[Surgical technique of aortic valve replacement for small aortic annulus in elderly patients]

Recent reports have shown that aortic valve replacement in elderly patients over 65 years with atherosclerotic aortic stenosis and a small aortic annulus is possible by using a small sized bioprosthesis (Carpentier-Edwards pericardial valve). Here we present out surgical technique. Firstly, the native calcified aortic valve was removed completely to gain total exposure of the surrounding aortic root and sinus of Valsalva like Bentall procedure. Secondly, a small sized bioprosthesis was implanted with intermittent noneverting mattress 2-0 sutures with spaghetti and small polytetrafluoroethylene (PTFE) felt. Aortic annulus is the dilated by inserting Hegar dilator sizing from 25 to 27 mm. Therefore, aortic valve replacement for small aortic annulus in intra- or supra-annular position should be easily accomplished. Good surgical results and hemodynamic state were achieved in 25 consecutive cases using this technique.

318 INHIBITION OF FIRST POLAR BODY EXTRUSION BY CYTOCHALASIN B DURING IN VITRO MATURATION OF PORCINE OOCYTES LEADS TO RE-ARRANGEMENT OF THE SEGREGATED CHROMOSOMES AND IMPROVEMENT IN THE QUALITY OF THE PARTHENOGENETIC BLASTOCYSTS

Diploid parthenotes are usually obtained by the inhibition of second polar body (PB2) extrusion after activation of metaphase II (MII) oocytes. However, diploid embryos can be generated by the inhibition of the first polar body (PB1) extrusion as well, using cytochalasin B (CB) during in vitro maturation prior the activation procedure. A higher percentage of mouse embryos generated by the activation of MII oocytes and the inhibition of PB2 extrusion were proven to be homozygous than for parthenotes obtained by the latter method (Kubiak et al. 1991 Development 111, 763-769). The aim of the present study was to examine if such difference has any effect on the development of parthenogenetic embryos in vitro. Nuclear progression and in vitro embryonic development after parthenogenetic activation of porcine oocytes exposed to CB during in vitro maturation (IVM) was investigated in the present study. The tendency of nuclear maturation was similar in oocytes matured in the presence of 1 �g/mL CB (IVM-CB group) and control oocytes matured without CB after 37 h of IVM; at this time the frequency of oocytes that had reached/or passed through anaphase-I stage did not differ significantly (P < 0.05) between the IVM-CB and the control groups (61.3% and 69.9%, respectively), however, no polar body extrusion was observed in the IVM-CB group and the two lumps of homologue chromosomes remained in the oocyte and turned into two irregular sets of condensed chromosomes. By 41 h of IVM, the double sets of chromosomes re-united in 89.5% of IVM-CB oocytes and formed a single large metaphase plate, whereas 68.8% of the control oocytes had reached metaphase-II stage (MII) by this time. When IVM-CB oocytes were electrically (1.5 kV/cm for 100 �s) activated and subsequently cultured without CB, 39% of the oocytes extruded a polar body (PB) and 82.9% of them had a female pronucleus. When those oocytes with PB were cultured, the blastocyst rate of the cleaved embryos did not differ (P < 0.05) from those of the control that were stimulated at MII and subsequently treated with CB (43.3% and 48.2%, respectively). The number of blastomeres in Day 6 blastocysts was significantly higher (P < 0.05) in the IVM-CB derived embryos than in those in the control group (47.8 and 40.7, respectively); moreover, the ratio of dead blastomeres (dead cells : live cells) was higher (P < 0.05) in the control than in the IVM-CB blastocysts (0.047 and 0.031, respectively). A possible explanation for this result might be a lower frequency of homozygous genes in IVM-CB parthenotes, in which segregation of sister chromatids were promoted instead of segregation of homologous chromosomes to obtain diploid embryos. In such embryos the expression of recessive lethal, sublethal and subvital genes might have a lower probability. This work was supported by the Japanese-Hungarian bilateral scientific and technological cooperation (TET JAP-11/02).

