CHARACTERISTICS AND FERTILITY OF SUMATRAN TIGER SPERMATOZOA CRYOPRESERVED WITH DIFFERENT SUGARS

BACKGROUND

Cryopreservation of semen is one of the most important methods for the preservation of endangered tigers.

OBJECTIVE

This study evaluated the effects of sugar supplementation on the cryosurvival of spermatozoa from Sumatran tigers (Panthera tigris sumatrae).

MATERIALS AND METHODS

The post-thaw characteristics and fertility of spermatozoa cryopreserved with different sugars (glucose, lactose, and trehalose) were evaluated using heterologous in-vitro fertilisation with cat oocytes.

RESULTS

All parameters of post-thaw spermatozoa significantly decreased as compared with those of fresh spermatozoa. The index of sperm motility for semen cryopreserved with lactose was significantly higher than that for semen cryopreserved with trehalose. The percentage of total fertilisation for tiger spermatozoa cryopreserved with trehalose was significantly lower than that for control cat spermatozoa.

CONCLUSION

Our findings indicated that supplementation with lactose or glycerol as the main sugar in the egg yolk extender resulted in a better motility and fertility potential for post-thawed spermatozoa.

47 EFFECT OF L-CARNITINE TREATMENT DURING OOCYTE MATURATION ON THE POST-THAW DEVELOPMENT OF PORCINE EMBRYOS VITRIFIED AT THE PRONUCLEAR STAGE

The extreme cryo-sensitivity of porcine oocytes and embryos is attributed to their endemically high content of cytoplasmic lipid droplets. In attempts to improve the cryo-tolerance of porcine embryos, various strategies have been used to reduce the amount of lipid droplets present in the cytoplasm before vitrification. Recently, the cryo-tolerance of bovine oocytes vitrified at the metaphase II stage was improved by supplementing in vitro maturation (IVM) medium with l-carnitine (LC), a stimulator of lipid metabolism (Chakitisakul et al. 2013 Theriogenology 79, 590–598). The objective of this study was to determine the effect of supplementing IVM medium with LC on the post-thaw development of porcine embryos vitrified at the pronuclear stage. Oocytes recovered from the ovaries of prepubertal gilts were matured in modified porcine oocyte medium supplemented with 0 (control) or 12 mM LC during the final 22 h of IVM. Following IVF, presumptive zygotes were cultured in porcine zygote medium-3. At the pronuclear stage, cohorts of embryos from each group were either vitrified using a solid surface vitrification procedure (Somfai et al. 2009 Biol. Reprod. 80, 42–49) or cultured for 7 d without being vitrified. Vitrified zygotes were subsequently warmed and cultured for 7 d. The rates of cleavage, blastocyst formation, and hatching were recorded, and all blastocysts were stained to determine the total cell numbers. Three replicates were performed. Proportional data were arcsine transformed and subjected to ANOVA, and cell number data were analysed by t-test. The post-thaw survival rates of the embryos that were vitrified did not differ between the groups (control: 95.7%; LC: 97.1%; P > 0.05). There were no significant effects of LC treatment or vitrification on the rates of cleavage, blastocyst formation, and hatching (Table 1). Vitrified embryos derived from LC-treated oocytes produced blastocysts with fewer cells than vitrified embryos derived from untreated oocytes (Table 1; P < 0.05). In contrast to previous findings in other species, the results indicate that supplementing IVM medium with LC did not enhance the post-thaw development of porcine embryos vitrified at the pronuclear stage. Table 1.Effect of l-carnitine (LC) treatment and vitrification on porcine embryo development C. Grupen was supported by an OECD Fellowship.

Optimization of cryoprotectant treatment for the vitrification of immature cumulus-enclosed porcine oocytes: comparison of sugars, combinations of permeating cryoprotectants and equilibration regimens

Our aim was to optimize the cryoprotectant treatment for the preservation of immature porcine cumulus-oocyte complexes (COCs) by solid surface vitrification. In each experiment, the vitrification solution consisted of 50 mg/ml polyvinyl pyrrolidone, 0.3 M of the actual sugar and in total 35% (v/v) of the actual permeating cryoprotectant (pCPA) combination. After warming, the COCs were subjected to in vitro maturation, fertilization and embryo culture. In Experiment 1, trehalose and sucrose were equally effective during vitrification and warming in terms of facilitating oocyte survival and subsequent embryo development. In Experiment 2, when equilibration was performed at 38.5 C in a total of 4% (v/v) pCPA for 15 min, the combination of ethylene glycol and propylene glycol (EG + PG = 1:1) was superior to EG and dimethyl sulfoxide (EG + DMSO = 1:1) in terms of oocyte survival after vitrification and the quality of resultant blastocysts. In Experiment 3, equilibration in 4% (v/v) pCPA for 15 min before vitrification was superior to that in 15% (v/v) CPA for 5 min for achievement of high survival rates irrespective of the pCPA combination used. In Experiment 4, when equilibration was performed in 4% EG + PG for 5 min, 15 min or 25 min, there was no difference in oocyte survival and subsequent embryo development after vitrification and warming; however, the developmental competence of cleaved embryos was tendentiously reduced when equilibration was performed for 25 min. In conclusion, trehalose and sucrose were equally effective in facilitating vitrification, and the optimum pCPA treatment was 5–15 min equilibration in 4% (v/v) of EG + PG followed by vitrification in 35% (v/v) EG + PG.

MR Imaging-Based Analysis of Glioblastoma Multiforme: Estimation of IDH1 Mutation Status

BACKGROUND AND PURPOSE

Glioblastoma multiforme is highly aggressive and the most common type of primary malignant brain tumor in adults. Imaging biomarkers may provide prognostic information for patients with this condition. Patients with glioma with isocitrate dehydrogenase 1 (IDH1) mutations have a better clinical outcome than those without such mutations. Our purpose was to investigate whether the IDH1 mutation status in glioblastoma multiforme can be predicted by using MR imaging.

