the kinetics of release of Ca2+ from a single cluster is changed only insignificantly. Based on a computational model that accurately reproduces elemental Ca2+ release kinetics from channel clusters, we propose that the changing spatial organization of signaling effectors is a common underlying cause for all the above described observations as the Ca2+ signaling machinery matures.

Ullah, Aman; Ullah, Ghanim; Jung, Peter; Machaca, Khaled

2009-03-01

67

Cryopreservation of Human Oocytes and Embryos  

Microsoft Academic Search

\\u000a With the advent of assisted reproductive technology, controled ovarian hyperstimulation (COH) is usually carried out to stimulate\\u000a the growth of multiple follicles and produce multiple oocytes. Accordingly, multiple embryos are transferred to the uterus\\u000a to increase the chances of success. However, multiple embryos can also increase the likelihood of multiple pregnancies, which\\u000a are accompanied by a whole series of complications

Barry Behr; Yimin Shu

68

Membrane currents in the oocyte of the toad Bufo arenarum.  

PubMed

The amphibian oocyte cell model is widely used for heterologous expression of ionic channels and receptors. Little is known, however, about the physiology of oocyte cell models other than Xenopus laevis. In this study, the two-electrode voltage clamp technique was used to assess the most common electrical patterns of oocytes of the South American toad Bufo arenarum. Basal membrane resistance, resting potential, and ionic currents were determined in this cell model. The oocyte transmembrane resistance was 0.35 M(Omega), and the resting potential in normal saline was about -33 mV with a range between -20 mV and -50 mV. This is, to our knowledge, the first attempt to begin an understanding of the ion transport mechanisms of Bufo arenarum oocytes. This cell model may provide a viable alternative to the expression of ion channels, in particular those endogenously observed in Xenopus laevis oocytes. PMID:11857475

Kotsias, Basilio A; Damiano, Alicia E; Godoy, Sebastian; Assef, Yanina; Ibarra, Cristina; Cantiello, Horacio F

2002-03-01

69

Nongenomic Steroid-Triggered Oocyte Maturation: Of Mice and Frogs  

PubMed Central

Luteinizing hormone (LH) mediates many important processes in ovarian follicles, including cumulus cell expansion, changes in gap junction expression and activity, sterol and steroid production, and the release of paracrine signaling molecules. All of these functions work together to trigger oocyte maturation (meiotic progression) and subsequent ovulation. Many laboratories are interested in better understanding both the extra-oocyte follicular processes that trigger oocyte maturation, as well as the intra-oocyte molecules and signals that regulate meiosis. Multiple model systems have been used to study LH-effects in the ovary, including fish, frogs, mice, rats, pigs, and primates. Here we provide a brief summary of oocyte maturation, focusing primarily on steroid-triggered meiotic progression in frogs and mice. Furthermore, we present new studies that implicate classical steroid receptors rather than alternative non-classical membrane steroid receptors as the primary regulators of steroid-mediated oocyte maturation in both of these model systems. PMID:19071151

Deng, James; Carbajal, Liliana; Evaul, Kristen; Rasar, Melissa; Jamnongjit, Michelle; Hammes, Stephen R

2009-01-01

70

Campylobacter cinaedi is normal intestinal flora in hamsters.  

PubMed Central

During the course of studies to reproduce proliferative enteritis in hamsters, Campylobacter cinaedi was recovered from the feces of the majority of healthy hamsters obtained from two commercial sources. The organisms were cultured by using filtration, a nonselective medium, and a microaerophilic atmosphere containing hydrogen. Isolation was hindered by the fastidious nature of C. cinaedi and by the presence of other Campylobacter species in the hamster intestine. All hamster C. cinaedi isolates were phenotypically similar to C. cinaedi ATCC 35683. Comparison of whole-cell protein profiles of one hamster isolate with a reference strain of C. cinaedi by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with C. cinaedi-specific rabbit antiserum supported the phenotypic identification of these isolates. Hamsters may be an animal reservoir for human C. cinaedi infections. Images PMID:2768458

Gebhart, C J; Fennell, C L; Murtaugh, M P; Stamm, W E

1989-01-01

71

Rapamycin Rescues the Poor Developmental Capacity of Aged Porcine Oocytes  

PubMed Central

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

2014-01-01

72

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

73

Taste Qualities of Solutions Preferred by Hamsters  

Microsoft Academic Search

Molecules of diverse chemical structure are sweet to humans and several lines of evidence (genetic, physiological, behavioral) suggest that there may be distinct sweet perceptual qualities. To address how many perceptual categories these molecules elicit in hamsters (Mesocricetus auratus), we studied patterns of generalization of conditioned taste aversions for seven sweeteners: 100 mM sucrose, 320 mM maltose, 32 mM D-phenylalanine,

Bruce I. MacKinnon; Marion E. Frank; Thomas P. Hettinger; Bradley G. Rehnberg

1999-01-01

74

Nipah Virus Transmission in a Hamster Model  

Microsoft Academic Search

Based on epidemiological data, it is believed that human-to-human transmission plays an important role in Nipah virus outbreaks. No experimental data are currently available on the potential routes of human-to-human transmission of Nipah virus. In a first dose-finding experiment in Syrian hamsters, it was shown that Nipah virus was predominantly shed via the respiratory tract within nasal and oropharyngeal secretions.

Emmie de Wit; Trenton Bushmaker; Dana Scott; Heinz Feldmann; Vincent J. Munster

2011-01-01

75

Oogenesis of microlecithal oocytes in the viviparous teleost Heterandria formosa.  

PubMed

Viviparous teleosts exhibit two patterns of embryonic nutrition: lecithotrophy (when nutrients are derived from yolk that is deposited in the oocyte during oogenesis) and matrotrophy (when nutrients are derived from the maternal blood stream during gestation). Nutrients contained in oocytes of matrotrophic species are not sufficient to support embryonic development until term. The smallest oocytes formed among the viviparous poeciliid fish occur in the least killifish, Heterandria formosa, these having diameters of only 400 ?m. Accordingly, H. formosa presents the highest level of matrotrophy among poeciliids. This study provides histological details occurring during development of its microlecithal oocytes. Five stages occur during oogenesis: oogonial proliferation, chromatin nucleolus, primary growth (previtellogenesis), secondary growth (vitellogenesis), and oocyte maturation. H. formosa, as in all viviparous poeciliids, has intrafollicular fertilization and gestation. Therefore, there is no ovulation stage. The full-grown oocyte of H. formosa contains a large oil globule, which occupies most of the cell volume. The oocyte periphery contains the germinal vesicle, and ooplasm that includes cortical alveoli, small oil droplets and only a few yolk globules. The follicular cell layer is initially composed of a single layer of squamous cells during early previtellogenesis, but these become columnar during early vitellogenesis. They are pseudostratified during late vitellogenesis and reduce their height becoming almost squamous in full-grown oocytes. The microlecithal oocytes of H. formosa represent an extreme in fish oogenesis typified by scarce yolk deposition, a characteristic directly related to matrotrophy. PMID:21210493

Uribe, Mari Carmen; Grier, Harry J

2011-02-01

76

Inhibition of bovine sperm-oocyte fusion by a monoclonal antibody recognising the TEC-2 epitope on bovine oocytes.  

PubMed

The TEC-2 antigenic determinant is a carbohydrate epitope located on a glycoprotein carrier molecule. In the mouse, this epitope is expressed on the zona pellucida and plasma membrane of the oocyte and is associated with the ZP2 glycoprotein and involved in the secondary sperm receptor mechanism. On the bovine oocyte expression is confined to the plasma membrane. The aim of this study was to determine the role the TEC-2 epitope plays during fertilization in the bovine species using the monoclonal antibody TEC-02. Incubating oocytes with the TEC-02 antibody prior to fertilization inhibited cleavage in a dose-dependent manner-the cleavage rate decreased as the concentration of the antibody increased. Significantly more sperm were bound to oocytes exposed to TEC-02 (12 sperm/oocyte) compared to oocytes that were not incubated with the antibody (4 sperm/oocyte). Oocytes treated with the TEC-02 antibody had a 7.5 +/- 3.2% fusion rate and no cortical granule exocytosis compared with oocytes not exposed to the antibody, with 86.5 +/- 5.8% of sperm-oocyte fusions and release of cortical granules. The block to sperm-oocyte fertilization observed in the pretreated group was overcome using intracytoplasmic sperm injection as the method of fertilization that bypassed the fusion process. Although sperm were binding to the oolemma these results suggest that fusion was not occurring and this may be due to the antibody occupying TEC-2 epitope sites involved in the fusion process. In conclusion, the TEC-2 epitope seems to be involved in sperm-oocyte interaction in the bovine species and appears to be involved specifically during the fusion events of fertilization. PMID:10471477

Gougoulidis, T; Trounson, A; Dowsing, A

1999-10-01

77

Molecular and immunological characterization of the first allergenic lipocalin in hamster: the major allergen from Siberian hamster (Phodopus sungorus).  

PubMed

The most frequent pet allergy is to cat and dog, but in recent years, it has become increasingly popular to have other pets, and the risk of exposure to new allergens is more prevalent. The list of new pets includes hamsters, and one of the most popular hamsters is the Siberian hamster (Phodopus sungorus). The aim of this study was the characterization and cloning of the major allergen from this hamster. The study of its allergenicity and cross-reactivity could improve the specific diagnosis and treatment for hamster-allergic patients. Thirteen Siberian hamster-allergic patients were recruited at the outpatient clinic. Protein extracts were prepared from the hair, urine, and salivary glands of four hamster species (European, golden, Siberian, and Roborovski). IgE-binding proteins were detected by immunoblotting and identified by mass spectrometry. The recombinant protein was produced in Escherichia coli and then purified by metal chelate affinity chromatography. The allergenic properties of the recombinant protein were tested by ELISA and immunoblotting, and biological activity was tested according to capacity for basophil activation. Three IgE-binding proteins were identified in extracts obtained from Siberian hamster hair, urine, and salivary glands. All proteins corresponded to the same protein, which was identified as a lipocalin. This lipocalin had no cross-reactivity with common and golden hamsters. The recombinant allergen was cloned and purified, showing similar IgE reactivity in vitro to Siberian hamster protein extracts. Also, the recombinant allergen was capable of producing biological activation in vivo. The major Siberian hamster allergen was cloned, and allergenic properties were characterized, providing a new tool for specific diagnosis of allergy to Siberian hamster. PMID:24993820

Torres, José Alberto; de Las Heras, Manuel; Maroto, Aroa Sanz; Vivanco, Fernando; Sastre, Joaquín; Pastor-Vargas, Carlos

2014-08-22

78

Bisphenol-A and human oocyte maturation in vitro  

PubMed Central

STUDY QUESTION Does exposure to bisphenol-A (BPA) affect the maturation of human oocytes in vitro? SUMMARY ANSWER There was a dose–response association of BPA exposure with altered human oocyte maturation in vitro. WHAT IS KNOWN ALREADY There is widespread exposure of the general population to BPA. BPA has been detected in the human follicular fluid. Animal studies have shown that BPA exposure is associated with maturation arrest and spindle abnormalities in maturing oocytes. STUDY DESIGN, SIZE, DURATION A randomized trial, using 352 clinically discarded oocytes from 121 patients. PARTICIPANTS/MATERIALS, SETTING, METHODS The study population was drawn from patients undergoing IVF/ICSI cycles in our program at Brigham and Women's Hospital from March 2011 to April 2012. Oocytes from only one cycle for each patient were included in the study. Cycles with at least two germinal vesicle stage oocytes were included with random allocation of one oocyte to culture for 30 h without BPA and remaining sibling oocytes to medium-containing BPA (20, 200 ng/ml or 20 µg/ml). Oocytes were fixed and labeled for tubulin, actin and chromatin and examined with immunofluorescence and confocal microscopy. Oocytes were assessed for meiotic stage (n = 292), and those at metaphase II (MII, n = 175) were further classified according to their spindle configurations and patterns of chromosome alignment. McNemar's test was used to compare dichotomized maturation status. Generalized estimating equations were used to account for the correlation between oocytes from the same woman and for the spindle analysis. MAIN RESULTS AND THE ROLE OF CHANCE As the BPA dose increased, there was a decrease in the percentage of oocytes that progressed to MII (P = 0.002) and increases in the percentage of oocytes that were degenerated (P = 0.01) or that had undergone spontaneous activation (P = 0.007). Among MII oocytes, as the BPA dose increased, there was a significant trend (by test for trend) for a decreased incidence of bipolar spindles (P < 0.0001) and aligned chromosomes (P = 0.02). LIMITATIONS, REASONS FOR CAUTION Although we used sibling oocytes to overcome potential confounders, such as infertility diagnosis and maternal age, additional studies with a larger number of oocytes are required to confirm the present results. Having access only to clinically discarded oocytes, we were limited to evaluating only those oocytes that failed to mature in vivo despite having been exposed to gonadotrophin stimulation and the ovulatory trigger of HCG. WIDER IMPLICATIONS OF THE FINDINGS To our knowledge, this is the first study investigating the effect of BPA on oocyte meiotic maturation, spindle morphology and chromosome alignment in human oocytes. Together with prior animal studies, the data support the negative influences of BPA on cell cycle progression, spindle architecture and chromosome organization during oocyte maturation. Furthermore, the increased rates of abnormal maturation in oocytes exposed to BPA may be relevant to our understanding of the decrease in fertility reported in the last decades. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by the NIEHS Center Grant Pilot Project (P30-ES000002). R.M. was sponsored by a fellowship from the Environmental Health Fund, Israel and by the Frederick L. Hisaw Endowment, Harvard School of Public Health. There are no conflicts of interest. TRIAL REGISTRATION NUMBER n/a. PMID:23904465

Machtinger, Ronit; Combelles, Catherine M.H.; Missmer, Stacey A.; Correia, Katharine F.; Williams, Paige; Hauser, Russ; Racowsky, Catherine

2013-01-01

79

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

80

Effect of lower than expected number of oocyte on the IVF results after oocyte-pickup  

PubMed Central

Objectives: To investigate whether a lower than expected number of oocyte after ?14 mm follicle aspiration during OPU has any effect on pregnancy outcomes Methods: This is a retrospective study done between 2010 and 2013 at the IVF Unit of the Zeynep Kamil Women and Children Diseases Education and Research Hospital, dealing with the medical records of infertile patients who underwent IVF cycle and controlled ovarian stimulation with long agonist or fix antogonist protocol. The patients included into the study were those diagnosed with a primary infertility, aged between 23 and 39, at a BMI of 22-28 kg/m2 and having received the first or second IVF treatment. Male factor, presence of uterine anomaly, patients with serious endometriosis and patients with low ovarian reserve were all excluded from the study. Typically, oocyte pick-up was performed in all the patients 35.5 hours after the hCG implementation. Single or double embryo transfer was performed, where available. Patients were classified into two groups. Group 1 consisted of those with no difference between ?14 mm aspirated follicle number and expected number of oocyte or with 1 missing number of oocyte at the most. Group 2 consisted of those with at least ?2 missing number of oocyte between aspirated follicle number and expected number of oocyte. Statistical analysis was performed using Student’s t test for continuous variables and chi-square test for categorical variables. Additionally, a Linear regression analysis was conducted between the total number of oocyte and pregnancy. Results: In total, 387 treatment cycles were included into the study. Group 1 consisted of 134 patients and Group 2 consisted of 252 patients. Antral follicle number (12.8 ± 4.3 and 14.5 ± 4.1, P = 0.0007), hCG day E2 value (1990.7 ± 1056.4 and 2515.2 ± 1332.7, P < 0.0001) and the the number of aspirated follicle during OPU (9.1 ± 4.4 and 13.7 ± 5.5, P < 0.0001) were significantly higher in Group 2; whereas on the other hand, daily gonadotropin dose (290.9 ± 79.9 and 273.4 ± 74.4, P = 0.034) and total gonadotropin doses (2545 ± 1031.8 and 2247.7 ± 901.9, P = 0.004) were significantly higher in Group 1. The pregnancy rate was significantly higher in Group 1 (29.1% and 19.4%, P = 0.041). No correlation was observed between the number of oocyte and pregnancy (r = 0.082, P = 0.107). Conclusions: The number of aspirated follicles during IVF treatment being higher than the collected number of oocyte leads to a statistically significant fall in the pregnancy rates. There is no correlation between the number of oocyte and pregnancy. PMID:25126190

Gonca, Suheyla; Gun, Ismet; Ovayolu, Ali; Silfeler, Dilek; Sofuoglu, Kenan; Ozdamar, Ozkan; Yilmaz, Ali; Tunali, Gulden

2014-01-01

81

Penetration of yawed projectiles  

SciTech Connect

We used computer simulations and experiment to study the penetration of tungsten-alloy projectiles into a thick, armored steel target. These projectiles, with length-to-diameter ratios of 4, strike the target with severe yaws, up to 90{degree}(side-on-impact), such as might be induced in an originally longer projectile by a multiple-spaced plate array. In this study, we focus on the terminal ballistics of these projectiles and ignore how the yaw was induced. We found that the minimum penetration depth occurs at 90{degree}yaw. This case is well approximated by the two-dimensional plane-strain penetration of a side-on cylinder. The ratio of penetration depth to diameter, P:D, for this case is larger than that for a sphere because the plane-strain geometry lacks hoop stress, which is activated in axisymmetric geometry. A more surprising result of work is that the penetration at 60{degree} yaw is only slightly deeper than that of the side-on impact. 8 refs., 15 figs., 3 tabs.

Reaugh, J.E.

1990-10-08

82

The influence of sperm concentration, length of the gamete co-culture and the evolution of different sperm parameters on the in vitro fertilization of prepubertal goat oocytes.  

PubMed

The aims of the present study were: (1) to evaluate the influence of sperm concentration (ranging from 0.5 × 10(6) to 4 × 10(6) spermatozoa/ml) and length of the gamete co-incubation time (2, 4, 6, 8, 10, 12, 16, 20, 24 or 28 h) on in vitro fertilization (IVF), assessing the sperm penetration rate; (2) to investigate the kinetics of different semen parameters as motility, viability and acrosome status during the co-culture period; and (3) to analyse the effect of the presence of cumulus-oocytes complexes (COCs) on these parameters. To achieve these objectives, several experiments were carried out using in vitro matured oocytes from prepubertal goats. The main findings of this work are that: (1) in our conditions, the optimum sperm concentration is 4 × 10(6) sperm/ml, as this sperm:oocyte ratio (approximately 28,000) allowed us to obtain the highest penetration rate, without increasing polyspermy incidence; (2) the highest percentage of viable acrosome-reacted spermatozoa is observed between 8-12 h of gamete co-culture, while the penetration rate is maximum at 12 h of co-incubation; and (3) the presence of COCs seems to favour the acrosome reaction of free spermatozoa on IVF medium, but not significantly. In conclusion, we suggest that a gamete co-incubation for 12-14 h, with a concentration of 4 × 10(6) sperm/ml, would be sufficient to obtain the highest rate of penetration, reducing the exposure of oocytes to high levels of reactive oxygen species produced by spermatozoa, especially when a high sperm concentration is used to increase the caprine IVF outcome. PMID:20334721

Palomo, M J; Mogas, T; Izquierdo, D; Paramio, M T

2010-11-01

83

Oxidative stress and ageing of the post-ovulatory oocyte.  

PubMed

With extended periods of time following ovulation, the metaphase II stage oocyte experiences deterioration in quality referred to as post-ovulatory oocyte ageing. Post-ovulatory ageing occurs both in vivo and in vitro and has been associated with reduced fertilization rates, poor embryo quality, post-implantation errors and abnormalities in the offspring. Although the physiological consequences of post-ovulatory oocyte ageing have largely been established, the molecular mechanisms controlling this process are not well defined. This review analyses the relationships between biochemical changes exhibited by the ageing oocyte and the symptoms associated with the ageing phenotype. We also discuss molecular events that are potentially involved in orchestrating post-ovulatory ageing with a particular focus on the role of oxidative stress. We propose that oxidative stress may act as the initiator for a cascade of events that create the aged oocyte phenotype. Specifically, oxidative stress has the capacity to cause a decline in levels of critical cell cycle factors such as maturation-promoting factor, impair calcium homoeostasis, induce mitochondrial dysfunction and directly damage multiple intracellular components of the oocyte such as lipids, proteins and DNA. Finally, this review addresses current strategies for delaying post-ovulatory oocyte ageing with a particular focus on the potential use of compounds such as caffeine or selected antioxidants in the development of more refined media for the preservation of oocyte integrity during IVF procedures. PMID:23950493

Lord, Tessa; Aitken, R John

2013-12-01

84

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

85

In Vitro Growth and Maturation of Vitrified-Warmed Bovine Oocytes Collected from Early Antral Follicles  

PubMed Central

Abstract. Cryopreservation of growing oocytes enriches the choice of timing and location of artificial embryo production. However, completion of oocyte growth after warming is crucial when using such cryopreserved oocytes. Our research objective was to develop a sequential system that incorporates cryopreservation of growing bovine oocytes and their subsequent in vitro growth. Oocyte-granulosa cell complexes with a mean oocyte diameter of approximately 100 µm were vitrified-warmed and then cultured for 14 days. The percentage of surviving oocytes following cryopreservation and 14-day culture was approximately 80%. More than half of the surviving oocytes were capable of maturing to metaphase II after in vitro maturation; the rate was comparable to that of control oocytes grown in vitro without cryopreservation. Taken together, the combined protocols for vitrification-warming of growing oocytes and subsequent in vitro growth can produce oocytes capable of undergoing meiotic maturation. PMID:24126072

HIRAO, Yuji; SOMFAI, Tamas; NARUSE, Kenji

2013-01-01

86

Hypervelocity impact penetration mechanics  

Microsoft Academic Search

Inert dense metal penetrators having a mass and geometry capable of missile delivery offer significant potential for countering underground facilities at depths of tens of meters in hard rock. The proliferation of such facilities among countries whose support for terrorism and potential possession of Weapons of Mass Destruction (WMD) constitutes threats to world peace and U.S. Security. The Defense Threat

C. McFarland; P. Papados; M. Giltrud

2008-01-01

87

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

88

Role of caloric homeostasis and reward in alcohol intake in Syrian golden hamsters  

Microsoft Academic Search

The Syrian golden hamster drinks alcohol readily, but only achieves moderate blood alcohol levels, and does not go through withdrawal from alcohol. Because the hamster is a model of caloric homeostasis, both caloric content and reward value may contribute to the hamster's alcohol consumption. The current study examines alcohol consumption in the hamster when a caloric or non-caloric sweet solution

Danielle Gulick; Alan I. Green

2010-01-01

89

Kinetics of Leptospira interrogans Infection in Hamsters after Intradermal and Subcutaneous Challenge  

PubMed Central

Background Leptospirosis is a zoonosis caused by highly motile, helically shaped bacteria that penetrate the skin and mucous membranes through lesions or abrasions, and rapidly disseminate throughout the body. Although the intraperitoneal route of infection is widely used to experimentally inoculate hamsters, this challenge route does not represent a natural route of infection. Methodology/Principal Findings Here we describe the kinetics of disease and infection in hamster model of leptospirosis after subcutaneous and intradermal inoculation of Leptospira interrogans serovar Copenhageni, strain Fiocruz L1-130. Histopathologic changes in and around the kidney, including glomerular and tubular damage and interstitial inflammatory changes, began on day 5, and preceded deterioration in renal function as measured by serum creatinine. Weight loss, hemoconcentration, increased absolute neutrophil counts (ANC) in the blood and hepatic dysfunction were first noted on day 6. Vascular endothelial growth factor, a serum marker of sepsis severity, became elevated during the later stages of infection. The burden of infection, as measured by quantitative PCR, was highest in the kidney and peaked on day 5 after intradermal challenge and on day 6 after subcutaneous challenge. Compared to subcutaneous challenge, intradermal challenge resulted in a lower burden of infection in both the kidney and liver on day 6, lower ANC and less weight loss on day 7. Conclusions/Significance The intradermal and subcutaneous challenge routes result in significant differences in the kinetics of dissemination and disease after challenge with L. interrogans serovar Copenhageni strain Fiocruz L1-130 at an experimental dose of 2×106 leptospires. These results provide new information regarding infection kinetics in the hamster model of leptospirosis. PMID:25411782

Coutinho, Mariana L.; Matsunaga, James; Wang, Long-Chieh; de la Peña Moctezuma, Alejandro; Lewis, Michael S.; Babbitt, Jane T.; Aleixo, Jose Antonio G.; Haake, David A.

2014-01-01

90

Tumor-Penetrating Peptides  

PubMed Central

Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC), contains the integrin-binding RGD motif. RGD mediates tumor-homing through binding to ?v integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR) motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular “zip code” of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies, and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is present in the blood. PMID:23986882

Teesalu, Tambet; Sugahara, Kazuki N.; Ruoslahti, Erkki

2013-01-01

91

Biomechanics of penetrating trauma.  

PubMed

It is well known that injuries and deaths due to penetrating projectiles have become a national and an international epidemic in Western society. The application of biomedical engineering to solve day-to-day problems has produced considerable advances in safety and mitigation/prevention of trauma. The study of penetrating trauma has been largely in the military domain where war-time specific applications were advanced with the use of high-velocity weapons. With the velocity and weapon caliber in the civilian population at half or less compared with the military counterpart, wound ballistics is a largely different problem in today's trauma centers. The principal goal of the study of penetrating injuries in the civilian population is secondary prevention and optimized emergency care after occurrence. A thorough understanding of the dynamic biomechanics of penetrating injuries quantifies missile type, caliber, and velocity to hard and soft tissue damage. Such information leads to a comprehensive assessment of the acute and long-term treatment of patients with penetrating injuries. A review of the relevant military research applied to the civilian domain and presentation of new technology in the biomechanical study of these injuries offer foundation to this field. Relevant issues addressed in this review article include introduction of the military literature, the need for secondary prevention, environmental factors including projectile velocity and design, experimental studies with biological tissues and physical models, and mathematical simulations and analyses. Areas of advancement are identified that enables the pursuit of biomechanics research in order to arrive at better secondary prevention strategies. PMID:9719858

Yoganandan, N; Pintar, F A

1997-01-01

92

Mitochondrial DNA deletion in human oocytes and embryos.  

PubMed

Mitochondrial DNA (mtDNA) deletions are present in both human oocytes and embryos. It has been found that these tissues contain a mtDNA mutation which is present in high amounts in patients with Kearns-Sayre syndrome (KSS) and progressive external ophthalmoplegia. In the present study, the frequency of this KSS deletion was investigated in human oocytes and embryos. Using a nested primer polymerase chain chian reaction (PCR) strategy, the frequency of the KSS deletion in 74 human oocytes and 137 embryos was found to be 32.8 and 8.0% respectively. Using a 'long PCR-short PCR' nested primer strategy, the frequency of the KSS deletion in 181 human oocytes and 104 embryos was found to be 47.0 and 20.2% respectively. There was no statistical correlation between the age of the patients at the time of oocyte retrieval and the presence of the deleted molecules. There was a statistical difference between the presence of the deleted molecules in oocytes versus embryos using either technique (P < 0.0001). The relevance of these findings to the accumulation of low levels of deleted mtDNA in both oocytes and embryos is discussed in this study. PMID:9783850

Brenner, C A; Wolny, Y M; Barritt, J A; Matt, D W; Munné, S; Cohen, J

1998-09-01

93

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

94

Comparison of bulk enucleation methods for porcine oocytes.  

PubMed

Cloning of mammalian oocytes requires that the recipient oocyte is enucleated to remove all genetic material associated with the chromosomes. The procedure currently used in most species requires careful micromanipulation of oocytes treated with cytochalasin B to prevent structural damage. Although functional, this procedure requires time and limits the number of oocytes available for cloning, and our ability to understand the mechanisms of nuclear reprogramming. Therefore, this study aimed at evaluating different procedures to enucleate large pools of oocytes in a time-efficient manner. Two different approaches were tested. The first approach involved centrifugation of zona-free oocytes through a percoll gradient to separate the portion containing the chromatin from the cytoplasmic portion. The second used etoposide to prevent chromatin segregation at first metaphase and resulting in the expulsion of all chromosomes in the polar body. Using the chemical approach an average enucleation rate of 39.4 +/- 7.5% was obtained, while the centrifugation approach resulted in an average enucleation rate of 66.9 +/- 6. In terms of time efficiency, the control manipulation method takes 0.11 min and the centrifugation took an average of 0.52 min per oocyte. The MPF activity at the end of procedure was estimated through the measurement of H1 activity and as expected, the etoposide-cycloheximide treated oocytes had lower H1 activity which was restored by further incubation in the maturation medium for 5 hr while the centrifugation gave a nonsignificant intermediary result. In conclusion, the results presented suggest that both the chemical and the mechanical methods are usable alternatives to micromanipulation of oocytes to generate a large number of chromosome free cytoplasm for biochemical analysis. Mol. Reprod. Dev. 67: 70-76, 2004. PMID:14648876

Savard, Christian; Novak, Susan; Saint-Cyr, Antoine; Moreau, Marc; Pothier, Francois; Sirard, Marc-André

2004-01-01

95

The Human Oocyte Preservation Experience (HOPE) a phase IV, prospective, multicenter, observational oocyte cryopreservation registry  

PubMed Central

Background It has been recommended by the American Society of Clinical Oncology and the American Society of Reproductive Medicine that options to preserve fertility be presented at the outset of treatment for cancer. This recommendation may have arisen, in part, to the increasing survival of patients with cancer and the realization that certain forms of cancer treatment can lead to infertility. One option for these patients, particularly those with ethical or religious objections to freezing embryos is oocyte cryopreservation. However universal acceptance of these procedures has yet to be established, most likely due to a poor history of success and concerns that there has yet to be a comprehensive approach to evaluating these techniques. In light of this, a registry of patients undergoing oocyte cryopreservation, called the HOPE registry, is being implemented. Discussion The intent of the HOPE Registry is to enroll approximately 400 women of reproductive age who will undergo thawing/warming of oocytes and subsequent transfer. Data from the patients enrolled will be collected via a uniform, standardized form and will document important parameters such as demographics, laboratory procedures and outcomes, including following the outcomes of babies born for one year after birth. The results of the registry will be published on a yearly basis. Summary A patient registry has been established in order to systematically document the techniques and outcomes of oocyte cryopreservation procedures. The results will be published in order to provide a widely accessible resource that will allow patients who are considering these procedures validated information in order to make informed decisions as to how their treatment will proceed. PMID:19473532

Ezcurra, Diego; Rangnow, Jennifer; Craig, Maryellen; Schertz, Joan

2009-01-01

96

Pitfalls in penetrating trauma.  

PubMed

In Western Europe the most frequent cause of multiple injuries is blunt trauma. Only few of us have experience with penetrating trauma, without exception far less than in the USA or South-Africa. In Rotterdam, the Erasmus Medical Centre is a level I trauma centre, situated directly in the town centre. All penetrating traumas are directly presented to our emergency department by a well organized ambulance service supported by a mobile medical team if necessary. The delay with scoop and run principles is very short for these cases, resulting in severely injured reaching the hospital alive in increasing frequency. Although the basic principles of trauma care according to the guidelines of the Advanced Trauma Life Support (ATLS) (1-2) are the same for blunt and penetrating trauma with regard to priorities, diagnostics and primary therapy, there are some pitfalls in the strategy of management in penetrating trauma one should be aware of. Simple algorithms can be helpful, especially in case of limited experience (3). In case of life-saving procedures, the principles of Damage Control Surgery (DCS) must be followed (4-5). This approach is somewhat different from "traditional" surgical treatment. In the Ist phase prompt interventions by emergency thoracotomy and laparotomy are carried out, with only two goals to achieve: surgical control of haemorrhage and contamination. After temporary life-saving procedures, the 2nd phase is characterized by intensive care treatment, dealing with hypothermia, metabolic acidosis and clotting disturbances. Finally in the 3rd phase, within 6-24 hours, definitive surgical care takes place. In this overview, penetrating injuries of neck, thorax, abdomen and extremities will be outlined. Penetrating cranial injuries, as a neurosurgical emergency with poor prognosis, are not discussed. History and physical examination remain the corner stones of good medical praxis. In a work-up according to ATLS principles airway, breathing and circulation should be evaluated with great care. Neurovascular examination related to trauma of the spinal cord, peripheral nerves as well as vascular involvement should be carried out also in extremity injuries. Physical examination should be completed by localization of all stabwounds, in- and outshot openings as well as recto-vaginal examination and inspection of the oropharynx. PMID:14524152

van Vugt, A B

2003-08-01

97

Effects of bull and heparin and sperm concentrations on in vitro fertilization of buffalo (Bubalus bubalis ) oocytes matured in vitro.  

PubMed

A study was undertaken to assess the ability of spermatozoa from 6 buffalo bulls, at different levels of heparin and sperm concentrations, to achieve an acceptable level of fertilization in vitro. Frozen-thawed spermatozoa, 3 dosages of heparin (0, 10 and 100 ug/ml) in the presence and absence of penicillamine, hypotaurine and epinephrine (PHE), and 4 sperm concentrations (1 x 10(6), 2 x 10(6), 3 x 10(6) and 4 x 10(6) /ml) were studied using 3202 buffalo oocytes. The mean proportions of fertilized oocytes in the group treated with 10 ug/ml of heparin were significantly higher (P<0.05) with the semen of Bulls A, B and C (44.7 to 64.3%) than in medium devoid of heparin. An increase in the dosage of heparin from 10 ug/ml to 100 ug/ml reduced the overall fertilization rate. However, optimal fertilization (30.9%) at 100 ug/ml heparin was observed for semen from Bull D. Bulls E and F yielded the lowest fertilization rate (9.6 and 14.2%, respectively) at the above mentioned heparin dosage. Analysis of sperm density revealed that a concentration of 2 x 10(6) spermatozoa yielded optimal fertilization rates in vitro. Higher sperm concentrations (3 x 10(6) or 4 x 10(6)) resulted in higher oocyte penetration rates but gave rise to polyspermy. PMID:16727261

Totey, S M; Pawshe, C H; Singh, G P

1993-04-01

98

[Effect of alpha-fetoprotein on isolated mouse oocytes].  

PubMed

Data are presented which indicate a possible action of alpha-fetoprotein (AFP) on female germinal cells. The in vitro maturation of mature mice oocytes was significantly inhibited when mouse AFP replaced albumin in the culture medium. In addition, the degenerative aspect of oocytes cultured with AFP seemed to indicate that this meïotic inhibition was caused by a premature degeneration of oocytes rather than by a blockage at a specific stage of maturation. Thus AFP, perhaps through its ligands, may play a role in the reduction of germinal cells during fetal and immediate post-natal life rather than in the arrest of meïosis at the diplotene stage. PMID:2423206

Lambert, J C; Vallette, G; Seralini, G E; Vranckx, R; Nunez, E; Stora, C

1986-01-01

99

Ground-penetrating rada  

NASA Astrophysics Data System (ADS)

The theory and applications of digital Ground-Penetrating Radar were discussed at a 5-day seminar held at the China University of Geosciences in Wuhan, People's Republic of China, in April. Cohosted by the Department of Applied Geophysics and Canada-China Geoscience, more than 60 senior geophysicists, engineers, technical specialists, university professors and researchers attended.Focus of the meeting was the expanded uses of the new deep-penetrating fully digital PulseEKKO, which is gaining wide acceptance around the world. Attendees showed intense interest in this new and unique technology. Applications covered were groundwater and mineral exploration; engineering, construction and toxic waste site surveying; tunnel and underground mine probing for potential geological hazards, blind ore zones, karst cavities and solution pathways; and locating buried objects such as petroleum storage tanks, unexploded bombs and archeological remains.

Thuma, W. R.

100

Periscope For Viewing Weld Penetration  

NASA Technical Reports Server (NTRS)

Periscope enables viewing of weld joint from inside cylindrical duct to determine when weld penetration occurs. Supplies steady stream of inert gas to shield joint. Device used to calibrate and evaluate techniques for sensing weld penetration.