357 FERTILIZATION AND EMBRYONIC DEVELOPMENT OF PORCINE OOCYTES FOLLOWING INTRACYTOPLASMIC SPERM HEAD INJECTION ENHANCED BY ELECTRIC STIMULATION TO OOCYTES BUT NOT BY PRE-TREATMENT OF SPERMATOZOA WITH DITHIOTHREITOL

Failure of sperm nuclear decondensation has been reported after injection into oocytes in pigs (Kren et al. 2003 J. Reprod. Dev. 49, 271-273). We examined the effects of pretreatment of spermatozoa with Triton X-100 (TX-100) and dithiothreitol (DTT) and electric stimulation of oocytes after injection on sperm decondensation, male pronuclear formation, and in vitro development to the blastocyst stage. We performed three replicates in each experimental group, with a total of about 70 oocytes per group. In Experiment 1, spermatozoa were pretreated with 1% TX-100 and 5 mM DTT (T+D), and injected into IVM oocytes that were collected from crossbred gilts. Electric stimulation (1.5 kV/cm, 20 �s; Nakai et al. 2003 Biol. Reprod. 68, 1003-1008) was applied 1 h to the oocytes after the injection (the stimulated group) or was not applied (the nonstimulated group). Some of the oocytes in each group were evaluated for morphological changes of sperm nuclei at hourly intervals until 10 h post-injection. Of nonstimulated oocytes, those injected with untreated spermatozoa showed a delayed peak in nuclear decondensation (39.4 to 44.1%, 3-6 h after the injection) compared to that of oocytes injected with T+D treated spermatozoa (57.0 to 52.6%, 1-1 h). The rate of male pronuclear formation increased after 4 h post-stimulation (by 40 to 60%) when the injected oocytes were stimulated, whether or not spermatozoa were pretreated. In nonstimulated oocytes, the rate of male pronuclear formation stayed at the basal level (less than 20%) throughout the culture period regardless of sperm treatments. Thus, the T+D treatment of spermatozoa did not affect decondensation and pronuclear formation. In Experiment 2, the effects of electric stimulation and sperm treatments with T+D on the rate of blastocyst formation and the mean numbers of cells per blastocyst were evaluated. Oocytes that were stimulated after injection of either T+D-treated or untreated spermatozoa showed significantly higher percentages of blastocyst formation (24.8% and 27.1%, respectively) than did nonstimulated oocytes (1.1% and 4.1% for T+D-treated and untreated, respectively; P < 0.01). The rate of blastocyst formation was not different between the T+D-treated and the untreated groups. The mean number of cells per blastocyst was not different among all groups (14.0-29.4). In conclusion, the pretreatment of sperm with TX-100 and DTT shifted the timing of sperm nuclear decondensation forward. However, pronuclear formation and development to the blastocyst stage in vitro were not improved by the sperm treatment. Electric stimulation to the injected oocytes enhances in vitro development to the blastocyst stage in pigs.

280 PORCINE BLASTOCYSTS DERIVED FROM IN VITRO-MATURED OOCYTES INJECTED INTRACYTOPLASMICALLY WITH SPERM FROM TESTICULAR TISSUE XENOGRAFTED INTO NUDE MICE

The utilization of spermatogonia from testicular tissue after xenografting into immuno-deficient mice should lead to new insights for the conservation of male gametes. However, successful embryo production using sperm cells from xenografted testicular tissues has been limited to rhesus monkeys (Honaramooz et al. 2004 Biol. Reprod. 70, 1500-1503). In the present study, the objective was to establish this new technology for pig conservation in combination with intracytoplasmic sperm injection. Testes were obtained from male piglets 6 to 15 days old, in which most of the germ cells were gonocytes; these were minced into pieces of approximately 1.5 � 1.5 � 1.5 mm. Approximately 20 fragments were transplanted under the back skin of castrated nude mice 5 to 8 weeks old. The testicular grafts were recovered between 125 and 192 days after xenografting, minced in Dulbecco's phosphate-buffered saline, and centrifuged several times, to serve as a sperm suspension. In vitro maturation of the recipient oocytes (Kikuchi et al. 2002 Biol. Reprod. 66, 1033-1041) and injection with an intact spermatozoon, followed by electrical stimulation at 1 h post-injection (Nakai et al. 2003 Biol. Reprod. 68, 1003-1008), were carried out. The putative zygotes were cultured in vitro for 6 days (Kikuchi et al. 2002), and were then fixed, stained, and assessed for embryonic development and quality. From a total of 27 mice that were xenografted with testicular tissues, spermatids and spermatozoa were obtained in 19 of the mice (70.4%). Most of the spermatozoa were matured morphologically, showing faint motility after release into the collection medium. From a total of 253 oocytes (four replications) that were injected with sperm, 63 (24.9 � 7.1%) oocytes developed to the blastocyst stage. The average total cell number was 41.9 � 3.9. These values are comparable to those in in vitro fertilization by frozen-thawed spermatozoa, resulting in developmental ability to piglets after embryo transfer (25.3% and 48.7 cells; Kikuchi et al. 2002). These results suggest the possibility of embryo production using porcine spermatozoa that are differentiated from gonocytes within the xenografts.