MATERIALS AND METHODS

We retrospectively studied 55 patients with glioblastoma multiforme with wild type IDH1 and 11 patients with mutant IDH1. Absolute tumor blood flow and relative tumor blood flow within the enhancing portion of each tumor were measured by using arterial spin-labeling data. In addition, the maximum necrosis area, the percentage of cross-sectional necrosis area inside the enhancing lesions, and the minimum and mean apparent diffusion coefficients were obtained from contrast-enhanced T1-weighted images and diffusion-weighted imaging data. Each of the 6 parameters was compared between patients with wild type IDH1 and mutant IDH1 by using the Mann-Whitney U test. The performance in discriminating between the 2 entities was evaluated by using receiver operating characteristic analysis.

RESULTS

Absolute tumor blood flow, relative tumor blood flow, necrosis area, and percentage of cross-sectional necrosis area inside the enhancing lesion were significantly higher in patients with wild type IDH1 than in those with mutant IDH1 (P < .05 each). In contrast, no significant difference was found in the ADC(minimum) and ADC(mean). The area under the curve for absolute tumor blood flow, relative tumor blood flow, percentage of cross-sectional necrosis area inside the enhancing lesion, and necrosis area were 0.850, 0.873, 0.739, and 0.772, respectively.

CONCLUSIONS

Tumor blood flow and necrosis area calculated from MR imaging are useful for predicting the IDH1 mutation status.

Influence of co-culture with denuded oocytes during in vitro maturation on fertilization and developmental competence of cumulus-enclosed porcine oocytes in a defined system

Co-culture of cumulus-oocyte complexes (COCs) with denuded oocytes (DOs) during in vitro maturation (IVM) was reported to improve the developmental competence of oocytes via oocyte-secreted factors in cattle. The aim of the present study was to investigate if addition of DOs during IVM can improve in vitro fertilization (IVF) and in vitro culture (IVC) results for oocytes in a defined in vitro production system in pigs. The maturation medium was porcine oocyte medium supplemented with gonadotropins, dbcAMP and β-mercaptoethanol. Cumulus-oocyte complexes were matured without DOs or with DOs in different ratios (9 COC, 9 COC+16 DO and 9 COC+36 DO). Consequently; oocytes were subjected to IVF as intact COCs or after denudation to examine if DO addition during IVM would affect cumulus or oocyte properties. After fertilization, penetration and normal fertilization rates of zygotes were not different between all tested groups irrespective of denudation before IVF. When zygotes were cultured for 6 days, no difference could be observed between all treatment groups in cleavage rate, blastocyst rate and cell number per blastocyst. In conclusion, irrespective of the ratio, co-culture with DOs during IVM did not improve fertilization parameters and embryo development of cumulus-enclosed porcine oocytes in a defined system.

62 COMPARISON OF SUGARS, COMBINATIONS OF PERMEABLE CRYOPROTECTANTS, AND EQUILIBRATION REGIMENS FOR THE SOLID SURFACE VITRIFICATION OF IMMATURE PORCINE OOCYTES

Cryotop and solid surface vitrification are frequently used methods for the cryopreservation of porcine oocytes. These methods differ not only in the vitrification carrier but also in the cryoprotectant (CPA) treatment including the type of sugar, permeable CPA (pCPA) combinations, and the equilibration regimen. This study compared the distinct points of CPA treatment of these 2 methods to determine the optimum CPA treatment for the solid surface vitrification of immature porcine oocytes. We vitrified and warmed follicular cumulus-oocyte complexes by our method (Somfai et al. 2014 PLoS One 9, e97731). In each experiment, the vitrification solution consisted of 50 mg mL–1 polyvinyl pyrrolidone, 0.3 M of the actual sugar, and 35% [v/v] in total of the actual pCPA combination (depending on the experiment). After warming, the cumulus-oocyte complexes were subjected to in vitro maturation, IVF, and embryo culture (Kikuchi et al. 2002 Biol. Reprod. 66, 1033–1041). Oocyte survival was assessed after IVF by morphological evaluation, and live oocytes were subjected to in vitro embryo culture. Cleavage and blastocyst rates were calculated from cultured oocytes on Day 2 (Day 0 = IVF) and Day 6, respectively. Each experiment was replicated at least 3 times. Results were analysed by ANOVA. In Experiment 1, we compared trehalose (n = 416) and sucrose (n = 440) as supplementations during vitrification and warming (0.3 M and 0.4 M of each, respectively). There was no significant difference between oocytes vitrified with trehalose or sucrose in terms of survival, cleavage, and blastocyst development (83.2% v. 80.3%, 39.7% v. 42.4%, and 3.6% v. 5.9%, respectively). Thus, vitrification and warming media were supplemented with sucrose thereafter. In Experiment 2, we compared 1 : 1 combinations of ethylene glycol with propylene glycol (EG+PG group, n = 452) and ethylene glycol with dimethyl sulfoxide (EG+DMSO group, n = 465) used as pCPA for equilibration (4% [v/v] pCPA in total for 15 min) and vitrification (35% [v/v] pCPA in total for 30 s). Oocyte survival rate was higher (P < 0.05) in the EG+PG group compared with the EG+DMSO group (73.8% v. 51.1%, respectively); however, cleavage and blastocyst development rates of surviving oocytes were not significantly different between the 2 groups (30.5% v. 44.5% and 4.1% v. 6.3%, respectively). In Experiment 3, we compared an equilibration treatment in 4% [v/v] of EG+PG for 13 to 15 min (regimen A, n = 368) with an equilibration in 15% [v/v] of EG+PG for 5 to 7 min (regimen B, n = 363) for oocyte vitrification. Survival, cleavage, and blastocyst development rates were higher (P < 0.01) for oocytes vitrified using regimen A compared with those vitrified using regimen B (82.5% v. 22.7%, 24.0% v. 7.7%, and 3.2% v. 0%, respectively). In conclusion, trehalose and sucrose are equally effective during vitrification and warming, the combination of EG+PG as pCPA is superior to EG+DMSO, and equilibration in 4% pCPA for 13 to 15 min is superior to that in 15% pCPA for 5 to 7 min for the vitrification of immature porcine oocytes.This work was partly supported by JSPS KAKENHI Grant Number 26870839.