Gordon, Stephen S.; Marman, Jonathan M.

1988-01-01

101

Endoplasmic reticulum protein 29 (ERp29), a protein related to sperm maturation is involved in sperm-oocyte fusion in mouse  

PubMed Central

Background Sperm-oocyte fusion is a critical step in fertilization, which requires a series of proteins from both spermatozoa and oocyte to mediate membrane adhesion and subsequent fusion. A rat spermatozoa membrane protein is endoplasmic reticulum protein 29 (ERp29), which significantly increases on the sperm surface as well as in the cytoplasm of epididymal epithelia from caput to cauda as the sperm undergo epididymal maturation. Moreover, ERp29 facilitates viral infection via mediating membrane penetration. We determined if in addition to promoting sperm maturation ERp29 may also play a role in facilitating gamete fusion during the fertilization process. Methods Laser scanning confocal microscopy (LSCM) and Western blot analysis were employed to probe for ERp29 protein in BALB/c mouse epididymal and acrosome-reacted spermatozoa. We prepared rabbit polyclonal antibodies against mouse recombinant ERp29 (rERp29) to characterize: 1) fertilization rate (FR); 2) fertilization index (FI); 3) sperm motility and 4) acrosome reaction (AR). Results Confocal microscopy indicated that ERp29 was partially localized at the sperm head of the epididymal caput as well as over the whole head and part of the principal piece of the tail region from the epididymal cauda. However, when the acrosome reacted, ERp29 remained in the equatorial and post-acrosomal regions of the sperm head, which is the initial site of sperm-oocyte membrane fusion. Such localization changes were confirmed based on the results of Western blot analysis. Furthermore, the antibodies against mouse rERp29 inhibited the spermatozoa from penetrating into the zona pellucida (ZP)-free oocytes. The functional blocking antibodies reduced both mouse sperm-oocyte FR and FI at concentrations of 100 and 200 micro g/ml compared with pre-immunized rabbit IgG or with anti-mouse recombinant bactericidal/permeability-increasing protein (BPI, a sperm surface protein unrelated to sperm-oocyte fusion) antibodies (100 micro g/ml), but they had no effect on sperm motility and AR. Conclusion This study demonstrates that ERp29 on mouse spermatozoa membrane changes during epididymal transit and AR. Accordingly, in mice this protein may be one of the important factors involved in sperm fertilization by facilitating sperm-oocyte membrane fusion. PMID:20132541

2010-01-01

102

Percutaneous Penetration Enhancers: An Overview  

Microsoft Academic Search

Transdermal drug delivery is the controlled release of drugs through the skin to obtain therapeutic levels systematically. Several technological advances have been made in the recent decades to enhance percutaneous drug penetration. This overview focuses on the physical, biochemical, and chemical means of penetration enhancement, as well as the classification and mechanisms of chemical penetration enhancers, their application in transdermal

H.-Y. Thong; H. Zhai; H. I. Maibach

2007-01-01

103

Pesticide clastogenicity in Chinese hamster ovary cells.  

PubMed

Paraquat, alachlor, butachlor, phorate and monocrotophos, several of the most extensively used pesticides in Taiwan, were investigated for their clastogenicity using chromosome aberration (CAb) induction in Chinese hamster ovary (CHO) cells. Significance levels of the binomial trend analysis and binomial mutagenicity data test were two criteria for the summary judgement of the pesticide clastogenicity. Except for phorate, all pesticides tested were clastogenic to CHO cells in the absence of in vitro metabolic activation by S9. 5 microliters/ml rat-liver extract, S9, were used as the source of in vitro metabolic activation. 3 different outcomes were found after the addition of S9. Paraquat: significant decrease in induced CAbs. Monocrotophos: concomitant occurrence of decreased cytotoxicity and increased clastogenicity. Alachlor, butachlor and phorate: increased cytotoxicities with no sign of enhancement in clastogenicity. PMID:3600690

Lin, M F; Wu, C L; Wang, T C

1987-07-01

104

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

105

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

106

Taste qualities of solutions preferred by hamsters.  

PubMed

Molecules of diverse chemical structure are sweet to humans and several lines of evidence (genetic, physiological, behavioral) suggest that there may be distinct sweet perceptual qualities. To address how many perceptual categories these molecules elicit in hamsters (Mesocricetus auratus), we studied patterns of generalization of conditioned taste aversions for seven sweeteners: 100 mM sucrose, 320 mM maltose, 32 mM D-phenylalanine, 3.2 mM sodium saccharin, 16 mM calcium cyclamate, 10 mM dulcin and 32 mM sodium m-nitrobenzene sulfonate. Each stimulus was preferred versus water in two-bottle intake tests and stimulated the chorda tympani nerve. For each of seven experimental groups the conditional stimulus (CS) was a sweetener and for the control group the CS was water. Apomorphine.HCl was injected i.p. after a CS was sampled and, after recovery, test stimuli (TS) were presented for 1 h daily. The intake (ml) of each TS consumed by experimental animals was compared with mean TS intake by the control group. Learned aversions for 18/21 stimulus pairs cross-generalized, resulting in a single cluster of generalization patterns for the seven stimuli. Cross-generalization failures (maltose-cyclamate, maltose-sucrose, cyclamate-NaNBS) may be the consequence of particular stimulus features (e.g. salience, cation taste), rather than the absence of a 'sucrose-like' quality. The results are consistent with a single hamster perceptual quality for a diverse set of chemical structures that are sweet to humans. PMID:10192473

MacKinnon, B I; Frank, M E; Hettinger, T P; Rehnberg, B G

1999-02-01

107

Effects of defolliculation on membrane current responses of Xenopus oocytes.  

PubMed Central

1. Catecholamines, adenosine, gonadotrophins, vasoactive intestinal peptide (VIP) and E-series prostaglandins all elicit K+ currents in follicle-enclosed Xenopus oocytes. Evidence suggests that cyclic nucleotides act as intracellular messengers in the activation of this K+ conductance. Muscarinic agonists and some divalent cations (e.g. Co2+, Mn2+, Ni2+ and Cd2+) elicit slow oscillatory Cl- currents, which are activated through hydrolysis of inositol phospholipids and mobilization of intracellular calcium by inositol phosphates. 2. We investigated whether these membrane current responses were generated in the oocyte itself or in enveloping follicular cells which are coupled to the oocyte by gap junctions. Oocytes were defolliculated, either enzymatically using collagenase, or by manual dissection combined with rolling over poly-L-lysine-coated slides. Removal of follicular cells was checked using scanning electron microscopy. Membrane current responses of defolliculated oocytes were compared with responses seen in follicle-enclosed oocytes taken from the same ovary. 3. The K+ responses evoked by all the various hormones/neurotransmitters were either drastically reduced (greater than 90%) or abolished by defolliculation. K+ currents generated by the adenylate cyclase activator forskolin and by intraoocyte injection of adenosine 3',5'-cyclic monophosphate (cyclic AMP), or guanosine 3',5'-cyclic monophosphate were similarly reduced in defolliculated oocytes. In contrast, oscillatory Cl- currents to acetylcholine and divalent cations were selectively preserved through defolliculation. 4. Injection of cyclic AMP (1-20 pmol) into defolliculated oocytes had little or no effect on oscillatory Cl- currents elicited by ACh. However, the calcium-dependent transient Cl- current, activated by depolarization of the oocyte membrane, was consistently potentiated (100-900%) by injections of cyclic AMP (1-10 pmol). 5. These experiments suggest that cyclic nucleotide-activated K+ currents arise essentially in follicular cells and are monitored within the oocyte through electrical coupling by gap junctions. Oscillatory Cl- responses evoked by ACh and divalent cations are produced largely or wholly in the oocyte itself. Images Fig. 1 Plate 1 Plate 2 PMID:2558177

Miledi, R; Woodward, R M

1989-01-01

108

Micro-bioreactor design for Chinese hamster ovary cells  

E-print Network

The research objective is to design a micro-bioreactor for the culture of Chinese Hamster Ovary (CHO) cells. There is an increasing demand for upstream development in high-throughput micro-bioreactors specifically for the ...

Goh, Shireen

2013-01-01

109

The metabolism of radiohafnium in marmosets and hamsters.  

PubMed

The whole body retention of 181Hf was studied in marmosets (Callithrex jacchus) and found to be closely similar to that in rats and Chinese hamsters. Limited tissue distribution studies suggest a higher uptake in liver and much lower deposition in skin and muscle in the marmoset as compared to the rat or Chinese hamster. Studies in Chinese hamsters showed that treatment with the chelating agent diethylenetriaminepentaacetic acid resulted in only a small reduction in the whole body retention of 181Hf. The absorption of orally administered 181Hf, in various chemical forms, was found to be between 0.04 and 0.13% of the ingested dose and was unaffected by age between 5 and 21 months but was increased by fasting. The measured absorption of 181Hf in Chinese hamsters and in rats was similar to that of plutonium suggesting that radiohafnium could be used as a surrogate for plutonium for selected studies in human volunteers. PMID:3833824

Taylor, D M; Seidel, A; Doerfel, H

1985-01-01

110

Epinephrine promotes development potential of vitrified mouse oocytes.  

PubMed

Cryopreserved oocytes show low developmental ability. To understand the mechanism underlying their development impairment, study was designed to determine the effect of epinephrine on the in vitro developmental competence of vitrified mouse oocytes. Mature oocytes were vitrified using Open Pulled Straw (OPS) method. The vitrified oocytes were warmed and introduced into M2 medium which contains epinephrine at different concentrations (10(-2), 10(-4), 10(-6), 10(-8) mol L(-1) in an incubator for 1 h. Then the survival rate of the oocytes was evaluated and the subsequent development of oocytes was assessed through in vitro Fertilization (IVF). Furthermore, the levels of intracellular ROS, GSH and the concentration of ATP were determined among 10(-4) mol L(-1) epinephrine-treated group, vitrification group and fresh group. Results showed that vitrified oocytes treated with 10(-4)) mol L(-1) epinephrine had significant higher rates of cleavage (66.4 vs.45.2%) and blastocyst (47.2 vs. 34.7%) than no epinephrine treated group, as well as more blastocyst cells (54.5 vs. 36.8) and lower ratio of apoptotic cells (5.9 vs. 21.5%; p < 0.05). Further experiment found that 10(-4) mol L(-1) epinephrine treatment could significantly reduce intracellular ROS level and enhance cytoplasmic ATP concentration (p < 0.05), but there was no different in GSH level compared to vitrification group. In conclusion, epinephrine could promote vitrified oocytes cryosurvival and their subsequent development ability, which maybe related with the changes of intracellular ROS level and ATP content. PMID:24783810

Wang, Liang; Fu, Xiangwei; Zeng, Yan; Zhu, Shien

2014-01-15

111

Visualization of mRNA Localization in Xenopus Oocytes  

PubMed Central

Visualization of in vivo mRNA localization provides a tool for understanding steps in the mechanism of transport. Here we detail a method of fluorescently labeling mRNA transcripts and microinjecting them into Xenopus laevis oocytes followed with imaging by confocal microscopy. This technique overcomes a significant hurdle of imaging RNA in the frog oocyte while providing a rapid method of visualizing mRNA localization in high resolution. PMID:21431735

Gagnon, James A.; Mowry, Kimberly L.

2011-01-01

112

Automated fast perfusion of Xenopus oocytes for drug screening  

Microsoft Academic Search

Fast (‘concentration jump’) applications of neurotransmitters are crucial for screening studies on ligand-gated ion channels. In this paper, we describe a method for automated fast perfusion of neurotransmitters (or drugs) during two-microelectrode voltage-clamp experiments on Xenopus oocytes. The oocytes are placed in a small bath chamber that is covered by a glass plate with two channels for the microelectrodes that

I. Baburin; S. Beyl; S. Hering

2006-01-01

113

Streptozotocin and renal amyloidosis in the Syrian hamster.  

PubMed

In the Syrian hamster, administration of the drug streptozotocin was associated with an increased incidence and severity of renal amyloidosis. Some of the more severely affected animals showed a frankly nephrotic picture. Although some of the diseased animals showed decreased levels of serum albumin, no other definite changes in serum proteins were noted, nor was there any evidence of glomerular immunoglobulin or immune complex deposition. None of the lesions previously found after administration of streptozotocin in the Chinese hamster were encountered. PMID:59551

Berman, L; Stilmant, M; Hayes, J A

1976-07-01

114

Lesions of the Thalamic Intergeniculate Leaflet Alter Hamster Circadian Rhythms  

Microsoft Academic Search

We have investigated the effects of destruction of the geniculo-hypothalamic tract (GHT) on the circadian system of golden hamsters. In the first experiment, intact hamsters were housed in constant darkness, and phase shifts in running-wheel activity rhythms were assessed following 15-min light pulses administered at circadian time (CT) 12 (defined as the beginning of activity), CT 14, CT 18, and

Mary E. Harrington; Benjamin Rusak

1986-01-01

115

Isolation of two chloroethylnitrosourea-sensitive Chinese hamster cell lines  

Microsoft Academic Search

1-((4-Amino-2-methylpyrimidin-5-yl)methyl)-3-(2-chloroethyl)-3- nitrosourea hydrochloride (ACNU), a cancer chemotherapeutic bifunctional alkylating agent, causes chloroethylation of DNA and subsequent DNA strand cross-linking through an ethylene bridge. We isolated and characterized two ACNU-sensitive mutants from mutagenized Chinese hamster ovary cells and found them to be new drug-sensitive recessive Chinese hamster mutants. Both mutants were sensitive to various monofunctional alkylating agents in a way similar

H. Hata; M. Numata; H. Tohda; A. Yasui; A. Oikawa

1991-01-01

116

The Effects of Progesterone on Oocyte Maturation and Embryo Development  

PubMed Central

Oocyte maturation and embryo development are controlled by intra-ovarian factors such as steroid hormones. Progesterone (P4) exists in the follicular fluid that contributes to normal mammalian ovarian function and has several critical functions during embryo development and implantation, including endometrial receptivity, embryonic survival during gestation and transformation of the endometrial stromal cells to decidual cells. It is well known that the physiological effects of P4 during the pre-implantation stages of some mammal’s embryos are mediated by P4 receptors and their gene expression is determined. The effects of P4 on oocytes and embryo development have been assessed by some investigations, with contradictory results. P4, a dominant steroid in follicular fluid at approximately 18 hours after the luteinizing hormone (LH ) surge may have a critical role in maturation of oocytes at the germinal stage. However, it has been shown that different concentrations of P4 could not improve in vitro maturation rates of germinal vesicles (GV) in cumulus oocyte complexes (COCs) and cumulus denuded oocytes (CDOs). Culture media supplemented with P4 significantly improved mouse embryo development. In addition, an in vivo experimental design has shown high blastocyst survival and implantation rates in P4-treated mice. In this review we explain some of the findings that pertain to the effects of P4 on oocyte maturation and embryo development both in vitro and in vivo. PMID:24520467

Salehnia, Mojdeh; Zavareh, Saeed

2013-01-01

117

Selective degradation of transcripts during meiotic maturation of mouse oocytes  

PubMed Central

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 was utilized to minimize the impact of complex variations in transcript polyadenylation prevalent during this transition. Transcripts were identified and quantified using the Affymetrix Mouse Genome 430 v2.0 GeneChip. The significantly changed and stable transcripts were analyzed using Ingenuity Pathways Analysis and GenMAPP/MAPPFinder to characterize the biological themes underlying global changes in oocyte transcripts during maturation. It was concluded that the destruction of transcripts during the GV to MII transition is a selective rather than promiscuous process in mouse oocytes. In general, transcripts involved in processes that are associated with meiotic arrest at the GV-stage and the progression of oocyte maturation, such as oxidative phosphorylation, energy production, and protein synthesis and metabolism, were dramatically degraded. In contrast, transcripts encoding participants in signaling pathways essential for maintaining the unique characteristics of the MII-arrested oocyte, such as those involved in protein kinase pathways, were the most prominent among the stable transcripts. PMID:17022963

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

2007-01-01

118

Regulation of Greatwall kinase during Xenopus oocyte maturation.  

PubMed

Greatwall kinase has been identified as a key element in M phase initiation and maintenance in Drosophila, Xenopus oocytes/eggs, and mammalian cells. In M phase, Greatwall phosphorylates endosulfine and related proteins that bind to and inhibit protein phosphatase 2A/B55, the principal phosphatase for Cdk-phosphorylated substrates. We show that Greatwall binds active PP2A/B55 in G2 phase oocytes but dissociates from it when progesterone-treated oocytes reach M phase. This dissociation does not require Greatwall kinase activity or phosphorylation at T748 in the presumptive T loop of the kinase. A mutant K71M Greatwall, also known as Scant in Drosophila, induces M phase in the absence of progesterone when expressed in oocytes, despite its reduced stability and elevated degradation by the proteasome. M phase induction by Scant Greatwall requires protein synthesis but is not associated with altered binding or release of PP2A/B55 as compared to wild-type Greatwall. However, in vitro studies with Greatwall proteins purified from interphase cells indicate that Scant, but not wild-type Greatwall, has low but detectable activity against endosulfine. These results demonstrate progesterone-dependent regulation of the PP2A/B55-Greatwall interaction during oocyte maturation and suggest that the cognate Scant Greatwall mutation has sufficient constitutive kinase activity to promote M phase in Xenopus oocytes. PMID:21551066

Yamamoto, Tomomi M; Blake-Hodek, Kristina; Williams, Byron C; Lewellyn, Andrea L; Goldberg, Michael L; Maller, James L

2011-07-01

119

Regulation of Greatwall kinase during Xenopus oocyte maturation  

PubMed Central

Greatwall kinase has been identified as a key element in M phase initiation and maintenance in Drosophila, Xenopus oocytes/eggs, and mammalian cells. In M phase, Greatwall phosphorylates endosulfine and related proteins that bind to and inhibit protein phosphatase 2A/B55, the principal phosphatase for Cdk-phosphorylated substrates. We show that Greatwall binds active PP2A/B55 in G2 phase oocytes but dissociates from it when progesterone-treated oocytes reach M phase. This dissociation does not require Greatwall kinase activity or phosphorylation at T748 in the presumptive T loop of the kinase. A mutant K71M Greatwall, also known as Scant in Drosophila, induces M phase in the absence of progesterone when expressed in oocytes, despite its reduced stability and elevated degradation by the proteasome. M phase induction by Scant Greatwall requires protein synthesis but is not associated with altered binding or release of PP2A/B55 as compared to wild-type Greatwall. However, in vitro studies with Greatwall proteins purified from interphase cells indicate that Scant, but not wild-type Greatwall, has low but detectable activity against endosulfine. These results demonstrate progesterone-dependent regulation of the PP2A/B55–Greatwall interaction during oocyte maturation and suggest that the cognate Scant Greatwall mutation has sufficient constitutive kinase activity to promote M phase in Xenopus oocytes. PMID:21551066

Yamamoto, Tomomi M.; Blake-Hodek, Kristina; Williams, Byron C.; Lewellyn, Andrea L.; Goldberg, Michael L.; Maller, James L.

2011-01-01

120

Greatwall kinase is required for meiotic maturation in porcine oocytes.  

PubMed

Meiotic maturation in many species is initiated by the activation of maturation-promoting factor (MPF) with concomitant inactivation of counteracting phosphatases, most notably protein phosphatase 2A (PP2A). Recently, Greatwall (GWL) has been identified as a cell cycle regulator that inhibits PP2A activity. In this study, we demonstrate that GWL is required for meiotic maturation in porcine oocytes. GWL expression increases from germinal vesicle (GV) to metaphase II (MII) stages of porcine oocytes and dramatically decreases with progression of the meiotic cell cycle. GWL is initially localized in the nucleus of GV oocytes and is associated with spindle fibers following GV breakdown. Depletion of GWL inhibited or delayed meiotic maturation secondary to defects in chromosome congression and spindle formation. Conversely, overexpression of GWL overcame meiotic arrest and initiated progression to MII stage. However, these oocytes had severe spindle defects. Furthermore, MII oocytes depleted of GWL progressed to pronuclear formation. Taken together, our data demonstrate that GWL is required not only for meiotic maturation but also for maintenance of MII arrest in porcine oocytes. PMID:23843240

Li, Ying-Hua; Kang, Hyoeun; Xu, Yong-Nan; Heo, Young-Tae; Cui, Xiang-Shun; Kim, Nam-Hyung; Oh, Jeong Su

2013-09-01

121

Resveratrol Protects Mouse Oocytes from Methylglyoxal-Induced Oxidative Damage  

PubMed Central

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

122

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

123

Penetrating Fire Extinguisher  

NASA Astrophysics Data System (ADS)

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

124

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

PubMed Central

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/CCORT, 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.

2014-01-01

125

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

126

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

127

Overview: Hard Rock Penetration  

SciTech Connect

The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

Dunn, J.C.

1992-08-01

128

Penetration in GTA welding  

SciTech Connect

The size and shape of the weld bead produced in GTA welding depends on the magnitude and distribution of the energy incident on the workpiece surfaces as well as the dissipation of that energy in the workpiece. The input energy is largely controllable through the welding parameters selected, however the dissipation of that energy in the workpiece is less subject to control. Changes in energy dissipation can produce large changes in weld shape or penetration. Heat transport away from the weld pool is almost entirely by conduction, but heat transport in the weld pool is more complicated. Heat conduction through the liquid is an important component, but heat transport by convection (mass transport) is often the dominant mechanism. Convective heat transport is directional and changes the weld pool shape from that produced by conduction alone. Surface tension gradients are often the dominant forces driving fluid flow in GTA weld pools. These gradients are sensitive functions of weld pool chemistry and the energy input distribution to the weld. Experimental and theoretical work conducted primarily in the past decade has greatly enhanced our understanding of weld pool fluid flow, the forces which drive it, and its effects on weld pool shape. This work is reviewed here. While less common, changes in energy dissipation through the unmelted portion of the workpiece can also affect fusion zone shape or penetration. These effects are also described. 41 refs., 9 figs.

Heiple, C.R.; Burgardt, P.

1990-01-01

129

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

130

[The action of neurotransmitters and their antagonists on oocyte maturation. The action of serotonin antagonists on the in-vitro maturation of amphibian oocytes].  

PubMed

Serotonin antagonists (inmecarb hydrochloride and inmecarb methiodide) stimulate in vitro maturation of Bufo viridis and Xenopus laevis oocytes or potentiate the action of progesterone. In contrast to that, serotonin inhibits or blocks oocyte maturation stimulated by progesterone or serotonin antagonists. Sensitivity of B. viridis oocytes to serotonin, its agonists and antagonists is subject to seasonal changes. A maximum sensitivity of intact oocytes is observed in February-March, and that of denuded ones in May-June. We suggest that endogenous serotonin is involved in maintenance of the block of meiosis and in the oocyte maturation control in amphibians. PMID:8371904

Nikitina, L A; Trubnikova, O B; Buznikov, G A

1993-01-01

131

Active maturation-promoting factor is present in mature mouse oocytes  

PubMed Central

Cytoplasmic extracts of meiotically mature mouse oocytes were injected into immature Xenopus laevis oocytes, which underwent germinal vesicle breakdown within 2 h. Germinal vesicle breakdown was not inhibited by incubation of the Xenopus oocytes in cycloheximide (20 micrograms/ml). Identically prepared extracts of meiotically immature mouse oocytes, arrested at the germinal vesicle stage by dibutyryl cyclic AMP (100 micrograms/ml), did not induce germinal vesicle breakdown in Xenopus oocytes. The results show that maturation-promoting factor activity appears during the course of oocyte maturation in the mouse. PMID:3886670

1985-01-01

132

Membrane currents elicited by divalent cations in Xenopus oocytes.  

PubMed Central

1. Membrane currents were recorded from voltage-clamped Xenopus oocytes in response to bath application of various divalent cations. 2. In oocytes from 93 of 160 frogs tested, Co2+ ions evoked slow, oscillatory membrane currents. Sensitivity to Co2+ varied greatly between oocytes from different frogs, but was relatively consistent for oocytes taken from the same ovary. Oocytes with high sensitivity had response thresholds of 5-10 microM, and gave currents greater than 1 microA to 1 mM-CoCl2. In contrast, oocytes from some frogs gave no oscillatory response even to 10 mM-CoCl2. With responsive oocytes, Cd2+, Ni2+, Zn2+, Mn2+ and Cr2+ ions (5 microM to 1 mM) also elicited oscillations, whereas Sr2+, Ba2+ and Ca2+ (0.1-10 mM) showed very little activity, and Mg2+ ions, none. 3. Responses to divalent cation were well preserved in defolliculated oocytes, indicating they were generated in the oocyte membrane itself, and were not dependent on the presence of enveloping follicular cells. 4. The oscillatory currents reversed around -20 mV (the chloride equilibrium potential) and rectified strongly at potentials more negative than about -60 mV. The oscillations were mimicked by intraoocyte injection of inositol 1,4,5-trisphosphate (IP3), were largely preserved after removal of external Ca2+, but were abolished following chelation of intracellular Ca2+ by EGTA. Intraoocyte injection of Co2+ ions failed to generate oscillatory currents. 5. Currents elicited by divalent cations resembled the oocyte's oscillatory responses to acetylcholine and a serum protein. However, the response to divalent cations was not blocked by atropine and furthermore, the relative sensitivities to these agonists varied independently between oocytes from different frogs. 6. We conclude that extracellular Cd2+, Ni2+, Zn2+, Co2+, Mn2+ and Cr2+ interact with the oocyte surface to raise cytosolic levels of inositol phosphates. This causes mobilization of intracellular Ca2+, in turn activating Ca2+-gated Cl- channels in the oocyte membrane. 7. In addition to the large oscillatory currents, divalent cations generated small (5-50 nA), smooth, maintained currents associated with decreases in membrane conductance. The size and ionic basis of these currents varied between oocytes from different frogs. 8. Zinc ions also elicited smooth currents, associated with an increase in membrane conductance, and carried predominantly by K+. This response was specific to Zn2+ and occurred independently of oscillatory Cl- currents. The K+ current was abolished by defolliculation, was potentiated by the cyclic AMP phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine,and showed facilitation with K+ currents generated by the adenylate cyclase activator forskolin.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2482882

Miledi, R; Parker, I; Woodward, R M

1989-01-01

133

Water penetration study  

NASA Technical Reports Server (NTRS)

Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. An experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included.

Lockwood, H. E.

1973-01-01

134

Advanced ground penetrating radar  

SciTech Connect

An advanced Ground Penetrating Radar (GPR) system has the potential for efficiently and reliably providing high resolution images for inspecting concrete civil structures for defects and damage assessment. To achieve the required performance, improvements in radar hardware, and development and adaptation of advanced 2- and 3-dimensional synthetic aperture imaging techniques are needed. Recent and continuing advancement in computer and computer-related technology areas have made it possible to consider more complex and capable systems for a variety of imaging applications not previously conceived. The authors developed conceptual designs, analyzed system requirements, and performed experiments, modeling, and image reconstructions to study the feasibility of improving GPR technology for non-destructive evaluation of bridge decks and other high-value concrete structures. An overview and summary of practical system concepts and requirements, are presented.

Warhus, J.P.; Mast, J.E.; Johansson, E.M.; Nelson, S.D. [Lawrence Livermore National Lab., CA (United States). Electronics Engineering Dept.

1994-07-26

135

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

136

Proteomic analysis of Chinese hamster ovary cells.  

PubMed

To complement the recent genomic sequencing of Chinese hamster ovary (CHO) cells, proteomic analysis was performed on CHO cells including the cellular proteome, secretome, and glycoproteome using tandem mass spectrometry (MS/MS) of multiple fractions obtained from gel electrophoresis, multidimensional 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 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 the 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. Five-hundred four 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

2012-11-01

137

Factors influencing the biochemical markers for predicting mammalian oocyte quality.  

PubMed

The need for accurate selection of the best oocytes for in vitro fertilization protocols and thus, production of embryos has driven the search for oocyte quality markers from morphological criteria to biochemical parameters. Current studies are focused on the biochemical constituents of the follicular fluid and gene expression profiling of the cumulus cells. These parameters are, however, affected by factors that must be considered before making a judgment of the oocyte's quality. These includes factors such as the type of hormonal stimulation protocol, age of oocyte donor and heat stress on the donor, all of which have been reported to influence the concentrations of many hormones, apolipoproteins, metabolites, fatty acids and growth factors in the follicular fluid and the expression of several genes in the cumulus cells. Another important point to note is species variation in the response to these extraneous influences, which thus calls for species targeted investigations. As reports are still scanty and investigations assumed to be very keen, we employed this review paper to bring attention of researchers and clinicians to those factors that may come to bear on the outcome of their investigations on oocyte and embryo quality. PMID:22976454

Ola, Safiriyu Idowu; Sun, Qing-Yuan

2012-01-01

138

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

139

Cryopreservation of equine oocytes using glycerol as the cryoprotectant and cumulus investment as a parameter  

E-print Network

cumulus layer; and 3) corona radiata only. All oocytes were stained with fluorescein diacetate (FDA) to determine viability before freezing. Forty viable oocytes from each group were frozen to be evaluated post-thaw using FDA and orcein stains. None...

Lippert, Jennifer Johnson

2012-06-07

140

High-throughput optofluidic system for the laser microsurgery of oocytes.  

PubMed

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

141

Hamster and murine models of severe destructive Lyme arthritis.  

PubMed

Arthritis is a frequent complication of infection in humans with Borrelia burgdorferi. Weeks to months following the onset of Lyme borreliosis, a histopathological reaction characteristic of synovitis including bone, joint, muscle, or tendon pain may occur. A subpopulation of patients may progress to a chronic, debilitating arthritis months to years after infection which has been classified as severe destructive Lyme arthritis. This arthritis involves focal bone erosion and destruction of articular cartilage. Hamsters and mice are animal models that have been utilized to study articular manifestations of Lyme borreliosis. Infection of immunocompetent LSH hamsters or C3H mice results in a transient synovitis. However, severe destructive Lyme arthritis can be induced by infecting irradiated hamsters or mice and immunocompetent Borrelia-vaccinated hamsters, mice, and interferon-gamma- (IFN-?-) deficient mice with viable B. burgdorferi. The hamster model of severe destructive Lyme arthritis facilitates easy assessment of Lyme borreliosis vaccine preparations for deleterious effects while murine models of severe destructive Lyme arthritis allow for investigation of mechanisms of immunopathology. PMID:22461836

Munson, Erik; Nardelli, Dean T; Du Chateau, Brian K; Callister, Steven M; Schell, Ronald F

2012-01-01

142

Tamoxifen inhibits estrogen-induced hepatic injury in hamsters.  

PubMed

Estrogens have an unusual toxic effect on the liver of two hamster species, the Armenian and the Chinese hamster. The hepatotoxicity was detectable clinically by hyperbilirubinemia and confirmed histologically by the presence of hepatic degenerative-regenerative changes. Administration of tamoxifen with estrogen [either ethynyl estradiol or diethylstilbestrol (DES)] completely abrogated the hepatotoxic effects, suggesting that estrogen receptor (ER) was necessary for estrogen to damage liver. In Armenian hamsters, estrogens decreased hepatic synthesis of female protein (FP); tamoxifen also abolished this DES effect and resulted in a net increase in serum FP levels. DES administration produced higher serum bilirubin levels and lower serum FP levels in females than in males. Paradoxically, tamoxifen blocked these DES effects more effectively and efficiently in females than in males. Estrogens did not injure uteri of Armenian and Chinese hamsters and were nontoxic to livers of other hamsters species, such as Syrian and Turkish. This model provides another perspective of the acute cellular derangement that can be effected by estrogen-ER complex and may indicate a yet unknown mode of ER action. PMID:3335202

Coe, J E; Ross, M J

1988-01-01

143

Saprophytic and cycloheximide resistant fungi isolated from golden hamster.  

PubMed

Healthy hair samples from golden hamsters were examined for the presence of dermatophytes and non-dermatophytes using baiting technique and direct inoculation. Thirty-four species and 2 varieties attributed to 17 genera were recovered. Paecilomyces variotii (isolated from 84.4% of the examined hair) and Aspergillus niger (81.3%) were the more frequent isolates on Sabouraud's dextrose agar (SDA) without cycloheximide. Our results have clearly demonstrated that the hair of hamster was free from true dermatophytes. Using the dilution plate method many fungal species were isolated from cage material (7 genera and 10 species + 1 variety); from faeces (10 genera and 17 species); from standard chow (3 genera and 6 species) of hamster. P. variotii which was the most frequent fungus in the preceding 3 substrates was completely absent in the presence of cycloheximide in SDA. The present study has demonstrated for the first time the isolation of Trichophyton rubrum from hamster faeces. Also, several saprophytic and cycloheximide resistant fungi were isolated. In the air of hamster cage Cladosporium cladosporioides, Penicillium chrysogenum, Alternaria alternata and Scopulariopsis brevicaulis were the most dominant species on SDA with or without cycloheximide. Using the agar diffusion method, Aloe sap, onion oil, garlic bulb extract and aqueous leaf extracts of Andropogon citratus, Euphorbia sp. and Ruta graveolens were tested for their antifungal activity on 10 fungal species. It was observed that onion oil exhibited a high inhibitory effect against most of the tested fungi. PMID:9768288

Bagy, M M; el-Shanawany, A A; Abdel-Mallek, A Y

1998-01-01

144

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

145

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

146

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

147

Mitochondrial Distribution and ATP Content of Vitrified, In vitro Matured Mouse Oocytes  

PubMed Central

Background The objective of this study was to investigate the effect of vitrification and in vitro maturation on the mitochondrial distribution and ATP content of oocytes. Methods The oocytes at Germinal Vesicle (GV) and Metaphase II (MII) stages were recovered from 6-8 week old NMRI strain female mice. The oocytes were divided into vitrified and non-vitrified groups. Vitrification was done by the cryotop method using ethylene glycol, dimethylsulfoxide and sucrose as cryoprotectants. The GV oocytes were cultured in maturation medium for 24 hrs. The collected in vitro matured oocytes (IVM-MII) and ovulated metaphase II (OV-MII) oocytes were inseminated with capacitated sperm. The ATP content of the oocytes was measured by luciferin-luciferase reaction. Distribution of oocyte mitochondria was studied using Mito Tracker Green staining under fluorescent microscope. Results The survival rates of vitrified oocytes at GV and MII stages were 87.39 and 89.5%, respectively. There was no significant difference in the developmental and hatching rates of vitrified and non-vitrified oocytes. The ATP content of GV and MII oocytes derived from in vivo and in vitro condition was not significantly different in vitrified and non-vitrified samples. The pattern of mitochondrial distribution in vitrified and non-vitrified GV and MII oocytes was similar but it was different between MII oocytes collected from fallopian tube and in vitro matured MII oocytes. However, the florescent intensity of mitochondrial staining was different in all the groups in the study. Conclusion Vitrification did not affect mouse oocyte developmental competence, ATP content at different developmental stages but some alteration was seen in mitochondria distribution of in vitro matured oocytes in comparison to their controls.

Nazmara, Zohreh; Salehnia, Mojdeh; HosseinKhani, Saman

2014-01-01

148

Potassium rectifications of the starfish oocyte membrane and their changes during oocyte maturation.  