34 DEVELOPMENTAL ABILITY OF ZONA-FREE PORCINE CLONED EMBRYOS RECONSTRUCTED BY SOMATIC CELLS AND CENTRIFUGED CYTOPLASTS

The combination of bulk enucleation and zona-free cloning will offer simplification of the conventional nuclear transfer technique. A bulk enucleation method such as enucleation by centrifugation could reduce the time of manipulation that is necessary for removing genetic materials from the oocytes. The present study was conducted to examine the ability of cytoplasts obtained by centrifugation of zona-free in vitro maturation (IVM) porcine oocytes to support remodeling of the somatic cell nucleus and the subsequent development in vitro of somatic cell nuclear transferred (SCNT) embryos. A primary culture of cumulus cells was used as the source of donor cells, and recipient cytoplasts were derived from IVM oocytes that were cultured for 48 h, denuded of zonae pellucidae, and subjected to gradient centrifugation in Percoll solution to separate the ooplasm into fragments. Fragments were stained with Hoechst-33342 and cytoplasts were selected under an epifluorescence microscope. Then two or three cytoplasts were aggregated with a single somatic cell in phytohemagglutinin solution (500 �g/mL). Fusion between somatic cell and cytoplasts was induced by two DC pulses of 1.5 kV/cm for 20 �s, and activation was accomplished by two DC pulses of 0.8 kV/cm for 30 �s at 1 h after fusion in 0.28 M mannitol solution supplemented with 0.05 mM CaCl2 and 0.1 mM MgSO4. The resultant embryos were transferred to a WOW culture system (Vajta et al. 2000 Mol. Reprod. Dev. 55, 256-264) and cultured in glucose-free NCSU-37 containing 4 mg/mL BSA supplemented with 0.17 mM sodium pyruvate and 2.73 mM sodium lactate from Days 0 to 2; from Days 2 to 7 they were cultured in NCSU-37 supplemented with 5.55 mM {D}-glucose and 5% FCS. Some of the reconstructed embryos were fixed at 1, 10, and 24 h after activation and stained with 1% (w/v) orcein to display the morphology of the transferred somatic nuclei. The results showed that 53.6% (30/56) of the SCNT embryos underwent premature chromosome condensation at 1 h, 90.9% (50/55) formed pseudo-pronuclei at 10 h, and 21% (19/90) of them cleaved to the two-cell stage at 24 h after the activation. The development to the blastocyst stage of the embryos that were reconstructed by quartet cells (three cytoplasts and one somatic cell; 8.9%, 10/112) was significantly higher (P < 0.05) than that of the triplet ones (2.2%, 3/139). However, these blastocyst rates were significantly lower (P < 0.05) than the blastocyst development rate of parthenogenetic embryos with the intact zonae pellucidae (28.3%, 17/60). These results suggest that (1) cytoplasts obtained by gradient centrifugation could support reprogramming of somatic cells and in vitro development of SCNT embryos to the blastocyst stage, and (2) the volume of cytoplasts apparently affects their in vitro development in pigs.

