136 IMPACT OF SELECTION SYSTEM BY KINETICS ON THE EARLY EMBRYONIC DEVELOPMENT IN BOVINE OVUM PICKUP-IVF EMBRYOS

Recently, in vitro-produced (IVP) embryos have been increasingly produced using ovum pickup (OPU) and IVF in cows worldwide. However, the conception rate of IVP embryos is lower than that of in vivo-derived embryos. This study was conducted to determine the proportion of embryos that led to a high conception rate when the embryos were selected according to the 4 predicting factors. A total of 30 Holstein and 20 Japanese Black cows were used, and 81 OPU-IVF sessions were performed from October 2014 to May 2016. The collected cumulus-oocyte complexes (COC) were cultured for 22 h. Capacitated sperm (at a final concentration of 5 × 106 spermatozoa/mL) were incubated with COC for 6 h. After insemination, presumptive zygotes were separated from cumulus cells and sperm by pipetting. Then, the presumptive zygotes were cultured for 9 days in CR1aa supplemented with 5% calf serum by using a micro-well culture dish (Dai Nippon Printing, Tokyo, Japan). The kinetics of embryo development was observed at 27, 31, and 55 h post-insemination (hpi). The 4 factors used to select embryos were as follows: (1) time at which first cleavage occurred (less than 27 hpi, or less than 31 hpi, in case any of the zygotes did not cleave at 27 hpi in each culture dish); (2) 2 blastomeres after first cleavage at 31 hpi; (3) absence of fragments after first cleavage at 31 hpi; and (4) 8 or more blastomeres at 55 hpi. The number of blastocysts was analysed at 7, 8, and 9 days post IVF. Additionally, the number of produced embryos that could be used for embryo transfer (ET) was determined. The data were analysed using the chi-square test. The total numbers of blastocysts and produced embryos were 615 and 503, respectively. The numbers of blastocysts and produced embryos selected using the combination of factors 1 to 4 were 200 (32.5%) and 169 (27.5%), respectively. The numbers of blastocysts and produced embryos selected using factor 1 were 397 (64.6%) and 340 (67.6%), using factor 2 were 445 (71.3%) and 378 (75.1%), using factor 3 were 364 (81.8%) and 307 (81.2%), and using factor 4 were 374 (60.8%) and 308 (61.2%), respectively. The numbers of blastocysts and produced embryos that were rejected using a combination of factors 1 to 4 were 123 (27.5%) and 90 (17.9%), respectively. The conception rate of fresh embryo transfer was 46.6% (n = 73). We found that the conception rate of the embryos selected using factors 1 to 4 was significantly (P < 0.05) higher than that of embryos without one factor or more [60.0% (n = 35) v. 29.4% (n = 34)]. These results show the applicability and efficiency of the 4 factors for producing embryos with a high competence for conception.