PubMed Central

1. The current-voltage relations of the oocyte membrane of the starfish, Asterina pectinifera, and their changes during maturation were investigated using current-clamp techniques. 2. The resting potential of the oocyte membrane in sea water was found to be determined by the diffusion potential of K ions. 3. In the absence of Na and Ca inward currents the steady-state current-voltage relation of the oocyte membrane had inward-going K rectification at membrane potentials more negative than -65 mV and outward-going K rectification at potentials more positive than -30 mV, forming a S-shaped I-V curve. 4. A negative resistance region of the steady-state I-V curve was revealed with voltage-clamp technique in the potential range between -65 and -30 mV. 5.Transient K activation occurred when the membrane was brought from a resting potential of about -75 mV to potentials more positive than -20 mV, and this was immediately followed by K inactivation. Accordingly, the steady-state I-V relation showed only slight outward-going rectification. 6. At the beginning of meiosis, which is signalled by break-down of the nucleus, the limiting slope conductance in the inward rectifying region of the I-V curve decreased sevenfold. The cell membrane lost its selective permeability to K ions and was depolarized from -70 to between -20 and OmV in standard artificial sea-water. The depolarized resting potential was partly due to the relative increase in Na permeability. K conductance began to increase again within 30 min after breakdown of the nucleus. The resting potential became gradually larger and eventually attained -70 mV in the mature egg. 7. In the mature egg, K activation upon depolarization was no longer followed by inactivation. Accordingly, the slope conductance in the outward rectifying region of the I-V curve increased. 8. The action potential was augmented at the stage of nuclear breakdown. Thereafter the maximum rate of rise decreased and the duration of the action potential shortened. These changes were caused primarily by changes in K conductance during maturation. 9. Fertilization of the egg during the maturation process did not affect the changes in the I-V relation described above, except for a transient change of the membrane permeability upon fertilization. PMID:1169320

Miyazaki, S I; Ohmori, H; Sasaki, S

1975-01-01

149

Cryopreservation of Embryos and Oocytes in Human Assisted Reproduction  

PubMed Central

Both sperm and embryo cryopreservation have become routine procedures in human assisted reproduction and oocyte cryopreservation is being introduced into clinical practice and is getting more and more widely used. Embryo cryopreservation has decreased the number of fresh embryo transfers and maximized the effectiveness of the IVF cycle. The data shows that women who had transfers of fresh and frozen embryos obtained 8% additional births by using their cryopreserved embryos. Oocyte cryopreservation offers more advantages compared to embryo freezing, such as fertility preservation in women at risk of losing fertility due to oncological treatment or chronic disease, egg donation, and postponing childbirth, and eliminates religious and/or other ethical, legal, and moral concerns of embryo freezing. In this review, the basic principles, methodology, and practical experiences as well as safety and other aspects concerning slow cooling and ultrarapid cooling (vitrification) of human embryos and oocytes are summarized. PMID:24779007

Konc, János; Kanyó, Katalin; Kriston, Rita; Somosk?i, Bence; Cseh, Sándor

2014-01-01

150

Cryopreservation of embryos and oocytes in human assisted reproduction.  

PubMed

Both sperm and embryo cryopreservation have become routine procedures in human assisted reproduction and oocyte cryopreservation is being introduced into clinical practice and is getting more and more widely used. Embryo cryopreservation has decreased the number of fresh embryo transfers and maximized the effectiveness of the IVF cycle. The data shows that women who had transfers of fresh and frozen embryos obtained 8% additional births by using their cryopreserved embryos. Oocyte cryopreservation offers more advantages compared to embryo freezing, such as fertility preservation in women at risk of losing fertility due to oncological treatment or chronic disease, egg donation, and postponing childbirth, and eliminates religious and/or other ethical, legal, and moral concerns of embryo freezing. In this review, the basic principles, methodology, and practical experiences as well as safety and other aspects concerning slow cooling and ultrarapid cooling (vitrification) of human embryos and oocytes are summarized. PMID:24779007

Konc, János; Kanyó, Katalin; Kriston, Rita; Somosk?i, Bence; Cseh, Sándor

2014-01-01

151

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

152

Production of Sry knockout mouse using TALEN via oocyte injection  

PubMed Central

Recently developed transcription activator-like effector nuclease (TALEN) technology has enabled the creation of knockout mice, even for genes on the Y chromosome. In this study, we generated a knockout mouse for Sry, a sex-determining gene on the Y chromosome, using microinjection of TALEN RNA into pronuclear stage oocytes. As expected, the knockout mouse had female external and internal genitalia, a female level of blood testosterone and a female sexually dimorphic nucleus in the brain. The knockout mouse exhibited an estrous cycle and performed copulatory behavior as females, although it was infertile or had reduced fertility. A histological analysis showed that the ovary of the knockout mouse displayed a reduced number of oocytes and luteinized unruptured follicles, implying that a reduced number of ovulated oocytes is a possible reason for infertility and/or reduced fertility in the KO mouse. PMID:24190364

Kato, Tomoko; Miyata, Kohei; Sonobe, Miku; Yamashita, Satoshi; Tamano, Moe; Miura, Kento; Kanai, Yoshiakira; Miyamoto, Shingo; Sakuma, Tetsushi; Yamamoto, Takashi; Inui, Masafumi; Kikusui, Takefumi; Asahara, Hiroshi; Takada, Shuji

2013-01-01

153

Brief communication Effects of weasel odor on behavior and physiology of two hamster species  

Microsoft Academic Search

This study examined the behavioral and physiological effects of long-term exposure to overdose of aversive odor (predator odor) in two species of hamsters. About 0.05 mg of anal gland secretions of Siberian weasels (Mustela sibirica) was smeared at the oronasal groove of wild male ratlike hamsters (Cricetulus triton) (natural prey) and laboratory golden hamsters (Mesocricetus auratus) once every day for

Jian-Xu Zhang; Cheng Cao; Heng Gao; Zhong-Shun Yang; Lixing Sun; Zhi-Bin Zhang; Zu-Wang Wang

154

Twelve-Hour Phase Shifts of Hamster Circadian Rhythms Elicited by Voluntary Wheel Running  

Microsoft Academic Search

Running in a novel wheel can serve as a nonphotic zeitgeber to entrain or phase shift circadian rhythms in hamsters. In this study, hamsters were entrained to a light:dark schedule of 14:10 h but had no access to running wheels. At four different phase points of the light cycle, hamsters were transferred to constant darkness and provided with running wheels.

Robert L. Gannon; Michael A. Rea

1995-01-01

155

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

156

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

157

Effect of ovarian stimulation on oocyte gene expression in cattle.  

PubMed

The objective was to analyze the impact of follicle stimulating hormone (FSH, ovarian stimulation) on the transcriptome of in vivo bovine oocytes three times around the luteinizing hormone (LH) surge. In vivo bovine oocytes were collected 2 h pre-LH surge, 6 h post-LH surge, and 22 h post-LH surge in both naturally ovulating and superovulated animals. To assess potential changes in gene levels, samples were hybridized using a custom bovine microarray. Two series of hybridizations were performed: the first comparing natural vs. stimulated cycles, the second according to time of collection. Among the potential candidates, 13 genes were selected according to their degree of differential expression and their potential link to oocyte competence. Measurements of their relative mRNA levels was made using QPCR. Gene candidates BTG4 (P = 0.0006), PTTG1 (P = 0.0027), PAPOLA (P = 0.0245), and LEO1 (P = 0.0393) had higher mRNA levels in oocytes treated with FSH for all collection times when compared to oocytes produced through the natural cycle. Among our selected candidates, only one gene, GDF9 (P = 0.0261), was present at a higher level in oocytes collected at -2 h and 6 h than 22 h post-LH for all treatments, regardless of the presence of FSH. Although the number of genes influenced by ovarian stimulation seemed low, the observed differences occurred at a time of minimal transcriptional activity and supported the potential impact on the future embryo. These impacts could have been epigenetic in nature, as embryo quality was not reported to be different from stimulated animals. PMID:22444561

Chu, T; Dufort, I; Sirard, M-A

2012-06-01

158

Cholesterol Depletion Disorganizes Oocyte Membrane Rafts Altering Mouse Fertilization  

PubMed Central

Drastic membrane reorganization occurs when mammalian sperm binds to and fuses with the oocyte membrane. Two oocyte protein families are essential for fertilization, tetraspanins and glycosylphosphatidylinositol-anchored proteins. The firsts are associated to tetraspanin-enriched microdomains and the seconds to lipid rafts. Here we report membrane raft involvement in mouse fertilization assessed by cholesterol modulation using methyl-?-cyclodextrin. Cholesterol removal induced: (1) a decrease of the fertilization rate and index; and (2) a delay in the extrusion of the second polar body. Cholesterol repletion recovered the fertilization ability of cholesterol-depleted oocytes, indicating reversibility of these effects. In vivo time-lapse analyses using fluorescent cholesterol permitted to identify the time-point at which the probe is mainly located at the plasma membrane enabling the estimation of the extent of the cholesterol depletion. We confirmed that the mouse oocyte is rich in rafts according to the presence of the raft marker lipid, ganglioside GM1 on the membrane of living oocytes and we identified the coexistence of two types of microdomains, planar rafts and caveolae-like structures, by terms of two differential rafts markers, flotillin-2 and caveolin-1, respectively. Moreover, this is the first report that shows characteristic caveolae-like invaginations in the mouse oocyte identified by electron microscopy. Raft disruption by cholesterol depletion disturbed the subcellular localization of the signal molecule c-Src and the inhibition of Src kinase proteins prevented second polar body extrusion, consistent with a role of Src-related kinases in fertilization via signaling complexes. Our data highlight the functional importance of intact membrane rafts for mouse fertilization and its dependence on cholesterol. PMID:23638166

Buschiazzo, Jorgelina; Ialy-Radio, Come; Auer, Jana; Wolf, Jean-Philippe; Serres, Catherine

2013-01-01

159

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

160

Redundant control of the Caenorhabditis elegans sperm oocyte switch by PUF-8 and FBF-1,  

E-print Network

is also critical for the hermaphrodite sperm oocyte switch. Most puf-8 mutant hermaphrodites make both-1 puf-8 double mutants fail in the hermaphrodite sperm oocyte switch. Therefore, puf-8 and fbf-1 act- rhabditis elegans sperm oocyte switch. C. elegans can exist as either a self-fertile hermaphrodite or a male

Kimble, Judith

161

Healthy twins delivered after oocyte cryopreservation and bilateral ovariectomy for ovarian cancer  

Microsoft Academic Search

Anti-neoplastic treatments have significantly increased the survival of cancer patients, but female patients risk premature menopause. Oocyte cryopreservation has been proposed as a fertility-saving option. This report describes the first live birth achieved with autologous cryopreserved oocytes in an ovariectomized borderline cancer patient. A patient with a borderline ovarian tumour asked for oocyte cryopreservation after a right adnexectomy. Ovulation induction

E Porcu; S Venturoli; G Damiano; PM Ciotti; L Notarangelo; R Paradisi; M Moscarini; G Ambrosini

2008-01-01

162

Selection of prepubertal goat oocytes using the brilliant cresyl blue test  

Microsoft Academic Search

Brilliant cresyl blue stain allows us to determine the activity of glucose-6-phosphate dehydrogenase (G6PD), an enzyme synthesized in growing oocytes but with decreased activity in oocytes that have finished their growth phase. The objective of this study was to evaluate the utility of the brilliant cresyl blue (BCB) test as an indirect measure of oocyte growth, in order to select

E. Rodr??guez-González; M. López-Béjar; E. Velilla; M. T. Paramio

2002-01-01

163

Developmental competence of heifer oocytes selected using the brilliant cresyl blue (BCB) test  

Microsoft Academic Search

The aim of this study was to evaluate the usefulness of the brilliant cresyl blue (BCB) test in the selection of more competent heifer oocytes for in vitro embryo production (IVEP). IVEP from selected BCB heifer oocytes was compared to IVEP from morphologically selected heifer (control group) and cow oocytes. BCB staining determines the activity of glucose-6-phosphate dehydrogenase (G6PD), an

Marc Pujol; Manel López-Béjar; Maria-Teresa Paramio

2004-01-01

164

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

165

Trout coelomic fluid suitability as Goldfish oocyte extender can be determined by a simple turbidity test  

Microsoft Academic Search

Regeneration technologies such as androgenesis, intracytoplasmic sperm injection, and nuclear transfer require that handling conditions do not alter oocyte ability to sustain embryo development. One important parameter in the maintenance of oocyte quality in fish is the possibility to prevent oocytes activation during manipulation. In Cyprinid, such activation is known to be delayed when Salmonid coelomic fluid is used as

A. Depince; L. Marandel; L. Goardon; P.-Y. Le Bail; C. Labbe

2011-01-01

166

Development of vitrified–thawed bovine oocytes after in vitro fertilization and somatic cell nuclear transfer  

Microsoft Academic Search

Cryopreservation could be a useful technique for providing a steady source of oocytes for nuclear transfer and in vitro embryo production. The purpose of this study was to develop a method for cryopreservation of bovine oocytes while maintaining the developmental potential following subsequent in vitro fertilization (IVF) or somatic cell nuclear transfer (SCNT). Following vitrification–thawing, the surviving oocytes were (a)

Byoung-Chul Yang; Gi-Sun Im; Dong-Hun Kim; Boh-Suk Yang; Hyun-Ju Oh; Hyo-Suk Park; Hwan-Hoo Seong; Sung-Woo Kim; Hak-Hyun Ka; Chang-Kyu Lee

2008-01-01

167

A Syrian golden hamster model recapitulating ebola hemorrhagic fever.  

PubMed

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

2013-01-15

168

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

169

Antibody inhibition of protein activity in starfish oocytes.  

PubMed

Antibodies are widely utilized in cell and molecule biology for immunoblots, immunostaining, immunoprecipitation, immunoaffinity purification, and immunoassay. Some antibodies can be used for in vivo inhibition experiments. These antibodies bind to their target molecules and neutralize their functions, providing functional information in the study of their biological role. Here, we describe our methods for obtaining inhibitory antibodies against desired proteins. We then describe in the starfish oocyte system how to inhibit a target protein, even in the nucleus, by injection of antibody into the cytoplasm, and how to evaluate antibody inhibition of cell cycle regulators in small numbers of oocytes. PMID:24567224

Okumura, Eiichi; Hara, Masatoshi; Kishimoto, Takeo

2014-01-01

170

Artificial intelligence techniques for embryo and oocyte classification.  

PubMed

One of the most relevant aspects in assisted reproduction technology is the possibility of characterizing and identifying the most viable oocytes or embryos. In most cases, embryologists select them by visual examination and their evaluation is totally subjective. Recently, due to the rapid growth in the capacity to extract texture descriptors from a given image, a growing interest has been shown in the use of artificial intelligence methods for embryo or oocyte scoring/selection in IVF programmes. This work concentrates the efforts on the possible prediction of the quality of embryos and oocytes in order to improve the performance of assisted reproduction technology, starting from their images. The artificial intelligence system proposed in this work is based on a set of Levenberg-Marquardt neural networks trained using textural descriptors (the local binary patterns). The proposed system was tested on two data sets of 269 oocytes and 269 corresponding embryos from 104 women and compared with other machine learning methods already proposed in the past for similar classification problems. Although the results are only preliminary, they show an interesting classification performance. This technique may be of particular interest in those countries where legislation restricts embryo selection. One of the most relevant aspects in assisted reproduction technology is the possibility of characterizing and identifying the most viable oocytes or embryos. In most cases, embryologists select them by visual examination and their evaluation is totally subjective. Recently, due to the rapid growth in our capacity to extract texture descriptors from a given image, a growing interest has been shown in the use of artificial intelligence methods for embryo or oocyte scoring/selection in IVF programmes. In this work, we concentrate our efforts on the possible prediction of the quality of embryos and oocytes in order to improve the performance of assisted reproduction technology, starting from their images. The artificial intelligence system proposed in this work is based on a set of Levenberg-Marquardt neural networks trained using textural descriptors (the 'local binary patterns'). The proposed system is tested on two data sets, of 269 oocytes and 269 corresponding embryos from 104 women, and compared with other machine learning methods already proposed in the past for similar classification problems. Although the results are only preliminary, they showed an interesting classification performance. This technique may be of particular interest in those countries where legislation restricts embryo selection. PMID:23177416

Manna, Claudio; Nanni, Loris; Lumini, Alessandra; Pappalardo, Sebastiana

2013-01-01

171

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

172

Hamster thecal cells express muscle characteristics  

SciTech Connect

Contraction of the follicular wall about the time of ovulation appears to be a coordinated event; however, the cells that mediate it remain poorly studied. We examined the theca externa cells in the wall of hamster follicles for the presence of a functional actomyosin system, both in developing follicles and in culture. We used a monoclonal antibody (HHF35) that recognizes the alpha and gamma isoelectric variants of actin normally found in muscle, but not the beta variant associated with non-muscle sources, to evaluate large preovulatory follicles for actin content and composition. Antibody staining of sectioned ovaries showed intense circumferential reactivity in the outermost wall of developing follicles. Immunoblots from two-dimensional gels of theca externa lysates demonstrated the presence of the two muscle-specific isozymes of actin. Immunofluorescence of cultured follicular cells pulse-labeled with (3H) thymidine (for autoradiographic detection of DNA replication) revealed the presence, in many dividing cells, of actin filaments aligned primarily along the longitudinal axis of the cells. In cultures exposed to the calcium ionophore A23187 (10(-4) M) for varying periods (5 min to 1 h), contraction of many individual muscle-actin-positive cells was observed. Immunofluorescence of these cells, fixed immediately after ionophore-induced contraction, revealed compaction of the actin filaments. Our findings demonstrate that the cells of the theca externa contain muscle actins from an early stage and that these cells are capable of contraction even while proliferating in subconfluent cultures. They suggest that follicular growth may include a naturally occurring developmental sequence in which a contractile cell type proliferates in the differentiated state.

Self, D.A.; Schroeder, P.C.; Gown, A.M.

1988-08-01

173

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

174

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

175

[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

176

Projectile penetration into ballistic gelatin.  

PubMed

Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (<120m/s). The results of sphere penetration depth versus projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. PMID:24184862

Swain, M V; Kieser, D C; Shah, S; Kieser, J A

2014-01-01

177

[Serotonin inhibits phorbol ester-induced oocyte maturation in the green toad (Bufo viridis)].  

PubMed

The activator of protein kinase C phorbol-12-myristat-13-acetate (PMA) induces maturation of the definitive intact (coated with the follicular envelopes) and defolliculated oocytes of the green toad. This effect is more pronounced in case of defolliculated oocytes. The amount of matured oocytes depends on the PMA concentration in solution. Serotonin (5-HT) inhibits or blocks maturation of the oocytes induced either by progesterone or by PMA. A possible mechanism of this effect is discussed with special reference to its role in regulation of oocyte maturation. PMID:8725438

Nikitina, L A; Buznikov, G A

1996-01-01

178

Steroid hormones promote bovine oocyte growth and connection with granulosa cells.  

PubMed

Many approaches have been investigated for growing oocytes in vitro in mammals. To support oocyte growth in vitro, the culture systems must meet certain conditions for maintaining connections between oocytes and surrounding granulosa cells. The aims of this study were to determine the effects of combinations of 17?-estradiol (E2) and androstenedione (A4) on in vitro growth of bovine oocytes and to determine the number of connections between the oocyte and granulosa cells. Oocyte-granulosa cell complexes (OGCs) collected from early antral follicles (0.4-0.7 mm in diameter) were cultured for 14 days in a medium with different concentrations of E2 and A4, either alone or in combinations. We then assessed the number of transzonal projections (TZPs), which extend from granulosa cells through the zona pellucida to the oolemma. During in vitro growth culture, OGC structures were maintained in the medium with steroid hormones. The mean diameter of oocytes grown in the medium with both E2 and A4 was increased from 95.8 ?m to around 120 ?m, larger than oocytes grown without steroid hormones (109.9 ?m) and similar in size to in vivo fully grown oocytes (119.4 ?m) from 4- to 6-mm antral follicles. In subsequent in vitro maturation culture (22 hours), 30% (12 of 40) and 34% (14 of 41) of oocytes grown with E2 or A4 alone, respectively, matured to metaphase II; meanwhile, oocytes grown with a combination of E2 and A4 matured to metaphase II at a high rate (58%, 23 of 40). Growing oocytes isolated from early antral follicles had many uniformly distributed TZPs throughout the zona pellucida. After 14 days of culture, there was a significant decrease in the number of TZPs in oocytes grown without steroid hormones, whereas the number of TZPs was maintained in oocytes grown with steroid hormones. In particular, oocytes grown with E2 alone or with a combination of E2 and A4 had numbers of TZPs similar to oocytes before growth culture. In conclusion, a combination of E2 and A4 maintained the connections between oocytes and granulosa cells during in vitro growth culture of bovine oocytes for 14 days, resulting in the complete oocyte growth and the acquisition of meiotic competence in more than half the oocytes. PMID:24985562

Makita, Miho; Miyano, Takashi

2014-09-01

179

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

180

Oocytes Selected Using BCB Staining Enhance Nuclear Reprogramming and the In Vivo Development of SCNT Embryos in Cattle  

Microsoft Academic Search

The selection of good quality oocytes is crucial for in vitro fertilization and somatic cloning. Brilliant cresyl blue (BCB) staining has been used for selection of oocytes from several mammalian species. However, the effects of differential oocyte selection by BCB staining on nuclear reprogramming and in vivo development of SCNT embryos are not well understood. Immature compact cumulus–oocyte complexes (COCs)

Jianmin Su; Yongsheng Wang; Ruizhe Li; Hui Peng; Song Hua; Qian Li; Fusheng Quan; Zekun Guo; Yong Zhang

2012-01-01

181

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

182

Efficient Gene Targeting in Golden Syrian Hamsters by the CRISPR/Cas9 System  

PubMed Central

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

Meng, Qinggang; Shi, Bi; Bunch, Thomas D.; White, Kenneth L.; Kong, Il-Keun; Wang, Zhongde

2014-01-01

183

THE KINETICS OF PENETRATION  

PubMed Central

A model is described which throws light on the mechanism of accumulation. In the model used an external aqueous phase A is separated by a non-aqueous phase B (representing the protoplasm) from the artificial sap in C. A contains KOH and C contains HCl: they tend to mix by passing through the non-aqueous layer but much more KOH moves so that most of the KCl is formed in C, where the concentration of potassium becomes much greater than in A. This accumulation is only temporary for as the system approaches equilibrium the composition of A approaches identity with that of C, since all the substances present can pass through the non-aqueous layer. Such an approach to equilibrium may be compared to the death of the cell as the result of which accumulation disappears. During the earlier stages of the experiment potassium tends to go in as KOH and at the same time to go out as KCl. These opposing tendencies do not balance until the concentration of potassium inside becomes much greater than outside (hence potassium accumulates). The reason is that KCl, although its driving force be great, moves very slowly in B because its partition coefficient is low and in consequence its concentration gradient in B is small. This illustrates the importance of partition coefficients for penetration in models and in living cells. It also indicates that accumulation depends on the fact that permeability is greater for the ingoing compound of the accumulating substance than for the outgoing compound. Other things being equal, accumulation is increased by maintaining a low pH in C. Hence we may infer that anything which checks the production of acid in the living cell may be expected to check accumulation and growth. This model recalls the situation in Valonia and in most living cells where potassium accumulates as KCl, perhaps because it enters as KOH and forms KA in the sap (where A is an organic anion). In some plants potassium accumulates as KA but when HCl exists in the external solution it will tend to enter and displace the weaker acid HA (if this be carbonic it can readily escape): hence potassium may accumulate to a greater or less extent as KCl. Injury of the cell may produce a twofold effect, (1) increase of permeability, (2) lessened accumulation. The total amount of electrolyte taken up in a given time will be influenced by these factors and may be greater than normal in the injured cell or less, depending somewhat on the length of the interval of time chosen. PMID:19872797

Osterhout, W. J. V.; Kamerling, S. E.

1934-01-01

184

Characterization of 1-methyladenine binding in starfish oocyte cortices  

SciTech Connect

1-Methyladenine (1MeAde) is the naturally occurring maturation-inducing hormone of starfish oocytes. The authors have prepared a biologically active ({sup 3}H)1MeAde of high purity and relatively high specific radioactivity. This ligand binds to cortices isolated from full-grown prophase-arrested oocytes of the starfish Asterina pectinifera. The binding of ({sup 3}H)1MeAde to cortices was rapid and reached equilibrium in {approx}15 min. This is in excellent agreement with the hormone-dependent period required for the induction of oocyte maturation. Binding was maximal between pH 6.4 and 8.0 and diminished sharply above and below this range. Analysis of Scatchard plots of the equilibrium binding of ({sup 3}H)1MeAde to cortices indicates the existence of a single class of binding site with a dissociation constant of 0.3 {mu}M and a binding capacity of 0.02 fmol per cortex. Whereas biologically active analogs (1-benzyladenine, 1-ethyladenine) inhibited the specific binding of ({sup 3}H)1MeAde by cortices, biologically inactive analogs (2-methyladenine, 3-methyladenine, 1,9-dimethyladenine, and 1-methylhypoxanthine) did not. These results suggest that the 1MeAde binding characterized herein is necessary for the maturational action of 1MeAde on starfish oocytes.

Yoshikuni, Michiyasu (National Institute for Basic Biology, Okazaki (Japan) Shizuoka Univ. (Japan)); Ishikawa, Katsutoshi (Nagoya Univ. (Japan)); Isobe, Minoru; Goto, Toshio (Shizuoka Univ. (Japan)); Nagahama, Yoshitaka (National Institute for Basic Biology, Okazaki (Japan))

1988-03-01

185

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

186

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

187

Selective protein incorporation by vitellogenic Salmo gairdneri oocytes in vitro  

E-print Network

Selective protein incorporation by vitellogenic Salmo gairdneri oocytes in vitro C. M. CAMPBELL B into the ovarian follicles of rainbow trout (Salmo gairdneri). A protein induced into serum of S, gairdneri, after) characterized a serum protein in Parophyrys vetulus, Hippoglossus steno- lepis, Gadus morhua and Salmo gairdneri

Boyer, Edmond

188

Ecdysteroids and oocyte development in the black fly Simulium vittatum  

PubMed Central

Background Oocyte development was studied in the autogenous black fly, Simulium vittatum (Diptera, Nematocera), a vector of Onchocerca volvulus, the causative agent of onchocerciasis. Results Oocyte growth was nearly linear between adult eclosion and was complete by 72 hours at 21°C. The oocyte became opaque at 14 hours after eclosion indicating the initiation of protein yolk deposition. The accumulation of vitellogenin was measured using SDS-PAGE. The density of the yolk protein bands at about 200 and 65 kDa increased during the first and second days after eclosion. The amount of protein in the 200 kDa band of vitellogenin, determined using densitometry, rapidly increased between 12 and 25 hours after eclosion. Ecdysteroid levels were measured using a competitive ELISA. Ecdysteroid levels increased rapidly and subsequently declined during the first day after eclosion. Conclusion These data show a correlation between the appearance of vitellogenin in the oocyte, and the rise in ecdysteroids. A possible relationship to molting of the nematode, Onchocerca volvulus, is discussed. PMID:12015816

Noriega, Rafael; Ramberg, Frank B; Hagedorn, Henry H

2002-01-01

189

Effect of semen preparation on IVF of prepubertal goat oocytes  

Microsoft Academic Search

The aim of these experiments was to study the effects of different methods of washing and selection of spermatozoa on the IVF of IVM oocytes from prepubertal goats. Fresh ejaculates from 3 males of proven fertility were processed according to the following treatments: 1) centrifugation in TALP, 2) centrifugation in sucrose-based Ficoll medium, 3) centrifugation in Percoll gradients at 40

M. J Palomo; D Izquierdo; T Mogas; M. T Paramio

1999-01-01

190

The portrayal of healthy women requesting oocyte cryo-preservation  

PubMed Central

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

191

Effects of postmortem interval on mouse ovary oocyte survival and maturation.  

PubMed

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

192

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

193

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

194

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

195

Raman Micro-Spectroscopy Can Be Used to Investigate the Developmental Stage of the Mouse Oocyte  

PubMed Central

In recent years, the uptake of assisted reproductive techniques such as in vitro fertilisation has risen exponentially. However, there is much that is still not fully understood about the biochemical modifications that take place during the development and maturation of the oocyte. As such, it is essential to further the understanding of how oocyte manipulation during these procedures ultimately affects its developmental potential; yet, there are few methods currently available which are capable of providing a quantitative measure of oocyte quality. Raman spectroscopy enables investigation of the global biochemical profile of intact cells without the need for labelling. Here, Raman spectra were acquired from the ooplasm of mouse oocytes at various stages of development, from late pre-antral follicles, collected after in vitro maturation within their ovarian follicles and from unstimulated and stimulated ovulatory cycles. Using a combination of univariate and multivariate statistical methods, it was found that ooplasm lipid content could be used to discriminate between different stages of oocyte development. Furthermore, the spectral profiles of mature oocytes revealed that oocytes which have developed in vitro are protein-deficient when compared to in vivo grown oocytes. Finally, the ratio of two Raman peak intensities, namely 1605?1447 cm?1, used as a proxy for the protein-to-lipid ratio of the ooplasm, was shown to be indicative of the oocyte’s quality. Together, results indicate that Raman spectroscopy may present an alternative analytical tool for investigating the biochemistry of oocyte developmental stage and quality. PMID:23840882

Davidson, Bryony; Murray, Alison A.

2013-01-01

196

Anti-M?llerian 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

197

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

198

Calcium transients during early development in single starfish (Asterias forbesi) oocytes  

SciTech Connect

Maturation and fertilization of the starfish oocyte are putative calcium-dependent events. The authors have investigated the spatial distribution and temporal dynamics of this calcium dependence in single oocytes of Asterias forbesi. They used the calcium photoprotein, aequorin, in conjunction with a microscope-photomultiplier and microscope-image intensifier. Surprisingly, in contrast to earlier work with Marasthenias glacialis, there is no detectable increase in intracellular-free calcium in the oocyte of A. forbesi in response to the maturation hormone 1-methyl adenine. During fertilization of the same, matured, A. forbesi oocyte there is a large increase in intracellular-free calcium. The calcium concentration increases to approx.1 ..mu..M at the point of insemination and the region of elevated free calcium expands across the oocyte in approx.20 s (17-19/sup 0/C). After the entire oocyte reaches an elevated concentration of free calcium, the concentration decreases uniformly throughout the oocyte over the next several minutes.

Eisen, A.; Reynolds, G.T.

1984-11-01

199

Femtosecond laser based enucleation of porcine oocytes for somatic cell nuclear transfer  

NASA Astrophysics Data System (ADS)

Cloning of several mammalian species has been achieved by somatic cell nuclear transfer (SCNT) in recent years. However, this method still results in very low efficiencies around 1% which originate from suboptimal culture conditions and highly invasive techniques for oocyte enucleation and injection of the donor cell using micromanipulators. In this paper, we present a new minimal invasive method for oocyte imaging and enucleation based on the application of femtosecond (fs) laser pulses. After imaging of the oocyte with multiphoton microscopy, ultrashort pulses are focused onto the metaphase plate of MII-oocytes in order to ablate the DNA molecules. We show that fs laser based enucleation of porcine oocytes completely inhibits the first mitotic cleavage after parthenogenetic activation while maintaining intact oocyte morphology in most cases. In contrast, control groups without previous irradiation of the metaphase plate are able to develop to the blastocyst stage. Further experiments have to clarify the suitability of fs laser based enucleated oocytes for SCNT.

Kütemeyer, K.; Lucas-Hahn, A.; Petersen, B.; Hassel, P.; Lemme, E.; Niemann, H.; Heisterkamp, A.

2009-07-01

200

Apoptosis in batch cultures of Chinese Hamster Ovary cells  

Microsoft Academic Search

One of the main problems in the culture of Chinese Hamster Ovary (CHO) cells continues to be the inability to maintain the viability of the cultures over an extended period of time. The rapid decline in viability at the end of the culture is exacerbated by the absence of serum. In trying to reduce the extent of death in these

J. Goswami; A. J. Sinskey; H. Steller; G. N. Stephanopoulos; D. I. C. Wang

1999-01-01

201

DOSE RESPONSE OF ELASTASE-INDUCED EMPHYSEMA IN HAMSTERS  

EPA Science Inventory

Elastase-induced emhysema in hamsters was studied using pulmonary function tests in an effort to develop techniques for determining the effects of air pollutants on the progression of this disease. It appears that as little as 6 units of elastase produces mild emphysema in hamste...

202

Development of the occipital corticotectal projection in the hamster  

Microsoft Academic Search

Anterograde and retrograde labelling with the carbocyanine dye, Di-I, was used to assess the development of the visual cortical projection to the superior colliculus (SC) in pre- and postnatal hamsters. Posterior cortical axons arrive in the SC on postnatal (P-) day one (the first 24 hours after birth = P-0) and begin to arborize in the superficial laminae (the stratum

R. W. Rhoades; B. Figley; R. D. Mooney; S. E. Fish

1991-01-01

203

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 ...

204

Photoperiodic Regulation of Compensatory Testicular Hypertrophy in Hamsters1  

Microsoft Academic Search

In mammals, removal of one testis results in compensatory testicular hypertrophy (CTH) of the remaining gonad. Although CTH is ubiquitous among juveniles of many species, laboratory rats, laboratory mice, and humans unilaterally castrated in adulthood fail to display CTH. We documented CTH in pre- and postpubertally hemi-castrated Syrian and Siberian hamsters and tested whether day length affects CTH in juvenile

Matthew J. Paul; Jin Ho Park; Teresa H. Horton; Maria I. Alvarez; Morgan K. Burke; Irving Zucker

205

Relationship between Autonomic and Behavioral Thermoregulation in the Golden Hamster.  

National Technical Information Service (NTIS)

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 gradien...

C. J. Gordon, K. S. Fehlner, M. D. Long

1986-01-01

206

Photoperiod and stress affect wound healing in Siberian hamsters  

Microsoft Academic Search

Changes in day length alter several indices of immune function in Siberian hamsters. These experiments tested the hypothesis that photoperiodic changes in immune function are integrated at an organismal level as reflected by the ability to heal a cutaneous wound. Given the well-documented effects of psychological stressors on immune function, we also tested the hypothesis that photoperiod modulates the effects

Steven G. Kinsey; Brian J. Prendergast; Randy J. Nelson

2003-01-01

207

Hamster bite peritonitis: Pasteurella pneumotropica peritonitis in a dialysis patient  

Microsoft Academic Search

We report the first case of Pasteurella pneumotropica peritonitis in a peritoneal dialysis patient. This rare infection was the result of contamination of the dialysis tubing\\u000a by a pet hamster. We stress the importance of household pets as a source of infection in the peritoneal dialysis population.

A. Campos; J. H. Taylor; M. Campbell

2000-01-01

208

Stress and the development of agonistic behavior in golden hamsters  

Microsoft Academic Search

Aggressive behavior can be studied as either offensive or defensive responses to a stimulus. The studies discussed in this review are focused on the peripubertal development of offensive aggression in male golden hamsters and its responsiveness to repeated social stress. Quantitative and qualitative changes in offensive responses were analyzed during this period. Quantitative changes in offensive responses were observed as

Yvon Delville; J. Tracey David; Kereshmeh Taravosh-Lahn; Joel C. Wommack

2003-01-01

209

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

210

Demonstration of survivable space penetrator  

NASA Astrophysics Data System (ADS)

This work was performed in support of MoonLITE which is a proposed UK space mission to the moon. The basic premise is to deploy 4 instrumented penetrators, one each on the near-side, farside and at the poles of the moon, with an impact velocity of approximately 300m/s. The primary science aims are to set up a passive seismometer network, investigate the presence of water and volatiles and determine thermal gradients in the lunar soil (i.e. regolith). A key requirement is that the penetrator shell survives the impact together with the instrument payload and supporting subsystems. The material chosen for the penetrator shell was 7075 aluminium alloy, which is a good compromise between high compressive strength and low mass. The baseline penetrator design was evaluated and refined using the DYNA3D hydrocode to determine the survivability of the penetrator in sand at an impact velocity of 300m/s and an attack angle of 8°. The simulations predicted that the penetrator design would survive this severe impact condition which was confirmed by experiments on the Pendine rocket test track.