153 ALLEVIATIVE EFFECTS OF ANTIOXIDANT ADMINISTRATION ON MATERNAL HYPERTHERMIA-INDUCED EARLY EMBRYONIC DEATH IN MICE

Hyperthermia-induced early embryonic death is generally ascribed to the high susceptibility of early embryos to elevated maternal body temperature. However, recent studies have indicated that the disruption of embryonic development by maternal hyperthermia has relevance to not only high temperature exposure to the embryo, but also hyperthermia-associated changes in the maternal body. Hyperthermia enhances physiological production of reactive oxygen species (ROS) systemically. Early embryos are susceptible to oxidative stress and it becomes easy to arrest their development when the oxidative stress is exposed. These findings led us to speculate that maternal hyperthermia-induced early embryonic death is caused by an increase in oxidative stress to the embryo. Vitamin E and melatonin are both well known to function as antioxidants in vivo when they are administered exogenously. In this study, we administered vitamin E or melatonin to heat-stressed pregnant mice, aiming to alleviate the hyperthermia-induced embryonic death. Female mice were heat-stressed (35�C with 60% relative humidity) for 12 h on the day of mating. In Experiment 1, vitamin E (1000 mg/kg body weight) was injected intraperitoneally just before stress treatment, or melatonin (3 mg/kg body weight) was injected subcutaneously for every 2 h during heat exposure. Then, zygotes were collected and in vitro developmental ability was assessed. In Experiment 2, intracellular glutathione (GSH) content in the zygote, ROS level and free radical scavenging activity (FRSA) in the oviduct, and lipid peroxidation level in the liver were measured to evaluate the effects of melatonin administration on physiological redox status. All data were analyzed using one-way ANOVA followed by Fisher's protected least-significant test. The percentage of embryos that developed to the morula or blastocyst stage was significantly (P < 0.01) increased by administration of either vitamin E (58.6%) or melatonin (47.9%) compared with that in heat-stressed mice that were administered placebos (14.8%). Intracellular GSH content in zygotes derived from melatonin-administered mice was not significantly different from that in unstressed mice (1.67 and 1.82 pmol/zygote, respectively), whereas in heat-stressed mice that were administered placebo, intracellular GSH content was significantly decreased (1.48 pmol/zygote, P < 0.05) compared to that in unstressed mice. There were no significant differences in lipid peroxidation levels in the liver and in ROS levels in the oviduct between melatonin-administered stressed mice and unstressed mice, although these parameters in heat-stressed mice with placebo were significantly higher than in unstressed mice (P < 0.05). Furthermore, FRSA in the oviduct was significantly (P < 0.05) higher in the melatonin-administered mice than in the heat-stressed mice. These findings suggest that antioxidant administration to heat-stressed mice alleviates the hyperthermia-induced early embryonic death, and this may be accomplished in part by maintaining a neutral redox status within the mother.

172 ADMINISTRATION OF GLUTATHIONE OR THIOREDOXIN TO MEDIUM REDUCES INTRACELLULAR REDOX STATUS AND IMPROVES EMBRYONIC DEVELOPMENT TO THE BLASTOCYST STAGE OF PORCINE IVM/IVF OOCYTES

Successful in vitro production of blastocysts from immature oocytes can be carried out using in vitro oocyte maturation (IVM), fertilization (IVF), and embryo culture (IVC) at a high level of repeatability in the porcine. However, the rates of in vitro development of IVM/IVF oocytes to the blastocyst stage remained around 20%. The environment in vitro is so simple and materially limited that there exist several stressors in vitro that disturb normal embryo development. Oxidative stress, which is caused by excess production of reactive oxygen species, is a major disturbing factor for the development of pre-implantation embryos in vitro. The series of present experiments were conducted using culture conditions with enhanced reducing capacity by the addition of glutathione (GSH) or thioredoxin to the culture medium to monitor developmental competence of porcine embryos and to verify their intracellular redox status. Cumulus-oocyte complexes were obtained from ovaries recovered from prepubertal gilts. Putative zygotes were produced by IVM of oocytes, followed by IVF (designated as Day 0). They were then cultured in modified NCSU-37 media containing GSH or thioredoxin as an antioxidant, or without any antioxidant (control), and blastocyst development rates on Day 6 were monitored. In addition, intracellular GSH content as a reducing parameter and intracellular H2O2 level as an oxidative parameter were measured; the intracellular redox status in the embryo was verified by the ratio of the GSH to the H2O2. Measurements in each group were replicated six times. Percentages of the embryos that developed to the blastocyst stage were significantly increased when 0.5 or 1.0 �M GSH (29.6 � 2.7% or 30.4 � 3.5%, and P < 0.05 or 0.01, respectively) or 1.0 mg/mL thioredoxin (30.6 � 2.4%, P < 0.01) was added to the medium compared to the percentage in the control group (20.1 � 2.2%). Intracellular redox status in embryos at the 8- to 12-cell stage or blastocysts was drastically reduced in GSH- or thioredoxin-added groups compared to that in the control group (P < 0.05 to 0.001). Furthermore, GSH or thioredoxin addition to the medium increased total cell numbers (48.3 � 2.1 to 49.2 � 2.1) and lowered ratios of apoptotic cells (6.2 � 0.6% to 7.0 � 0.7%) in blastocyst compared to those values in the control group (P < 0.05; cell number = 39.3 � 2.0, apoptosis rate = 11.1 � 1.1%) (37 to 53 embryos in each group were used for the TUNEL assay). These results suggest that the administration of GSH or thioredoxin to the culture medium improves in vitro embryonic development after IVM/IVF of oocytes, and that these beneficial effects are associated with maintenance of the intracellular redox status in a reduced state in porcine embryos.