49 SUCCESSFUL CRYOPRESERVATION USING LOW ETHYLENE GLYCOL CONCENTRATION FOR IN VITRO-PRODUCED BOVINE EMBRYOS

In vitro-produced (IVP) bovine embryos tend to have a lower survival rate after cryopreservation than in vivo embryos do. Therefore, the freezing medium (FM) and concentration of cryoprotectant are very important factors. This study was to investigate the effect of 1.2 M ethylene glycol (EG) with 0.1 M sucrose (SUC) on survival of IVP embryos after freezing. The COC were matured in 25 mM HEPES-buffered TCM199 (TCM199) supplemented with 5% calf serum (CS) and 0.02 AU mL−1 FSH. Oocytes (20 to 25) were cultured in 100-μL droplets of maturation medium for 20 h. After 6 h of gamete co-culture (5 × 106 sperm/mL), the presumptive zygotes were cultured in CR1aa medium supplemented with 5% CS for 9 days (fertilization = Day 0). Only the expanded blastocysts from Days 7 to 9 were used in this experiment and separated into 3 treatment groups. The first and second groups were frozen in Dulbecco’s phosphate-buffered saline (D-PBS) supplemented with 20% CS, 0.1 M SUC, and 1.2 or 1.5 M EG (groups 1.2 or 1.5 M EG), respectively. The third group was D-PBS supplemented with 20% fetal calf serum (FCS), 0.25 M SUC, and 1.4 M glycerol (group GLY). In each group, embryos were equilibrated with their FM for 10 min and loaded into 0.25-mL straws individually. These straws were placed into the cooling chamber of a programmable freezer precooled to −7°C. After 2 min, the straws were seeded and then held for a further 13 min at −7°C. Then, the straws were cooled to −30°C at −0.3°C/min before being plunged into liquid nitrogen. The cryopreserved embryos were thawed by allowing the straws to stand in air for 7 s and then warming them in a 30°C water bath for 20 s. The thawed embryos were washed twice using 38°C D-PBS supplemented with 20% FCS. Subsequently, they were immersed in the same medium, held at 38°C for 10 min, and then each embryo was cultured in 20-μL droplets of TCM199 supplemented with 20% FCS and 0.1 mM β-mercaptoethanol for 72 h. The rates of embryos developing to the re-expanded and hatching blastocyst stages were determined 72 h after thawing. All data were analysed by the chi-squared test with Yates’ correction. The re-expanded and hatching rates of frozen-thawed embryos after 72 h in culture were not significantly different between 1.2 M EG (n = 39: 71.8% and 69.2%), 1.5 M EG (n = 38: 76.3% and 63.2%), and 1.4 M GLY (n = 37: 75.7% and 64.9%) groups (P > 0.05). Survival and hatching rates according to embryo quality were also not significantly different between 1.2 M EG (good n = 18: 88.9% and 88.9%; fair n = 21: 57.1% and 52.4%), 1.5 M EG (good n = 19: 89.5% and 84.2%; fair n = 19: 63.2% and 42.1%), and 1.4 M GLY (good n = 18: 77.8% and 66.7%; fair n = 19: 73.7% and 63.2%) (P > 0.05). In conclusion, cryoprotectant type and concentration did not affect embryo survival or development after cryopreservation in this study. Therefore, the ethylene glycol concentration used for the cryopreservation of IVP embryos can be reduced.

164 EFFECTS OF KINETICS AND MORPHOLOGY ON EARLY EMBRYONIC DEVELOPMENT IN BOVINE OPU-IVF EMBRYOS

In recent years, the use of ovum pick up (OPU) and IVF for embryo production has increased worldwide; however, the conception rate of embryo transfer is lower for OPU-IVF embryos than for in vivo-derived embryos. This study aimed to determine the efficacy of embryo selection by a 3-step observation method by using a micro-well culture dish (Dai Nippon Printing, Tokyo, Japan). In this study, 9 Holstein and 15 Japanese Black cows were used, and the OPU-IVF was conducted from October 2014 to May 2015. The collected cumulus-oocyte complexes (COC) were cultured for 22 h in 25 mM HEPES-buffered TCM-199 supplemented with 5% calf serum (CS) and 0.02 AU mL–1 of FSH. Sperm (at a final concentration of 5 × 106 spermatozoa mL–1) were incubated with COC for 6 h. After insemination, presumptive zygotes were separated from cumulus cells and sperm by pipetting. Then, the presumptive zygotes were cultured for 9 days in CR1aa supplemented with 5% CS by using a micro-well culture dish. Kinetics and morphology were observed at 27, 31, and 55 h post-insemination (hpi). The presumptive zygotes were divided to 3 groups (more than 2 cells, 2 cells, and no cleavage) at 27 and 31 hpi. Then, embryos at the 2-cell stage at 31 hpi were divided into 2 groups: 2-cell with normal cleavage and 2-cell embryos with abnormal cleavage (unequal cleavage, 2-cell with fragments, and 2-cell with protrusion). Subsequently, embryos were classified as 8-cell and more than 8 cell, or less than 8 cell at 55 hpi. The blastocyst rate (BL%) was analysed at 7, 8, and 9 days post IVF. Embryos selected by the 3-step observation method were used for fresh embryo transfer. The data were analysed by chi-squared test. In total, 856 oocytes were collected by OPU and 633 oocytes were cultured, of which 39.7% (263/663) developed to the blastocyst stage. The BL% of 2-cell embryos (72.5%, 116/160) was significantly higher (P < 0.01) than that of no cleavage (47.0%, 117/249) at 27 hpi. The BL% of 2-cell (65.4%, 206/315) and more than 2-cell (53.0%, 35/66) was significantly higher (P < 0.01 and P < 0.05) than that of embryos divided as no cleavage (25.9%, 22/85) at 31 hpi. The BL% was not significantly different between 2-cell with normal cleavage (68.5%, 172/251) and abnormal cleavage (53.1%, 34/64). The BL% of 8-cell and more than 8-cell stage (72.8%, 182/250) was significantly higher (P < 0.01) than that of embryos with less than 8 cells (38.8%, 81/209) at 55 hpi. Overall, 2-cell embryos at 27 hpi, 2-cell embryos with normal cleavage at 31 hpi, and 8-cell and more than 8 cell at 55 hpi showed the highest BL% (82.1%, 78/91). The conception rate was higher for following the selected fresh embryo transfer that was 70.6% (12/17) than average of in vitro fertilization embryos transfer that was 40.0%. These results demonstrate that the 3-step observation method used in this study can be effectively applied for the selection of IVF embryos that have a strong ability to develop into blastocysts and high competence for conception.