Church, Philip; Huntington-Thresher, William; Bruce, Alan; Penny, Nick; Smith, Alan; Gowan, Rob

2012-03-01

211

Optimal Information Security Investment with Penetration Testing  

E-print Network

techniques, is a relevant tool of information security practitioners. This paper adds penetration testing referred to as "ethical hacking" because the com- missioned penetration testers investigate the target

Bencsáth, Boldizsár

212

Effects of oocyte quality, semen donor and embryo co-culture system on the efficiency of blastocyst production in goats  

Microsoft Academic Search

The aim of the study was to determine whether the selection of immature oocytes by a combination of cumulus–oocyte-complexes (COCs) morphology and staining with brilliant cresyl blue (BCB) would be helpful in selecting developmentally competent oocytes, and thereby increase the efficiency of blastocyst production from ovarian oocytes of FSH-primed, adult goats. In a second experiment the interaction between oocyte quality

L. K?tska-Ksi??kiewicz; J. Opiela; B. Ry?ska

2007-01-01

213

Characterization of the effects of metformin on porcine oocyte meiosis and on AMP-activated protein kinase activation in oocytes and cumulus cells.  

PubMed

Summary The adenosine monophosphate-activated protein kinase (AMPK) activators 5-aminoimidazole-4-carboxamide 1-?-d-ribofuranoside (AICAR) and metformin (MET) inhibit resumption of meiosis in porcine cumulus-enclosed oocytes. The objective of this study was to characterize the inhibitory effect of MET on porcine oocyte meiosis by: (1) determining the effects of an AMPK inhibitor and of inhibitors of signalling pathways involved in MET-induced AMPK activation in other cell types on MET-mediated meiotic arrest in porcine cumulus-enclosed oocytes; (2) determining whether MET and AICAR treatments lead to increased activation of porcine oocyte and/or cumulus cell AMPK as measured by phosphorylation of its substrate acetyl-CoA carboxylase; and (3) determining the effects of inhibition of the AMPK kinase, Ca2+/calmodulin-dependent protein kinase kinase (CaMKK), and Ca2+ chelation on oocyte meiotic maturation and AMPK activation in porcine oocytes and cumulus cells. The AMPK inhibitor compound C (CC; 1 ?M) did not reverse the inhibitory effect of AICAR (1 mM) and MET (2 mM) on porcine oocyte meiosis. Additionally, CC had a significant inhibitory effect on its own. eNOS, c-Src and PI-3 kinase pathway inhibitors did not reverse the effect of metformin on porcine oocyte meiosis. The level of acetyl-CoA carboxylase (ACC) phosphorylation in oocytes and cumulus cells did not change in response to culture in the presence of MET, AICAR, CC, the CaMKK inhibitor STO-609 or the Ca2+ chelator BAPTA-AM for 3 h, but STO-609 increased the percentage of porcine cumulus-enclosed oocytes (CEO) that remained at the germinal vesicle (GV) stage after 24 h of culture. These results indicate that the inhibitory effect of MET and AICAR on porcine oocyte meiosis was probably not mediated through activation of AMPK. PMID:23578544

Bilodeau-Goeseels, Sylvie; Magyara, Nora; Collignon, Coralie

2014-05-01

214

Mechanisms by which a lack of germinal vesicle (GV) material causes oocyte meiotic defects: a study using oocytes manipulated to replace GV with primary spermatocyte nuclei.  

PubMed

Oocytes with germinal vesicles (GVs) replaced with somatic nuclei exhibit meiotic abnormalities. Although this suggests an exclusive role for GV material in meiosis, mechanisms by which a lack of GV material causes meiotic defects are unknown. Knowledge of these mechanisms will help us to understand meiotic control, nuclear-cytoplasmic interactions, and cellular reprogramming. This study showed that although oocytes with prometaphase I chromosomes replaced with primary spermatocyte nuclei (PSN) did not, oocytes with GV replaced with PSN (PSG oocytes) did display meiotic defects. Among the defects, insufficient chromosome condensation with chromosome bridges was associated with spindle abnormalities. Abnormal spindle migration, cortical nonpolarization, and the aberrant spindle caused randomly positioning of cleavage furrows, leading to large first polar bodies (PB1) and unequal allocation of chromosomes and mitogen-activated protein kinases (MAPK) between oocyte and PB1. Spindle assembly checkpoint was activated but did not stop the incorrect division. The unequal MAPK allocation resulted in differences in pronuclear formation and PB1 degeneration; oocytes receiving more MAPK were more capable of forming pronuclear rudiments, whereas PB1 receiving more MAPK degenerated sooner than those that received less. Because none of the PSG oocytes or the enucleated GV oocytes injected with sperm heads showed cortical polarization in spite of chromosome localization close to the oolemma and because the PSG oocytes receiving more MAPK could form only pronuclear rudiments and not normal pronuclei, we suggest that the GV material plays essential roles in polarization and pronuclear formation on top of those played by chromosomes or MAPK. In conclusion, using PSG oocytes as models, this study has revealed the primary pathways by which a lack of GV material cause meiotic defects, laying a foundation for future research on the role of GV material in oocyte meiotic control. PMID:23946539

Zhang, Jie; Cui, Wei; Li, Qing; Wang, Tian-Yang; Sui, Hong-Shu; Wang, Jun-Zuo; Luo, Ming-Jiu; Tan, Jing-He

2013-10-01

215

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

216

Are zona pellucida laser drilling and polar body biopsy safe for in vitro matured oocytes?  

PubMed Central

Introduction Preconception diagnosis requires first polar body biopsy. When the hole in the zona pellucida is made with a laser beam, heat propagation could, like the biopsy itself, be deleterious. Our aim was to evaluate the effect of this technique on human in vitro matured oocyte and embryo development. Methods One hunded fifty five retrieved immature oocytes from 75 women, matured in vitro, were distributed in 3 groups: 50 oocytes in a control group, without laser drilling and first polar body biopsy, 52 oocytes in a group with only laser drilling, and 53 oocytes in a group with both laser drilling and first polar body biopsy. Safety was evaluated using four criteria: [1] oocyte lysis rate, [2] oocyte activation rate, [3] oocyte development after calcium ionophore treatment, [4] and embryo chromosome breakage incidence after Tarkowski preparation. Results No difference in the four criteria was observed between the 3 oocyte groups. Conclusions We did not find evidence of deleterious effect of laser drilling and first polar body biopsy on in vitro matured oocytes, according to our criteria. PMID:20495883

Hammoud, Ibrahim; Molina-Gomes, Denise; Albert, Martine; Bergere, Marianne; Bailly, Marc; Wainer, Robert; Selva, Jacqueline

2010-01-01

217

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

218

Phospholipase C? rescues failed oocyte activation in a prototype of male factor infertility  

PubMed Central

Objective To determine the effect of infertility-linked sperm phospholipase C? (PLC?) mutations on their ability to trigger oocyte Ca2+ oscillations and development, and also to evaluate the potential therapeutic utility of wild-type, recombinant PLC? protein for rescuing failed oocyte activation and embryo development. Design Test of a novel therapeutic approach to male factor infertility. Setting University medical school research laboratory. Patient(s) Donated unfertilized human oocytes from follicle reduction. Intervention(s) Microinjection of oocytes with recombinant human PLC? protein or PLC? cRNA and a Ca2+-sensitive fluorescent dye. Main Outcome Measure(s) Measurement of the efficacy of mutant and wild-type PLC?-mediated enzyme activity, oocyte Ca2+ oscillations, activation, and early embryo development. Result(s) In contrast to the wild-type protein, mutant forms of human sperm PLC? display aberrant enzyme activity and a total failure to activate unfertilized oocytes. Subsequent microinjection of recombinant human PLC? protein reliably triggers the characteristic pattern of cytoplasmic Ca2+ oscillations at fertilization, which are required for normal oocyte activation and successful embryo development to the blastocyst stage. Conclusion(s) Dysfunctional sperm PLC? cannot trigger oocyte activation and results in male factor infertility, so a potential therapeutic approach is oocyte microinjection of active, wild-type PLC? protein. We have demonstrated that recombinant human PLC? can phenotypically rescue failed activation in oocytes that express dysfunctional PLC?, and that this intervention culminates in efficient blastocyst formation. PMID:22999959

Nomikos, Michail; Yu, Yuansong; Elgmati, Khalil; Theodoridou, Maria; Campbell, Karen; Vassilakopoulou, Vyronia; Zikos, Christos; Livaniou, Evangelia; Amso, Nazar; Nounesis, George; Swann, Karl; Lai, F. Anthony

2013-01-01

219

The study of mammalian oocyte competence by transcriptome analysis: progress and challenges.  

PubMed

Various morphological and cytological traits of oocytes and their surrounding cumulus cells may be used to select oocytes for assisted reproduction. However, even with careful selection, successful IVF and subsequent embryo development remain uncertain. The factors that ensure oocyte competence are unclear and other approaches to assessing developmental potential must be explored. With the constant development of the molecular toolbox, genomic/transcriptomic analysis is becoming a more and more interesting approach to understand oocyte quality on the basis of RNA composition. Using bovine and mouse models as well as human oocytes of known developmental potential, various efforts are underway to characterize the mRNA profile of the competent oocyte using microarray technology. The proliferation of gene expression data sets raises new opportunities to identify the mechanisms involved in this complex phenotype, which should lead to improved techniques of assisted reproduction. Although several molecular markers of oocyte quality are known, translating these into cellular functions remains challenging, largely due to the poor correlation between mRNA level and protein synthesis. Unlike most somatic cells, the oocyte can store mRNA for days, with transcriptional activity remaining at a halt during the 4-5 days beginning before ovulation and ending with embryonic genome activation. This review provides an overview of the transcriptomic data obtained from oocytes of different quality as well as interesting avenues to explore in order to improve our understanding of oocyte competence. PMID:24233546

Labrecque, Rémi; Sirard, Marc-André

2014-02-01

220

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

221

Developmental potential of pig embryos reconstructed by use of sow versus pre-pubertal gilt oocytes after somatic cell nuclear transfer.  

PubMed

In this study, the developmental ability of cloned embryos using gilt versus sow oocytes was evaluated under the hypothesis that the efficiency of nuclear transfer using gilt oocytes was lower than that of sow oocytes, but that it could be optimized. Five experiments were performed with routine production of cloned embryos with sow oocytes serving as the control. Results showed that: Experiment 1: Blastocyst rates of cloned embryos with gilt oocytes was about half compared with control. Experiment 2: An extended maturation time of 48 h used for gilt oocytes resulted in lower blastocyst rates after cloning. Experiment 3: Development of cloned embryos with gilt oocytes was improved by co-culture with sow oocytes. Experiment 4: After maturation of gilt oocytes using follicular fluid from gilt instead of sow, the oocytes were sorted into large and small oocytes, and after cloning, blastocyst rates were higher using large gilt oocytes compared with small oocytes; however, the rate remained lower compared with control. Experiment 5: Six sow recipients received a total of 503 morulae and blastocysts cloned from gilt oocytes (four recipients) and 190 cloned from sow oocytes (two recipients). All recipients became pregnant and went to term, resulting in 26 (gilt oocytes) and six (sow oocytes) piglets. In conclusion, results confirmed that nuclear transfer efficiency was higher using sow versus gilt oocytes, but the use of gilt oocytes can be optimized by sorting after ooplasm size following maturation and by maturing gilt and sow oocytes together. PMID:23331714

Li, Juan; Pedersen, Hanne Skovsgaard; Li, Rong; Adamsen, Janne; Liu, Ying; Schmidt, Mette; Purup, Stig; Callesen, Henrik

2014-08-01

222

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

223

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

224

Effect of estradiol during culture of bovine oocyte-granulosa cell complexes on the mitochondrial DNA copies of oocytes and telomere length of granulosa cells.  

PubMed

Summary During the development of oocytes from early antral follicles (EAFs) to antral follicles (AFs), the mitochondrial DNA copy number (Mt DNA number) increases, and granulosa cells markedly proliferate. This study examined the effect of supplementation of culture medium with estradiol-17? (E2) on the in vitro growth of oocytes, and increases in the Mt DNA number, and telomere length during the in vitro culture of oocytes derived from EAFs (0.4-0.7 mm in diameter). The E2 supplementation improved antrum formation and the ratio of oocytes reaching the metaphase II (MII) stage, and there was a significant difference in these values between addition E2 concentrations of 10 ?g/ml and 0.1 ?g/ml. When the oocytes were cultured in the medium containing 10 ?g/ml E2, the Mt DNA number determined by real-time polymerase chain reaction (PCR) significantly increased, and the ratio of the Mt DNA number at the end of culture to the Mt DNA number at the beginning of the culture was greatly different among cows, and could be predicted by the degree of the difference between the Mt DNA number of oocytes derived from EAFs and that of oocytes derived from AFs (3-6 mm in diameter). When oocytes were cultured for 16 days in a medium containing 10 ?g/ml E2 or 0.1 ?g/ml E2, the Mt DNA number of oocytes grown in vitro did not differ, but the telomere length of the granulosa cells was significantly greater in the 10 ?g/ml E2 group than in the 0.1 ?g/ml group. In conclusion, E2 supplementation in culture medium improved the growth of oocytes derived from EAFs, and a high E2 concentration increased the telomere length of the granulosa cells. PMID:23232110

Endo, M; Kimura, K; Kuwayama, T; Monji, Y; Iwata, H

2014-11-01

225

Immature oocyte retrieval: lessons from unstimulated IVF cycles  

Microsoft Academic Search

Objective: To describe retrieval of immature oocytes during unstimulated IVF and assess the in vitro maturation and fertilization rates.Design: Retrospective analysis.Setting: The USC program for assisted reproduction.Patient(s): Spontaneously ovulatory women with predominantly pelvic factor as their principal cause of infertility, under the age of 40, and no male factor.Intervention(s): HCG administration in mid-cycle, aspiration of all visible follicles, in vitro

Melvin H Thornton; Mary M Francis; Richard J Paulson

1998-01-01

226

[High velocity mechanical injection of foreign DNA into fish oocytes].  

PubMed

High-velocity tungsten microprojectiles were used to introduce into fertilized eggs of loach (Misgurnus fossilis), Rainbow trout (Salmo gairdneri Rich.) and Zebra fish (Brachydanio rerio) DNA sequences of beta-galactosidase and neomycin phosphotransferase genes. No more than 30% of fish oocytes died as a result of bombardment. Experiments revealed marked activity of both enzymes in developing fishes. Neo gene DNA sequences were found in total danio DNA using PCR technique. PMID:1964924

Kolesnikov, V A; Alimov, A A; Barmintsev, V A; Beniumov, A O; Zelenina, I A; Krasnov, A M; Dzhabur, R; Zelenin, A V

1990-12-01

227

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

228

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

229

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

230

Lipid droplet analysis using in vitro bovine oocytes and embryos.  

PubMed

The aim of this study was to quantify the content of lipid droplets in bovine oocytes and embryos from Bos indicus (Bi), Bos taurus (Bt) and Bos indicus × Bos taurus (Bi × Bt). Oocytes were aspirated post-mortem and subjected to in vitro maturation, in vitro fertilization and in vitro development; the medium employed at each stage (TCM-199, TALP, SOF) was supplemented with (i) serum replacement (SR), (ii) foetal calf serum (FCS) or (iii) oestrous cow serum (ECS). The structure and distribution of the lipid droplets were established using electron microscopy, but were quantified using an optical microscope on semi-fine toluidine blue-stained sections. The highest percentage of embryos corresponded to those produced with FCS and ECS, which differed from embryos generated with SR (p < 0.05). The highest percentage of morulae and the lowest percentage of blastocysts were obtained with the SR supplement (p < 0.05). The oocytes cultured in FCS demonstrated a higher number of lipid droplets compared to those cultured in SR and ECS (p < 0.05). Less accumulation of lipids was observed in embryos supplemented with SR. The lowest and highest numbers of lipid droplets in oocytes corresponded to the Bi and Bt strain, respectively. The lowest amount of lipid droplets in embryos was observed in Bi (p < 0.05). In conclusion, supplementation of the in vitro development culture medium (synthetic oviduct fluid) with a synthetic substitute serum produced similar results in terms of embryo development compared to those obtained with FCS, but a decreased degree of lipid droplet accumulation was observed in the in vitro-cultured embryos. PMID:24467659

Ordoñez-Leon, E A; Merchant, H; Medrano, A; Kjelland, M; Romo, S

2014-04-01

231

Heat and cold acclimation in helium-cold hypothermia in the hamster.  

NASA Technical Reports Server (NTRS)

A study was made of the effects of acclimation of hamsters to high (34-35 C) and low (4-5 C) temperatures for periods up to 6 weeks on the induction of hypothermia in hamsters. Hypothermia was achieved by exposing hamsters to a helox mixture of 80% helium and 20% oxygen at 0 C. Hypothermic induction was most rapid (2-3 hr) in heat-acclimated hamsters and slowest (6-12 hr) in cold-acclimated hamsters. The induction period was intermediate (5-8 hr) in room temperature nonacclimated animals (controls). Survival time in hypothermia was relatable to previous temperature acclimations. The hypothesis that thermogenesis in cold-acclimated hamsters would accentuate resistance to induction of hypothermia was substantiated.

Musacchia, X. J.

1972-01-01

232

Restoration of immune responses of aging hamsters by treatment with isoprinosine.  

PubMed Central

Immune competence declines with advanced age in hamsters, as in other laboratory mammals and in humans. We found significant alterations in the functional parameters of different populations of immunocytes (natural killer cells, T cells, monocytes, and suppressor cells) in aging hamsters, beginning at approximately 14 mo of age. Natural killer cytotoxicity, phytohemagglutinin-induced lymphocyte stimulation, and monocyte chemotaxis were decreased in aging Lak:LvG(Syr) outbred hamsters. When old hamsters were given a single injection (5 mg/kg body wt) of isoprinosine, a chemical immune potentiator, these three immune parameters increased almost to the levels found in young adult hamsters but returned to pretreatment levels after 7 d. Suppressor cell activity for the lymphocyte response to phytohemagglutinin, which increased with age, was decreased after treatment. In old hamsters treated with weekly injections of isoprinosine, these four immunological parameters remained at or near the levels found in young adults. PMID:6190840

Tsang, K Y; Fudenberg, H H; Gnagy, M J

1983-01-01

233

Simple, fast, and efficient method of manual oocyte enucleation using a pulled Pasteur pipette.  

PubMed

Cloning mammals by somatic cell nuclear transfer entails the replacement of oocyte chromosomes with the nucleus of a somatic cell. A major step in this technique is to efficiently produce large batches of enucleated oocytes, a process that requires considerable micromanipulation skills and expensive equipments. Here, a simple, fast, and efficient method of manual oocyte enucleation was introduced that can be adopted in every laboratory with the minimum equipments. Common laboratory glass pipettes were pulled on the flame of a burner and then used for manual bisection or enucleation of sheep and goat zona-free oocytes by passing them through the discontinuous cutting border of culture medium and mineral oil. The described techniques showed a certain efficiency to conveniently bisect or enucleate large batches of sheep, and goat oocytes being pre-treated with demecolcine. The method may be straightforward for simple manipulation of oocytes of other species and for development of automated cloning methods as well. PMID:23824953

Hosseini, S M; Moulavi, F; Asgari, V; Shirazi, A; Abazari-Kia, A H; Ghanaei, H R; Nasr-Esfahani, M H

2013-09-01

234

Effects of in vitro maturation of monkey oocytes on their developmental capacity  

PubMed Central

The study of in vitro maturation (IVM) of rhesus monkey oocytes has important implications for biomedical research and human infertility treatment. In vitro-matured rhesus monkey oocytes show much less developmental potential than IVM oocytes of other species. Since about 1980 when rhesus monkey IVM, in vitro fertilization (IVF) and in vitro embryo culture (IVC) systems were established, numerous efforts have been made to improve the developmental competence of oocytes and to understand the mechanisms regulating oocyte maturation. This review describes recent progress in this area, particularly the effects of factors such as steroid hormones, energy substrates, amino acids, ovarian follicle status, maternal age and breeding season on the developmental competence, gene expression patterns and genome integrity of rhesus IVM oocytes. PMID:17081707

Zheng, P.

2007-01-01

235

Distribution pattern and activity of mitochondria during oocyte growth and maturation in the ascidian Styela plicata.  

PubMed

Summary The process of oocyte maturation is underlined by a redistribution of cellular organelles, among which mitochondria play a functional role for the acquisition of fertilization and developmental competence. In this paper, we applied electron and confocal microscopy by using DIOC6 and JC-1 stain to evaluate mitochondria distribution pattern and activity during different stages of oocyte growth in the ascidian Styela plicata. Three categories of oocytes at the germinal vesicle stage underlying the vitellogenic process were characterized on the basis of size, pigmentation and accessory cells. Mitochondria were spread throughout the cytoplasm at the smallest oocyte stage and gradually migrated to the periphery of the subcortical cytoplasm at the intermediate stage. At the fully grown oocyte stage, mitochondria were aggregated in the subcortical cytoplasm. This pattern of polarized mitochondria distribution correlates significantly with an increase in mitochondria potential and activity. In this paper we discuss the relationship of mitochondria to the acquisition of oocyte developmental competence. PMID:23331624

Bezzaouia, Amina; Gallo, Alessandra; Silvestre, Francesco; Tekaya, Saïda; Tosti, Elisabetta

2014-11-01

236

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

237

Ovarian germline stem cells: an unlimited source of oocytes?  

PubMed

While there has been progress in directing the development of embryonic stem cells and induced pluripotent stem cells toward a germ cell state, their ability to serve as a source of functional oocytes in a clinically relevant model or situation has yet to be established. Recent studies suggest that the adult mammalian ovary is not endowed with a finite number of oocytes, but instead possesses stem cells that contribute to their renewal. The ability to isolate and promote the growth and development of such ovarian germline stem cells (GSCs) would provide a novel means to treat infertility in women. Although such ovarian GSCs are well characterized in nonmammalian model organisms, the findings that support the existence of adult ovarian GSCs in mammals have been met with considerable evidence that disputes their existence. This review details the lessons provided by model organisms that successfully utilize ovarian GSCs to allow for a continual and high level of female germ cell production throughout their life, with a specific focus on the cellular mechanisms involved in GSC self-renewal and oocyte development. Such an overview of the role that oogonial stem cells play in maintaining fertility in nonmammalian species serves as a backdrop for the data generated to date that supports or disputes the existence of GSCs in mammals as well as the future of this area of research in terms of its potential for any application in reproductive medicine. PMID:24382341

Hanna, Carol B; Hennebold, Jon D

2014-01-01

238

Identifying new human oocyte marker genes: a microarray approach  

PubMed Central

Efficiency in classical IVF (cIVF) techniques is still impaired by poor implantation and pregnancy rates after embryo transfer. This is mostly due to a lack of reliable criteria for the selection of embryos with sufficient development potential. Several studies have provided evidence that some genes’ expression levels could be used as objective markers of oocytes and embryos competence and of their capacity to sustain a successful pregnancy. These analyses usually used reverse transcription-polymerase chain reaction to look at small sets of pre-selected genes. However, microarray approaches permit to identify a wider range of cellular marker genes. Thus they allow the identification of additional and perhaps more suited genes that could serve as embryo selection markers. Microarray screenings of circa 30 000 genes on U133P Affymetrix™ gene chips made it possible to establish the expression profile of these genes as well as other related genes in human oocytes and cumulus cells. In this study, we identified new potential regulators and marker genes such as BARD1, RBL2, RBBP7, BUB3 or BUB1B, which are involved in oocyte maturation. PMID:17298719

Gasca, Stephan; Pellestor, Franck; Assou, Said; Loup, Vanessa; Anahory, Tal; Dechaud, Herve; De Vos, John; Hamamah, Samir

2007-01-01

239

Lariat intronic RNAs in the cytoplasm of Xenopus tropicalis oocytes.  

PubMed

We previously demonstrated that the oocyte nucleus (germinal vesicle or GV) of Xenopus tropicalis contains a population of stable RNA molecules derived from the introns of most expressed genes. Here we show that similar stable intronic sequence (sis) RNAs occur in the oocyte cytoplasm. About 9000 cytoplasmic sisRNAs have been identified, all of which are resistant to the exonuclease RNase R. About half have been confirmed as lariat molecules and the rest are presumed to be lariats, whereas nuclear sisRNAs are a mixture of lariat and linear molecules. Cytoplasmic sisRNAs are more abundant on a molar basis than nuclear sisRNAs and are derived from short introns, mostly under 1 kb in length. Both nuclear and cytoplasmic sisRNAs are transmitted intact to the egg at GV breakdown and persist until at least the blastula stage of embryogenesis, when zygotic transcription begins. We compared cytoplasmic sisRNAs derived from orthologous genes of X. tropicalis and X. laevis, and found that the specific introns from which sisRNAs are derived are not conserved. The existence of sisRNAs in the cytoplasm of the oocyte, their transmission to the fertilized egg, and their persistence during early embryogenesis suggest that they might play a regulatory role in mRNA translation. PMID:25051970

Talhouarne, Gaëlle J S; Gall, Joseph G

2014-09-01

240

High hydrostatic pressure treatment of porcine oocytes induces parthenogenetic activation.  

PubMed

An innovative technique called high hydrostatic pressure (HHP) treatment has recently been reported to improve the cryosurvival of gametes and embryos in certain mammalian species, including the mouse, pig, and cattle. In the present study the parthenogenetic activation (PA) of pig oocytes caused by HHP treatment was investigated in different holding media with or without Ca(2+). The efficiency of activation was tested at different pressure levels and media including T2 (HEPES-buffered TCM-199 containing 2% cattle serum), and mannitol-PVA fusion medium with (MPVA + Ca(2+)) or without Ca(2+) and Mg(2+)(MPVA). The results showed that HHP cannot induce PA in T2, but only in MPVA + Ca(2+) with low Ca(2+) concentration and MPVA without Ca(2+). The highest activation efficiency was achieved with 10 min HHP treatment using 100 or 200 bars for oocytes in MPVA + Ca(2+) or MPVA, respectively. In the light of these results, the possible source of Ca(2+) during activation was investigated. It was found that even after a total of 30-min wash with TL-HEPES-PVA buffer without Ca(2+) before HHP treatment in MPVA, the oocytes could still be activated, indicating the possibility of an intracellular Ca(2+) source caused cytoplasmic free Ca(2+) elevation. In conclusion, parthenogenetic activation could be induced by HHP in certain holding media with low or zero Ca(2+) content. Further experiments are needed to identify the exact mechanisms of activation. PMID:20698785

Lin, Lin; Pribenszky, Csaba; Molnár, Miklós; Kragh, Peter M; Du, Yutao; Zhang, Xiuqing; Yang, Huanming; Bolund, Lars; Callesen, Henrik; Macháty, Zoltán; Vajta, Gábor

2010-08-01

241

Cell volume regulation in mammalian oocytes and preimplantation embryos.  

PubMed

The earliest stages of preimplantation embryos are particularly sensitive to increased osmolarity, even within the physiological range. This sensitivity contributed to persistent developmental arrest, even when embryos were cultured in vitro in older, conditioned culture media, and seems to arise when embryos at the 1- and 2-cell stages accumulate inorganic ions used for cell volume homeostasis at too high a level, through activation of coupled Na(+)/H(+) and HCO(3)-/Cl(-) exchange. Such accumulation of inorganic ions can be disruptive since, above a certain level, the increased ionic strength disrupts cellular biochemistry and macromolecular functions and alters membrane potential. To counter this, embryos have evolved mechanisms of cell volume regulation that are unique to early preimplantation embryogenesis. The primary role of these is glycine accumulation via the GLYT1 transporter, with a secondary contribution by betaine accumulation via the SIT1 transporter. Independent cell-volume regulation first arises in the oocyte only after ovulation is triggered, when the strong oocyte-zona pellucida adhesion present in germinal vesicle stage oocytes in the ovarian follicle is released and GLYT1 becomes activated to begin accumulating glycine. Open questions still remain regarding how these processes are regulated. PMID:23011956

Baltz, Jay M; Zhou, Chenxi

2012-12-01

242

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, Edouard W; Richard, Francois J; Hyttel, Poul; Robert, Claude

2014-10-01

243

Pharmaceutical Options for Triggering of Final Oocyte Maturation in ART  

PubMed Central

Since the pioneering days of in vitro fertilization, hCG has been the gold standard to induce final follicular maturation. We herein reviewed different pharmaceutical options for triggering of final oocyte maturation in ART. The new upcoming agent seems to be GnRHa with its potential advantages over hCG trigger. GnRHa triggering elicits a surge of gonadotropins resembling the natural midcycle surge of gonadotropins, without the prolonged action of hCG, resulting in the retrieval of more mature oocytes and a significant reduction in or elimination of OHSS as compared to hCG triggering. The induction of final follicular maturation using GnRHa represents a paradigm shift in the ovulation triggering concept in ART and, thus, a way to develop a safer IVF procedure. Kisspeptins are key central regulators of the neuroendocrine mechanisms of human reproduction, who have been shown to effectively elicit an LH surge and to induce final oocyte maturation in IVF cycles. This new trigger concept may, therefore, offer a completely new, “natural” pharmacological option for ovulation induction. Whether kisspeptins will be the future agent to trigger ovulation remains to be further explored. PMID:25133168

Humaidan, Peter; Bernabeu, Rafael

2014-01-01

244

Rapid induction of glomerular lipidosis in APA hamsters by streptozotocin.  

PubMed Central

The pathology of male Syrian hamsters of APA strain which were injected intraperitoneally with 40 mg/kg body weight of streptozotocin (SZ) at 2 months of age was examined. It showed long-lasting prominent hyperglycaemia and hyperlipidaemia with glucosuria and the development of glomerular lipidosis from 1 month after SZ-injection (1 MAI). Glomerular lesions were restricted to the juxtamedullary cortex at 1 MAI and then extended to the subcapsular cortex. At 3 MAI, glomerular lesions were characterized by focal segmental glomerulosclerosis showing segmental expansion of the mesangial area due to an increase of basement membrane-like material and mesangial cells with lipid droplets and foam cells. SZ-induced diabetic APA hamsters will be a useful model for the investigation of glomerular lipidosis and focal segmental glomerulosclerosis. Images Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:1533531

Han, J. S.; Sugawara, Y.; Doi, K.

1992-01-01

245

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

246

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

247

Twilights Widen the Range of Photic Entrainment in Hamsters  

Microsoft Academic Search

The range of entrainment of the circadian rhythm of locomotor activity was compared in four groups of Syrian hamsters (eight animals per group) initially exposed to daily light-dark (LD) cycles with either abrupt transitions between light and darkness (LD-rectangular) or simulated twilights (LD- twilight). Lighting was provided by arrays of white light-emitting diodes; daytime illuminance (10 lux) and the total

Ziad Boulos; M. Mila Macchi; Michael Terman

2002-01-01

248

Calcium carbonate concretions: cyclic occurrence in the hamster vagina.  

PubMed

Three crystalline forms of calcium carbonate were identified in washings of the hamster vagina. Spherical concretions of vaterite and hexagonal concretions of calcite predominate on days 3 and 4 of the 4-day estrous cycle. Dumbbell-like concretions of aragonite predominate during pregnancy and pseudopregnancy. Each polymorph is associated with an acid-insoluble matrix. Concretions disappear after ovariectomy and reappear during daily injections of estrogen and progesterone. PMID:5114824

Alleva, J J; Alleva, F R; Fry, B E; Eanes, E D

1971-11-01

249

Circadian arrhythmia dysregulates emotional behaviors in aged Siberian hamsters.  

PubMed

Emotional behaviors are influenced by the circadian timing system. Circadian disruptions are associated with depressive-like symptoms in clinical and preclinical populations. Circadian rhythm robustness declines markedly with aging and may contribute to susceptibility to emotional dysregulation in aged individuals. The present experiments used a model of chronic circadian arrhythmia generated noninvasively, via a series of circadian-disruptive light treatments, to investigate interactions between circadian desynchrony and aging on depressive- and anxiety-like behaviors, and on limbic neuroinflammatory gene expression that has been linked with emotionality. We also examined whether a social manipulation (group housing) would attenuate effects of arrhythmia on emotionality. In aged (14-18 months of age) male Siberian hamsters, circadian arrhythmia increased behavioral despair and decreased social motivation, but decreased exploratory anxiety. These effects were not evident in younger (5-9 months of age) hamsters. Social housing (3-5 hamsters/cage) abolished the effects of circadian arrhythmia on emotionality. Circadian arrhythmia alone was without effect on hippocampal or cortical interleukin-1? (IL-1?) and indoleamine 2,3-dioxygenase (Ido) mRNA expression in aged hamsters, but social housing decreased hippocampal IL-1? and Ido mRNAs. The data demonstrate that circadian disruption can negatively impact affective state, and that this effect is pronounced in older individuals. Although clear associations between circadian arrhythmia and constitutive limbic proinflammatory activity were not evident, the present data suggest that social housing markedly inhibits constitutive hippocampal IL-1? and Ido activity, which may contribute to the ameliorating effects of social housing on a number of emotional behaviors. PMID:24333374

Prendergast, Brian J; Onishi, Kenneth G; Patel, Priyesh N; Stevenson, Tyler J

2014-03-15

250

Effect of mono-(2-ethylhexyl) phthalate on bovine oocyte maturation in vitro.  

PubMed

The effect of mono(2-ethylhexyl) phthalate (MEHP) on bovine oocyte maturation in vitro was examined. Cumulus-oocyte complexes (COCs) were cultured in maturation medium supplemented with various levels of MEHP for 24h, and then examined for the degree of cumulus expansion and the stage of maturation. A higher percentage of oocytes remained at the germinal vesicle (GV) stage after exposure to 75 and 100 micro M MEHP treatments (13.8 and 44.9% of oocytes, respectively) than the control (2.1% of oocytes). The proportion of oocytes that progressed to the metaphase II (MII) stage was significantly decreased with 25 micro M (59.6% of oocytes), 50 micro M (19.8%), 75 micro M (21.3%), and 100 micro M (3.1%) treatments than the control (77.3%). MEHP did not affect the process of cumulus expansion. For denuded oocytes, MEHP treatment of 50-100 micro M resulted in a significantly higher rate of oocytes remained at the GV stage compared to the control (53.4, 80.2, 88.4, and 5.4%, respectively). The rate of MII formation was significantly decreased with 10 micro M (60.9%) and 25 micro M (22.5%) MEHP treatments compared to control (68.9%). Furthermore, with 50, 75 or 100 micro M MEHP, no oocyte reached the MII stage. When COCs were cultured for 24h with 50 or 100 micro M MEHP and then cultured for an additional 24h in MEHP-free medium, most of the oocytes reached the MII stage (71.1 and 64.5%, respectively).Taken together, these results indicate that MEHP, at doses lower than those reported in blood transfusion patients, could negatively modulate bovine oocyte meiotic maturation in vitro, suggesting possible risks for human and other mammalians reproductive health. PMID:12759099

Anas, Mohamed-Kheir Idris; Suzuki, Chie; Yoshioka, Koji; Iwamura, Shokichi

2003-01-01

251

Protective effects of the cumulus-corona radiata complex during vitrification of horse oocytes.  