283 EFFECTS OF CUMULUS CELL REMOVAL ON IN VITRO OOCYTE MATURATION, FERTILIZATION, AND EMBRYONIC DEVELOPMENT IN PIGS

It is generally accepted that cumulus cells (CCs) support the nuclear maturation of immature oocytes in mammals. However, the precise mechanism of interaction between cumulus cells and oocytes has not been clarified. Furthermore, the role of cumulus cells in embryonic development has not been reported. In the present study, the effect of denuding cumulus cells from porcine oocytes on oocyte maturation, ertilization, and their subsequent development to the blastocyst stage was examined in vitro. In vitro maturation, fertilization, and culture were carried out as previously reported (Kikuchi et al. 2002 Biol. Reprod. 66, 1033-1041). Porcine cumulus-oocyte complexes (COCs) were collected; some of them were completely denuded of cumulus cells immediately after the collection (DO-0 group). The remaining intact COCs and the DO-0 oocytes were cultured for 24 h in the presence of dbcAMP and hormones. After the initial culture, some of the intact COCs were denuded either completely (DO-24 group) or partially (H-DO-24 group). Additionally, some of DO-24 oocytes were co-cultured with the cumulus cells removed at 0 h and pre-cultured for 24 h (DO-24 + CCs group). The denuded oocytes in each experimental group and intact COCs (control) were further cultured for total 46 h. The remaining oocytes with a first polar body were either examined for the levels of intracellular glutathione (GSH) or fertilized in vitro with frozen-thawed boar spermatozoa. The inseminated oocytes were cultured and examined for their fertilization status after 10 h and for their developmental competence after 6 days. Data were analyzed by ANOVA, followed by the Duncan's multiple range tests. The maturation rates of all denuded groups were significantly lower (P < 0.05; 34.3 to 45.0%) than that of the control group (64.5%). Intracellular GSH concentrations of all denuded groups were also significantly lower (P < 0.05; 4.03 to 7.00 pmol/oocyte) than that of the control group (9.60 pmol/oocyte); however, the GSH level of H-DO-24 oocytes was significantly higher (P < 0.05) than the GSH levels in the other denuded groups. Male pronuclear formation rates of completely denuded oocytes (DO-0, DO-24, and DO-24 + CCs groups) were significantly lower (P < 0.05; 41.4 to 59.3%) than those of the control (89.4%) and the H-DO-24 (80.0%) groups. The blastocyst rate of the control group was significantly higher (P < 0.05; 19.9%) than that of H-DO-24 group (11.6%), and these rates were significantly higher (P < 0.05) than those of the completely denuded groups (3.0 to 4.5%). The results suggest that the presence of cumulus cells during maturation culture improves nuclear maturation of oocytes and plays an important role in embryonic development to the blastocyst stage in vitro.

Alterations in follicular dynamics and steroidogenic abilities induced by heat stress during follicular recruitment in goats

We investigated the changes in follicular dynamics and steroidogenic activity during heat stress in goats. Adult female goats were exposed to heat stress at 36 degrees C and 70% relative humidity for 48 h and then injected with prostaglandin (PG) F2alpha (the time of PGF2alpha injection was designated as 0 h). In experiment 1, every follicle greater than 2 mm in diameter was monitored by ultrasonography to investigate the follicular dynamics, and plasma concentrations of FSH, LH, progesterone, and oestradiol were measured from -48 h to 120 h. In experiment 2, the follicles were recovered from the goats at 48 h, and the concentration of oestradiol, the aromatase activity, and the LH receptor level in the follicles were determined. In control (non-heat-stressed) goats, ovulatory follicles were mainly recruited from -24 h to 0 h, whereas no follicles recruited during that period were ovulated in the heat-stressed goats. The timing of the recruitment of ovulatory follicles was delayed by heat stress by approximately 24 h. The plasma concentration of oestradiol in the heat-stressed goats was significantly lower from 36 to 54 h compared with the controls, although the concentrations of FSH and progesterone did not differ between the treatments. In addition, the concentration of oestradiol, the aromatase activity, and the LH receptor level in the follicles from heat-stressed goats were significantly lower compared with the controls. These results indicate that heat stress during follicular recruitment suppresses subsequent growth to ovulation, accompanied by decreased LH receptor level and oestradiol synthesis activity in the follicles.