296 IMPACT OF CO-CULTURING CUMULUS-ENCLOSED PORCINE OOCYTES WITH DENUDED OOCYTES DURING IN VITRO MATURATION IN A DEFINED MEDIUM ON CUMULUS EXPANSION AND OOCYTE MATURATION

Recent research has revealed that oocyte-secreted factors (OSF) affect cumulus expansion and play important roles during maturation and embryo development of mammalian oocytes. The use of denuded oocytes (DO) as supplements during in vitro maturation (IVM) in a nondefined medium improved developmental competence of cumulus-enclosed porcine oocytes (COC; Gomez et al. 2012 Zygote 20, 135–145). We investigated the effect of DO on cumulus expansion and nuclear maturation of COC in pigs during IVM using a defined medium. If the DO exert a positive influence on IVM, the defined medium can then be analysed for the presence of OSF. Immature COC were collected in the slaughterhouse from prepubertal gilts. To obtain DO, some COC were completely denuded by pipetting through a narrow-bore glass pipette. The COC used as a source for DO fulfilled the same morphological criteria as the COC used for IVM. The IVM medium was porcine oocyte medium (POM; Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213) with hormone supplementations applied only during the first 20 h of the IVM period. The COC were fixed to the bottom of 35-mm plastic Petri dishes in 3 × 3 grids by Cell-Tak (BD Bioscience, Bedford, MA, USA) in 100-µL droplets POM covered by paraffin oil. Culture droplets (each including 1 COC grid) were supplemented with (DO+ group, n = 179) or without 16 DO (DO– group, n = 143). After 20 h of IVM, the medium was replaced with a preincubated hormone-free POM and oocytes were cultured for an additional 28 h. At 0, 20, and 48 h of IVM, images of each grid were taken at the same magnification. The size of each COC was measured as a 2-dimensional area in pixels by analysing images with ImageJ software. Relative cumulus expansion was calculated at 20 and 48 h of IVM on the basis of the initial COC size at 0 h, which was assigned as 1. At 48 h of IVM, the COC were denuded and examined for oocyte maturation by orcein staining. The experiment was replicated 5 times. Cumulus expansion ratios at 20 and 48 h of IVM were compared between the DO+ and DO– groups by ANOVA. Maturation rates were compared between the DO+ and DO– groups by binary logistic regression. No difference in cumulus expansion between DO– and DO+ could be observed at 20 h (1.83 ± 0.04 and 1.75 ± 0.03, respectively) and 48 h (1.41 ± 0.03 and 1.47 ± 0.02, respectively) of IVM. Nuclear maturation rates of COC in DO– and DO+ groups did not differ significantly (39.0 ± 5.4 and 32.9 ± 8.8%, respectively). In conclusion, addition of DO to the defined IVM medium did not affect the cumulus expansion and oocyte maturation of follicular porcine COC. Further research is needed to assess the effects of DO during IVM on subsequent fertilization. If DO prove to be beneficial for fertilization, the nature of the OSF will be investigated.This study was supported by FCWO of UGent and by FWO-Flanders (grant number FWO11/ASP/276).

61 THE EFFECTS OF COLLECTION SEASON AND STORAGE DURATION IN LIQUID NITROGEN ON POST-WARMING SURVIVAL AND NUCLEAR MATURATION OF IMMATURE PORCINE OOCYTES PRESERVED BY SOLID SURFACE VITRIFICATION

We investigated the effects of collection season and storage duration of vitrified porcine oocytes in liquid nitrogen (LN2) on their survival and maturation ability after warming. A total of 3338 cumulus-enclosed oocytes were vitrified using solid surface vitrification, preserved, and warmed according to previous report (Somfai et al. 2014 PLoS One 9, e97731) in 26 occasions between October 2012 and March 2014. Vitrified oocytes were stored in LN2 for various durations from 0 (vitrified but without storage) to 243 days. The date of preservation and length of storage (days) of vitrified oocytes in LN2 were recorded. Warming of vitrified oocytes was conducted on a hotplate set at 42°C. After warming, oocytes were subjected to in vitro maturation according to Kikuchi et al. (2002 Biol. Reprod. 66, 1033–1041). Then oocytes were denuded and their live/dead status and nuclear maturation were assessed under stereo microscope based on their morphology and the presence of the first polar body. After linear regression analysis, it was found that there was no correlation between the duration of storage of vitrified oocytes in LN2 for up to 243 days and their survival rate after warming (R = 0.254; P = 0.210) or the maturation rate of surviving oocytes (R = 0.147; P = 0.471). Vitrification during spring (March 1–May 31) resulted in significantly higher rates of survived oocytes compared with vitrification during winter (December 1–February 28; 86.9 and 73.1%, respectively; P < 0.05), whereas the mean survival rates of oocytes vitrified during summer (June 1–August 31; 79.0%) and autumn (September 1–November 31; 81.9%) did not differ significantly from those of other seasons (ANOVA). After in vitro maturation, nuclear maturation of surviving oocytes did not differ significantly among oocytes vitrified at different seasons (ranging between 59.1 and 67.8%). The results indicate that the oocyte collection season affects survival of vitrified oocytes, whereas storage duration in LN2 does not affect this parameter. Furthermore, nuclear maturation of oocytes that survive after vitrification and warming is not affected by their collection season and storage length.This work was supported by JSPS KAKENHI Grant Number 26870839.

Lymphaticovenular anastomosis to prevent cellulitis associated with lymphoedema

BACKGROUND

One of the complications of lymphoedema is recurrent cellulitis. The aim was to determine whether lymphaticovenous anastomosis (LVA) was effective at reducing cellulitis in patients with lymphoedema.