PubMed

Vitrifying oocytes is a potentially valuable means of preserving the female germ line, but significantly compromises oocyte developmental competence. This study examined the hypothesis that the cumulus complex protects the oocyte during vitrification. Vitrified-warmed immature cumulus oocyte complexes (COCs) were labelled with a plasma membrane impermeant DNA marker (ethidium homodimer-1) to examine the percentage and location of dead cumulus cells, and to investigate the effect of the proportion of dead cells (+1,+2 or +3) on the success of in vitro maturation (IVM). Further, oocytes were labelled for connexin-43 or injected with Lucifer yellow dye to determine whether the integrity of the gap junctions between an oocyte and its cumulus was compromised by vitrification. Finally, the effect of denuding immature and mature oocytes on their ability to withstand vitrification was examined. Cryopreserving immature COCs increased the number of dead cumulus cells (13 vs 2.6% for controls; P<0.05). However, an increased proportion of dead cumulus cells did not affect post-warming maturation rates (approximately 30% MII) presumably because dead cells were located at the periphery of the cumulus mass and cumulus-oocyte gap junction communication was not disrupted. Moreover, cumulus removal prior to IVM or vitrification indicated that while the cumulus does protect immature oocytes during vitrification it does so by mechanisms other than support during maturation. Cumulus presence was also found to protect mature equine oocytes against vitrification-induced damage since cumulus-enclosed MII oocytes preserved their meiotic spindle quality better during vitrification than denuded oocytes (38.1 vs 3.1% normal spindles; P<0.05). PMID:19073713

Tharasanit, T; Colleoni, S; Galli, C; Colenbrander, B; Stout, T A E

2009-03-01

252

Classification of differentiating oocytes during ovarian cycle in the giant freshwater prawn, Macrobrachium rosenbergii de man  

Microsoft Academic Search

Based on the light microscopic observations of cells' sizes, chromatin patterns, amount of lipid droplets and yolk granules, the female germ cells could be classified into four different phases, which include 1) oogonia (Oog), 2) primary oocytes (pOc), 3) secondary oocytes (sOc), and 4) mature oocyte (mOc). Oog are small oval-shaped cells with irregular-shaped nuclei sizing 4–6 ?m in diameter. They

Prasert Meeratana; Prasert Sobhon

2007-01-01

253

Maturation, Fertilization, and the Structure and Function of the Endoplasmic Reticulum in Cryopreserved Mouse Oocytes1  

PubMed Central

Oocyte cryopreservation is a promising technology that could benefit women undergoing assisted reproduction. Most studies examining the effects of cryopreservation on fertilization and developmental competence have been done using metaphase II-stage oocytes, while fewer studies have focused on freezing oocytes at the germinal vesicle (GV) stage, followed by in vitro maturation. Herein, we examined the effects of vitrifying GV-stage mouse oocytes on cytoplasmic structure and on the ability to undergo cytoplasmic changes necessary for proper fertilization and early embryonic development. We examined the endoplasmic reticulum (ER) as one indicator of cytoplasmic structure, as well as the ability of oocytes to develop Ca2+ release mechanisms following vitrification and in vitro maturation. Vitrified GV-stage oocytes matured in culture to metaphase II at a rate comparable to that of controls. These oocytes had the capacity to release Ca2+ following injection of inositol 1,4,5-trisphosphate, demonstrating that Ca2+ release mechanisms developed during meiotic maturation. The ER remained intact during the vitrification procedure as assessed using the lipophilic fluorescent dye DiI. However, the reorganization of the ER that occurs during in vivo maturation was impaired in oocytes that were vitrified before oocyte maturation. These results show that vitrification of GV-stage oocytes does not affect nuclear maturation or the continuity of the ER, but normal cytoplasmic maturation as assessed by the reorganization of the ER is disrupted. Deficiencies in factors that are responsible for proper ER reorganization during oocyte maturation could contribute to the low developmental potential previously reported in vitrified in vitro-matured oocytes. PMID:19299317

Lowther, Katie M.; Weitzman, Vanessa N.; Maier, Donald; Mehlmann, Lisa M.

2009-01-01

254

?-endosulfine (ENSA) regulates exit from prophase I arrest in mouse oocytes.  

PubMed

Mammalian oocytes in ovarian follicles are arrested in meiosis at prophase I. This arrest is maintained until ovulation, upon which the oocyte exits from this arrest, progresses through meiosis I and to metaphase of meiosis II. The progression from prophase I to metaphase II, known as meiotic maturation, is mediated by signals that coordinate these transitions in the life of the oocyte. ENSA (?-endosulfine) and ARPP19 (cAMP-regulated phosphoprotein-19) have emerged as regulators of M-phase, with function in inhibition of protein phosphatase 2A (PP2A) activity. Inhibition of PP2A maintains the phosphorylated state of CDK1 substrates, thus allowing progression into and/or maintenance of an M-phase state. We show here ENSA in mouse oocytes plays a key role in the progression from prophase I arrest into M-phase of meiosis I. The majority of ENSA-deficient oocytes fail to exit from prophase I arrest. This function of ENSA in oocytes is dependent on PP2A, and specifically on the regulatory subunit PPP2R2D (also known as B55?). Treatment of ENSA-deficient oocytes with Okadaic acid to inhibit PP2A rescues the defect in meiotic progression, with Okadaic acid-treated, ENSA-deficient oocytes being able to exit from prophase I arrest. Similarly, oocytes deficient in both ENSA and PPP2R2D are able to exit from prophase I arrest to an extent similar to wild-type oocytes. These data are evidence of a role for ENSA in regulating meiotic maturation in mammalian oocytes, and also have potential relevance to human oocyte biology, as mouse and human have genes encoding both Arpp19 and Ensa. PMID:24675883

Matthews, Lauren M; Evans, Janice P

2014-05-15

255

Development of human oocytes matured in vitro for 28 or 36 hours  

Microsoft Academic Search

Objective: To compare the effects on human oocytes of in vitro maturation periods of 28 hours and 36 hours.Design: Retrospective analysis.Setting: University teaching hospital.Patient(s): A total of 48 infertile patients undergoing 55 cycles who volunteered for the experimental treatments.Intervention(s): Immature oocytes were aspirated with use of transvaginal ultrasonography. Oocytes were matured, fertilized by intracytoplasmic sperm injection, and cultured for 2.5

Steven Dale Smith; Anne-Lis Mikkelsen; Svend Lindenberg

2000-01-01

256

Parthenogenic Blastocysts Derived from Cumulus-Free In Vitro Matured Human Oocytes  

PubMed Central

Background Approximately 20% of oocytes are classified as immature and discarded following intracytoplasmic sperm injection (ICSI) procedures. These oocytes are obtained from gonadotropin-stimulated patients, and are routinely removed from the cumulus cells which normally would mature the oocytes. Given the ready access to these human oocytes, they represent a potential resource for both clinical and basic science application. However culture conditions for the maturation of cumulus-free oocytes have not been optimized. We aimed to improve maturation conditions for cumulus-free oocytes via culture with ovarian paracrine/autocrine factors identified by single cell analysis. Methodology/Principal Finding Immature human oocytes were matured in vitro via supplementation with ovarian paracrine/autocrine factors that were selected based on expression of ligands in the cumulus cells and their corresponding receptors in oocytes. Matured oocytes were artificially activated to assess developmental competence. Gene expression profiles of parthenotes were compared to IVF/ICSI embryos at morula and blastocyst stages. Following incubation in medium supplemented with ovarian factors (BDNF, IGF-I, estradiol, GDNF, FGF2 and leptin), a greater percentage of oocytes demonstrated nuclear maturation and subsequently, underwent parthenogenesis relative to control. Similarly, cytoplasmic maturation was also improved as indicated by development to blastocyst stage. Parthenogenic blastocysts exhibited mRNA expression profiles similar to those of blastocysts obtained after IVF/ICSI with the exception for MKLP2 and PEG1. Conclusions/Significance Human cumulus-free oocytes from hormone-stimulated cycles are capable of developing to blastocysts when cultured with ovarian factor supplementation. Our improved IVM culture conditions may be used for obtaining mature oocytes for clinical purposes and/or for derivation of embryonic stem cells following parthenogenesis or nuclear transfer. PMID:20539753

McElroy, Sohyun L.; Byrne, James A.; Chavez, Shawn L.; Behr, Barry; Hsueh, Aaron J.; Westphal, Lynn M.; Reijo Pera, Renee A.

2010-01-01

257

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

258

Teratogenicity and embryotoxicity of nickel carbonyl in Syrian hamsters  

SciTech Connect

Nickel carbonyl was administered to groups of pregnant hamsters by inhalation on days 4, 5, 6, 7, or 8 of gestation. The dams were killed on day 15 of gestation, and the fetuses were examined for malformations. Exposure to Ni(CO)/sub 4/ on days 4 or 5 of gestation resulted in malformation in 5.5% and 5.8% of the progeny, respectively. Progeny included 9 fetuses with cystic lungs, 7 fetuses with exencephaly, 1 fetus with exencephaly plus fused rib and 1 fetus with anophthalmia plus cleft palate. Hemorrhages into serious cavities were found. In progeny of dams exposed to Ni(CO)/sub 4/ on days 6 or 7 of gestation, there was 1 fetus with fused ribs and there were 2 fetuses with hydronephrosis. In another experiment, pregnant hamsters were exposed to inhalation of Ni(CO)/sub 4/ on day 5 of gestation; these dams were permitted to deliver their litters and to nurse their pups. There was no significant difference in the average number of live pups in the Ni(CO)/sub 4/-exposed litters compared to control litters. Neonatal mortality was increased in Ni(CO)/sub 4/-exposed litters. This study demonstrates that Ni(CO)/sub 4/ is teratogenic and embryotoxic in Syrian hamsters.

Sunderman, F.W. Jr.; Shen, S.K.; Reid, M.C.; Allpass, P.R.

1980-01-01

259

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

2008-01-01

260

A penetration-aspiration scale  

Microsoft Academic Search

The development and use of an 8-point, equalappearing interval scale to describe, penetration and aspiration events are described. Scores are determined primarily by the depth to which material passes in the airway and by whether or not material entering the airway is expelled. Intra-and interjudge reliability have been established. Clinical and scientific uses of the scale are discussed.

John C. Rosenbek; Jo Anne Robbins; Ellen B. Roecker; Jame L. Coyle; Jennifer L. Wood

1996-01-01

261

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

E-print Network

such as somatic cell nuclear transfer, or ?cloning? may potentially be an alternative to the preservation of superior genetics among various breeds, wild or endangered canids, or those of a beloved pet (Lee et al., 2005; Jang et al., 2007; Jang et al., 2008a.... The production of canine embryos in vitro by IVF, ICSI, or somatic cell nuclear transfer (SCNT) is equally inefficient as IVM of canine oocytes with limited successful outcomes. Although embryo collection and heterologous transfer attempts have been...

Willingham-Rocky, Lauri A.

2009-05-15

262

Transcription profile of candidate genes for the acquisition of competence during oocyte growth in cattle.  

PubMed

The aim of this study was to investigate the expression profile of candidate genes involved in competence during oocyte growth. The candidate genes (BMP15, OOSP1, H1FOO, H2A, H3A, H4, SLBP, DNMT1, DNMT3B, HAT1, HDAC2 and SUV39H1) were selected because of their possible involvement in determining oocyte developmental competence. Pre-antral and antral follicles were isolated from the ovaries of Zebu (Bos indicus) cows, measured and classified into the following categories according to their diameter: (i) oocytes from primordial follicles: diameter <20 ?m, (ii) oocytes from primary follicles: 25-35 ?m, (iii) oocytes from small secondary follicles: 40-60 ?m, (iv) oocytes from large secondary follicles: 65-85 ?m, (v) oocytes from small antral follicles: 100-120 ?m, and (vi) oocytes from large antral follicles: >128 ?m. Total RNA was extracted from four pools of 25 oocytes for each category of follicles, and the genes were quantified by qPCR. Target gene expression was normalized using the gene PPIA. The results suggest that stocks of the studied transcript genes accumulate before the final phase of folliculogenesis. The HDAC2 gene was the only gene in which a differential expression was observed at stage associated with competence acquisition. PMID:23574109

Bessa, I R; Nishimura, R C; Franco, M M; Dode, M A N

2013-10-01

263

Membrane Lipid Phase Transition Behavior of Oocytes from Three Gorgonian Corals in Relation to Chilling Injury  

PubMed Central

The lipid phase transition (LPT) from the fluid liquid crystalline phase to the more rigid gel structure phase that occurs upon exposure to low temperatures can affect physical structure and function of cellular membranes. This study set out to investigate the membrane phase behavior of oocytes of three gorgonian corals; Junceela fragilis, J. juncea and Ellisella robusta,at different developmental stages after exposure to reduced temperatures. Oocytes were chilled to 5°C for 48, 96 or 144 h, and the LPT temperature (LPTT) was determined with Fourier Transform Infrared (FTIR) spectroscopy. The J. fragilis oocytes had a higher LPTT (?23.0–23.7°C) than those of J. juncea and E. robusta oocytes (approximately 18.3–20.3°C). Upon chilling for 96 h at 5°C, the LPTTs of J. juncea and E. robusta oocytes in the early (18.0±1.0 and 18.3±0.6°C, respectively) and late (17.3±0.6 and 17.7±1.2°C, respectively) stages were significantly lower than those of J. fragilis oocytes (20.3±2.1 and 19.3±1.5°C for the early and late stages, respectively). The LPTTs of early stage gorgonian oocytes was significantly lower than those of late stage oocytes. These results suggest that the LPT of three gorgonian oocytes at different developmental stages may have been influenced by the phospholipid composition of their plasma membranes, which could have implications for their low temperature resistance. PMID:24671092

Lin, Chiahsin; Kuo, Fu-Wen; Chavanich, Suchana; Viyakarn, Voranop

2014-01-01

264

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

Jimenez-Trigos, Estrella; Vicente, Jose S.; Marco-Jimenez, Francisco

2013-01-01

265

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

266

Mouse Oocyte Control of Granulosa Cell Development and Function: Paracrine Regulation of Cumulus Cell Metabolism  

PubMed Central

Bi-directional communication between oocytes and the companion granulosa cells is essential for the development and functions of both compartments. Oocytes are deficient in their ability to transport certain amino acids and in carrying out glycolysis and cholesterol biosynthesis, and require that cumulus cells provide them with the specific amino acids and the products in these metabolic pathways. Oocytes control metabolic activities in cumulus cells by promoting the expression of genes in cumulus cells encoding specific amino acid transporters and enzymes essential for the oocyte-deficient metabolic processes. Hence, oocytes outsource metabolic functions to cumulus cells to compensate for oocyte metabolic deficiencies. Oocyte control of granulosa cell metabolism may also participate in regulating the rate of follicular development in coordination with endocrine, paracrine and autocrine signals. Oocytes influence granulosa cell development mainly by secretion of paracrine factors although juxtacrine signals probably also participate. Key oocyte-derived paracine factors include growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15) 15, and fibroblast growth factor 8B (FGF8B). PMID:19197803

Su, You-Qiang; Sugiura, Koji; Eppig, John J.

2009-01-01

267

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

268

Analysis of actinomycin D treated cattle oocytes and their use for somatic cell nuclear transfer  

Microsoft Academic Search

The present work aimed to evaluate the transcription and replication inhibitor, actinomycin D, for oocyte chemical enucleation. Cattle oocytes matured in vitro were treated with actinomycin D according to the following treatments: T1, control; T2=1.0?g\\/ml for 16h; T3=1.0?g\\/ml for 14h; T4=2.5?g\\/ml for 14h; T5=5.0?g\\/ml for 14h. The oocytes were denuded and activated during 24–26h of maturation. Oocytes were fixed to

Marcelo Tigre Moura; Regivaldo Vieira de Sousa; Ligiane de Oliveira Leme; Rodolfo Rumpf

2008-01-01

269

Investigation of temporal discounting in dwarf hamsters (Phodopus campbelli) and Sprague-Dawley rats (Rattus norvegicus) in an operant choice task.  

E-print Network

??The present experiment investigated whether dwarf hamsters (Phodopus campbelli) demonstrate temporal discounting. This was investigated by comparing the behavior of dwarf hamsters and Sprague-Dawley rats… (more)

Spieldenner, Jessica Maie Godin

2012-01-01

270

Prognostic value of various spermatological attributes as predictors of zona binding and zona penetration of buffalo (Bubalus bubalis) semen.  

PubMed

Twenty-four ejaculates from six (four ejaculates each) Surti buffalo bulls aged 4-8 years were used to assess various attributes of spermatozoa influencing the zona-binding and zona-penetration tests. Ejaculates from each bulls were subjected to in vitro sperm--zona binding and sperm--zona penetration tests (four replicates per bull) using immature buffalo oocytes. The average number of spermatozoa bound per oocyte was 27.79 +/- 5.90. The average number of spermatozoa penetrated per oocyte was 3.35 +/- 0.64. The average number of zona-bound and -penetrated spermatozoa differed significantly between animals. Significant difference (p < 0.05) was observed between the plasmalemma integrity as assessed by eosin--nigrosin stain and hypo-osmotic swelling (HOS) test. Furthermore, the percentage of cells positive for the HOS test, i.e. functional membrane integrity (51.25 +/- 2.32) was significantly (p < 0.05) higher than hypo-osmotic swelling-Giemsa (HOS-G) test, i.e. the subpopulation of spermatozoa positive for functional membrane and acrosomal integrities (42.87 +/- 4.56). The HOS test had significant correlations with plasmalemma integrity as measured by the vital stain, eosin--nigrosin (r = 0.85, p < 0.05). The HOS-G test also had significant correlation with plasmalemma integrity measured by vital stains such as eosin--nigrosin (r = 0.90, p < 0.05) and fluorogenic stains [carboxyfluorescein diacetate (CFDA) and propidium iodide (PI); r = 0.92, p < 0.01] and HOS test (r = 0.93), acrosomal integrity (r = 0.86, p < 0.05) and mitochondrial membrane potential (r = 0.99, p < 0.01). The plasmalemma integrity (fluorogenic stain), functional membrane integrity (HOS test), subpopulation of spermatozoa positive for functional membrane and acrosomal integrities (HOS-G test) and mitochondrial membrane potential had significant (p < 0.05) correlation with sperm zona binding and penetration. The present study indicates that these parameters could represent important determinants of sperm quality influencing zona binding and penetration. PMID:18673329

Selvaraju, S; Ghosh, J; Ravindra, J P

2009-02-01

271

Lack of correlation between oocyte- corona-cumulus complex morphology and nuclear maturity of oocytes collected in stimulated cycles for intracytoplasmic sperm injection  

Microsoft Academic Search

Objective: To evaluate the usefulness of morphology grading of the oocyte-corona-cumulus complex (OCCC) as a marker of oocyte nuclear maturity, fertilizability, embryo cleavage, and likelihood of pregnancy.Design: Prospective cohort study.Setting: Academic fertility center.Patient(s): Eighty-three infertile couples undergoing IVF-ET\\/intracytoplasmic sperm injection treatment.Intervention(s): All patients underwent a long stimulation protocol of GnRH agonist therapy followed by hMG administration and transvaginal oocyte recovery.Main

Manee Rattanachaiyanont; Arthur Leader; Marie-Claude Léveillé

1999-01-01

272

Developmental Changes in the ECG of a Hamster Model of Muscular Dystrophy and Heart Failure  

PubMed Central

Aberrant autonomic signaling is being increasingly recognized as an important symptom in neuromuscular disorders. The ?-sarcoglycan-deficient BIO TO-2 hamster is recognized as a good model for studying mechanistic pathways and sequelae in muscular dystrophy and heart failure, including autonomic nervous system (ANS) dysfunction. Recent studies using the TO-2 hamster model have provided promising preclinical results demonstrating the efficacy of gene therapy to treat skeletal muscle weakness and heart failure. Methods to accelerate preclinical testing of gene therapy and new drugs for neuromuscular diseases are urgently needed. The purpose of this investigation was to demonstrate a rapid non-invasive screen for characterizing the ANS imbalance in dystrophic TO-2 hamsters. Electrocardiograms were recorded non-invasively in conscious ?9-month old TO-2 hamsters (n?=?10) and non-myopathic F1B control hamsters (n?=?10). Heart rate was higher in TO-2 hamsters than controls (453?±?12?bpm vs. 311?±?25?bpm, P?hamsters (12.2?±?3.7?bpm vs. 38.2?±?6.8, P?hamsters. Power spectral analysis demonstrated reduced high frequency and low frequency contributions, indicating autonomic imbalance with increased sympathetic tone and decreased parasympathetic tone in dystrophic TO-2 hamsters. Similar observations in newborn hamsters indicate autonomic nervous dysfunction may occur quite early in life in neuromuscular diseases. Our findings of autonomic abnormalities in newborn hamsters with a mutation in the ?-sarcoglycan gene suggest approaches to correct modulation of the heart rate as prevention or therapy for muscular dystrophies. PMID:22629245

Hampton, Thomas G.; Kale, Ajit; McCue, Scott; Bhagavan, Hemmi N.; VanDongen, Case

2012-01-01

273

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

274

Develop to Term Rat Oocytes Injected with Heat-Dried Sperm Heads  

PubMed Central

This study investigated the development of rat oocytes in vitro and in vivo following intracytoplasmic injection of heads from spermatozoa heat-dried at 50°C for 8 h and stored at 4°C in different gas phases. Sperm membrane and chromosome are damaged by the process of heat-drying. Oocyte activation and cleavage of oocytes were worse in oocytes injected with spermatozoa heat-dried and stored for 1 week than unheated, fresh spermatozoa, but in heat-dried spermatozoa, there were no differences in these abilities of oocytes between the samples stored in nitrogen gas and in air. The oocytes injected with heat-dried spermatozoa stored for 1 week could develop to the morula and blastocyst stages without difference between the samples stored in nitrogen gas and in air after artificial stimulation. Cleavage of oocytes and development of cleaved embryos were higher when heat-dried spermatozoa were stored for 3 and 6 months in nitrogen gas than in air. However, the ability of injected oocytes to develop to the morula and blastocyst stages was not inhibited even when heat-dried spermatozoa stored in both atmosphere conditions for as long as 6 months were used. When 2-cell embryos derived from oocytes injected with heads from spermatozoa heat-dried and stored for 1 week and 1 month were transferred, each 1 of 4 recipients was conceived, and the conceived recipients delivered 1 live young each. These results demonstrate that rat oocytes can be fertilized with heat-dried spermatozoa and that the fertilized oocytes can develop to term. PMID:24223784

Lee, Kyung-Bon; Park, Ki-Eun; Kwon, In-Kiu; Tripurani, Swamy K.; Kim, Keun Jung; Lee, Ji Hye; Niwa, Koji; Kim, Min Kyu

2013-01-01

275

Rescue and maturation in vitro of follicular oocytes collected from nondomestic felid species.  

PubMed

The potential for rescuing immature oocytes from the ovaries of females of rare felid species which die or undergo medical ovariohysterectomy was evaluated. Ovaries were recovered from 13 species representing 35 individuals in good-to-poor health. Although the majority of females were 10 yr of age or older and in fair-to-poor health, a total of 846 oocytes were recovered of which 608 (71.9%) were classified as fair-to-excellent quality. One hundred of these oocytes were used for initial maturation classification and as parthogenetic controls. Overall, of the 508 fair-to-excellent quality oocytes placed in culture, 164 (32.3%) matured to metaphase II in vitro. For species in which 3 or more individuals yielded oocytes, mean oocyte maturation rates were as follows: 36.2%, tiger; 27.9% leopard; and 8.3%, cheetah. In vitro insemination of oocytes resulted in fertilization (2 polar bodies, 2 pronuclei, or cleavage) rates of 9.1% to 28.6% (leopard) using homologous fresh spermatozoa and 4.0% (lion) to 40.0% (puma) using homologous frozen-thawed spermatozoa. Inseminations using heterologous (domestic cat) spermatozoa also resulted in fertilized oocytes in the tiger, leopard, snow leopard, puma, serval, and Geoffroy's cat (range in fertilization rate, 5.0% for leopard to 46.2% for puma). Cleaved embryos resulted from the insemination of leopard oocytes with homologous sperm (n = 1 embryo) and puma oocytes with domestic cat sperm (n = 3 embryos). These results demonstrate that immature ovarian oocytes from rare felid species can be stimulated to mature in vitro despite an excision-to-culture interval as long as 36 h.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1805993

Johnston, L A; Donoghue, A M; O'Brien, S J; Wildt, D E

1991-12-01

276

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

277

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

278

Weld penetration and defect control  

NASA Astrophysics Data System (ADS)

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 necessity. 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.

1992-05-01

279

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....

280

Ballistic penetration of steel plates  

Microsoft Academic Search

This paper presents a research programme in progress where the main objective is to study the behaviour of Weldox 460 E steel plates impacted by blunt-nosed cylindrical projectiles in the lower ordnance velocity regime. A compressed gas gun is used to carry out high-precision tests, and a digital high-speed camera system is used to photograph the penetration process. A coupled

T. Børvik; M. Langseth; O. S. Hopperstad; K. A. Malo

1999-01-01

281

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

282

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

283

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

284

The partition of sodium fluxes in isolated toad oocytes  

PubMed Central

1. The rate constant for Na efflux from the oocyte calculated from (d/dt) (ln [Na*]i]) is only approximately 52% of that calculated from (d/dt)[(ln(d[Na*]i)dt)]. The difference may be interpreted by supposing that 48% of the internal Na of the oocyte is either bound to proteins or sequestered in cell organelles. 2. The mean rate constant for Na efflux was 6·4 × 10-3 min-1 corresponding to an apparent Na efflux rate of 13·3 p-mole/cm2.sec. When this is corrected for the increase in surface area produced by microvilli the true efflux rate is 1·1-1·3 p-mole/cm2.sec. 3. The action of ouabain (1-5 ?M) appears to involve two different effects: (a) there is 48-65% inhibition of the membrane Na pump, and (b) there is a release of some of the sequestered Na in the cell. 4. Removal of external K causes a 40% reduction in Na efflux although this value may be an underestimation owing to the presence of K which has leaked from the cell and may be retained near the cell surface. 5. Raising the external K concentration to 15 mM reduces the inhibitory effect of ouabain by approximately a half. 6. It was concluded that the Na pump in the toad oocyte may have a slightly lower level of activity than that in frog muscle, but that its general properties are similar to those in frog muscle and some other animal cells. PMID:6050106

Dick, D. A. T.; Lea, E. J. A.

1967-01-01

285

Effect of the apoptosis rate observed in oocytes and cumulus cells on embryo development in prepubertal goats.  

PubMed

Oocyte quality is the main factor that determines blastocyst yield; any factor that could affect it, such as apoptosis, could impair subsequent embryonic development. Our aim was to investigate the incidence of apoptosis in prepubertal goat oocytes and cumulus cells, assessed by Annexin-V staining and TUNEL assay, and their effect on embryo development. Oocyte-cumulus complexes (COCs) from slaughtered females were collected and classified depending on COC morphology as: Healthy (H) and Early Atretic (EA). Each one of these groups was classified depending on oocyte diameter: A: 110-125microm, B: 125-135microm and C: >135microm. The COCs were IVM for 27h, IVF with fresh semen and IVC for 8 days after insemination. Apoptosis analyses were performed before and after maturation. Annexin-positive oocytes decreased with diameter in the EA class (immature oocytes: A: 42.6%; B: 30.3%; C: 21%; IVM-oocytes: A: 17.5%; B: 4.8%; C: 0%), while TUNEL assay showed a decrease of apoptosis in the largest oocytes before and after IVM only in Healthy oocytes (immature oocytes: A: 51.5%; B: 43.3%; C: 12.1%; IVM-oocytes: A: 31.7%; B: 12%; C: 0%). Blastocyst rate increased with increasing oocyte diameter, and it was higher in H than in EA oocytes (Healthy; A: 0%; B: 5.3%; C: 14.4%; Early atretic: A: 0.3%; B: 4.1%; C: 5.1%). Oocyte diameter and COC morphology had no effect on the percentage of apoptosis in blastocyst cells. In conclusion, oocyte developmental competence in prepubertal goats is influenced by oocyte diameter and COC morphology. PMID:19217225

Anguita, B; Paramio, M T; Morató, R; Romaguera, R; Jiménez-Macedo, A R; Mogas, T; Izquierdo, D

2009-11-01

286

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...

287

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

288

POTENTIATION OF THE RESETTING EFFECTS OF LIGHT ON CIRCADIAN RHYTHMS OF HAMSTERS USING SEROTONIN  

E-print Network

POTENTIATION OF THE RESETTING EFFECTS OF LIGHT ON CIRCADIAN RHYTHMS OF HAMSTERS USING SEROTONIN, Smith College, Northampton, MA 01063, USA Abstract--Circadian rhythms are entrained by light/dark cycles. In hamsters, the effects of light on circadian rhythms can be modulated by serotonergic input

Harrington, Mary

289

Comparison of pulmonary and pleural responses of rats and hamsters to inhaled refractory ceramic fibers  

Microsoft Academic Search

The present study was designed to determine whether pleural fiber burdens or subchronic pleural fibroproliferative and inflam- matory changes can help explain the marked interspecies differ- ences in pleural fibrosis and mesothelioma that are observed fol- lowing long-term inhalation of RCF-1 ceramic fibers by rats and hamsters. Fischer 344 rats and Syrian golden hamsters were ex- posed to RCF-1 for

Thomas R. Gelzleichter; Edilberto Bermudez; James B. Mangum; Brian A. Wong; Derek B. Janszen; Owen R. Moss; Jeffrey I. Everitt

1999-01-01

290

Heterotransplantation of Human Prostatic Adenoma Cells, M A160, into Nonimmunosuppressed Hamsters  

Microsoft Academic Search

SUMMARY MA160 cells, derived in tissue culture from a benign prostatic adenoma, can produce large tumors in nonimmuno- suppressed hamsters. These tumors contain bone and hematopoietic precursors. Chromosome analysis of the tumors showed them to be human in genetic makeup, and serological tests failed to implicate any of the common DNA or RNA hamster tumor viruses. The data indicated that

Alan V. Richman; Monroe M. Vincent; Elmer C. Martino; Nicola M. Tauraso

291

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...

292

VGF-Derived Peptide, TLQP-21, Regulates Food Intake and Body Weight in Siberian Hamsters  

Microsoft Academic Search

The Siberian hamster survives winter by decreasing food in- take and catabolizing abdominal fat reserves, resulting in a sustained, profound loss of body weight. VGF gene expression is photoperiodically regulated in the hypothalamus with sig- nificantly higher expression in lean Siberian hamsters. The aim of this study was to investigate the role of VGF in regu- lating these seasonal cycles

Preeti H. Jethwa; Amy Warner; Kanishka N. Nilaweera; John M. Brameld; John W. Keyte; Wayne G. Carter; Neil Bolton; Michael Bruggraber; Peter J. Morgan; Perry Barrett; Francis J. P. Ebling

2007-01-01

293

Absence of Spiroplasma or Other Bacterial 16S rRNA Genes in Brain Tissue of Hamsters with Scrapie  

Microsoft Academic Search

Spiroplasma spp. have been proposed to be the etiological agents of the transmissible spongiform enceph- alopathies (TSEs). In a blind study, a panel of 20 DNA samples was prepared from the brains of uninfected hamsters or hamsters infected with the 263K strain of scrapie. The brains of the infected hamsters contained >1010 infectious doses\\/g. The coded panel was searched for

Irina Alexeeva; Ellen J. Elliott; Sandra Rollins; Gail E. Gasparich; Jozef Lazar; Robert G. Rohwer

2006-01-01

294

Effects of Induced Wheel Running on the Circadian Activity Rhythms of Syrian Hamsters: Entrainment and Phase Response Curve  

Microsoft Academic Search

The goal of this study was to provide an example of nonsocial and nonphotic entrainment in Syrian hamsters, together with a corresponding phase response curve (PRC). Fourteen male hamsters were given 2-hr bouts of induced activity (mostly wheel running) at 23.83-hr intervals in constant darkness (DD). The activity onsets of 10 hamsters entrained to this manipulation, with no anticipatory activity

Stephan G. Reebs; N. Mrosovsky

1989-01-01

295

The hermaphrodite sperm oocyte switch requires the Caenorhabditis elegans homologs of PRP2 and PRP22  

E-print Network

The hermaphrodite sperm oocyte switch requires the Caenorhabditis elegans homologs of PRP2 and PRP determination in the hermaphrodite germ line of Caenorhab- ditis elegans is controlled posttranscriptionally. In Caenorhabditis elegans, the hermaphrodite produces sperm during the fourth larval stage and oocytes in the adult

Kimble, Judith

296

Hypotonic regulation of mouse epithelial sodium channel in Xenopus laevis oocytes.  

PubMed

The regulation of the epithelial Na? channel (ENaC) during cell swelling is relevant in cellular processes in which cell volume changes occur, i.e., migration, proliferation and cell absorption. Its sensitivity to hypotonically induced swelling was investigated in the Xenopus oocyte expression system with the injection of the three subunits of mouse ENaC. We used voltage-clamp techniques to study the amiloride-sensitive Na? currents (INa(amil)) and video microscopic methodologies to assess oocyte volume changes. Under conditions of mild swelling (25 % reduced hypotonicity) inward current amplitude decreased rapidly over 1.5 min. In contrast, there was no change in current amplitude of H?O-injected oocytes to the osmotic insult. INa(amil) kinetics analysis revealed a decrease in the slower inactivation time constant during the hypotonic stimuli. Currents from ENaC-injected oocytes were not sensitive to external Cl? reduction. Neither short- nor long-term cytochalasin D treatment affected the observed response. Oocytes expressing a DEG mutant ?-ENaC subunit (?-S518K) with an open probability of 1 had reduced INa(amil) hypotonic response compared to oocytes injected with wild-type ENaC subunits. Finally, during the hypotonic response ENaC-injected oocytes did not show a cell volume difference compared with water-injected oocytes. On this basis we suggest that hypotonicity-dependent ENaC inhibition is principally mediated through an effect on open probability of channels in the membrane. PMID:24121666

Galizia, Luciano; Marino, Gabriela I; Ojea, Alejandro; Kotsias, Basilio A

2013-12-01

297

Suppression of chemically induced and spontaneous mouse oocyte activation by AMP-activated protein kinase.  

PubMed

Oocyte activation is an important process triggered by fertilization that initiates embryonic development. However, parthenogenetic activation can occur either spontaneously or with chemical treatments. The LT/Sv mouse strain is genetically predisposed to spontaneous activation. LT oocytes have a cell cycle defect and are ovulated at the metaphase I stage instead of metaphase II. A thorough understanding of the female meiosis defects in this strain remains elusive. We have reported that AMP-activated protein kinase (PRKA) has an important role in stimulating meiotic resumption and promoting completion of meiosis I while suppressing premature parthenogenetic activation. Here we show that early activation of PRKA during the oocyte maturation period blocked chemically induced activation in B6SJL oocytes and spontaneous activation in LT/SvEiJ oocytes. This inhibitory effect was associated with high levels of MAPK1/3 activity. Furthermore, stimulation of PRKA partially rescued the meiotic defects of LT/Sv mouse oocytes in concert with correction of abnormal spindle pole localization of PRKA and loss of prolonged spindle assembly checkpoint activity. Altogether, these results confirm a role for PRKA in helping sustain the MII arrest in mature oocytes and suggest that dysfunctional PRKA contributes to meiotic defects in LT/SvEiJ oocytes. PMID:23390161

Ya, Ru; Downs, Stephen M

2013-03-01

298

Suppression of Chemically Induced and Spontaneous Mouse Oocyte Activation by AMP-Activated Protein Kinase1  

PubMed Central

ABSTRACT Oocyte activation is an important process triggered by fertilization that initiates embryonic development. However, parthenogenetic activation can occur either spontaneously or with chemical treatments. The LT/Sv mouse strain is genetically predisposed to spontaneous activation. LT oocytes have a cell cycle defect and are ovulated at the metaphase I stage instead of metaphase II. A thorough understanding of the female meiosis defects in this strain remains elusive. We have reported that AMP-activated protein kinase (PRKA) has an important role in stimulating meiotic resumption and promoting completion of meiosis I while suppressing premature parthenogenetic activation. Here we show that early activation of PRKA during the oocyte maturation period blocked chemically induced activation in B6SJL oocytes and spontaneous activation in LT/SvEiJ oocytes. This inhibitory effect was associated with high levels of MAPK1/3 activity. Furthermore, stimulation of PRKA partially rescued the meiotic defects of LT/Sv mouse oocytes in concert with correction of abnormal spindle pole localization of PRKA and loss of prolonged spindle assembly checkpoint activity. Altogether, these results confirm a role for PRKA in helping sustain the MII arrest in mature oocytes and suggest that dysfunctional PRKA contributes to meiotic defects in LT/SvEiJ oocytes. PMID:23390161

Ya, Ru; Downs, Stephen M.