299 IN VITRO DEVELOPMENT OF IMMATURE PORCINE OOCYTES FERTILIZED IN VITRO TO THE BLASTOCYST STAGE

In vitro fertilization (IVF) and embryonic development of mature and meiotically arrested porcine oocytes were compared in this study. After in vitro maturation (IVM) for 48 h of cumulus-oocyte complexes, 75.4% (n = 442) of them extruded a visible polar body (PB). Most oocytes with a polar body (PB+ group) were found to be at metaphase II (M-II) stage (91.4%). Most oocytes without a visible polar body (PB− group, n = 144) appeared to be arrested at the germinal vesicle (GV) (41.6%) and first meiotic metaphase (M-I) (34.0%) stages. After IVF of oocytes (the day of IVF = Day 0), there was no significant difference between PB+ and PB− groups in rates of sperm penetration, monospermy, and oocyte activation after the penetration. Embryonic development was assessed by staining with 1% orcein. On Day 2, although there was no difference between the embryo cleavage in PB+ (n = 447) and PB− (n = 217) groups (47.0% and 35.9%, respectively), PB+ embryos had more cells than the PB− embryos (3.37 and 2.81 cells, respectively) (P < 0.05; ANOVA). On Day 4, the cleavage rate of PB+ embryos was higher than that of PB− embryos (45.4% and 24.3%, respectively), and PB+ embryos had more cells than the PB− embryos (8.26 and 6.0 cells, respectively) (P < 0.05; ANOVA). On Day 6, a significantly higher number of PB+ embryos developed to the blastocyst stage than that of the PB− embryos (34.6% and 20.7%, respectively) (P < 0.05). However, by subtracting the GV oocytes from the PB− group, there was no difference in blastocyst rates between the M-I arrested and M-II oocytes (35.3% and 34.6%, respectively). The number of blastomer nuclei in embryos obtained from the PB+ group (52.0) was significantly higher than that of the PB− group (29.1); however, the proportion of inner cell mass and trophectoderm cells in PB+ and PB− blastocysts did not differ significantly (1:1.9 and 1:2.2, respectively) (P < 0.05). Chromosome analysis revealed that PB+ blastocysts had significantly more diploid blastomeres (69.7%) than PB− blastocysts (44.0%), whereas PB− blastocysts had significantly more triploid cells (34.0%) compared with PB+ oocytes (8.4%)(P < 0.05; χ2 test). These results indicate that porcine oocytes arrested at the M-I stage undergo cytoplasmic maturation during culture and have the same ability to develop to blastocysts after IVF as M-II oocytes but with a lower cell number; the latter might be caused by the slower embryonic development.

321 DEVELOPMENT IN VIVO AND IN VITRO OF PORCINE OOCYTES FERTILIZED BY INTRACYTOPLASMIC INJECTION OF A FREEZE - DRIED SPERM HEAD

The present study investigated the development in vivo and in vitro of in vitro matured porcine oocytes injected with a freeze-dried (FD) boar sperm head. In mice, DNA damage was induced during the holding period after rehydration and before sperm injection (Wakayama, T. and Yanagimachi, R. 1998, Nat. Biotechnol., 16, 639–641). Here, we examined the relationship between duration of rehydration of FD sperm and in vitro development of FD sperm-injected porcine oocytes. We also assessed the in vivo developmental competence of the injected oocytes after embryo transfer. Ejaculated boar spermatozoa were suspended in Pig-FM (Suzuki, K. et al. 2002, Int. J. Androl. 25, 84–93) and sonicated for 1 min to separate sperm heads from the tails. An aliquot (100 μL) of the sperm suspension was put into a glass tube and then pre-cooled at −40°C for 6 h. Each tube was attached to a freeze-dry system (DuraDry μP, FTS Systems, Stone Ridge, NY, USA) for 12 h. The ampules were closed and stored at 4°C for more than 7 days before use. For rehydration, 100 μL of distilled water was added into the ampules. In Experiment I, we injected FD sperm heads which were kept for 0–60, 60–120, or 120–180 min after rehydration. At 1 h after the injection, the injected oocytes were stimulated with a DC pulse and cultured for 6 days. The rate of blastocyst formation and the number of cells in the blastocysts were examined. Embryos after in vitro fertilization (IVF) were evaluated as a control. As shown in Table 1, the rates of blastocyst formation were not different (by χ2 test) for duration of rehydration and the control. However, the cell numbers of FD groups were lower (P < 0.05; by Student's t-test) than that in the control. In Experiment II, oocytes injected with a single FD sperm head and stimulated were transferred to both oviducts of a total of ten recipient gilts. Two recipients were diagnosed as pregnant at Day 30 of gestation. At Day 39, one of the pregnant recipients had an abortion, and two fetuses were recovered. The other pregnancy was not maintained. The results suggest that oocytes fertilized with a single FD sperm head have competence to be implanted and to develop to the early fetal stage, and also that the duration for rehydration does not influence in vitro developmental ability in pigs. Table 1. Effects of the duration from rehydration of freeze-dried sperm heads to the injection of the heads into in vitro matured oocytes on in vitro development of the oocytes in pigs