METHODS

This was a retrospective review of patients with arm/leg lymphoedema who underwent LVA. The frequency of cellulitis was compared before and after surgery. The diagnostic criteria for cellulitis were a fever of 38·5°C or higher, and warmth/redness in the affected limb(s).

RESULTS

A total of 95 patients were included. The mean number of episodes of cellulitis in the year preceding surgery was 1·46, compared with 0·18 in the year after surgery (P < 0·001).

CONCLUSION

LVA reduced the rate of cellulitis in these patients with lymphoedema.

Porcine sperm capacitation involves tyrosine phosphorylation and activation of aldose reductase

Mammalian sperm must be activated in the tubal isthmus through capacitation to induce the acrosome reaction and subsequent fertilization. Although the molecular mechanisms involved in capacitation have yet to be fully elucidated, increased concentrations of reactive oxygen species (ROS) and the extent of tyrosine phosphorylation of proteins have been suggested to play central roles in the completion of capacitation. In this study, aldose reductase was for the first time identified as one of the tyrosine-phosphorylated proteins involved in the capacitation of porcine cauda epididymal sperm. Both tyrosine phosphorylation and activity of aldose reductase associated with the particulate fraction of sperm cells were significantly enhanced during capacitation. Alrestatin, a membrane-permeable and specific inhibitor of aldose reductase, plays a role in the inhibition of aldose reductase activity, elevation of intracellular levels of ROS, and induction of hyperactivated motility, all at similar dose dependencies. Alrestatin canceled both the increase in the tyrosine phosphorylation of aldose reductase and the decrease in the glutathione levels in sperm-induced during capacitation. The hyperactivated motility was induced to a higher extent in the presence of glucose than in the presence of fructose. These results indicate that aldose reductase plays an important role in induction of hyperactivation and capacitation of sperm through the elevation of ROS in sperm cells. Furthermore, aldose reductase was shown to be added to sperm during transit through the epididymis, suggesting that aldose reductase is one of the key proteins that support the functional maturation of sperm.

Saving genetic resources of native pigs in Occidental and Oriental countries - practical examples of the characterization and utilization of native pigs in Hungary and Laos

Worldwide, only a few "fatty" pig breeds exist with different and/or regional utilization. Using the Hungarian Mangalica, which almost went extinct in Europe and the Lao Moo Lat pig, which still has a large population in South-East Asia as exemples, we wanted to demonstrate that indigenous (fatty) pig breeds may represent both national value and tremendous economic potential. Since these less prolific and less productive breeds cannot contribute to mass production, new market roles and methods should be established for them in the premium segment of pork trading. Thus their preservation and propagation needs the comprehensive collaboration of commercial, governmental actors and researchers. Briefly summarizing the history, we report the current results of reproductive physiology research. The commercial renaissance of Mangalica pigs is indebted to the enthusiastic efforts of basic scientists, pig breeding experts and dedicated Mangalica producers. Scientific achievements were applied to practical breeding and production of delicious pork and processed products, which ultimately made the economic success in the Mangalica sector possible. Both, research on and utilization of endangered (pig) breeds maintain not only breed diversities, but also may improve the livelihood of farmers worldwide.

Generation of live piglets from cryopreserved oocytes for the first time using a defined system for in vitro embryo production

We report the successful piglet production from cryopreserved oocytes for the first time by using a simple, high capacity vitrification protocol for preservation and a defined system for in vitro embryo production. Immature cumulus-oocyte complexes (COCs) from prepubertal gilts were vitrified in microdrops and stored in liquid nitrogen. After warming, COCs were subjected to in vitro maturation (IVM), fertilization (IVF), and subsequent culture (IVC). Adjusting warmplate temperature to 42°C during warming prevented temperature drops in a medium below 34.0°C and significantly increased the percentage of oocyte survival and thus blastocyst yields obtained from total vitrified oocytes compared with that of warming at 38°C (87.1% vs 66.9% and 4.4% vs 2.7%, respectively). Nuclear maturation and fertilization of oocytes were not affected by vitrification and warming temperature. Blastocyst development on day 7 (day 0 = IVF) of the surviving oocytes after warming at 38°C and 42°C was not different but lower (P<0.05) than those of non-vitrified control oocytes (4.6%, 5.2% and 17.9%, respectively). However, blastocyst cell numbers in the control and vitrified groups were similar irrespective of warming temperature. Omitting porcine follicular fluid (pFF) from IVM medium (POM) did not affect maturation, fertilization and embryo development of vitrified-warmed oocytes. Transfer of blastocysts obtained on day 5 from vitrified oocytes matured either with or without pFF into 4 recipients (2 for each group) resulted in 4 pregnancies and the delivery of a total of 18 piglets. In conclusion, optimization of warming temperature was a key factor for achieving high survival rates, and surviving oocytes could be utilized in vitro using defined media. Using these modifications, live piglets could be obtained from cryopreserved oocytes for the first time.

Delay in cleavage of porcine embryos after intracytoplasmic sperm injection (ICSI) shows poorer embryonic development

In pigs, the embryonic developmental ability after intracytoplasmic sperm injection (ICSI) is inferior to that resulting from in vitro fertilization (IVF). We evaluated the timing of cell division up to blastocyst formation on embryonic development after ICSI using either whole sperm (w-ICSI) or the sperm head alone (h-ICSI) and IVF as a control. At 10 h after ICSI or IVF, we selected only zygotes, and each of the zygotes/embryos was evaluated for cleavage every 24 h until 168 h. We then observed a delay in the 1st and 2nd cleavages of h-ICSI embryos and also in blastocoele formation by w-ICSI embryos in comparison with IVF embryos. The rate of blastocyst formation and the quality of blastocysts in both ICSI groups were inferior to those in the IVF group. In conclusion, the delay in cleavage of porcine ICSI embryos shows poorer embryonic development.