2013-01-01

299

Treatment of ovine oocytes with certain water-soluble vitamins during in vitro maturation (IVM)  

Microsoft Academic Search

The main aim of this study was to evaluate the effects of water-soluble vitamins (singly or in combination), on in vitro maturation (IVM) and subsequent embryonic development of sheep oocytes. Cumulus oocyte complexes (COCs) were evaluated in three experiments. Experiment 1: COCs were matured in modified synthetic oviduct fluid maturation medium (mSOFM), with or without various protein supplements (polyvinyl alcohol

H. Karami Shabankareh; F. Kafilzadeh; L. Soltani

300

Xenopus tropicalis oocytes as an advantageous model system for the study of intracellular Ca2+  

E-print Network

Xenopus 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 and Xenopus laevis, with respect to their utility for studying Ca2+ signalling mechanisms and for expression

Marchant, Jonathan

301

High-throughput optofluidic system for the laser microsurgery of oocytes  

E-print Network

are confined against a microfluidic barrier using a steady fluid flow provided by an external computer-controlled nucleolinus within the oocyte nucleolus. Oocytes were the followed and assayed for polar body ejection. © 2012 Society of Photo- Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JBO.17.1.015001] Keywords

Chen, Zhongping

302

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

303

Transvaginal Aspiration of Oocytes from Hormone-Treated Pregnant Beef Cattle for In Vitro Fertilization112  

Microsoft Academic Search

The ability to produce oocytes from genetically valuable, pregnant donors in a safe, repeatable manner would broaden the application of in vitro fertilization (IVF) procedures for beef and dairy cattle. The objectives of this study were to evaluate two gonadotropin treatment schedules for follicle stimulation of pregnant donor cattle and to determine the efficacy and safety of the repeated oocyte

M. Meintjes; M. S. Bellow; J. R. Broussardt; J. B. Paul; R. A. Godke

2010-01-01

304

Ooplast-mediated developmental rescue of bovine oocytes exposed to ethidium bromide  

Microsoft Academic Search

Ooplasm transfer has been used successfully to treat infertility in women with ooplasmic insufficiency and has culminated in the birth of healthy babies. To investigate whether mitochondrial dysfunction is a factor in ooplasmic insufficiency, bovine oocytes were exposed to ethidium bromide, an inhibitor of mitochondrial DNA replication and transcription, during in-vitro maturation (IVM). Exposure of immature oocytes to ethidium bromide

Marcos Roberto Chiaratti; Christina Ramires Ferreira; Felipe Perecin; Simone Cristina Méo; Juliano Rodrigues Sangalli; Lígia Garcia Mesquita; Júlio César de Carvalho Balieiro; Lawrence Charles Smith; Joaquim Mansano Garcia; Flávio Vieira Meirelles

2011-01-01

305

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 bass (Ambloplites rupestris) were investigated. Only oocytes in which the germinal vesicle bass (Ambloplites rupestris-Centrarchidae-Perciformes) is very similar to that observed in the percid

Paris-Sud XI, Université de

306

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...

307

Evolutionary conservation of the oocyte transcriptome among vertebrates and its implications for understanding human reproductive function.  

PubMed

Cross-phylum and cross-species comparative transcriptomic analyses provide an evolutionary perspective on how specific tissues use genomic information. A significant mRNA subset present in the oocytes of most vertebrates is stabilized or stored for post-LH surge use. Since transcription is arrested in the oocyte before ovulation, this RNA is important for completing maturation and sustaining embryo development until zygotic genome activation. We compared the human oocyte transcriptome with an oocyte-enriched subset of mouse, bovine and frog (Xenopus laevis) genes in order to evaluate similarities between species. Graded temperature stringency hybridization on a multi-species oocyte cDNA array was used to measure the similarity of preferentially expressed sequences to the human oocyte library. Identity analysis of 679 human orthologs compared with each identified official gene symbol found in the subtractive (somatic-oocyte) libraries comprising our array revealed that bovine/human similarity was greater than mouse/human or frog/human similarity. However, based on protein sequence, mouse/human similarity was greater than bovine/human similarity. Among the genes over-expressed in oocytes relative to somatic tissue in Xenopus, Mus and Bos, a high level of conservation was found relative to humans, especially for genes involved in early embryonic development. PMID:23340479

Sylvestre, Eve-Lyne; Robert, Claude; Pennetier, Sophie; Labrecque, Rémi; Gilbert, Isabelle; Dufort, Isabelle; Léveillé, Marie-Claude; Sirard, Marc-André

2013-06-01

308

A comparative analysis of metabolism and viability in porcine oocytes during in vitro maturation  

Microsoft Academic Search

The importance of oocyte quality cannot be overstated, because it impacts all subsequent events during development of the embryo, the fetus and even the resulting offspring. Oocyte metabolism plays a critical role in supporting developmental competence via multiple mechanisms. It is beginning to be understood that metabolic pathways not only affect cytoplasmic maturation but may control nuclear maturation as well.

R. L. Krisher; A. M. Brad; J. R. Herrick; M. L. Sparman; J. E. Swain

2007-01-01

309

Expression of Cardiac Na Channels with Appropriate Physiological and Pharmacological Properties in Xenopus Oocytes  

Microsoft Academic Search

The objective of this study was to determine whether the Xenopus laevis oocyte can express an exogenous cardiac Na channel that retains its normal physiological and pharmacological properties. Cardiac Na channels were expressed in oocytes following injection of RNA from guinea pig, rat, and human heart and detailed analysis was performed for guinea pig cardiac Na channels. Average current amplitudes

D. S. Krafte; W. A. Volberg; K. Dillon; A. M. Ezrin

1991-01-01

310

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

311

Osmolarity- and stage-dependent effects of glycine on parthenogenetic development of pig oocytes.  

PubMed

The osmolarities of media that are most effective for in vitro culture of mammalian oocytes and embryos are lower than that of oviductal fluid. Oocytes and embryos can survive the high physiological osmolarity in vivo perhaps owing to the presence of amino acids such as glycine, which serve as organic osmolytes in the female reproductive tract. In the present study, the effects of glycine on the parthenogenetic development of pig oocytes were examined in hypotonic or isotonic media. The results showed that culturing oocytes in isotonic media improved the cleavage rates (P<0.01) at 2 days in culture but inhibited any further development beyond cleavage when compared with the hypotonic media. However, addition of 4 mM glycine to the isotonic media resulted in improved blastocyst formation rates compared with that observed in the hypotonic media (P<0.01), and there was no inhibition of development beyond the cleavage stages in oocytes. The beneficial effects of glycine were observed only when oocytes were cultured in isotonic media and glycine was added at day 2 or 3 in culture. The results from the present study indicate that an isotonic medium with glycine is useful for in vitro culture of pig oocytes and that glycine may protect pig oocytes against the detrimental effects of increased osmolarity. PMID:24990770

Miyoshi, Kazuchika; Mizobe, Yamato

2014-10-23

312

Treatments resulting in pregnancy in nonovulating, hormone-treated oocyte recipient mares  

Microsoft Academic Search

Synchronization of follicle growth between oocyte donor and recipient mares is difficult. To avoid this, recipient mares in a clinical program were used during a period of low follicular activity, and were treated with estrogen before transfer and progesterone after transfer. Five pregnancies were established after oocyte transfer to nonovulating, hormone-treated recipient mares. One pregnancy was lost before 30 d

K. Hinrichs; P. J. Provost; E. M. Torello

2000-01-01

313

Full-term development of mice from enucleated oocytes injected with cumulus cell nuclei  

Microsoft Academic Search

Until recently, fertilization was the only way to produce viable mammalian offspring, a process implicitly involving male and female gametes. However, techniques involving fusion of embryonic or fetal somatic cells with enucleated oocytes have become steadily more successful in generating cloned young. Dolly the sheep was produced by electrofusion of sheep mammary-derived cells with enucleated sheep oocytes. Here we investigate

T. Wakayama; A. C. F. Perry; M. Zuccotti; K. R. Johnson; R. Yanagimachi

1998-01-01

314

Fertility preservation for breast-cancer patients using IVM followed by oocyte or embryo vitrification  

Microsoft Academic Search

Unstimulated in-vitro maturation (IVM) cycles are considered for fertility preservation in breast cancer due to avoidance of ovarian stimulation and shortened time to oocyte retrieval. This study evaluated the efficacy of this approach in a retrospective cohort analysis of 66 patients with breast cancer. Immature oocytes were collected and matured in vitro and then either vitrified or fertilized and preserved

Einat Shalom-Paz; Benny Almog; Fady Shehata; Jack Huang; Hananel Holzer; Ri-Cheng Chian; Weon-Young Son; Seang Lin Tan

2010-01-01

315

The effects of Isopropyl-N-Phenylcarbomate on meiotic maturation of mammalian oocytes  

E-print Network

and rabbit oocytes. This drug, which has antimitotic properties on cells lacking centrioles (plants, algae been demonstrated on different algae (Coss and Pickett-Heaps, 1974) and unicellular organisms (Mergulis of the first polar body and arrest at metaphase II if the oocyte is not fertilized or activated (Donahue, 1968

Paris-Sud XI, Université de

316

Hierarchical molecular events driven by oocyte-specific factors lead to rapid and extensive reprogramming.  

PubMed

Nuclear transfer to oocytes is an efficient way to transcriptionally reprogram somatic nuclei, but its mechanisms remain unclear. Here, we identify a sequence of molecular events that leads to rapid transcriptional reprogramming of somatic nuclei after transplantation to Xenopus oocytes. RNA-seq analyses reveal that reprogramming by oocytes results in a selective switch in transcription toward an oocyte rather than pluripotent type, without requiring new protein synthesis. Time-course analyses at the single-nucleus level show that transcriptional reprogramming is induced in most transplanted nuclei in a highly hierarchical manner. We demonstrate that an extensive exchange of somatic- for oocyte-specific factors mediates reprogramming and leads to robust oocyte RNA polymerase II binding and phosphorylation on transplanted chromatin. Moreover, genome-wide binding of oocyte-specific linker histone B4 supports its role in transcriptional reprogramming. Thus, our study reveals the rapid, abundant, and stepwise loading of oocyte-specific factors onto somatic chromatin as important determinants for successful reprogramming. PMID:25066233

Jullien, Jerome; Miyamoto, Kei; Pasque, Vincent; Allen, George E; Bradshaw, Charles R; Garrett, Nigel J; Halley-Stott, Richard P; Kimura, Hiroshi; Ohsumi, Keita; Gurdon, John B

2014-08-21

317

Hierarchical Molecular Events Driven by Oocyte-Specific Factors Lead to Rapid and Extensive Reprogramming  

PubMed Central

Summary Nuclear transfer to oocytes is an efficient way to transcriptionally reprogram somatic nuclei, but its mechanisms remain unclear. Here, we identify a sequence of molecular events that leads to rapid transcriptional reprogramming of somatic nuclei after transplantation to Xenopus oocytes. RNA-seq analyses reveal that reprogramming by oocytes results in a selective switch in transcription toward an oocyte rather than pluripotent type, without requiring new protein synthesis. Time-course analyses at the single-nucleus level show that transcriptional reprogramming is induced in most transplanted nuclei in a highly hierarchical manner. We demonstrate that an extensive exchange of somatic- for oocyte-specific factors mediates reprogramming and leads to robust oocyte RNA polymerase II binding and phosphorylation on transplanted chromatin. Moreover, genome-wide binding of oocyte-specific linker histone B4 supports its role in transcriptional reprogramming. Thus, our study reveals the rapid, abundant, and stepwise loading of oocyte-specific factors onto somatic chromatin as important determinants for successful reprogramming. PMID:25066233

Jullien, Jerome; Miyamoto, Kei; Pasque, Vincent; Allen, George E.; Bradshaw, Charles R.; Garrett, Nigel J.; Halley-Stott, Richard P.; Kimura, Hiroshi; Ohsumi, Keita; Gurdon, John B.

2014-01-01

318

Prolactin affects bovine oocytes through direct and cumulus-mediated pathways.  

PubMed

The available evidence points to participation of PRL in regulation of mammalian oocyte maturation. The aim of the present study was to characterize pathways of PRL action on bovine oocytes. We analyzed (1) the presence of the PRL receptor and its mRNA isoforms in oocytes and cumulus cells; (2) the effect of PRL on meiosis resumption and the role of cumulus cells, the NO/NO synthase system, protein kinase C, and tyrosine kinases in this effect; and (3) PRL effects in the presence of gonadotropins on the developmental capacity of cumulus-free and cumulus-enclosed oocytes. The transcript and protein expression of the PRL receptor in the cells were detected by reverse transcription polymerase chain reaction and immunocytochemistry, respectively. The nuclear status of oocytes was assessed after culture of cumulus-oocyte complexes (COCs) and denuded oocytes (DOs) with or without PRL (5-500 ng/mL) for 7, 14, or 24 hours. Besides, DOs were incubated for 7 hours in the absence or the presence of PRL (50 ng/mL) and/or L-NAME (an inhibitor of NO synthase), genistein (an inhibitor of tyrosine kinases), or calpostin C (a protein kinase C inhibitor). After IVM in 2 different systems containing PRL (50 ng/mL) and/or gonadotropic hormones, a part of oocytes underwent IVF and IVC and the embryo development was tracked until the blastocyst stage. Messenger RNA of long and short isoforms of the PRL receptor was revealed in both oocytes and cumulus cells. Immunocytochemistry confirmed the presence of the PRL receptor in oocytes and the cumulus investment. In the absence of gonadotropins (system 1), PRL retarded meiosis resumption in DOs but not in cumulus-enclosed oocytes, with this effect being short term, dose dependent, suppressed by L-NAME and genistein, and unaffected by calpostin. In systems containing gonadotropins, PRL did not affect nuclear maturation and the cleavage rate of cumulus-free and cumulus-enclosed oocytes. However, in the case of COCs, it raised the blastocyst yield both in system 2 (from 20.5%-40.9%, P < 0.01) and in system 3 (from 21.7%-33.9%, P < 0.05). The findings show for the first time the functioning of the direct pathway of PRL signaling into bovine oocytes, as confirmed by the expression of receptors of PRL and its direct meiosis-retarding effect involving activation of tyrosine kinases and NO synthase. Furthermore, this is the first demonstration that the beneficial effect of PRL on the oocyte developmental capacity is achieved via cumulus cells containing PRL receptors. PMID:25212395

Lebedeva, Irina Y; Singina, Galina N; Volkova, Natalia A; Vejlsted, Morten; Zinovieva, Natalia A; Schmidt, Mette

2014-11-01

319

Effect of different cryopreservation protocols on cytoskeleton and gap junction mediated communication integrity in feline germinal vesicle stage oocytes  

Microsoft Academic Search

Oocyte cryopreservation in carnivores can significantly improve assisted reproductive technologies in animal breeding and preservation programs for endangered species. However, the cooling process severely affects the integrity and the survival of the oocyte after thawing and may irreversibly compromise its subsequent developmental capability.In the present study, two different methods of oocyte cryopreservation, slow freezing and vitrification, were evaluated in order

Alberto M. Luciano; Sara Chigioni; Valentina Lodde; Federica Franciosi; Gaia C. Luvoni; Silvia C. Modina

2009-01-01

320

Prepubertal goat oocytes from large follicles result in similar blastocyst production and embryo ploidy than those from adult goats  

Microsoft Academic Search

Developmental competence of oocytes from prepubertal females is lower than those from adult females. Oocyte development competence is positively related to follicular diameter. Most of the follicles of prepubertal goat ovaries are smaller than 3 mm. The aim of this study was to compare oocytes of two follicle sizes (< 3 mm and ? 3 mm) from prepubertal goats with

R. Romaguera; X. Moll; R. Morató; M. Roura; M. J. Palomo; M. G. Catalá; A. R. Jiménez-Macedo; S. Hammami; D. Izquierdo; T. Mogas; M. T. Paramio

2011-01-01

321

Reorganization of the Endoplasmic Reticulum and Development of Ca2+ Release Mechanisms During Meiotic Maturation of Human Oocytes1  

PubMed Central

Oocyte maturation in rodents is characterized by a dramatic reorganization of the endoplasmic reticulum (ER) and an increase in the ability of an oocyte to release Ca2+ in response to fertilization or inositol 1,4,5-trisphosphate (IP3). We examined if human oocytes undergo similar changes during cytoplasmic meiotic maturation both in vivo and in vitro. Immature, germinal vesicle (GV)-stage oocytes had a fine network of ER throughout the cortex and interior, whereas the ER in the in vivo-matured, metaphase II oocytes was organized in large (diameter, ?2–3 ?m) accumulations throughout the cortex and interior. Likewise, oocytes matured in vitro exhibited cortical and interior clusters with no apparent polarity in regard to the meiotic spindle. In vivo-matured oocytes contained approximately 1.5-fold the amount of IP3 receptor protein and released significantly more Ca2+ in response to IP3 compared with GV-stage oocytes; however, oocytes matured in vitro did not contain more IP3 receptor protein or release more Ca2+ in response to IP3 compared with GV-stage oocytes. These results show that at least one cytoplasmic change occurs during in vitro maturation of human oocytes that might be important for fertilization and subsequent embryonic development, but they suggest that a low developmental competence of in vitro-matured oocytes could be the result of deficiencies in the ability to release Ca2+ at fertilization. PMID:20610804

Mann, Jessica S.; Lowther, Katie M.; Mehlmann, Lisa M.

2010-01-01

322

Improvement of a porcine somatic cell nuclear transfer technique by optimizing donor cell and recipient oocyte preparations  

Microsoft Academic Search

This study was conducted to improve a porcine somatic cell nuclear transfer (SCNT) technique by optimizing donor cell and recipient oocyte preparations. Adult and fetal fibroblasts, and cumulus and oviduct cells were used as donor cells, and in vivo- and in vitro-matured oocytes were employed as recipient oocytes. The percentages of fusion and development to the blastocyst stage, the ratio

Gab-sang Lee; Sang-hwan Hyun; Hye-soo Kim; Dae-young Kim; So-hyun Lee; Jeong-mook Lim; Eun-song Lee; Sung-keun Kang; Byeong-chun Lee; Woo-suk Hwang

2003-01-01

323

The circadian system of the Turkish hamster, Mesocricetus brandti: responses to light.  

PubMed

The circadian system of the Turkish hamster controlling wheel-running activity responded to single 1-hr light pulses and to repeated 1-hr pulses in a similar way as that of Syrian hamsters studied previously. At constant light of 100 lx, the period length (tau) of the freerunning activity rhythm of Turkish hamsters was longer and the activity time (alpha) was shorter than that of Syrian hamsters. Among individuals, the ability of the system to be entrained by one 1-hr light pulse per cycle was related to the range (advance plus delay amplitude) of the phase response curve (PRC) derived from single light pulses and to the compression of alpha caused by the pulse Zeitgeber. The data support the hypothesis derived from experiments on Syrian hamsters that the range of the PRC is functionally related with alpha, possibly reflecting the phase relations (coupling) between two oscillators. PMID:2863051

Pohl, H

1985-01-01

324

Centrosome dynamics during mammalian oocyte maturation with a focus on meiotic spindle formation.  

PubMed

Oocyte maturation is an important process required to achieve optimal oocyte quality, and later affects fertilization potential and subsequent embryo development. The maturation process includes synchronized nuclear and cytoplasmic remodeling, in which cytoskeletal and centrosome dynamics play an important role and significantly participate in cellular signaling. Centrosome remodeling within the maturing oocyte is essential for accurate meioisis I and II spindle formation, specifically to separate chromosomes accurately during the two successive, highly asymmetric meiotic cell divisions. Centrosomal abnormalities result in inaccurate microtubule organization and inaccurate chromosome alignment, with failures in chromosome segregation leading to aneuploidy and chromosomal abnormalities. The present review is focused on cytoskeletal and centrosome remodeling during oocyte maturation, with specific attention to ?-tubulin, pericentrin, the Nuclear Mitotic Apparatus (NuMA) protein, and microtubule organization. Species-specific differences will be discussed for rodent (mouse) and non-rodent (bovine, porcine) species, and for human oocytes. PMID:21887720

Schatten, Heide; Sun, Qing-Yuan

2011-01-01

325

[Role of hydration in ovulation of common frog oocytes in vitro].  

PubMed

Stimulation of ovulation of the common frog Rana temporaria oocytes with homologous pituitary extract caused an increase in their volume. Factors that are known to inhibit hydration in teleostean oocytes (potassium-free Ringer solution and inhibitor of Na+, K(+)-ATPase--ouabain), as well as use of aquaporin inhibitors (mercuric chloride and methylmethanethiosulphonate) inhibited also homologous pituitary extract-induced volume increase in follicle-enclosed oocytes and let to reduced percentage of ovulated oocytes. Volume of denuded oocytes remained unchanged in the course of maturation when exposed to progesterone or other treatments. The data obtained suggest that stimulation ofoocyte ovulation in the common frog caused an increase in their hydration that in necessary for their ovulation but this did not occur in denuded cells. PMID:24450177

Skoblina, M N

2013-01-01

326

Follicular fluid steroid levels in relation to oocyte maturity and in vitro fertilization.  

PubMed

Steroid levels in follicular fluid (FF) obtained from stimulated ovaries in patients undergoing in vitro fertilization (IVF) were measured by capillary gas chromatography. The correlation between these levels and the maturity of the oocyte, judged from the morphology of the oocyte corona cumulus complex (OCCC) and the fertilizability of the oocytes was analysed. Oocyte maturity was associated with higher FF levels of progesterone, 17-hydroxyprogesterone, 16 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone. Follicular fluids containing oocytes that became fertilized had significantly higher levels of 20 alpha-dihydroprogesterone and progesterone and lower levels of androstenedione. Of all the steroids determined, 20 alpha-dihydroprogesterone provides the most significant group differences. Enhanced 20 alpha-dihydrogenation in the presence of decreased 16 alpha- and 17-hydroxylation appears to be an important characteristic of the ultimate ripening stages and early luteinization, at least in stimulated cycles. PMID:1997126

Vanluchene, E; Hinting, A; Dhont, M; De Sutter, P; Van Maele, G; Vandekerckhove, D

1991-01-01

327

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

328

The effect of lysophosphatidic acid during in vitro maturation of bovine oocytes: embryonic development and mRNA abundances of genes involved in apoptosis and oocyte competence.  

PubMed

In the present study we examined whether LPA can be synthesized and act during in vitro maturation of bovine cumulus oocyte complexes (COCs). We found transcription of genes coding for enzymes of LPA synthesis pathway (ATX and PLA2) and of LPA receptors (LPAR 1-4) in bovine oocytes and cumulus cells, following in vitro maturation. COCs were matured in vitro in presence or absence of LPA (10(-5)?M) for 24?h. Supplementation of maturation medium with LPA increased mRNA abundance of FST and GDF9 in oocytes and decreased mRNA abundance of CTSs in cumulus cells. Additionally, oocytes stimulated with LPA had higher transcription levels of BCL2 and lower transcription levels of BAX resulting in the significantly lower BAX/BCL2 ratio. Blastocyst rates on day 7 were similar in the control and the LPA-stimulated COCs. Our study demonstrates for the first time that bovine COCs are a potential source and target of LPA action. We postulate that LPA exerts an autocrine and/or paracrine signaling, through several LPARs, between the oocyte and cumulus cells. LPA supplementation of maturation medium improves COC quality, and although this was not translated into an enhanced in vitro development until the blastocyst stage, improved oocyte competence may be relevant for subsequent in vivo survival. PMID:24729661

Boruszewska, Dorota; Torres, Ana Catarina; Kowalczyk-Zieba, Ilona; Diniz, Patricia; Batista, Mariana; Lopes-da-Costa, Luis; Woclawek-Potocka, Izabela

2014-01-01

329

Developmental potential of human oocytes matured in vitro followed by vitrification and activation  

PubMed Central

Background Oocyte in vitro maturation (IVM) and cryopreservation at the time of routine ovarian tissue freezing may be offered to cancer patients as an additional option for fertility preservation. This study aimed to investigate the developmental capacity of oocytes isolated from unstimulated ovaries. Methods Immature oocytes (n = 63) from seven consenting premenopausal patients were analysed. Oocytes were collected during routine laparoscopic examination with biopsy of an ovary (cystic adnexal mass, n = 3; cervical adenocarcinoma, n = 2) or oophorectomy (sex reassignment surgery, n = 2) without previous stimulation of the ovaries. The stage of the patient’s menstrual cycle was not considered. Oocytes in all visible antral follicles were aspirated from ovaries, cultured in IVM medium and vitrified at the MII stage before being kept in liquid nitrogen for at least one month. After warming, oocytes were subjected to parthenogenetic activation by chemical stimulus. Their further development was recorded at intervals of 24 hours for up to 6 days of culture. Results 61.9% of oocytes matured in vitro within 48 hours. The survival rate after vitrification and warming was 61.5%. A total of 75% of surviving oocytes were able to respond to artificial activation, 44.4% of the parthenotes developed to early embryonic stage. However, only 1 in 18 (5.6%) of the resulting embryos reached blastocyst stage. Conclusions Oocytes matured in vitro from unstimulated ovaries seem to have limited developmental potential after cryopreservation and artificial activation. Although the outcome of IVM for non-stimulated oocytes is poor, it is currently the only chance besides cryopreservation of ovarian tissue for women for whom ovarian stimulation is not possible due to life circumstances. Based on our preliminary results, we suggest that the use of cryopreserved ovaries for fertility preservation in women with cancer warrants further investigation. PMID:23597104

2013-01-01

330

Fatty acid synthesis and oxidation in cumulus cells support oocyte maturation in bovine.  

PubMed

Oocyte meiotic maturation requires energy from various substrates including glucose, amino acids, and lipids. Mitochondrial fatty acid (FA) ?-oxidation (FAO) in the oocyte is required for meiotic maturation, which is accompanied by differential expression of numerous genes involved in FAs metabolism in surrounding cumulus cells (CCs) in vivo. The objective was to elucidate components involved in FAs metabolism in CCs during oocyte maturation. Twenty-seven genes related to lipogenesis, lipolysis, FA transport, and FAO were chosen from comparative transcriptome analysis of bovine CCs before and after maturation in vivo. Using real-time PCR, 22 were significantly upregulated at different times of in vitro maturation (IVM) in relation to oocyte meiosis progression from germinal vesicle breakdown to metaphase-II. Proteins FA synthase, acetyl-coenzyme-A carboxylase, carnitine palmitoyltransferase, perilipin 2, and FA binding protein 3 were detected by Western blot and immunolocalized to CCs and oocyte cytoplasm, with FA binding protein 3 concentrated around oocyte chromatin. By mass spectrometry, CCs lipid profiling was shown to be different before and after IVM. FAO inhibitors etomoxir and mildronate dose-dependently decreased the oocyte maturation rate in vitro. In terms of viability, cumulus enclosed oocytes were more sensitive to etomoxir than denuded oocytes. In CCs, etomoxir (150 ?M) led to downregulation of lipogenesis genes and upregulated lipolysis and FAO genes. Moreover, the number of lipid droplets decreased, whereas several lipid species were more abundant compared with nontreated CCs after IVM. In conclusion, FAs metabolism in CCs is important to maintain metabolic homeostasis and may influence meiosis progression and survival of enclosed oocytes. PMID:25058602

Sanchez-Lazo, Laura; Brisard, Daphné; Elis, Sébastien; Maillard, Virginie; Uzbekov, Rustem; Labas, Valérie; Desmarchais, Alice; Papillier, Pascal; Monget, Philippe; Uzbekova, Svetlana

2014-09-01

331

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

332

Transvaginal sonographically controlled follicle puncture for oocyte retrieval.  

PubMed

Transvaginal sonographically guided follicle aspiration under local anesthesia was performed on more than 100 patients and compared favorably with the other techniques that have been proposed to retrieve oocytes for in vitro fertilization. Sonography employs a sector scanner placed on the abdomen, and the needle is introduced through the posterior fornix of the vagina into the cul-de-sac and the ovary. In case of a high ovary, a transvaginal-transvesical variation may be used. The method is not painful and is easy to learn and perform. The sole adverse incidents have involved inadvertent venous puncture with no sequelae. The number and quality of recovered oocytes are good, and five normal children conceived after this method of retrieval were recently born. The technique permits substantial simplification of egg recovery for in vitro fertilization, which can now be performed in an outpatient setting without the risk and expense of laparoscopy and general anesthesia or the discomfort of transabdominal-transvesical ultrasound-guided aspiration. PMID:3932103

Dellenbach, P; Nisand, I; Moreau, L; Feger, B; Plumere, C; Gerlinger, P

1985-11-01

333

Cytokines in ovarian folliculogenesis, oocyte maturation and luteinisation.  

PubMed

Cytokines are key regulators of ovarian physiology, particularly in relation to folliculogenesis and ovulation, where they contribute to creating an environment supporting follicle selection and growth. Their manifold functions include regulating cellular proliferation/differentiation, follicular survival/atresia, and oocyte maturation. Several cytokines, such as TGF-?-superfamily members, are involved at all stages of folliculogenesis while the production of others is stage-dependent. This review draws upon evidence from both human and animal models to highlight the species-specific roles at each milestone of follicular development. Given these pivotal roles and their ease of detection in follicular fluid, cytokines have been considered as attractive biomarkers of oocyte maturational status and of successful assisted reproductive outcome. Despite this, our understanding of cytokines and their interactions remains incomplete, and is still frequently limited to overly simplistic descriptions of their interrelationships. Given our increased appreciation of cytokine activity in complex and highly regulated networks, we put forward the case for using Bayesian modelling approaches to describe their hierarchical relationships in order to predict causal physiological interactions in vivo. PMID:24273059

Field, Sarah L; Dasgupta, Tathagata; Cummings, Michele; Orsi, Nicolas M

2014-04-01

334

Management of penetrating brain injury  

PubMed Central

Penetrating brain injury (PBI), though less prevalent than closed head trauma, carries a worse prognosis. The publication of Guidelines for the Management of Penetrating Brain Injury in 2001, attempted to standardize the management of PBI. This paper provides a precise and updated account of the medical and surgical management of these unique injuries which still present a significant challenge to practicing neurosurgeons worldwide. The management algorithms presented in this document are based on Guidelines for the Management of Penetrating Brain Injury and the recommendations are from literature published after 2001. Optimum management of PBI requires adequate comprehension of mechanism and pathophysiology of injury. Based on current evidence, we recommend computed tomography scanning as the neuroradiologic modality of choice for PBI patients. Cerebral angiography is recommended in patients with PBI, where there is a high suspicion of vascular injury. It is still debatable whether craniectomy or craniotomy is the best approach in PBI patients. The recent trend is toward a less aggressive debridement of deep-seated bone and missile fragments and a more aggressive antibiotic prophylaxis in an effort to improve outcomes. Cerebrospinal fluid (CSF) leaks are common in PBI patients and surgical correction is recommended for those which do not close spontaneously or are refractory to CSF diversion through a ventricular or lumbar drain. The risk of post-traumatic epilepsy after PBI is high, and therefore, the use of prophylactic anticonvulsants is recommended. Advanced age, suicide attempts, associated coagulopathy, Glasgow coma scale score of 3 with bilaterally fixed and dilated pupils, and high initial intracranial pressure have been correlated with worse outcomes in PBI patients. PMID:21887033

Kazim, Syed Faraz; Shamim, Muhammad Shahzad; Tahir, Muhammad Zubair; Enam, Syed Ather; Waheed, Shahan

2011-01-01

335

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

336

Taenia solium Oncosphere Adhesion to Intestinal Epithelial and Chinese Hamster Ovary Cells In Vitro?  

PubMed Central

The specific mechanisms underlying Taenia solium oncosphere adherence and penetration in the host have not been studied previously. We developed an in vitro adhesion model assay to evaluate the mechanisms of T. solium oncosphere adherence to the host cells. The following substrates were used: porcine intestinal mucosal scrapings (PIMS), porcine small intestinal mucosal explants (PSIME), Chinese hamster ovary cells (CHO cells), epithelial cells from ileocecal colorectal adenocarcinoma (HCT-8 cells), and epithelial cells from colorectal adenocarcinoma (Caco-2 cells). CHO cells were used to compare oncosphere adherence to fixed and viable cells, to determine the optimum time of oncosphere incubation, to determine the role of sera and monolayer cell maturation, and to determine the effect of temperature on oncosphere adherence. Light microscopy, scanning microscopy, and transmission microscopy were used to observe morphological characteristics of adhered oncospheres. This study showed in vitro adherence of activated T. solium oncospheres to PIMS, PSIME, monolayer CHO cells, Caco-2 cells, and HCT-8 cells. The reproducibility of T. solium oncosphere adherence was most easily measured with CHO cells. Adherence was enhanced by serum-binding medium with >5% fetal bovine serum, which resulted in a significantly greater number of oncospheres adhering than the number adhering when serum at a concentration less than 2.5% was used (P < 0.05). Oncosphere adherence decreased with incubation of cells at 4°C compared with the adherence at 37°C. Our studies also demonstrated that T. solium oncospheres attach to cells with elongated microvillus processes and that the oncospheres expel external secretory vesicles that have the same oncosphere processes. PMID:17698575

Verastegui, Manuela; Gilman, Robert H.; Arana, Yanina; Barber, Dylan; Velasquez, Jeanette; Farfan, Marilu; Chile, Nancy; Kosek, Jon C.; Kosek, Margaret; Garcia, Hector H.; Gonzalez, Armando

2007-01-01

337

Efficacy of 9-?-d-Arabinofuranosylhypoxanthine 5?-Monophosphate in Therapy of Equine Abortion Virus-Induced Hepatitis in Hamsters1  

PubMed Central

Equine abortion virus (EAV)-induced hepatitis in hamsters presents an interesting animal model for the evaluation of drugs possessing anti-deoxyribonucleic acid virus activity. These experiments demonstrate that 9-?-d-arabinofuranosylhypoxanthine 5?-monophosphate (ara-HxMP), a new synthetic, water-soluble, antiviral agent, effectively controls this disease in hamsters with a therapeutic index of ?60. Ara-HxMP prevented hepatitis-associated deaths in hamsters, reduced the titer of EAV developing in hamsters, and inhibited the increase of serum glutamic pyruvic transaminase in EAV-infected hamsters. PMID:172009

Allen, Lois B.; Huffman, John H.; Revankar, Ganapathi R.; Tolman, Robert L.; Simon, Lionel N.; Robins, Roland K.; Sidwell, Robert W.

1975-01-01

338

Schedule to inject in vitro matured oocytes may increase pregnancy after intracytoplasmic sperm injection.  