Quantitative flow visualization of fluidized-bed heat exchanger by neutron radiography

Quantitative flow visualization of a gas-solid fluidized-bed installed vertical tube-bank has been successfully conducted using neutron radiography and image processing technique. The quantitative data of void fraction distribution as well as the fluctuation data are presented. The time-averaged void fraction is well correlated by the drift-flux model. The bubbles formed in the bed, rise along the vertical tubes and the observed bubble size is smaller than that in a free bubbling bed without tube-banks. The bubble diameter is well correlated by the modified Mori and Wen's correlation taking into account the pitch of tube arrangement. The bubble rise velocity is also well correlated by applying the drift-flux model. These results are consistent for both bed materials of Geldart's B- and A-particles, while the bubble size is significantly different between two kinds of particles.

277ENERGY REQUIREMENT DURING DEVELOPMENT TO THE BLASTOCYST STAGE OF PORCINE EMBRYOS PRODUCED IN VITRO

A successful in vitro production (IVP) of porcine blastocysts, which enables piglet production after transfer to recipients, was reported (Kikuchi et al., 2002 Biol. Reprod. 66, 1033–1041). Generally, in the IVP system, both glucose and glutamine as energy sources were included in vitro culture (IVC) medium from Day 2 (Day 0=the day of in vitro fertilization) until Day 6. However, the exact requirement of these substances for the development to the blastocyst stage of IVP embryos has not yet been clarified. The objective of the present study was to evaluate whether these two substances are necessary for embryonic development to the blastocyst stage in culture during the period. Porcine cumulus-oocyte complexes were matured for 46h and fertilized in vitro as reported by Kikuchi et al. (see above). After removal of cumulus cells and spermatozoa, the oocytes were cultured subsequently in NCSU-37 supplemented with pyruvate and lactate (IVC-PyrLac) for 2 days. Then they were cultured until Day 6 in other IVC medium prepared as follows (1–6); Basic IVC medium (BM) was a modified NCSU-37 consisting of 108.7mM NaCl, 4.8mM KCl, 1.7mM CaCl2, 1.2mMKH2PO4, 1.2mM MgSO4, 25.1mM NaHCO3 and 4mgmL−1 fatty acid-free BSA. Then one or more of the following energy sources were supplemented to BM;; (1) 12mM sorbitol (SigmaUltra), 5.55mM glucose (Wako special grade) and 1.0mM glutamine (Sigma) (NCSU-37/Gln+), (2) 19.2mM sorbitol and 1.0mM glutamine (IVC-Sorbitol/Gln+); (3) 19.2mM mannitol (SigmaUltra) and 1.0mM glutamine (IVC-Mannitol/Gln+), (4) 12mM sorbitol and 5.55mM glucose (NCSU-37/Gln−); 5) 19.2mM sorbitol (IVC-Sorbitol/Gln−); and 6) 19.2mM mannitol (IVC-Mannitol/Gln−). The osmolarity of these media was adjusted to 283–285 osmolg−1. All embryos were fixed as whole mounts, stained and evaluated. The rate of blastocysts in NCSU-37/Gln+ (26.8%) was significantly higher (P&lt;0.05; by analysis of variance and Duncan’s multiple range test) than those in IVC-Sorbitol/Gln+, IVC-Mannitol/Gln+ and NCSU-37/Gln− (19.0%, 17.0% and 15.5%, respectively). A remarkable decrease in the rates in IVC-Sorbitol/Gln− and IVC-Mannitol/Gln− (P&lt;0.05; 1.4% and 2.0%, respectively) was observed. The cell numbers of NCSU-37/Gln+, IVC-Sorbitol/Gln+, IVC-Mannitol/Gln+ and NCSU-37/Gln− (55.5, 52.0, 49.6 and 58.7, respectively) had a tendency to be higher than those of IVC-Sorbitol/Gln− and IVC-Mannitol/Gln− (38.0 and 35.2, respectively). These results confirm that the supplementation of maturation medium with at least one energy source (glucose or glutamine) promotes embryonic development in vitro to the blastocyst stage, that the combination of both sources improves the chance of the embryonic survival, and that porcine embryos do not utilize sorbitol or mannitol as an energy source. The importance of glucose and glutamine is suggested for the development to the blastocyst stage of porcine IVP embryos.