Production of Middle White piglets after transfer of embryos produced in vitro

The present study was conducted to examine the feasibility of in vitro embryo production and transfer technologies for producing Middle White piglets. After collection from three retired Middle White sows, a total of 222 oocytes were matured, fertilized and cultured in vitro, and a total of 50 embryos from the 4-cell to blastocyst stage were produced by the 4th or 5th day. These embryos were transferred individually into three recipients along with 5 in vivo-derived Duroc blastocysts. All of the recipients became pregnant, and they farrowed a total of 9 Middle White and 9 Duroc piglets. These results suggest that in vitro embryo production using ovaries from retired sows is useful for reproduction of pigs of pure breeds including the Middle White for breeding activities and conservation/utilization of genetic resources.

Roles of the zona pellucida and functional exposure of the sperm-egg fusion factor 'IZUMO' during in vitro fertilization in pigs

The zona pellucida (ZP) is considered to play important roles in the prevention of polyspermy in mammalian oocytes. However, in pigs we have shown that the presence of the ZP accelerates sperm penetration into the ooplasm during in vitro fertilization (IVF). In the present study, we investigated the effects of the ZP on sperm binding, acrosomal status, and functional exposure of IZUMO, a critical factor involved in sperm-egg fusion, during IVF in pigs. We evaluated the numbers and acrosomal statuses of sperm binding to the ZP and oolemma, and being present in the ZP and perivitelline space (PVS) using ZP-intact and ZP-free oocytes. More sperm bound to the ZP than to the oolemma. The average number of sperm present in the PVS was 0.44-0.51 per oocyte, and all sperm had lost their acrosomes. The proportion of sperm that were immunopositive for anti-IZUMO antibody was significantly higher after they were passing or had passed through the ZP. Furthermore, addition of anti-IZUMO antibody to the fertilization medium significantly inhibited the penetration of sperm into ZP-free oocytes. These results suggest that, in pigs, the ZP induces the acrosome reaction, which is associated with the functional exposure of IZUMO, resulting in completion of fertilization.

Evaluation of diffusivity in the anterior lobe of the pituitary gland: 3D turbo field echo with diffusion-sensitized driven-equilibrium preparation

BACKGROUND AND PURPOSE

3D turbo field echo with diffusion-sensitized driven-equilibrium preparation is a non-echo-planar technique for DWI, which enables high-resolution DWI without field inhomogeneity-related image distortion. The purpose of this study was to evaluate the feasibility of diffusion-sensitized driven-equilibrium turbo field echo in evaluating diffusivity in the normal pituitary gland.

MATERIALS AND METHODS

First, validation of diffusion-sensitized driven-equilibrium turbo field echo was attempted by comparing it with echo-planar DWI. Five healthy volunteers were imaged by using diffusion-sensitized driven-equilibrium turbo field echo and echo-planar DWI. The imaging voxel size was 1.5 × 1.5 × 1.5 mm(3) for diffusion-sensitized driven-equilibrium turbo field echo and 1.5 × 1.9 × 3.0 mm(3) for echo-planar DWI. ADCs measured by the 2 methods in 15 regions of interests (6 in gray matter and 9 in white matter) were compared by using the Pearson correlation coefficient. The ADC in the pituitary anterior lobe was then measured in 10 volunteers by using diffusion-sensitized driven-equilibrium turbo field echo, and the results were compared with those in the pons and vermis by using a paired t test.

RESULTS

The ADCs from the 2 methods showed a strong correlation (r = 0.79; P < .0001), confirming the accuracy of the ADC measurement with the diffusion-sensitized driven-equilibrium sequence. The ADCs in the normal pituitary gland were 1.37 ± 0.13 × 10(-3) mm(2)/s, which were significantly higher than those in the pons (1.01 ± 0.24 × 10(-3) mm(2)/s) and the vermis (0.89 ± 0.25 × 10(-3) mm(2)/s, P < .01).

CONCLUSIONS

We demonstrated that diffusion-sensitized driven-equilibrium turbo field echo is feasible in assessing ADC in the pituitary gland.

157 LEUKEMIA INHIBITORY FACTOR IMPROVES OOCYTE MATURATION AND DEVELOPMENTAL COMPETENCE IN PIGS

A variety of growth factors and cytokines that are present in follicular fluid provide oocytes with a suitable environment for their maturation. One such cytokine is leukemia inhibitory factor (LIF). Although LIF-supplemented medium enhances embryo development in human, mouse, and bovine, studies investigating the effects of LIF on in vitro maturation (IVM) and subsequent embryo development are inconclusive. Additionally, the underlying mechanisms of LIF in oocyte maturation and embryo development after IVF have not been studied yet. In the present study, we examined the effect of recombinant porcine LIF (pLIF), produced in our laboratory, on porcine oocyte maturation and the mechanism of how LIF involves in oocyte maturation process at molecular level. The biological activity of pLIF was evaluated by sustenance of mouse embryonic stem (ES) cells with an undifferentiating state in ES medium supplemented with pLIF, and the final concentration (1 : 200, equivalent to 1000 U mL–1 of mouse LIF) was determined by serial dilution. Porcine cumulus–oocyte complexes (COC) were cultured in modified NCSU-37 medium supplemented with pLIF during the first 22 h [pLIF (+, –)], the latter 22 h [pLIF (–, +)], or whole 44 h [pLIF (+, +)] of IVM and the proportion of metaphase II (M-II) stage oocytes was observed. Oocyte maturation was enhanced in each group by supplementation with pLIF [pLIF (+, –): 76.1%, n = 138; pLIF (–, +): 82.1%, n = 140; pLIF (+, +): 86.6%, n = 127], when compared with control [pLIF (–, –): 69.6%, n = 112], in which a significant increase of M-II rate (P < 0.05 by ANOVA) and cumulus expansion were observed in the pLIF (+, +) group. The effect of pLIF was only seen for COC but not for denuded oocytes. When oocytes were subjected to IVF (Kikuchi et al. 2002), those matured in pLIF (+, +)-supplemented medium demonstrated higher blastocyst developmental rates (21.1% v. 16.2%; P = 0.07) with increased cell numbers (50.2 cells v. 45.0 cells; P = 0.12) compared with pLIF (–, –) on Day 6 of embryo culture (IVF = 0). Examination of transcripts and proteins of the LIF signalling pathway revealed that mRNA and protein levels of LIF, LIF receptors, and signal transducer and activator of transcription 3 (STAT3) were similar in both pLIF (–, –) and pLIF (+, +) samples. However, notable phosphorylation of STAT3 was observed in the pLIF (+, +) sample. These results suggest that the LIF/STAT3-pathway is functional during oocyte maturation in pigs. Therefore, supplementation of maturation medium with pLIF could improve the developmental competence of oocytes by activation of this pathway. This project was supported by JSPS and HAS under the Japan-Hungary Research Cooperative Program.