242 PROMISING TWO-STEP EVALUATION SYSTEM FOR SELECTING HIGH DEVELOPMENTAL COMPETENCE IN VITRO FERTILIZED EMBRYOS IN CATTLE USING WELL-OF-THE-WELL DISH

Bovine IVF embryos are evaluated morphologically using light microscopy just before transfer. However, this evaluation method is subjective, and an objective method with more certainty is needed. Sugimura et al. (PLoS ONE 2012 7, e36627) reported a promising system for selecting healthy IVF bovine embryo by using time-lapse cinematography and 5 prognostic factors. This study was to investigate the efficacy of a 2-step evaluation system of IVF embryos using microscopy for selecting high developmental competence IVF embryos. Cumulus-oocyte complexes (COC) were collected by ovarian follicular aspiration (2 to 5 mm diameter) obtained from a local abattoir. The COC (n = 488) were matured in TCM-199 medium supplemented with 5% calf serum (CS) and 0.02 IU mL–1 of FSH at 38.5°C for 20 h in an atmosphere of 5% CO2 (20 COC 100 µL–1 droplets). After 10 h of gametes co-culture (5.0 × 106 sperm cells mL–1), the presumptive zygotes were cultured in 125 µL of CR1 aa medium supplemented with 5% CS in well of-the-well culture dishes (AS ONE, Japan; 25 zygotes well–1) at 38.5°C in an atmosphere of 5% CO2, 5% O2, and 90% N2 for 9 days. Two-step evaluations of embryos were done at 27 and 55 h post-IVF (hpi). In the first step of evaluation, cleavage patterns at 27 hpi were categorized as mono-cell, 2-cell with even blastomeres and without fragments (normal cleavage), 2-cell with uneven blastomeres, and ≥3 blastomeres. During the second step of evaluation, embryos were classified by their number of blastomeres (2 to 5 cells, 6 to 8 cells, and >8 cells) and the absence or presence of multiple fragments (<20 or >20%) at 55 hpi. The data were analysed by chi-square test. The blastocyst rate (BL%) of embryos cleaved before 27 hpi (56.6%, n = 106) was higher (P < 0.01) than those of embryos cleaved after 27 hpi (37.0%, n = 235). A greater percentage (P < 0.05) of 2-cell embryos with normal cleavage (68.0%, n = 50) developed to blastocysts than from with =3 blastomeres at 27 hpi (40.6%, n = 32). Superior BL% (P < 0.01) was obtained from embryos categorized as 6- to 8-cell stage (58.6%, n = 140) and >8 cell stage (70.6%, n = 25) compared with those embryos at the 2- to 5-cell stage at 55 hpi (26.1%, n = 176). Embryos with no fragments (58.0%, n = 467) had higher BL% (P < 0.01) compared with those with <20% fragments (30.7%, n = 127) and having with >20% fragments (17.5%, n = 25) at 55 hpi. The highest of BL% was observed in embryos showing a normal cleavage to 2-cells with at 27 hpi and having >6 cells with no fragments at 55 hpi (95.2%, n = 21, P < 0.01). These results demonstrate that the 2-step evaluation system at 27 and 55 hpi using microscopy is an effective method for selecting IVF embryos with high developmental competence.