Developmental competence and oxidative state of mouse zygotes heat-stressed maternally or in vitro

Mammalian preimplantation embryos are sensitive to maternal and direct heat stress. However, the mechanisms by which heat stress affects early embryonic development in vivo or in vitro are unknown. This study examined whether heat-stress-induced loss of developmental competence in mouse embryos was mediated by physiological changes in the maternal environment or by high temperatures alone. After fertilization, zygotes at the same stage were heat-stressed at 39.5 degrees C for 12 h either maternally (measured by maternal rectal temperature) or directly in culture. Zygotes in each group were cultured at 37.5 degrees C for a further 84 h to assess their developmental ability. Neither type of heat stress affected the first cleavage rate. However, the proportion of embryos that developed to morulae or blastocysts was significantly lower in the maternally heat-stressed group, but not in the directly heat-stressed group. Moreover, maternal heat stress significantly reduced intracellular glutathione concentrations and enhanced hydrogen peroxide concentrations in both zygotes and two-cell embryos that were recovered immediately after heat stress or 12 h later, respectively. In contrast, direct heat stress had little effect on concentrations of glutathione or hydrogen peroxide in cultured early embryos. These results demonstrate that maternal heat stress at the zygote stage reduces the developmental ability of mouse embryos via physiological changes in the maternal environment that lead to an increase in intracellular oxidative stress on the embryo.

Non-myeloablative haematopoietic stem cell transplantation for severe aplastic anaemia with various complications

We report a 20-year-old-male with severe aplastic anaemia who was treated with nonmyeloablative haematopoietic stem cell transplantation (NSCT) from a sibling donor. As the patient presented with complications consisting of mental retardation, severe obesity, a bone fracture, and recurrent infections, we selected NSCT instead of a myeloablative regimen, to reduce regimen-related toxicity (RRT). Conditioning therapy consisting of busulfan, fludarabine, antithymocyte globulin and FK506 was used to obtain immune suppression. RRT was limited and he is now in complete remission 19 months after NSCT. On day 91, he developed chronic graft-vs.-host disease; it was resolved by the combination of FK506, corticosteroids, and mycophenolate mofetil. Our experience contributes to the growing interest in NSCT as a modality for treating not only malignant haematological disorders associated with complications, but also nonmalignant haematological diseases.

Comparison of sequences of cDNA clones obtained from oligo-capping cDNA libraries with those from unigene

We compared in detail the characteristics of the sequences of the cDNA clones obtained by the oligo-capping method (oligo-capping clones) with that of the sequences in the UniGene database. To compare the completeness of the sequences, three new variables, "fullness-proportion of clones" (the ratio of complete clones to total clones in a library), "fullness-proportion of genes" (the ratio of complete genes to total genes in a library), and "fullness-proportion of database" (the ratio of complete genes to total genes in a database sampled from a library), were defined. The fullness-proportion of clones of oligo-capping clones was 57.3%, 2.2 times larger than that of UniGene (25.9%). The fullness-proportion of genes of oligo-capping clones was 41.8%, 2.4 times larger than that of UniGene (17.8%). When gene length was restricted to > or = 1.5 kb, the fullness-proportion of genes of oligo-capping clones was four times larger than that of UniGene. The fullness-proportion of database of oligo-capping clones was approximately the same as that of UniGene. By simulating the clone redundancy, this coincidence was found to be due to the large redundancy of the UniGene database. Consequently, the cDNA sequence database of oligo-capping clones enabled high throughput selection of full-length cDNA clones.