44 PRODUCTION OF LIVE PIGLETS AFTER CRYOPRESERVATION OF IMMATURE PORCINE OOCYTES

Development to term of vitrified porcine follicular oocytes is reported in the present study. Immature cumulus-oocyte complexes (COC) were collected from slaughtered prepubertal gilts and were vitrified according to our method published recently (Somfai et al. 2013 J. Reprod. Dev., in press). Briefly, after pretreatment with 7.5 μg mL–1 of cytochalasin B (CB) for 30 min in modified NCSU-37 (a basic medium, BM) at 38.5°C, groups of 88 to 121 COC were equilibrated in a mixture of 2% ethylene glycol (EG), 2% propylene glycol (PG), and 7.5 μg mL–1 CB for 13 to 15 min. Then, COC were washed in vitrification solution (17.5% EG, 17.5% PG, 5% polyvinyl pyrrolidone, and 0.3 M trehalose in BM) and then dropped with 2 μL of vitrification solution onto the surface of aluminum foil floating on liquid nitrogen (LN2). Microdroplets (each containing 10–25 COC) were transferred into cryotubes. After storage in LN2 for 2 to 4 weeks, the oocytes were warmed by dropping the microdroplets directly into 2.5 mL of warming solution (0.4 M trehalose in BM) kept in a 35-mm Petri dish on a 42°C hotplate for less than 1 min. Then, the warming dish was placed on a 38°C hotplate and COC were consecutively transferred for 1-min periods into BM containing 0.2, 0.1, or 0.05 M trehalose at 38°C. The COC were matured in vitro for 44 h using porcine oocyte medium (POM) supplemented with 10% follicular fluid (Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213). Then, oocytes were denuded, and their live/dead status and nuclear maturation were determined by their morphology and the presence of the first polar body, respectively. To assess their developmental competence, vitrified and non-vitrified (control) oocytes were in vitro fertilized (IVF; Kikuchi et al. 2002 Biol. Reprod. 66, 1033–1041) and then in vitro cultured in porcine zygote medium-5 (PZM-5; Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213). Blastocyst rates were recorded on Days 5, 6, and 7 of culture (Day 0 = the day of IVF). The experiment was replicated 4 times. Data were analysed with 1-way ANOVA and the Tukey test. The results revealed that 86.4% (364/424) of oocytes survived after vitrification, which was significantly lower (P < 0.05) than that of controls [100% (326/326)]. Live oocytes in vitrified and control groups did not differ statistically in terms of nuclear maturation (63.9 v. 65.3%). Blastocyst rates of surviving vitrified oocytes were significantly lower compared with controls on Days 5 (2.4 v. 12.7%), 6 (4.8 v. 17.6%), and 7 (5.6 v. 18.4%). To test their ability to develop to term, 16 and 27 blastocysts on Day 5 developing from vitrified COC were transferred into 2 recipients. Both recipients became pregnant and farrowed a total of 10 live piglets (4 and 6 piglets, respectively). These data demonstrate that large groups of immature porcine oocytes could be cryopreserved by this method showing high survival and maturation rates. Furthermore, despite a low rate of blastocyst development, transfer of Day-5 blastocysts generated from vitrified oocytes resulted in piglet production for the first time in the world. Partially supported by JSPS and HAS under the Japan-Hungary Research Cooperative Program.

Leukemia inhibitory factor promotes porcine oocyte maturation and is accompanied by activation of signal transducer and activator of transcription 3

We produced recombinant porcine leukemia inhibitory factor (pLIF) and examined its effect on in vitro maturation (IVM) of porcine oocytes and their developmental competence after in vitro fertilization. Porcine cumulus-oocyte complexes (COCs) were matured in a medium supplemented with pLIF during the first 22 hr, last 22 hr, or entire 44 hr duration of IVM. Oocytes in all groups tended to show enhanced nuclear maturation rates by the metaphase II (MII) stage (76.1%, 82.1%, and 86.6%, respectively) compared to the without-pLIF treatment group (69.6%, control). A significant increase in MII rate (P < 0.05) and obvious induction of cumulus expansion were observed over the whole time span (44 hr) in the IVM group. When cumulus cells were removed at 22 hr and denuded oocytes were further cultured, pLIF showed no effect on maturation rate. Oocytes matured in pLIF-supplemented medium showed a tendency for more rapid blastocyst development (21.1% vs. 16.2%, P = 0.0715). Examination of transcripts and proteins of the LIF signaling pathway in COCs revealed that LIF, LIF receptors, and signal transducer and activator of transcription 3 (STAT3) are present in both cumulus cells and oocytes. The amount of phosphorylated STAT3 (p-STAT3) markedly increased in both cumulus cells and oocytes cultured in pLIF-supplemented media, although oocyte p-STAT3 disappeared after 44 hr of IVM. These results suggest that the LIF/STAT3 pathway is functional during IVM of porcine oocytes, and supplementing pLIF in the IVM medium can improve oocyte maturation by activating this pathway.

Evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry for species identification of Acinetobacter strains isolated from blood cultures

The clinical relevance of Acinetobacter species, other than A. baumannii, as human pathogens has not been sufficiently assessed owing to the insufficiency of simple phenotypic clinical diagnostic laboratory tests. Infections caused by these organisms have different impacts on clinical outcome and require different treatment and management approaches. It is therefore important to correctly identify Acinetobacter species. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been introduced to identify a wide range of microorganisms in clinical laboratories, but only a few studies have examined its utility for identifying Acinetobacter species, particularly those of the non-Acinetobacter baumannii complex. We therefore evaluated MALDI-TOF MS for identification of Acinetobacter species by comparing it with sequence analysis of rpoB using 123 isolates of Acinetobacter species from blood. Of the isolates examined, we identified 106/123 (86.2%) to species, and 16/123 (13.0%) could only be identified as acinetobacters. The identity of one isolate could not be established. Of the 106 species identified, 89/106 (84.0%) were confirmed by rpoB sequence analysis, and 17/106 (16.0%) were discordant. These data indicate correct identification of 89/123 (72.4%) isolates. Surprisingly, all blood culture isolates were identified as 13 species of Acinetobacter, and the incidence of Acinetobacter pittii was unexpectedly high (42/123; 34.1%) and exceeded that of A. baumannii (22/123; 17.9%). Although the present identification rate using MALDI-TOF MS is not acceptable for species-level identification of Acinetobacter, further expansion of the database should remedy this situation.

Fertilization ability of porcine oocytes reconstructed from ooplasmic fragments produced and characterized after serial centrifugations

Mitochondria are reported to be critical in in vitro maturation of oocytes and subsequent embryo development after fertilization, but their contribution for fertilization has not been investigated in detail. In the present study, we investigate the contribution of mitochondria to fertilization using reconstructed porcine oocytes by fusion of ooplasmic fragments produced by serial centrifugations (centri-fusion). Firstly, we evaluated the characteristics of ooplasmic fragments. Three types of fragments were obtained by centrifugation of porcine oocytes matured in vitro for 46 h: brownish (B), transparent (T) and large (L) fragments containing both B and T parts in a fragment. The production efficiencies of these types of fragments were 71.7, 91.0 and 17.8 fragments/100 oocytes, respectively. In experiments, L fragments were excluded because they contained both brownish and transparent components that were apparently intermediate between B and T fragments. Observations by confocal microscopy after staining with MitoTracker Red CMXRos® and transmission electron microscopy revealed highly condensed active mitochondria in B fragments in contrast to T fragments that contained only sparse organelles. We reconstructed oocytes by fusion of a karyoplast and two cytoplasts from B and T fragments (B and T oocytes, respectively). The B oocytes showed higher sperm penetration (95.8%) and male pronuclear formation rates (94.2%) by in vitro fertilization than T oocytes (66.7% and 50.0%, respectively). These results suggest that the active mitochondria in oocytes may be related to their ability for fertilization.

Generation of live piglets for the first time using sperm retrieved from immature testicular tissue cryopreserved and grafted into nude mice

Cryopreservation of immature testicular tissues is essential for increasing the possibilities of offspring generation by testicular xenografting for agricultural or medical purposes. However, successful production of offspring from the sperm involved has never been reported previously. In the present study, therefore, using intracytoplasmic sperm injection (ICSI), we examined whether xenogeneic sperm obtained from immature pig testicular tissue after cryopreservation would have the capacity to produce live piglets. Testicular fragments from 9- to 11-day-old piglets were vitrified after 10- or 20-min immersion in vitrification solution containing ethylene glycol (EG), polyvinyl pyrrolidone (PVP) and trehalose as cryoprotectants, and then stored in liquid nitrogen for more than 140 days. Thirty nude mice were assigned to each immersion-time group. Testicular fragments were transplanted under the back skin of castrated mice immediately after warming and removal of the cryoprotectants. Blood and testicular grafts were then recovered from the recipient mice on days 60, 120, 180 and 230−350 (day 0 =  grafting). Histological assessment of the testicular grafts and analyses of inhibin and testosterone production revealed no significant differences between the two immersion-time groups, indicating equal growth activity of the cryopreserved tissues. A single sperm obtained from a mouse in each group on day 230−350 was injected into an in vitro-matured porcine oocyte, and then the ICSI oocytes were transferred to the oviducts of estrus-synchronized recipient gilts. One out of 4 gilts that had received oocytes fertilized using sperm from the 10-min immersion group delivered 2 live piglets, and one of another 4 gilts from the 20-min group delivered 4 live piglets. Thus, we have successfully generated porcine offspring utilizing sperm from immature testicular tissues after cryopreservation and transplantation into nude mice. The present model using pigs will be applicable to many large animals, since pigs are phylogenetically distant from the murine recipients.

Effects of the estrous cycle on the efficacy of oocyte collection and in vitro embryo production in Duroc-breed

Collection efficacy and in vitro embryo developmental ability of oocytes obtained from Duroc-breed ovary donors at different stages of the estrous cycle (days 6, 12 and 16 after estrus) were performed. The numbers of collected oocytes did not differ significantly among the different estrous cycle groups (total 72-90 oocytes per gilt). However, the blastocyst rates of oocytes collected on days 12 and 16 (9.2% and 19.4%, respectively) were significantly higher than those on day 6 (1.1%). More oocytes were obtained on day 16 from small follicles (<2 mm in diameter; 85.3 oocytes per gilt) than from medium-sized (≥2-<6 mm) and large (≥6 mm) follicles (17.5 and 12.8 oocytes, respectively). The blastocyst rates in both the medium-sized and large follicle groups (20.0% and 19.2%, respectively) were significantly higher than that in the small follicle group (6.3%). The blastocyst cell numbers in both the medium-sized and large follicle groups (39.4 and 43.3 cells, respectively) were significantly higher than that in the small follicle group (30.6 cells). The results suggest that oocyte collection from cycling Duroc pigs can be carried out efficiently from the late luteal to follicular stage. Those oocytes collected from medium-sized and large follicles show better embryo development.