PubMed

To ascertain the value of using immature oocytes in an intracytoplasmic sperm injection (ICSI) program, the authors designed a schedule, at 5 p.m. on day 1 (the day of oocyte retrieval) and at 8 a.m. and 2 p.m. on day 2, to recognize and inject the in vitro matured (IVM) oocytes. For the 1,166 oocytes retrieved in 107 ICSI cycles, 128 (11.0%) were at the stage of metaphase I (MI) and 113 (9.7%) at germinal vesicle. Routine ICSI for metaphase 11 oocytes was performed at 2 p.m. on day 1 (initial ICSI). In culture medium of human tubal fluid with 15% maternal serum, 85.1% (205/241) immature oocytes progressed to maturation in which 16.4% (21/128) of MI oocytes matured at 5 p.m. of day 1. The rate of normal fertilization for IVM oocytes (58.5%) was not significantly different from that of initial ICSI (64.0%). One patient received a transfer of two fertilized IVM oocytes alone that were injected at 5 p.m. of day 1, maturing from the MI stage, and achieved a normal pregnancy. The fertilized IVM oocytes were replaced along with the embryos from initial ICSI for 40 cycles that led to 14 (35%) clinical pregnancies. In 43 fertilized IVM oocytes donated for research, we observed that cleavage (95.3%) to the 2- to 4-cell stage was not distinct from that of initial ICSI (94.6%); however, the percentage of embryos of grade I and II morphology was significantly smaller (24.4% vs. 62.5%). Only five (11.6%) developed to blastocysts in vitro. Twenty-one fertilized IVM oocytes were frozen for future transfer. A schedule to inject IVM oocytes in ICSI cycles may generate more accessible embryos for fresh transfer or cryopreservation to increase the chance of pregnancy, although the embryo quality was relatively poor. PMID:10864367

Chen, S U; Chen, H F; Lien, Y R; Ho, H N; Chang, H C; Yang, Y S

2000-01-01

339

Delaying the oocyte maturation trigger by one day leads to a higher metaphase II oocyte yield in IVF/ICSI: a randomised controlled trial  

PubMed Central

Background The negative impact of rising progesterone levels on pregnancy rates is well known, but data on mature oocyte yield are conflicting. We examined whether delaying the oocyte maturation trigger in IVF/ICSI affected the number of mature oocytes and investigated the potential influence of serum progesterone levels in this process. Methods Between January 31, 2011, and December 31, 2011, 262 consecutive patients were monitored using ultrasound plus hormonal evaluation. Those with?>?=3 follicles with a mean diameter of?>?=18 mm were divided into 2 groups depending on their serum progesterone levels. In cases with a progesterone level?oocyte maturation was triggered the same day; for the other, maturation was triggered 24 hours later. Seventy-two patients with progesterone levels?>?1 ng/ml were randomised in the same manner, irrespective of the percentage of larger follicles (>?=?18 mm). The number of metaphase II oocytes was our primary outcome variable. Because some patients were included more than once, correction for duplicate patients was performed. Results In the study arm with low progesterone (<= 1 ng/ml), the mean number of metaphase II oocytes (+/-SD) was 10.29 (+/-6.35) in the group with delayed administration of the oocyte maturation trigger versus 7.64 (+/-3.26) in the control group. After adjusting for age, the mean difference was 2.41 (95% CI: 0.22-4.61; p?=?0.031). In the study arm with elevated progesterone (>1 ng/ml), the mean numbers of metaphase II oocytes (+/-SD) were 11.81 (+/-9.91) and 12.03 (+/-7.09) for the delayed and control groups, respectively. After adjusting for PCOS (polycystic ovary syndrome) and female pathology, the mean difference was -0.44 (95% CI: -3.65-2.78; p?=?0.79). Conclusions Delaying oocyte maturation in patients with low progesterone levels yields greater numbers of mature oocytes. Trial registration B67020108975 (Belgian registration) and NCT01980563 (ClinicalTrials.gov). PMID:24758641

2014-01-01

340

Acid-induced secretory cell metaplasia in hamster bronchi  

SciTech Connect

Hamsters were exposed to an intratracheal instillation of 0.5 ml of 0.08 N nitric, hydrochloric, or sulfuric acid to determine their airway epithelial response. Three weeks after exposure, the left intrapulmonary bronchi in Alcian blue/PAS-strained paraffin sections were evaluated for the amount of secretory product in the airway epithelium as a measure of secretory cell metaplasia (SCM). Compared to saline-treated control animals, all three acids caused statistically significant SCM. In addition to the bronchial lesion, all three acids caused similar interstitial fibrosis, bronchiolectasis, and bronchiolization of alveoli that varied in individual animals from mild to severe. In a separate experiment to study the persistence of the SCM, hamsters treated with a single instillation of 0.1 N nitric acid showed significant SCM 3, 7, and 17 weeks after exposure. There was a high correlation (r = 0.96) between a subjective assessment of SCM and objective assessment using a digital image-analysis system. We conclude that protons induce SCM independently of the associated anion; the SCM persists at least 17 weeks. Sulfuric acid is an atmospheric pollutant and nitric acid may form locally on the mucosa of lungs exposed to nitrogen dioxide. These acids may contribute to the development of maintenance of the SCM seen in the conducting airways of humans with chronic obstructive pulmonary disease.

Christensen, T.G.; Lucey, E.C.; Breuer, R.; Snider, G.L.

1988-02-01

341

Dose response of elastase-induced emphysema in hamsters.  

PubMed

Elastase-induced emphysema in hamsters was studied using pulmonary function tests in an effort to develop techniques for determining the effects of air pollutants on the progression of this disease. Single intratracheal injections of 6, 12, or 24 units of porcine pancreatic elastase produced dose-related changes in pulmonary function after 4 wk when compared with sham-injected control animals. Boyle's law end-expiratory volume and residual volume, measured by gas dilution, increased (p less than 0.05) at 12 and 24 units, respectively, whereas vital capacity, determined plethysmographically, and total lung capacity wee increased (p less than 0.05) at all 3 elastase doses. Respiratory system compliance, calculated by a nonlinear least squares regression fit of the deflation pressure-volume curve, increased (p less than 0.05) at 24 units only. The multiple-breath nitrogen washout slope (N2 slope) and the single-breath diffusing capacity for carbon monoxide (DLCO) decreased (p less than 0.05) at all 3 doses of elastase. Both histologic and physiologic evaluation showed dose-related pulmonary impairment. It appears, therefore, that as little as 6 units of elastase produces mild emphysema in hamsters, which is detectable by pulmonary function testing. Of these tests, the DLCO and N2 slope were the most effective in detecting the degree of impairment. PMID:6918202

Raub, J A; Mercer, R R; Miller, F J; Graham, J A; O'Neil, J J

1982-04-01

342

Sibling inhibition of hoarding in postweaning hamster pups (Mesocricetus auratus).  

PubMed

If hamster pups are placed in individual cages at weaning (21 days of age) they begin to hoard food immediately; within 2-6 days, they hoard 90% of the food they take from their food dish in the course of a 1-hr test, consuming only 10% of it. Pups that remain with their littermates after weaning in large group cages do not hoard food until they are placed in individual cages, when hoarding starts immediately. The inhibitory effect of littermates is just as pronounced in hamsters that have been allowed to hoard food in individual cages for 14 days after weaning and are then regrouped into litters. If litters are housed in divided cages that prevent physical interactions among littermates, but allow the interchange of olfactory, auditory, and some visual cues, hoarding is suppressed to an intermediate level. These results show that the presence of siblings inhibits the expression of hoarding, partly as a result of direct physical interactions and partly through the agency of sensory cues. The onset of hoarding following the dispersal of young from the nest cannot be explained as a motivational consequence of the young no longer having access to the mother's food hoard. PMID:3402669

Turpin, B; Johnston, T D; Fulk, K R

1988-07-01

343

Photoperiod can entrain circannual rhythms in pinealectomized European hamsters.  

PubMed

In mammals, the pineal hormone melatonin is thought to be essential to process environmental photoperiodic information. In this study, we demonstrate in a circannual species, the European hamster Cricetus cricetus, the existence of a melatonin-independent second pathway. In 4 physiological parameters (reproduction, body weight, activity pattern, body temperature), a large majority of pinealectomized European hamsters were entrained to an accelerated photoperiodic regime. It compressed the natural variations in the photoperiod to a 6-month cycle, which allowed us to record up to 6 complete physiological cycles during the life span of the individuals. We show further that whether a pinealectomized animal is able to entrain to changes in the photoperiod is influenced by the season of pinealectomy. The results do not disprove that melatonin is capable of entraining a circannual rhythm, but they show clearly that melatonin is not necessary, demonstrating another melatonin-independent pathway for circannual entrainment by the photoperiod. In view of these new insights, a revision of the original literature revealed that probably the melatonin-independent pathway plays an important role in most circannual mammals but only a minor role in photoperiodic species. Thus, the present work provides also the first evidence for different synchronization mechanisms in photoperiodic and circannual species. PMID:23929555

Monecke, Stefanie; Sage-Ciocca, Dominique; Wollnik, Franziska; Pévet, Paul

2013-08-01

344

Social forces can impact the circadian clocks of cohabiting hamsters.  

PubMed

A number of field and laboratory studies have shown that the social environment influences daily rhythms in numerous species. However, underlying mechanisms, including the circadian system's role, are not known. Obstacles to this research have been the inability to track and objectively analyse rhythms of individual animals housed together. Here, we employed temperature dataloggers to track individual body temperature rhythms of pairs of cohabiting male Syrian hamsters (Mesocricetus auratus) in constant darkness and applied a continuous wavelet transform to determine the phase of rhythm onset before, during, and after cohabitation. Cohabitation altered the predicted trajectory of rhythm onsets in 34% of individuals, representing 58% of pairs, compared to 12% of hamsters single-housed as 'virtual pair' controls. Deviation from the predicted trajectory was by a change in circadian period (?), which tended to be asymmetric-affecting one individual of the pair in nine of 11 affected pairs-with hints that dominance might play a role. These data implicate a change in the speed of the circadian clock as one mechanism whereby social factors can alter daily rhythms. Miniature dataloggers coupled with wavelet analyses should provide powerful tools for future studies investigating the principles and mechanisms mediating social influences on daily timing. PMID:24500164

Paul, Matthew J; Indic, Premananda; Schwartz, William J

2014-03-22

345

Differentiated cultures of primary hamster tracheal airway epithelial cells.  

PubMed

Primary airway epithelial cell cultures can provide a faithful representation of the in vivo airway while allowing for a controlled nutrient source and isolation from other tissues or immune cells. The methods used have significant differences based on tissue source, cell isolation, culture conditions, and assessment of culture purity. We modified and optimized a method for generating tracheal epithelial cultures from Syrian golden hamsters and characterized the cultures for cell composition and function. Soon after initial plating, the epithelial cells reached a high transepithelial resistance and formed tight junctions. The cells differentiated into a heterogeneous, multicellular culture containing ciliated, secretory, and basal cells after culture at an air-liquid interface (ALI). The secretory cell populations initially consisted of MUC5AC-positive goblet cells and MUC5AC/CCSP double-positive cells, but the makeup changed to predominantly Clara cell secretory protein (CCSP)-positive Clara cells after 14 d. The ciliated cell populations differentiated rapidly after ALI, as judged by the appearance of beta tubulin IV-positive cells. The cultures produced mucus, CCSP, and trypsin-like proteases and were capable of wound repair as judged by increased expression of matrilysin. Our method provides an efficient, high-yield protocol for producing differentiated hamster tracheal epithelial cells that can be used for a variety of in vitro studies including tracheal cell differentiation, airway disease mechanisms, and pathogen-host interactions. PMID:15780007

Rowe, Regina K; Brody, Steven L; Pekosz, Andrew

2004-01-01

346

Jet penetration of high explosive  

SciTech Connect

It is found that a transition between two flow patterns takes place in thick HE targets. In this case, the jet will initially propagate into the HE at the same rate as into an inert material of the same density. The part of the jet that has stagnated and is flowing nearly co-axially with the incoming jet (but at a much lower speed) is being forced toward the surface of the incoming jet by the pressure of the reaction products but has not as yet made contact. After it makes contact, both axial and perpendicular momentum transfer takes place between the two jet components. After this transition, a new steady state will develop for the propagating jet, with the unperturbed front of the jet propagating at a slower rate than previously. The perturbed front of the jet is still propagating at or near the original rate, having had relatively little axial momentum exchange. However, it has acquired radial momentum and is spreading out as it is propagating; it is therefore becoming less capable of penetrating downstream targets. It is the unperturbed part of the jet that is capable of penetrating downstream targets. A calculational method for predicting this case is presented in this report.

Poulsen, P

1999-08-11

347

Effect of Demecolcine-Assisted Enucleation on the MPF Level and Cyclin B1 Distribution in Porcine Oocytes  

PubMed Central

Demecolcine (DEM) treatment of oocytes induces formation of a membrane protrusion containing a mass of condensed maternal chromosomes, which can be removed with minimal damage prior to somatic cell nuclear transfer (SCNT). However, the effect of this method on the distribution of maturation-promoting factor (MPF) in porcine oocytes has not been reported. Here, the level of MPF and the distribution of cyclin B1 were assessed in porcine oocytes following DEM treatment. In addition, the efficiencies of DEM-assisted and mechanical enucleation were compared, as were the development (in vitro and in vivo) of these oocytes following SCNT. MPF was uniformly distributed in oocytes that had been treated with 0.4 ?g/ml DEM for 1 h. Immunofluorescence microscopy showed that in untreated oocytes, cyclin B1, the regulatory subunit of MPF, accumulated around the spindle, and was lowly detected in the cytoplasm. DEM treatment disrupted spindle microtubules, induced chromosome condensation, and reduced the level of cyclin B1 in the nuclear region. Cyclin B1 was uniformly distributed in DEM-treated oocytes and the level of MPF was increased. The potential of embryos generated from DEM-treated oocytes to develop in vivo was significantly greater than that of embryos generated from mechanically enucleated oocytes. This is the first study to report the effects of DEM-assisted enucleation of porcine oocytes on the distribution of cyclin B1. MPF in mature oocytes is important for the development of reconstructed embryos and for efficient SCNT. PMID:24626152

Jin, Jun-Xue; Hong, Yu; Zhu, Hai-Ying; Jin, Long; Gao, Qing-Shan; Yan, Chang-Guo; Cui, Cheng-Du; Li, Wen-Xue; Yin, Xi-Jun

2014-01-01

348

Recombinant human growth differentiation factor-9 improves oocyte reprogramming competence and subsequent development of bovine cloned embryos.  

PubMed

Previously, we found that oocyte-secreted factors (OSFs) secreted by denuded oocytes during in vitro maturation (IVM) enhance subsequent development of bovine somatic cell nuclear transfer (SCNT) embryos. This treatment requires many oocytes during IVM. Hence, the aim of this study was to investigate whether supplementing with recombinant growth differentiation factor-9 (GDF9), one of crucial OFSs, in oocyte maturation medium could improve developmental competence of bovine oocytes and subsequent development of cloned embryos. Cumulus-oocyte complexes (COCs) from antral follicles of bovine ovaries collected from an abattoir were cultured with (SCNT+GDF9 group) or without (SCNT group) 200 ng/mL recombinant human GDF9 in oocyte maturation medium. After 22 h, metaphase II (MII) oocytes were used for SCNT. The presence of 200 ng/mL GDF9 significantly increased oocyte maturation rates, the cleavage rate, and blastocyst formation rates of bovine cloned embryos. The blastocyst total, inner cell mass (ICM) cell numbers, and ratio of ICM:TE were higher, whereas the rate of apoptosis in bovine cloned blastocysts was lower in the SCNT+GDF9 group than in the SCNT group. The histone modifications at various sites were also different between each group. These results suggest that COCs cultured with recombinant GDF9 in oocyte maturation medium improve oocyte developmental competence and subsequent developmental competence of cloned embryo in cattle. PMID:24840335

Su, Jianmin; Hu, Guangdong; Wang, Yongsheng; Liang, Dong; Gao, Mingqing; Sun, Hongzheng; Zhang, Yong

2014-08-01

349

Seasonal variations in developmental competence and relative abundance of gene transcripts in buffalo (Bubalus bubalis) oocytes.  

PubMed

Hot season is a major constraint to production and reproduction in buffaloes. The present work aimed to investigate the effect of season on ovarian function, developmental competence, and the relative abundance of gene expression in buffalo oocytes. Three experiments were conducted. In experiment 1, pairs of buffalo ovaries were collected during cold season (CS, autumn and winter) and hot season (HS, spring and summer), and the number of antral follicles was recorded. Cumulus oocyte complexes (COCs) were aspirated and evaluated according to their morphology into four Grades. In experiment 2, Grade A and B COCs collected during CS and HS were in vitro matured (IVM) for 24 hours under standard conditions at 38.5 °C in a humidified air of 5% CO2. After IVM, cumulus cells were removed and oocytes were fixed, stained with 1% aceto-orcein, and evaluated for nuclear configuration. In vitro matured buffalo oocytes harvested during CS or HS were in vitro fertilized (IVF) using frozen-thawed buffalo semen and cultured in vitro to the blastocyst stage. In experiment 3, buffalo COCs and in vitro matured oocytes were collected during CS and HS, and then snap frozen in liquid nitrogen for gene expression analysis. Total RNA was extracted from COCs and in vitro matured oocytes, and complementary DNA was synthesized; quantitative Reverse Transcription-Polymerase Chain Reaction was performed for eight candidate genes including GAPDH, ACTB, B2M, GDF9, BMP15, HSP70, and SOD2. The results indicated that HS significantly (P < 0.01) decreased the number of antral follicles and the number of COCs recovered per ovary. The number of Grade A, B, and C COCs was lower (P < 0.05) during HS than CS. In vitro maturation of buffalo oocytes during HS significantly (P < 0.01) reduced the number of oocytes reaching the metaphase II stage and increased the percentage of degenerated oocytes compared with CS. Oocytes collected during HS also showed signs of cytoplasmic degeneration. After IVF, cleavage rate was lower (P < 0.01) for oocytes collected during HS, and the percentage of oocytes arrested at the two-cell stage was higher (P < 0.01) than oocytes IVF during CS. Oocytes matured during CS showed a higher (P < 0.01) blastocyst rate than those matured during HS. Also, COCs recovered in HS showed significant (P < 0.05) upregulation of HSP70 mRNA expression compared with those recovered in CS. For in vitro matured oocytes, CS down regulated the transcript abundance of ACTB and upregulated GAPDH and HSP70 mRNA levels compared with HS condition. In conclusion, HS could impair buffalo fertility by reducing the number of antral follicles and oocyte quality. In vitro maturation of buffalo oocytes during HS impairs their nuclear and cytoplasmic maturation, fertilization, and subsequent embryo development to the morula and blastocyst stages. This could be in part because of the altered gene expression found in COCs and in vitro matured oocytes. PMID:25156970

Abdoon, Ahmed S; Gabler, Christoph; Holder, Christoph; Kandil, Omaima M; Einspanier, Ralf

2014-11-01

350

Mitochondrial Fission Factor Drp1 Maintains Oocyte Quality via Dynamic Rearrangement of Multiple Organelles.  

PubMed

Mitochondria are dynamic organelles that change their morphology by active fusion and fission in response to cellular signaling and differentiation [1, 2]. The in vivo role of mitochondrial fission in mammals has been examined by using tissue-specific knockout (KO) mice of the mitochondria fission-regulating GTPase Drp1 [3, 4], as well as analyzing a human patient harboring a point mutation in Drp1 [5], showing that Drp1 is essential for embryonic and neonatal development and neuronal function. During oocyte maturation and aging, structures of various membrane organelles including mitochondria and the endoplasmic reticulum (ER) are changed dynamically [6, 7], and their organelle aggregation is related to germ cell formation and epigenetic regulation [8-10]. However, the underlying molecular mechanisms of organelle dynamics during the development and aging of oocytes have not been well understood. Here, we analyzed oocyte-specific mitochondrial fission factor Drp1-deficient mice and found that mitochondrial fission is essential for follicular maturation and ovulation in an age-dependent manner. Mitochondria were highly aggregated with other organelles, such as the ER and secretory vesicles, in KO oocyte, which resulted in impaired Ca(2+) signaling, intercellular communication via secretion, and meiotic resumption. We further found that oocytes from aged mice displayed reduced Drp1-dependent mitochondrial fission and defective organelle morphogenesis, similar to Drp1 KO oocytes. On the basis of these findings, it appears that mitochondrial fission maintains the competency of oocytes via multiorganelle rearrangement. PMID:25264261

Udagawa, Osamu; Ishihara, Takaya; Maeda, Maki; Matsunaga, Yui; Tsukamoto, Satoshi; Kawano, Natsuko; Miyado, Kenji; Shitara, Hiroshi; Yokota, Sadaki; Nomura, Masatoshi; Mihara, Katsuyoshi; Mizushima, Noboru; Ishihara, Naotada

2014-10-20

351

Toxic effects of Hoechst staining and UV irradiation on preimplantation development of parthenogenetically activated mouse oocytes.  

PubMed

Parthenogenetic activation of oocytes is a helpful tool to obtain blastocysts, of which the inner cell mass may be used for derivation of embryonic stem cells. In order to improve activation and embryonic development after parthenogenesis, we tried to use sperm injection and subsequent removal of the sperm head to mimic the natural Ca2+ increases by release of the oocyte activating factor. Visualization of the sperm could be accomplished by Hoechst staining and ultraviolet (UV) light irradiation. To exclude negative effects of this treatment, we examined toxicity on activated mouse oocytes. After activation, oocytes were incubated in Hoechst 33342 or 33258 stain and exposed to UV irradiation. The effects on embryonic development were evaluated. Our results showed that both types of Hoechst combined with UV irradiation have toxic effects on parthenogenetically activated mouse oocytes. Although activation and cleavage rate were not affected, blastocyst formation was significantly reduced. Secondly, we used MitoTracker staining for removal of the sperm. Sperm heads were stained before injection and removed again after 1 h. However, staining was not visible anymore in all oocytes after intracytoplasmic sperm injection. In case the sperm could be removed, most oocytes died after 1 day. As MitoTracker was also not successful, alternative methods for sperm identification should be investigated. PMID:22784634

Versieren, Karen; Heindryckx, Björn; Qian, Chen; Gerris, Jan; De Sutter, Petra

2014-02-01

352

Localization of interchromatin granule cluster and Cajal body components in oocyte nuclear bodies of the hemipterans.  

PubMed

An oocyte nucleus contains different extrachromosomal nuclear domains collectively called nuclear bodies (NBs). In the present work we revealed, using immunogold labeling electron microscopy, some marker components of interchromatin granule clusters (IGCs) and Cajal bodies (CBs) in morphologically heterogeneous oocyte NBs studied in three hemipteran species: Notostira elongata, Capsodes gothicus (Miridae) and Velia caprai (Veliidae). Both IGC and CB counterparts were revealed in oocyte nuclei of the studied species but morphological and biochemical criteria were found to be not sufficient to determine carefully the define type of oocyte NBs. We found that the molecular markers of the CBs (coilin and non-phosphorylated RNA polymerase II) and IGCs (SC35 protein) may be localized in the same NB. Anti-SC35 antibody may decorate not only a granular material representing "true" interchromatin granules but also masks some fibrillar parts of complex NBs. Our first observations on the hemipteran oocyte NBs confirm the high complexity and heterogeneity of insect oocyte IGCs and CBs in comparison with those in mammalian somatic cells and amphibian oocytes. PMID:17889915

Bogolyubov, D S; Batalova, F M; Ogorza?ek, A

2007-10-01

353

Nicotinamide: a Class III HDACi Delays In Vitro Aging of Mouse Oocytes  

PubMed Central

Abstract Postovulatory mammalian oocyte developmental potential decreases with aging in vivo and in vitro. Aging oocytes typically show cellular fragmentation and chromosome scattering with an abnormally shaped spindle over time. Previously, it was shown that histone acetylation in the mouse oocyte increased during aging and that treatment with trichostatin A (TSA), an inhibitor for class I and II histone deacetylases (HDACs), enhanced the acetylation, that is, aging. In this study, we examined the effect of nicotinamide (NAM), an inhibitor for class III HDACs, on in vitro aging of mouse oocytes as well as TSA. We found that treatment with NAM significantly inhibited cellular fragmentation, spindle elongation and astral microtubules up to 48 h of culture. Although presence of TSA partially inhibited cellular fragmentation and spindle elongation up to 36 h of culture, treatment with TSA induced chromosome scattering at 24 h of culture and more severe cellular fragmentation at 48 h of culture. Further, we found that ?-tubulin, a nonhistone protein, increased acetylation during aging, suggesting that not only histone but nonhistone protein acetylation may also increase with oocyte aging. Thus, these data indicate that protein acetylation is abnormally regulated in aging oocytes, which are associated with a variety of aging phenotypes, and that class I/II and class III HDACs may play distinct roles in aging oocytes. PMID:23474603

LEE, Ah Reum; KISHIGAMI, Satoshi; AMANO, Tomoko; MATSUMOTO, Kazuya; WAKAYAMA, Teruhiko; HOSOI, Yoshihiko

2013-01-01

354

Lectin from embryos and oocytes of Xenopus laevis. Purification and properties.  

PubMed

Soluble extracts of Xenopus laevis blastula stage embryos, oocytes, and adult liver contain lectin activities detected by agglutination of trypsinized, glutaraldehyde-fixed rabbit erythrocytes. Lectin from the embryos and oocytes was purified by affinity chromatography on a column derivatized with melibiose. Trace contaminants were removed either by preparative isoelectric focusing or by gel filtration. Based on its behavior on Sepharose 6B the purified oocyte lectin has an apparent molecular weight of approximately 480,000. On sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing conditions there were two major bands with molecular weight ranges of about 43,000 and 45,000, with diffuse trails. Since the purified lectin contains about 20% saccharides by weight and since both bands are glycosylated, diffuseness might be due to variable glycosylation. Heterogeneity was indicated by isoelectric focusing in polyacrylamide gels, which showed four protein bands with isoelectric points ranging from 4.4 to 4.9. Lectins from both embryos and oocytes comprised about 1 to 2% of the total soluble protein and could not be distinguished by sodium dodecyl sulfate polyacrylamide gel electrophoresis. However, the specific hemagglutination activity of the purified oocyte lectin was, on the average, 7-fold higher. Levels in crude extracts of liver were 3 orders of magnitude lower than those from oocytes. The hemagglutination activities of the lectins from embryos, oocytes, and adult liver required Ca2+ and were blocked by similar concentrations of both alpha- and beta-galactosides. PMID:7085636

Roberson, M M; Barondes, S H

1982-07-10

355

The rate of blastocysts production following vitrification with step-wise equilibration of immature mouse oocytes  

PubMed Central

Background: Cryopreservation and in vitro maturation (IVM) of oocyte is becoming an important technique in infertility treatment and fertility preservation. Also it has been proposed to establish a genetic resource bank for endangered or commercially important animal species. Objective: The aim of this study was to evaluate viability, maturation and fertilization rate of mouse immature oocytes after single and stepwise vitrification procedure. Materials and Methods: Oocytes were obtained from 4 weeks old female mice 48h after intraperitoneal injection of 7.5 IU pregnant mare serum gonadotropin (PMSG). Collected oocytes before vitrification were exposed to cryoprotectant, which was composed of 30% (v/v) ethylene glycol, 18% (w/v) Ficoll-70, and 0.3 M sucrose, either by single step or in a step-wise way. After vitrification and storage in liquid nitrogen, the oocytes were warmed and washed two times in medium TCM199 and then subjected to IVM, fertilization and subsequent development to blastocysts. Results: The oocytes survival rates after vitrifying-warming (88.96%), maturation rate (73.23%), the capacity of fertilization (57.80%) and embryonic development to blastocyst (16.41%) in the step-wise exposure were significantly higher (p<0.001) compared with corresponding rate in the single step procedure. Conclusion: The results suggest that vitrification with step-wise procedure has positive effects on maturation and developmental capacity of mice germinal vesicle oocytes in compare with single step vitrification procedure.

Mahmoudi, Reza; Rajaei, Farzad; Ragardi Kashani, Iraj; Abbasi, Mehdi; Amidi, Fardin; Sobhani, Aligholi; Amiri, Iraj

2012-01-01

356

Functional enucleation of porcine oocytes for somatic cell nuclear transfer using femtosecond laser pulses  

NASA Astrophysics Data System (ADS)

Cloning of several mammalian species has been achieved by somatic cell nuclear transfer over the last decade. However, this method still results in very low efficiencies originating from biological and technical aspects. The highly-invasive mechanical enucleation belongs to the technical aspects and requires considerable micromanipulation skill. In this paper, we present a novel non-invasive method for combined oocyte imaging and automated functional enucleation using femtosecond (fs) laser pulses. After three-dimensional imaging of Hoechst-labeled porcine oocytes by multiphoton microscopy, our self-developed software automatically determined the metaphase plate position and shape. Subsequent irradiation of this volume with the very same laser at higher pulse energies in the low-density-plasma regime was used for metaphase plate ablation. We show that functional fs laser-based enucleation of porcine oocytes completely inhibited further embryonic development while maintaining intact oocyte morphology. In contrast, non-irradiated oocytes were able to develop to the blastocyst stage without significant differences to control oocytes. Our results indicate that fs laser systems offer great potential for oocyte imaging and enucleation as a fast, easy to use and reliable tool which may improve the efficiency of somatic cell clone production.

Kuetemeyer, K.; Lucas-Hahn, A.; Petersen, B.; Hassel, P.; Lemme, E.; Niemann, H.; Heisterkamp, A.

2010-02-01

357

Nicotinamide: a class III HDACi delays in vitro aging of mouse oocytes.  

PubMed

Postovulatory mammalian oocyte developmental potential decreases with aging in vivo and in vitro. Aging oocytes typically show cellular fragmentation and chromosome scattering with an abnormally shaped spindle over time. Previously, it was shown that histone acetylation in the mouse oocyte increased during aging and that treatment with trichostatin A (TSA), an inhibitor for class I and II histone deacetylases (HDACs), enhanced the acetylation, that is, aging. In this study, we examined the effect of nicotinamide (NAM), an inhibitor for class III HDACs, on in vitro aging of mouse oocytes as well as TSA. We found that treatment with NAM significantly inhibited cellular fragmentation, spindle elongation and astral microtubules up to 48 h of culture. Although presence of TSA partially inhibited cellular fragmentation and spindle elongation up to 36 h of culture, treatment with TSA induced chromosome scattering at 24 h of culture and more severe cellular fragmentation at 48 h of culture. Further, we found that ?-tubulin, a nonhistone protein, increased acetylation during aging, suggesting that not only histone but nonhistone protein acetylation may also increase with oocyte aging. Thus, these data indicate that protein acetylation is abnormally regulated in aging oocytes, which are associated with a variety of aging phenotypes, and that class I/II and class III HDACs may play distinct roles in aging oocytes. PMID:23474603

Lee, Ah Reum; Kishigami, Satoshi; Amano, Tomoko; Matsumoto, Kazuya; Wakayama, Teruhiko; Hosoi, Yoshihiko

2013-01-01

358

Incorporation of Phosphatase Inhibitor in Culture Prompts Growth Initiation of Isolated Non-Growing Oocytes  

PubMed Central

In vitro folliculogenesis of primordial and early preantral follicles is necessary for increment of reproductive efficiency in domestic animals, humans and endangered species. Recent study in phosphatase and tensin homolog (Pten) -knockout mice has revealed that this phosphatase acts as an inhibitory factor in follicle activation of primordial pool with the resultant inhibition of oocyte growth. To test in vitro effect of a phosphatase inhibitor on growth initiation of isolated non-growing oocytes in neonatal ovaries, we applied a specific inhibitor (bpV (HOpic)) for PTEN in culturing system. Non-growing oocytes isolated from the ovaries of newborn BDF1 (C57BL/6 × DBA/2) pups were divided to four culture groups. Five days after culture, the oocytes in 14 ?mol/l bpV only, 14 ?mol/l bpV plus 100 ng/ml Kit Ligand (KL), and 100 ng/ml KL groups showed significantly (P<0.05) growth (19.3±0.55, 25.8±0.53 and 21.6±0.29 ?m, respectively) compared with that of the control (no additive) (16.9±0.53 ?m). In addition, western blotting in those groups showed enhanced expression of phosphorylated Akt. In conclusion, we clearly demonstrate that isolated non-growing oocytes develop in phosphatase inhibitor, especially to PTEN, incorporated culturing system, and show first as we know that oocytes with zona Pellucidae can be obtained in vitro from isolated non-growing oocytes. PMID:24223714

Morohaku, Kanako; Hoshino, Yumi; Sasada, Hiroshi; Sato, Eimei

2013-01-01

359

Depletion of pericentrin in mouse oocytes disrupts microtubule organizing center function and meiotic spindle organization.  

PubMed

Accurate chromosome segregation is dependent on the formation and stability of the microtubule spindle apparatus. Meiotic spindle assembly in oocytes differs from the process used during mitosis, and is regulated by unique microtubule organizing centers (MTOCs) that lack centrioles. To gain insight into the molecular composition and function of acentriolar MTOCs in mouse oocytes, we assessed the role of a key MTOC-associated protein, pericentrin (PCNT). In somatic cells, pericentrin functions as a scaffold that binds specific proteins at MTOCs, including ?-tubulin, which is necessary for microtubule nucleation. Pericentrin is expressed in oocytes, but the conservation of its function is not known. Pericentrin localizes specifically to MTOCs during prophase-I arrest in mouse oocytes recovered from pre-ovulatory ovarian follicles, and remains associated with MTOCs at spindle poles during metaphase-I and -II. To test function, specific siRNAs were used to knock down Pcnt transcripts in mouse oocytes. Efficient protein depletion was confirmed by Western blot as well as immunofluorescence analysis. Notably, meiotic spindle structure and chromosome alignment were disrupted in Pcnt-depleted oocytes. Disorganized spindle structures with reduced microtubule density and misaligned chromosomes were observed in the majority of these oocytes (?70%). In addition, ?-tubulin localization to MTOCs was significantly reduced and microtubule regrowth, following cold treatment, was delayed in Pcnt-depleted oocytes. Thus, pericentrin is a key functional component of the unique acentriolar MTOCs of mouse oocytes, and plays an important role in regulating meiotic spindle assembly and/or stability. Mol. Reprod. Dev. 81: 1019-1029, 2014. © 2014 Wiley Periodicals, Inc. PMID:25266793

Ma, Wei; Viveiros, Maria M

2014-11-01

360

Loss of Ntrk2/Kiss1r signaling in oocytes causes premature ovarian failure.  

PubMed

Neurotrophins (NTs), once believed to be neural-specific trophic factors, are now known to also provide developmental cues to non-neural cells. In the ovary, NTs contribute to both the formation and development of follicles. Here we show that oocyte-specific deletion of the Ntrk2 gene that encodes the NTRK2 receptor (NTRK2) for neurotrophin-4/5 and brain-derived neurotrophic factor (BDNF) results in post-pubertal oocyte death, loss of follicular organization, and early adulthood infertility. Oocytes lacking NTRK2 do not respond to gonadotropins with activation of phosphatidylinositol 3-kinase (PI3K)-AKT-mediated signaling. Before puberty, oocytes only express a truncated NTRK2 form (NTRK2.T1), but at puberty full-length (NTRK2.FL) receptors are rapidly induced by the preovulatory gonadotropin surge. A cell line expressing both NTRK2.T1 and the kisspeptin receptor (KISS1R) responds to BDNF stimulation with activation of Ntrk2 expression only if kisspeptin is present. This suggests that BDNF and kisspeptin that are produced by granulosa cells (GCs) of periovulatory follicles act in concert to mediate the effect of gonadotropins on Ntrk2 expression in oocytes. In keeping with this finding, the oocytes of NTRK2-intact mice fail to respond to gonadotropins with increased Ntrk2 expression in the absence of KISS1R. Our results demonstrate that the preovulatory gonadotropin surge promotes oocyte survival at the onset of reproductive cyclicity by inducing oocyte expression of NTRK2.FL receptors that set in motion an AKT-mediated survival pathway. They also suggest that gonadotropins activate NTRK2.FL expression via a dual communication pathway involving BDNF and kisspeptin produced in GCs and their respective receptors NTRK2.T1 and KISS1R expressed in oocytes. PMID:24877631

Dorfman, Mauricio D; Garcia-Rudaz, Cecilia; Alderman, Zefora; Kerr, Bredford; Lomniczi, Alejandro; Dissen, Gregory A; Castellano, Juan Manuel; Garcia-Galiano, David; Gaytan, Francisco; Xu, Baoji; Tena-Sempere, Manuel; Ojeda, Sergio R

2014-08-01

361

Importance of the GDF9 signaling pathway on cumulus cell expansion and oocyte competency in sheep.  