Assessing Blood Flow in an Intracranial Stent: A Feasibility Study of MR Angiography Using a Silent Scan after Stent-Assisted Coil Embolization for Anterior Circulation Aneurysms

BACKGROUND AND PURPOSE

Blood flow in an intracranial stent cannot be visualized with 3D time-of-flight MR angiography owing to magnetic susceptibility and radiofrequency shielding. As a novel follow-up tool after stent-assisted coil embolization, we applied MRA by using a Silent Scan algorithm that contains an ultrashort TE combined with an arterial spin-labeling technique (Silent MRA). The purpose of this study was to determine whether Silent MRA could visualize flow in an intracranial stent placed in the anterior circulation.

MATERIALS AND METHODS

Nine patients treated with stent-assisted coil embolization for anterior circulation aneurysms underwent MRAs (Silent MRA and TOF MRA) and x-ray digital subtraction angiography. MRAs were performed in the same session on a 3T unit. Two neuroradiologists independently reviewed the MRA images and subjectively scored flow in a stent as 1 (not visible) to 4 (excellent) by referring to the latest x-ray digital subtraction angiography image as a criterion standard.

RESULTS

Both observers gave MRA higher scores than TOF MRA for flow in a stent in all cases. The mean score for Silent MRA was 3.44 ± 0.53, and for TOF MRA, it was 1.44 ± 0.46 (P < .001).

CONCLUSIONS

Silent MRA was able to visualize flow in an intracranial stent more effectively than TOF MRA. Silent MRA might be useful for follow-up imaging after stent-assisted coil embolization, though these study results may be only preliminary due to some limitations.

Denture wearing during sleep doubles the risk of pneumonia in the very elderly

Poor oral health and hygiene are increasingly recognized as major risk factors for pneumonia among the elderly. To identify modifiable oral health-related risk factors, we prospectively investigated associations between a constellation of oral health behaviors and incident pneumonia in the community-living very elderly (i.e., 85 years of age or older). At baseline, 524 randomly selected seniors (228 men and 296 women; mean age, 87.8 years) were examined for oral health status and oral hygiene behaviors as well as medical assessment, including blood chemistry analysis, and followed up annually until first hospitalization for or death from pneumonia. During a 3-year follow-up period, 48 events associated with pneumonia (20 deaths and 28 acute hospitalizations) were identified. Among 453 denture wearers, 186 (40.8%) who wore their dentures during sleep were at higher risk for pneumonia than those who removed their dentures at night (log rank P = 0.021). In a multivariate Cox model, both perceived swallowing difficulties and overnight denture wearing were independently associated with an approximately 2.3-fold higher risk of the incidence of pneumonia (for perceived swallowing difficulties, hazard ratio [HR], 2.31; and 95% confidence interval [CI], 1.11-4.82; and for denture wearing during sleep, HR, 2.38; and 95% CI, 1.25-4.56), which was comparable with the HR attributable to cognitive impairment (HR, 2.15; 95% CI, 1.06-4.34), history of stroke (HR, 2.46; 95% CI, 1.13-5.35), and respiratory disease (HR, 2.25; 95% CI, 1.20-4.23). In addition, those who wore dentures during sleep were more likely to have tongue and denture plaque, gum inflammation, positive culture for Candida albicans, and higher levels of circulating interleukin-6 as compared with their counterparts. This study provided empirical evidence that denture wearing during sleep is associated not only with oral inflammatory and microbial burden but also with incident pneumonia, suggesting potential implications of oral hygiene programs for pneumonia prevention in the community.