Telomere elongation during morula-to-blastocyst transition in cloned porcine embryos

Although telomeres are elongated during morula-to-blastocyst transition in cloned embryos, it is still unknown whether donor cell types have any effect on this elongation. In the present study, we examined the changes of telomere length during morula-to-blastocyst transition in cloned porcine embryos using different types of donor cells. Porcine embryonic stem-like cells (pESLCs), porcine cumulus cells (PCs), and porcine embryonic fibroblasts at passages 7 and 10 (PEF7s and PEF10s, respectively) were used as donor cells. Telomere lengths of pESLCs (35.8±1.5 kb), PCs (24.4±0.5 kb), PEF7s (18.7±0.6 kb), and PEF10s (17.2±0.1 kb) were significantly different. In contrast, telomere length in morulae derived from pESLCs (18.2±0.3 kb), PC (17.8±0.7 kb), PEF7 (18.5±0.3 kb), and PEF10 (18.4±0.4 kb) did not differ significantly. Likewise, telomeres in blastocysts derived from pESLCs (22.3±1.5 kb), PCs (23.5±2.6 kb), PEF7s (20.2±1.0 kb), and PEF10s (20.9±1.0 kb) had similar lengths. However, telomeres in blastocysts were significant longer (p<0.05) compared with morulae in each group. Relative telomerase activities of morulae derived from pESLCs (4.2±0.4), PCs (4.0±0.5), PEF7s (5.1±0.4), and PEF10s (4.9±0.4) were significantly lower (p<0.01) than those of blastocysts derived from pESLCs (8.2±1.1), PCs (8.6±0.6), PEF7s (12.5±2.9), and PEF10s (8.3±1.1). In conclusion, the telomere elongation in cloned pig embryos that occurred during morula-to-blastocyst transition may be related to the rise of telomerase activity. The telomere elongation may also be independent of the type and telomere length of the donor cell.

Proof-of-concept rare cancers in drug development: the case for rhabdomyosarcoma

Rare diseases typically affect fewer than 200,000 patients annually, yet because thousands of rare diseases exist, the cumulative impact is millions of patients worldwide. Every form of childhood cancer qualifies as a rare disease-including the childhood muscle cancer, rhabdomyosarcoma (RMS). The next few years promise to be an exceptionally good era of opportunity for public-private collaboration for rare and childhood cancers. Not only do certain governmental regulation advantages exist, but these advantages are being made permanent with special incentives for pediatric orphan drug-product development. Coupled with a growing understanding of sarcoma tumor biology, synergy with pharmaceutical muscle disease drug-development programs, and emerging publically available preclinical and clinical tools, the outlook for academic-community-industry partnerships in RMS drug development looks promising.

Evaluation of zona pellucida function for sperm penetration during in vitro fertilization in pigs

In porcine oocytes, the function of the zona pellucida (ZP) with regard to sperm penetration or prevention of polyspermy is not well understood. In the present study, we investigated the effects of the ZP on sperm penetration during in vitro fertilization (IVF). We collected in vitro-matured oocytes with a first polar body (ZP+ oocytes). Some of them were freed from the ZP (ZP− oocytes) by two treatments (pronase and mechanical pipetting), and the effects of these treatments on sperm penetration parameters (sperm penetration rate and numbers of penetrated sperm per oocyte) were evaluated. There was no evident difference in the parameters between the two groups. Secondly, we compared the sperm penetration parameters of ZP+ and ZP− oocytes using frozen-thawed epididymal spermatozoa from four boars. Sperm penetration into ZP+ oocytes was found to be accelerated relative to ZP− oocytes. Thirdly, we evaluated the sperm penetration of ZP+ and ZP− oocytes at 1−10 h after IVF (3 h gamete co-incubation). The proportions of oocytes penetrated by sperm increased significantly with time in both groups; however, the number of penetrated sperm per oocyte did not increase in ZP− oocytes. Finally, we performed IVF using ZP− oocytes divided into control (3 h) and prolonged gamete co-incubation (5 h) groups. Greater numbers of sperm penetrated in the 5 h group than in the control group. These results suggest that the ZP and oolemma are not competent factors for prevention of polyspermy in our present porcine IVF system. However, it appears that ZP removal is one of the possibilities for reducing polyspermic penetration in vitro in pigs.

Comparison of ethylene glycol and propylene glycol for the vitrification of immature porcine oocytes

Our aim was to optimize a cryoprotectant treatment for vitrification of immature porcine cumulus-oocyte complexes (COCs). Immature COCs were vitrified either in 35% ethylene glycol (EG), 35% propylene glycol (PG) or a combination of 17.5% EG and 17.5% PG. After warming, the COCs were in vitro matured (IVM), and surviving oocytes were in vitro fertilized (IVF) and cultured. The mean survival rate of vitrified oocytes in 35% PG (73.9%) was higher (P<0.05) than that in 35% EG (27.8%). Oocyte maturation rates did not differ among vitrified and non-vitrified control groups. Blastocyst formation in the vitrified EG group (10.8%) was higher (P<0.05) than that in the vitrified PG group (2.0%) but was lower than that in the control group (25.0%). Treatment of oocytes with 35% of each cryoprotectant without vitrification revealed a higher toxicity of PG on subsequent blastocyst development compared with EG. The combination of EG and PG resulted in 42.6% survival after vitrification. The maturation and fertilization rates of the surviving oocytes were similar in the vitrified, control and toxicity control (TC; treated with EG+PG combination without cooling) groups. Blastocyst development in the vitrified group was lower (P<0.05) than that in the control and TC groups, which in turn had similar development rates (10.7%, 18.1% and 23.3%, respectively). In conclusion, 35% PG enabled a higher oocyte survival rate after vitrification compared with 35% EG. However, PG was greatly toxic to oocytes. The combination of 17.5% EG and 17.5% PG yielded reasonable survival rates without toxic effects on embryo development.