PubMed

Acquisition of developmental competency in cumulus oocyte complexes (COCs) is derived from endocrine hormones and oocyte secreted factors. The contribution of these factors in oocyte maturation and development is an active area of research. The objective of this research was to investigate whether growth differentiation factor 9 (GDF9) that is secreted by oocyte affects cumulus expansion and oocyte development in sheep. Immature ovine COCs were cultured in the presence of recombinant human GDF9 (rhGDF9), denuded oocytes, SB-431542, a specific inhibitor of activin-like kinase 4/5/7; or a combination of these factors. Routine in vitro maturation of COCs and denuded oocytes were used as external control samples. Cultured COCs were used for assessment of (1) cumulus expansion; (2) expression of cumulus-related transcripts including pentraxin 3, hyaluronan synthase 2 (HAS2), tumor necrosis factor alpha-induced protein 6, prostaglandin synthase 2, B-cell lymphoma 2 (BCL2), and Bcl2-associated X (BAX); and (3) yield and quality of embryo development. It was observed that cumulus expansion was not affected by any of these treatments. HAS2 mRNA expression confirmed this observation. In the presence of exogenous GDF9, cleavage rate was reduced, blastocyst rate did not differ from other groups, and trophectoderm cell number significantly increased. This suggests that exogenous GDF9 could improve embryo quality. It was also observed that oocyte secreted factors reduced proapoptotic BAX mRNA, and BCL2 mRNA expression was not significantly different from other groups. This study provides evidence that GDF9 signaling might have a minor influence on ovine cumulus expansion and oocyte development and that other signaling pathway(s) might have a dominant role. PMID:23764009

Varnosfaderani, Sh Rouhollahi; Ostadhosseini, S; Hajian, M; Hosseini, S M; Khashouei, E Asadi; Abbasi, H; Hosseinnia, P; Nasr-Esfahani, M H

2013-09-15

362

Relationship between mitochondrial DNA Copy Number and SIRT1 Expression in Porcine Oocytes  

PubMed Central

The present study assessed the effect of resveratrol on the expression of SIRT1 and mitochondrial quality and quantity in porcine oocytes. Supplementing the maturation medium with 20 µM resveratrol increased the expression of SIRT1, and enhanced mitochondrial functions, as observed from the increased ATP content and mitochondrial membrane potential. Addition of resveratrol also improved the ability of oocytes to develop into the blastocyst stage following activation. The effects of resveratrol on mitochondrial number were examined by comparing the mitochondrial DNA copy number (Mt number) between group of oocytes collected from the same donor gilt ovaries. Supplementing the maturation medium with only resveratrol did not affect the Mt number in the oocytes. However, supplementing the maturation medium with 10 µM MG132, a proteasome inhibitor, significantly increased the amount of ubiquitinated proteins and Mt number by 12 and 14%, respectively. In addition, when resveratrol was added to the medium containing MG132, the Mt number increased significantly by 39%, this effect was diminished by the addition of the SIRT1 inhibitor EX527. Furthermore, supplementing the medium with MG132 and EX527 did not affect Mt number. The mean SIRT1 expression in 20 oocytes was significantly and positively correlated with the Mt number in oocytes collected from the same donor. This study suggests that the expression of SIRT1 is associated with the Mt number in oocytes. In addition, activation of SIRT1 by resveratrol enhances the biosynthesis and degradation of mitochondria in oocytes, thereby replenishing and improving mitochondrial function and the developmental ability of oocytes. PMID:24747689

Sato, Daichi; Itami, Nobuhiko; Tasaki, Hidetaka; Takeo, Shun; Kuwayama, Takehito; Iwata, Hisataka

2014-01-01

363

Muscarinic receptor heterogeneity in follicle-enclosed Xenopus oocytes  

PubMed Central

Ionic current responses elicited by acetylcholine (ACh) in follicle-enclosed Xenopus oocytes (follicles) were studied using the two-electrode voltage-clamp technique. ACh generated a fast chloride current (Fin) and inhibited K+ currents gated by cAMP (IK,cAMP) following receptor activation by adenosine, follicle-stimulating hormone or noradrenaline. These previously described cholinergic responses were confirmed to be of the muscarinic type, and were independently generated among follicles from different frogs.Inhibition of IK,cAMP was about 100 times more sensitive to ACh than Fin activation; the half-maximal effective concentrations (EC50) were 6.6 ± 0.4 and 784 ± 4 nm, respectively.Both responses were blocked by several muscarinic receptor antagonists. Using the respective EC50 concentrations of ACh as standard, the antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide blocked the two effects with very different potencies. Fin was blocked with a half-maximal inhibitory concentration (IC50) of 2.4 ± 0.07 nm, whilst the IC50 for IK,cAMP inhibition was 5.9 ± 0.2 ?m.Oxotremorine, a muscarinic agonist, preferentially stimulated IK,cAMP inhibition (EC50= 15.8 ± 1.4 ?m), whilst Fin was only weakly activated. In contrast, oxotremorine inhibited Fin generated by ACh with an IC50 of 2.3 ± 0.7 ?m.Fin elicited via purinergic receptor stimulation was not affected by oxotremorine, indicating that the inhibition produced was specific to the muscarinic receptor, and suggesting that muscarinic actions do not exert a strong effect on follicular cell-oocyte coupling.Using reverse transcription-PCR, transcripts of a previously cloned muscarinic receptor from Xenopus (XlmR) were amplified from the RNA of both the isolated follicular cells and the oocyte. The pharmacological and molecular characteristics suggest that XlmR is involved in IK,cAMP inhibition.In conclusion, follicular cells possess two different muscarinic receptors, one resembling the M2 (or M4) subtype and the other the M3 subtype. These receptors are coupled to distinct membrane mechanisms leading to independent regulation of two membrane conductances. PMID:10581312

Arellano, Rogelio O; Garay, Edith; Miledi, Ricardo

1999-01-01

364

Nuclear microinjection to assess how heterologously expressed proteins impact Ca2+ signals in Xenopus oocytes.  

PubMed

The Xenopus oocyte is frequently used for heterologous expression and for studying the spatiotemporal patterning of Ca(2+) signals. Here, we outline a protocol for nuclear microinjection of the Xenopus oocyte for the purpose of studying how subsequently expressed proteins impact intracellular Ca(2+) signals evoked by inositol trisphosphate (InsP3). Injected oocytes can easily be identified by reporter technologies and the impact of heterologously expressed proteins on the generation and properties of InsP3-evoked Ca(2+) signals can be resolved using caged InsP3 and fluorescent Ca(2+) indicators. PMID:23457340

Lin-Moshier, Yaping; Marchant, Jonathan S

2013-03-01

365

The role of perivitelline space abnormalities of oocytes in the developmental potential of embryos  

PubMed Central

Objective In assisted reproductive technology (ART), high embryo quality is closely related to high-quality oocytes. Cytoplasmic maturation and extracytoplasmic maturation are the most important components in determining oocyte quality. One of the most important components of extracytoplasmic maturation is perivitelline abnormalities. The aim of this study is to determine the effect of perivitelline abnormalities on the development of high-quality embryos. Material and Methods The study material consisted of 217 of 1154 oocytes from 98 intracytoplasmic sperm injection (ICSI) cycles undertaken due to male factor infertility. Only cycles with long gonadotropin-releasing hormone analogs combined with recombinant Follicle-stimulating hormone (rec-FSH) were included in study. We compared 105 metaphase-II oocytes that had dominantly perivitelline space abnormalities (large perivitelline space with or without granules) with 112 normal metaphase-II oocytes, based on the embryo grade determined by Alpha Scientists in Reproductive Medicine and the European Society of Human Reproduction and Embryology (ESHRE) Special Interest Group of Embryology. Normal metaphase-II oocytes were characterized by a round, clear zona pellucida; a small perivitelline space containing a single unfragmented first polar body; and a pale, moderately granular cytoplasm with no inclusions. Results The development rates of Grade I, II, and III embryos were 68.5%, 23.8%, and 7.7%, respectively, in the 105 oocytes with perivitelline abnormalities. The development rates of Grade I, II, and III embryos were 82.1%, 17.9%, and 0%, respectively, in the 112 morphologically normal oocytes. When compared with normal oocytes, Grade I (68.5% vs. 82.1%, p value; 0.019) and Grade III (7.7% vs. 0%, p value; 0.003) embryo development rates were significantly lower in oocytes that had perivitelline abnormalities. Conclusion It is important to analyze oocyte quality using multiple parameters, including the perivitelline space. Perivitelline space abnormalities might negatively affect embryo development in male factor-infertile couples that are stimulated with rec-FSH. Therefore, when choosing embryos for transfer, we must take into consideration the historical oocyte data. PMID:25317044

Hassa, Hikmet; Ayd?n, Yunus; Taplamac?oglu, Fulya

2014-01-01

366

Inherited effects from mouse immature oocytes following low-dose irradiation  

SciTech Connect

Immature oocytes represent the genetic pool in female mice as well as in women and therefore are principal cells of concern for genetic studies. Previous studies have demonstrated that genetic effects in female mice can be masked by the hypersensitive plasma membrane lethality target of immature oocytes. Studies have also shown that genetic effects can be detected when the plasma mambrane is sufficiently spared. Here, new data obtained using the mouse preimplantation embryo chimera assay are presented and discussed in light of previous findings for irradiated mouse oocytes.

Straume, T. [Lawrence Livermore National Lab., CA (United States); Khan, R.; Raabe, O.G.; Walsh, K.J.; Wiley, L.M. [California Univ., Davis, CA (United States). Institute of Toxicology and Environmental Health

1992-07-01

367

Oocyte cryopreservation: a feasible fertility preservation option for reproductive age cancer survivors  

Microsoft Academic Search

Purpose  To compare oocyte cryopreservation cycles performed in cancer patients to those of infertile women.\\u000a \\u000a \\u000a \\u000a Methods  Cancer patients referred for fertility preservation underwent counseling in compliance with the ASRM; those electing oocyte\\u000a cryopreservation were included. Ovarian stimulation was achieved with injectable gonadotropins and freezing was performed\\u000a using slow-cooling and vitrification methods.\\u000a \\u000a \\u000a \\u000a \\u000a Results  Fifty cancer patients (mean age 31 y) underwent oocyte cryopreservation; adequate ovarian

Nicole Noyes; Patty Ann Labella; James Grifo; Jaime M. Knopman

2010-01-01

368

Penetrating keratoplasty in atopic keratoconjunctivitis.  

PubMed

Penetrating keratoplasty (PK) may be required for visual rehabilitation or tectonic purposes in patients with severe keratopathy due to atopic keratoconjunctivitis (AKC). The outcome of PK is often poor in such patients because of adnexal and ocular surface abnormalities. We studied nine AKC patients requiring PK and evaluated the visual outcome and prognostic factors in 11 eyes. The mean follow-up was 87.2 months (range, 30-180 months). Preoperatively all patients had visual acuity of hand motion to 20/200. Eighteen grafts were performed. Final visual acuity was 20/40 or better in 46% of the eyes. Ten eyes retained clear grafts and improved an average of 4.5 Snellen acuity lines. PMID:8575184

Ghoraishi, M; Akova, Y A; Tugal-Tutkun, I; Foster, C S

1995-11-01

369

A lightweight ground penetrating radar  

SciTech Connect

The detection of buried objects, particularly unexploded ordnance (UXO), has gained significant interest in the US in the late 1990s. The desire to remediate the thousands of sites worldwide has become an increasing humanitarian concern. The application of radar to this problem has received renewed attention. Bechtel Nevada, Special Technologies Laboratory (STL) has developed several frequency modulated, continuous wave (FM-CW) ground penetrating radar (GPR) units for the US Department of Energy since 1984. To meet these new technical requirements for high resolution data and UXO detection, STL is moving forward with advances to GPR technology, signal processing, and imaging with the development of an innovative system. The goal is to design and fabricate a lightweight, battery operated unit that does not require surface contact and can be operated by a novice user.

Koppenjan, S.K.; Allen, C.M.; Gardner, D.; Wong, H.R.

1998-12-31

370

ENAM Mutations with Incomplete Penetrance.  

PubMed

Amelogenesis imperfecta (AI) is a genetic disease affecting tooth enamel formation. AI can be an isolated entity or a phenotype of syndromes. To date, more than 10 genes have been associated with various forms of AI. We have identified 2 unrelated Turkish families with hypoplastic AI and performed mutational analysis. Whole-exome sequencing identified 2 novel heterozygous nonsense mutations in the ENAM gene (c.454G>T p.Glu152* in family 1, c.358C>T p.Gln120* in family 2) in the probands. Affected individuals were heterozygous for the mutation in each family. Segregation analysis within each family revealed individuals with incomplete penetrance or extremely mild enamel phenotype, in spite of having the same mutation with the other affected individuals. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations. PMID:25143514

Seymen, F; Lee, K-E; Koruyucu, M; Gencay, K; Bayram, M; Tuna, E B; Lee, Z H; Kim, J-W

2014-10-01

371

Penetration equations for thermal protection materials  

Microsoft Academic Search

NASA has developed a number of penetration equations for a broad range of thermal protection system (TPS) materials used on the Space Shuttle Orbiter and other spacecraft including low-density ceramic tiles, reinforced carbon-carbon, flexible ceramic insulation and multi-layer insulation (MLI). The penetration equations describe the penetration depth or damage extent to be expected from hypervelocity particles as a function of

Eric L. Christiansen; Larry Friesen

1997-01-01

372

Residual contaminants in dye-penetrant testing  

SciTech Connect

Components of the dye-penetrant-testing process were characterized by microanalytical methods. Particulate material of a size range, which was small enough to plug the small leaks in thin-walled cans, was found. Testing of simulated leaks before and after dye-penetrant examination showed that the dye-penetrant testing had a high probability of plugging leaks < 1 x 10/sup -4/ atm-cm/sup 3//s of helium in size.

McLaughlin, J.F.; Schneider, P.G.; Eager, M.H.

1981-04-13

373

Heparin and penicillamine-hypotaurine-epinephrine (PHE) solution during bovine in vitro fertilization procedures impair the quality of spermatozoa but improve normal oocyte fecundation and early embryonic development.  

PubMed

The presence of heparin and a mixture of penicillamine, hypotaurine, and epinephrine (PHE) solution in the in vitro fertilization (IVF) media seem to be a prerequisite when bovine spermatozoa are capacitated in vitro, in order to stimulate sperm motility and acrosome reaction. The present study was designed to determine the effect of the addition of heparin and PHE during IVF on the quality and penetrability of spermatozoa into bovine oocytes and on subsequent embryo development. Sperm quality, evaluated by the integrity of plasma and acrosomal membranes and mitochondrial function, was diminished (P<0.05) in the presence of heparin and PHE. Oocyte penetration and normal pronuclear formation rates, as well as the percentage of zygotes presenting more than two pronuclei, was higher (P<0.05) in the presence of heparin and PHE. No differences were observed in cleavage rates between treatment and control (P>0.05). However, the developmental rate to the blastocyst stage was increased in the presence of heparin and PHE (P>0.05). The quality of embryos that reached the blastocyst stage was evaluated by counting the inner cell mass (ICM) and trophectoderm (TE) cell numbers and total number of cells; the percentage of ICM and TE cells was unaffected (P>0.05) in the presence of heparin and PHE (P<0.05). In conclusion, this study demonstrated that while the supplementation of IVF media with heparin and PHE solution impairs spermatozoa quality, it plays an important role in sperm capacitation, improving pronuclear formation, and early embryonic development. PMID:23949783

Gonçalves, F S; Barretto, L S S; Arruda, R P; Perri, S H V; Mingoti, G Z

2014-01-01

374

THE PENETRATION OF SOME CATIONS INTO MUSCLE  

PubMed Central

The influx of Na+, K+, Rb+, and Cs+ into frog sartorius muscle has been followed. The results show that a maximum rate is found for K+, while Na+ and Cs+ penetrate much more slowly. Similar measurements with Ca++, Ba++, and Ra++ show that Ba++ penetrates at a rate somewhat greater than that of either Ca++ or Ra++. All these divalent cations, however, penetrate at rates much slower than do the alkali cations. The results obtained are discussed with reference to a model that has been developed to explain the different penetration rates for the alkali cations. PMID:13631206

Mullins, L. J.

1959-01-01

375

Ultrastructural features of left ventricular myocytes in active and torpid hamsters compared with rats: a morphometric study.  

PubMed Central

Myocytes from the midmyocardium of the left ventricle of rats and hamsters were examined by transmission electron microscopy. The volume fraction of lipid droplets in such myocytes was about 6 times greater in the active hamster than in the rat, but it became progressively reduced during cold exposure and entry into hibernation to values similar to those of the rat. The volume fraction of the T-system as well as the surface density of its membranes were each found to be twice as large in hamster myocytes as in the rat but there was no difference in these parameters between control, cold-exposed and torpid hamsters. The surface density of the junctional sarcoplasmic reticulum coupled with elements of the T-system was greater in active hamsters when compared with those of the rat, and greater still in torpid hamsters. There was no significant difference in the surface density of free sarcoplasmic reticulum between control hamsters, cold-exposed hamsters and rats but it was almost doubled in torpid hamsters. It is proposed that these features represent inherent differences in the ultrastructure of the left ventricle between the rat and hamster that may facilitate entry into hibernation. Additionally, further structural modifications during entry into hibernation may be related to alterations in lipid metabolism and modifications of calcium handling. Images Fig. 1 Fig. 2 PMID:7559131

Skepper, J N; Navaratnam, V

1995-01-01

376

Adhesion and detachment characteristics of Chinese hamster cell membrane mutants  

PubMed Central

We have investigated the adhesion and detachment properties of wild- type Chinese hamster cells and of variant lines, which possess altered cell surface glycoproteins as detected by galactose oxidase- [3H]borohydride labeling. The wild-type and variant lines tested all adhered to protein-coated glass surfaces at the same rate; however, the variant cells differed from wild type and from each other in terms of the ease with which they were detached by trypsinization. Morphological differences between the various lines were also apparent. Our results suggest that the carbohydrate moieties of the terminal region of surface glycoproteins are not directly involved in the initial phase of cell-to-substratum attachment, but that they may modulate the proteolytic susceptibility of surface components which are involved in cell detachment. PMID:618896

1978-01-01

377

Chinese hamster pleiotropic multidrug-resistant cells are not radioresistant  

SciTech Connect

The inherent cellular radiosensitivity of a Chinese hamster ovary pleiotropic cell line that is multidrug resistant (CHRC5) was compared to that of its parental cell line (AuxB1). Radiation survival curve parameters n and D0 were 4.5 and 1.1 Gy, respectively, for the CHRC5 line and 5.0 and 1.2 Gy, respectively, for the parental line. Thus, the inherent radiosensitivity of the two lines was similar even though key intracellular free radical scavenging and detoxifying systems employing glutathione, glutathione transferase, and catalase produced enzyme levels that were 2.0-, 1.9-, and 1.9-fold higher, respectively, in the drug-resistant cell line. Glutathione depletion by buthionine sulfoximine resulted in the same extent of aerobic radiosensitization in both lines (approximately 10%). Incorporation of iododeoxyuridine into cellular DNA sensitized both cell lines to radiation. These studies indicate that pleiotropic drug resistance does not necessarily confer radiation resistance.

Mitchell, J.B.; Gamson, J.; Russo, A.; Friedman, N.; DeGraff, W.; Carmichael, J.; Glatstein, E.

1988-01-01

378

X-ray microanalysis of hamster tracheal epithelium  

SciTech Connect

Studies of ion transport across respiratory epithelia are of great interest if we are to understand the pathophysiology of diseases such as cystic fibrosis in which ion transport is abnormal. Concentrations of elements were determined in various subcellular regions of normal or isoproterenol-treated hamster tracheal epithelium, using X-ray microanalysis of freeze-dried cryosections. Samples of trachea were taken from animals under anesthesia and either frozen in situ or dissected and plunge frozen. Concentrations of Mg, P, S, Cl, K and Ca were higher in cytoplasm and nuclei of control epithelial cells in dissected samples than in cryoneedle samples. Following treatment with isoproterenol, a large decrease in the concentration of Cl was observed. The results confirm that cyclic AMP-regulated chloride secretion is unaffected by anesthesia.

Spencer, A.J.; Roomans, G.M. (Univ. of Uppsala (Sweden))

1989-06-01

379

In vitro and in vivo survival of frozen-thawed bovine oocytes after IVF, nuclear transfer, and parthenogenetic activation.  

PubMed

Cryopreservation of bovine oocytes would be beneficial both for nuclear transfer and for preservation efforts. The overall objective of this study was to evaluate the viability as well as the cryodamage to the nucleus vs. cytoplasm of bovine oocytes following freezing-thawing of oocytes at immature (GV) and matured (MII) stages using in vitro fertilization (IVF), parthenogenetic activation, or nuclear transfer assays. Oocytes were collected from slaughterhouse ovaries. Oocytes at the GV, MII, or MII but enucleated (MIIe) stages were cryopreserved in 5% (v/v) ethylene glycol; 6% (v/v) 1,2-propanediol; and 0.1-M sucrose in PBS supplemented with 20% (v/v) fetal bovine serum. Frozen-thawed oocytes were subjected to IVF, parthenogenetic activation, or nuclear transfer assays. Significantly fewer GV oocytes survived (i.e., remained morphologically intact during freezing-thawing) than did MII oocytes (47% vs. 84%). Subsequent development of the surviving frozen-thawed GV and MII oocytes was not different (58% and 60% cleavage development; 7% and 12% blastocyst development at Day 9, respectively, P > 0.05). Parthenogenetic activation of frozen-thawed oocytes resulted in significantly lower rates of blastocyst development for the GV than the MII oocyte groups (1% vs. 14%). Nuclear transfer with cytoplasts derived from frozen-thawed GV, MII, MIIe, and fresh-MII control oocytes resulted in 5%, 16%, 14%, and 17% blastocyst development, respectively. However, results of preliminary embryo transfer trials showed that fewer pregnancies were produced from cloned embryos derived from frozen oocytes or cytoplasts (9%, n = 11 embryos) than from fresh ones (19%, n = 21 embryos). Transfer of embryos derived by IVF from cryopreserved GV and MII oocytes also resulted in term development of calves. Our results showed that both GV and MII oocytes could survive freezing and were capable of developing into offspring following IVF or nuclear transfer. However, blastocyst development of frozen-thawed oocytes remains poorer than that of fresh oocytes, and our nuclear transfer assay suggests that this poorer development was likely caused by cryodamage to the oocyte cytoplasm as well as to the nucleus. PMID:9771648

Kubota, C; Yang, X; Dinnyes, A; Todoroki, J; Yamakuchi, H; Mizoshita, K; Inohae, S; Tabara, N

1998-11-01

380

An actin-depolymerizing protein (depactin) from starfish oocytes: properties and interaction with actin  

Microsoft Academic Search

Physico-chemical properties and interaction with actin of an actin-depolymerizing protein from mature starfish oocytes were studied. This protein, which is called depactin, exists in a monomeric form under physiological conditions. Its molecular weight is \\

ISSEI MABUCHI

1983-01-01

381

oocytes are currently very small. Several healthy children were born as a result of this  

E-print Network

survival rates and no difference in pregnancy rates (mouse) compared to controls. The aim of this study and antibiotics at 39 °C took place. Cumulus-oocyte complexes (COC's) were cultured in serum-free defined culture

Paris-Sud XI, Université de

382

SRC-FAMILY TYROSINE KINASES PARTICIPATE IN THE REGULATION OF MAMMALIAN OOCYTE MATURATION AND ZYGOTIC DEVELOPMENT  

E-print Network

Multiple signaling pathways act during ovulation to ensure that the oocyte is prepared for embryonic development. We combined pharmacological and cell biological methods to study the role of Src-family kinases (SFKs) during ...

McGinnis, Lynda K.

2009-02-05

383

Precocious induction of oocyte maturation and ovulation in rainbow trout (Salmo gairdneri) : problems when using  

E-print Network

Precocious induction of oocyte maturation and ovulation in rainbow trout (Salmo gairdneri. The experiment was carried out in December 1976 using 2-year old rainbow trout (Salmo gairdneri) weighing 400

Paris-Sud XI, Université de

384

A transgenic zebrafish model of targeted oocyte ablation and de novo oogenesis.  

PubMed

We describe here a novel transgenic zebrafish, Tg(zpc:G4VP16/UAS:nfsB-mCherry) that effectively demonstrates the targeted oocyte ablation in the adult zebrafish ovary. This transgenic line expresses bacterial nitroreductase enzyme (nfsB) under the control of the oocyte-specific zona pellucida C (zpc) gene promoter. Adult transgenic females exposed to the prodrug metronidazole demonstrated near-complete ablation of growing oocytes, resulting in ovarian degeneration and complete cessation of reproductive function. Within 4 weeks of prodrug removal, treated fish demonstrated complete anatomical regeneration of the ovary and, within 7 weeks, ovarian function (fertility) was fully restored. Together, these results demonstrate functional renewal of the oocyte pool in the adult zebrafish ovary. Accordingly, this transgenic zebrafish model system provides a novel means to investigate ovarian growth dynamics in a genetically tractable vertebrate, and may be useful for evaluating signaling interactions that regulate gonadal development processes such as de novo oogenesis. PMID:21761478

White, Yvonne A R; Woods, Dori C; Wood, Antony W

2011-08-01

385

A Rho-signaling pathway mediates cortical granule translocation in the sea urchin oocyte  

E-print Network

; Rho; Cortical granule; Actin; Microfilaments; Oocyte maturation; Fertilization 1. Introduction. Upon fertiliza- tion, these vesicles undergo a Ca2þ -dependent exocytosis releasing their content into the perivitelline space. Cortical granule contents includes enzymes and structural materials that contribute

Wessel, Gary M.

386

Localization of a putative epiboly-determining factor in oocytes of the goldfish ( Carassius auratus)  

NASA Astrophysics Data System (ADS)

It is unknown whether cytoplasmic determinants in goldfish eggs are asymetrically localized before maturation. In this study fully grown goldfish oocytes with intact germinal vesiles (GVs) were ligated with baby hair loops along desired planes into two parts, matured in vitro, and inseminated. Embryos developed from the animal halves with GV of oocytes ligated along the equator were unable to undergo epiboly, while those developed from the GV-containing parts of oocytes ligated along the animal-vegetal axis were able to. Also, embryos developed from the animal halves obtained from fertilized eggs could undergo epiboly. From these results, it was postulated that the goldfish's premature oocyte possessed a putative factor in the vegetal hemisphere which was responsible for epiboly of the embryonic cells.

Zhang, Shi-Cui; Wu, Xian-Han

1996-09-01

387

Oocyte differentiation is genetically dissociable from the meiotic program in mice  

E-print Network

Oogenesis is a developmental program by which a gametogenesis-competent germ cell becomes a fertilization-competent egg. During oogenesis, growth and differentiation of oocytes are closely coordinated with initiation and ...

Dokshin, Gregoriy A. (Gregoriy Aleksandrovich)

2013-01-01

388

Bovine oocytes cryoinjury and how to improve their development following cryopreservation.  

PubMed

Bovine oocytes are less likely to undergo successful cryopreservation than cleavage-stage embryos. Bovine oocytes characteristically contain high levels of lipids that represent one of the major obstacles limiting efficient cryopreservation. These droplets together with structures such as cumulus cells, zona pellucida, cytoplasm membrane, cortical granules, mitochondria, spindle, and cytoskeleton (microtubles and microfilaments) often incur serious damage during cooling and warming. The cryoinjury could, to some extent, be decreased by selection of proper permeable and non-permeable cryoprotectants, and of vitrification with high cooling and warming rates. Additionally, such measures may also enhance their cryotolerance as partial removal of cumulus cells, modification of oocyte membrane constituents, polarization of the cytoplasmic lipid droplets by centrifugation, and addition of cytoskeleton relaxants or ice blockers into vitrification solutions. The improvement in cryopreservation methodology for bovine oocytes will no doubt augment other technologies such as bovine cloning and the establishment of gene bank for transgenic cattle. PMID:23534957

Zhou, Guang Bin; Li, Ning

2013-01-01

389

Hijacked by an oocyte: hierarchical molecular changes in somatic cell nuclear transfer.  

PubMed

Xenopus oocytes can epigenetically reprogram mouse somatic cells toward totipotency. In this issue, Jullien et al. (2014) now describe rapid, interdependent molecular events that facilitate this reprogramming. PMID:25148360

Maza, Itay; Hanna, Jacob H

2014-08-21

390

Oocyte vitrification in the 21st century and post-warming fertility outcomes: a systematic review and meta-analysis.  

PubMed

Oocyte cryopreservation is a rapidly developing technology, which is increasingly being used for various medical, legal and social reasons. There are inconsistencies in information regarding survival rate and fertility outcomes. This systematic review and meta-analysis provides evidence-based information about oocyte survival and fertility outcomes post warming to help women to make informed choices. All randomized and non-randomized, controlled and prospective cohort studies using oocyte vitrification were included. The primary outcome measure was ongoing pregnancy rate/warmed oocyte. Sensitivity analysis for donor and non-donor oocyte studies was performed. Proportional meta-analysis of 17 studies, using a random-effects model, showed pooled ongoing pregnancy and clinical pregnancy rates per warmed oocyte of 7%. Oocyte survival, fertilization, cleavage, clinical pregnancy and ongoing pregnancy rates per warmed oocyte were higher in donor versus non-donor studies. Comparing vitrified with fresh oocytes, no statistically significant difference was observed in fertilization, cleavage and clinical pregnancy rates, but ongoing pregnancy rate was reduced in the vitrified group (odds ratio 0.74), with heterogeneity between studies. Considering the age of women and the reason for cryopreservation, reasonable information can be given to help women to make informed choices. Future studies with outcomes from oocytes cryopreserved for gonadotoxic treatment may provide more insight. PMID:24931362

Potdar, Neelam; Gelbaya, Tarek A; Nardo, Luciano G

2014-08-01

391

AUTONOMIC AND BEHAVIORAL THERMOREGULATION IN THE GOLDEN HAMSTER DURING SUBCHRONIC ADMINISTRATION OF CLORGYLINE  

EPA Science Inventory

Chronic administration of clorgyline, a type-A monoamine oxidase inhibitor, leads to a decrease in peritoneal (i.e., core) temperature of golden hamsters. o better understand the mechanisms of clorgyline's thermoregulatory effects, autonomic and behavioral thermoregulatory effect...

392

Metastasizing fibrosarcomas in hamsters (BMH) after injection of B77 sarcoma virus transformed mouse cells.  

PubMed

Injection of virogenic mouse cells B77-1026 into newborn Syrian hamsters resulted in arising of progressively growing autochthonous fibrosarcomas. From hamster tumors five stable tumor cell lines (BMH/1--BMH/5) were established in vitro. All cells of the newly established tumor cell lines had hamster karyotype, they were able to grow in soft agar and did not contain rescuable B77 viral genome. BMH tumor cells injected into syngeneic newborn as well as young adult hamsters produced tumors at the site of application and metastasized frequently into viscera. From metastases in different organs further tumor cell lines and single cell clones were established in vitro. All these tumor cell lines and clones exhibited higher metastatic capacity than the parent cell lines. PMID:6318137

Sabová, L; Smida, J; Smidová, V

1983-01-01

393

Cross-Protection in Hamsters Immunized with Group A Arbovirus Vaccines.  

National Technical Information Service (NTIS)

Cross-protection between Venezuelan, Eastern, and Western equine encephalomyelitis (VEE, EEE, WEE) viruses was studied in the hamster by using challenge responses and neutralizing antibody titers as indexes of protection. Formalin-inactivated vaccines ind...

F. E. Cole, R. W. McKinney

1971-01-01

394

Male-induced estrus synchronization in the female Siberian hamster (Phodopus sungorus sungorus)  

E-print Network

of research may be due to the physiology of the Phodopus genus; vaginal cytology cannot be used as a reliable sungorus) hamsters appears to be an unlikely event because vaginal cytology in both of these species shows

Carr, Leslie

395

Social Defeat Increases Food Intake, Body Mass, and Adiposity in Syrian Hamsters  

NSDL National Science Digital Library

Journal Article "Social defeat increases food intake, body mass, and adiposity in Syrian Hamsters" from the American Journal of Physiology--Regulatory, Integrative, and Comparative Physiology, by Timothy J. Bartness, Kim L. Huhman, Matia B. Solomon, and Michelle T. Foster.

PhD Timothy J. Bartness (Georgia State University Department of Biology); Kim L. Huhman (Georgia State University Psychology); Matia B. Solomon (Georgia State University Psychology); Michelle T. Foster (Georgia State University Department of Biology)

2006-05-01

396

Gonadal hormones masculinize and defeminize reproductive behaviors during puberty in the male Syrian hamster  

E-print Network

Gonadal hormones masculinize and defeminize reproductive behaviors during puberty in the male Three experiments were conducted to test whether testicular hormones secreted during puberty masculinize hormones during puberty masculinize behavioral responses to testosterone (T) in adulthood. Male hamsters

Sisk, Cheryl

397

Morphometric and histological analysis of the lungs of Syrian golden hamsters.  

PubMed Central

Hamster lung morphometry and histology have been studied in an attempt to determine differences between hamster and human lungs which may have relevance for lung carcinogenesis studies. Morphometric measurements were made on fresh lungs, lung casts, and histological sections. Cell type and frequency measurements were determined from frozen, paraffin, 1 micron plastic (glycol methacrylate) and electron microscopic sections. A standard terminology for hamster lung histology is established, and differences between hamster and human lung morphometry and histology are discussed. Images Fig. 2 Fig. 3 Fig. 4 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 Fig. 20 Fig. 21 Fig. 22 PMID:640957

Kennedy, A R; Desrosiers, A; Terzaghi, M; Little, J B

1978-01-01

398

Photoperiodic Control of Oestrous Cycles in Syrian Hamsters: Mediation by the Mediobasal Hypothalamus  

E-print Network

-day baseline values by week 22. We conclude that melatonin-binding sites in the MBH mediate suppression control of gonadotropin and prolactin secretion in female hamsters. Synchronization of seasonal

Zucker, Irving

399

Langerhans cell function dictates induction of contact hypersensitivity or unresponsiveness to DNFB in Syrian hamsters  

SciTech Connect

The relationship between distribution and function of Langerhans cells within the epidermis and the capacity of cutaneous surfaces to promote the induction of contact hypersensitivity to DNFB have been examined in inbred Syrian hamsters. In a manner very similar to previous findings in mice, the results indicate that hamster cutaneous surfaces deficient in normally functioning Langerhans cells, naturally (cheek pouch epithelium) or artificially (after perturbation with ultraviolet light), are inefficient at promoting DNFB sensitization. Instead, DNFB applied to these regions of skin results in the induction of a state of specific unresponsiveness. Viable lymphoid cells from unresponsive hamsters can transfer the unresponsiveness to naive hamsters suggesting that active suppression is at least partly responsible, probably mediated by T lymphocytes.

Streilein, J.W.; Bergstresser, P.R.

1981-09-01

400

Chinese hamster ovary cells can produce galactose-?-1,3-galactose antigens on proteins  

E-print Network

Chinese hamster ovary (CHO) cells are widely used for the manufacture of biotherapeutics, in part because of their ability to produce proteins with desirable properties, including 'human-like' glycosylation profiles. For ...

Bosques, Carlos J

401

Cross contamination of the genomes in human/hamster cell hybrids by multiple short recombination events.  

PubMed

We have isolated sites of de novo rearrangements from interspecific cell hybrids. Of 147,000 clones screened from a human/hamster hybrid genomic library, 14 clones were found with homology to both human and hamster repetitive DNA sequences. Five of these clones contained recombination events involving less than 13 kb of DNA, three with human DNA recombined into a section of hamster DNA, and two with hamster DNA recombined into human DNA. None of the clones involving human LI sequences were found to be de novo transposition events, but simply short recombination or insertion events. Considering the apparent random nature of these events, they are likely to involve unique as well as repetitive sequences and also involve integration into the homologous as well as heterologous chromosome sets. These results suggest that the chromosome sets in somatic cell hybrids may be randomly contaminated with small DNA segments derived from either set of chromosomes. PMID:8600567

Littlejohn, M R; Camakaris, J; Woodcock, D M

1995-11-01

402

Active Hypothermic Growth: A Novel Means For Increasing Total Interferon-? Production by Chinese Hamster Ovary Cells  

E-print Network

When grown under hypothermic conditions, Chinese Hamster Ovary (CHO) cells become growth arrested in the G?/G? phase of the cell cycle and also often exhibit increased recombinant protein production. In this study, we ...

Stephen R., Fox

403