Effects of volatile anesthetics on circadian rhythm in mice: a comparative study of sevoflurane, desflurane, and isoflurane

PURPOSE

Volatile anesthetics affect the circadian rhythm of mammals, although the effects of different types of anesthetics are unclear. Here, we anesthetized mice using several volatile anesthetics at two different times during the day. Our objective was to compare the effects of these anesthetics on circadian rhythm.

METHODS

Male adult C57BL/6 J mice were divided into eight groups (n = 8 each) based on the anesthetic (sevoflurane, desflurane, isoflurane, or no anesthesia) and anesthesia time (Zeitgeber time [ZT] 6-12 or ZT18-24). Mice were anesthetized for 6 h using a 0.5 minimum alveolar concentration (MAC) dose under constant dark conditions. The difference between the start of the active phase before and after anesthesia was measured as a phase shift. Clock genes were measured by polymerase chain reaction in suprachiasmatic nucleus (SCN) samples removed from mouse brain after anesthesia (n = 8-9 each).

RESULTS

Phase shift after anesthesia at ZT6-12 using sevoflurane (- 0.49 h) was smaller compared with desflurane (- 1.1 h) and isoflurane (- 1.4 h) (p < 0.05). Clock mRNA (ZT6-12, p < 0.05) and Per2 mRNA (ZT18-24, p < 0.05) expression were different between the groups after anesthesia.

CONCLUSION

0.5 MAC sevoflurane anesthesia administered during the late inactive to early active phase has less impact on the phase shift of circadian rhythm than desflurane and isoflurane. This may be due to differences in the effects of volatile anesthetics on the expression of clock genes in the SCN, the master clock of the circadian rhythm.

Postoperative norepinephrine versus dopamine in patients undergoing noncardiac surgery: a propensity-matched analysis using a nationwide intensive care database

BACKGROUND

Choosing catecholamines, such as norepinephrine and dopamine, for perioperative blood pressure control is essential for anesthesiologists and intensivists. However, studies specific to noncardiac surgery are limited. Therefore, we aimed to evaluate the effects of postoperative norepinephrine and dopamine on clinical outcomes in adult noncardiac surgery patients by analyzing a nationwide intensive care patient database.

METHODS

The Japanese Intensive care PAtient Database (JIPAD) was used for this multicenter retrospective study. Adult patients in the JIPAD who received norepinephrine or dopamine within 24 h after noncardiac surgery in 2018-2020 were included. We compared the norepinephrine and dopamine groups using a one-to-one propensity score matching analysis. The primary outcome was in-hospital mortality. Secondary outcomes were intensive care unit (ICU) mortality, hospital length of stay, and ICU length of stay.

RESULTS

A total of 6,236 eligible patients from 69 ICUs were allocated to the norepinephrine (n = 4,652) or dopamine (n = 1,584) group. Propensity score matching was used to create a matched cohort of 1,230 pairs. No differences in the in-hospital mortality was found between the two propensity score matched groups (risk difference: 0.41%, 95% CI [-1.15, 1.96], P = 0.608). Among the secondary outcomes, only the ICU length of stay was significantly shorter in the norepinephrine group than in the dopamine group (median length: 3 vs. 4 days, respectively; P < 0.001).

CONCLUSIONS

In adult patients after noncardiac surgery, norepinephrine was not associated with decreased mortality but was associated with a shorter ICU length of stay than dopamine.

Electrocardiogram Cream Reduces Skin-Electrode Impedance Upon Neuromuscular Monitoring Using TOF-Cuff®

Background Mechanistic insight into the high failure rate of TOF-Cuff® (RGB Medical Devices, Madrid, Spain) measurements on the lower leg is unclear. Aims We aimed to determine whether materials applied to pseudo-skin can reduce the impedance between a model arm and TOF-Cuff® electrodes and whether a material between TOF-Cuff® electrodes and the patient's skin surface decreases the skin-TOF-Cuff® electrode impedance within the appropriate range. Methods This was a combination of an in vitro study using non-living materials and a prospective observational clinical study. Eight patients aged > 70 years who had undergone elective surgery were eligible. One of the primary outcomes was whether water, electrocardiogram (ECG) cream, or ECG gel applied on the pseudo-skin could reduce the impedance between the model arm and the TOF-Cuff® electrodes in the in vitro study. Another was whether a material between the TOF-Cuff® electrodes and the patient's skin surface decreased the skin-TOF-Cuff® electrode impedance to an appropriate level of less than 5,000 Ω in the clinical study. Results The application of water, ECG cream, and ECG gel similarly reduced the impedance values within the electrical circuit in the in vitro study. ECG cream application between the patient's skin surface and the TOF-Cuff® electrodes decreased the skin-TOF-Cuff® electrode impedance (median (interquartile range (IQR)) Ω) from 8,600 (6,450 to 9,775) to 2,000 (1,600 to 2,600) (P = 0.012) in surgical patients. Conclusion ECG cream application between the patient's skin surface and the TOF-Cuff® electrodes decreased the skin-TOF-Cuff® electrode impedance appropriately, and thus, the application can facilitate precise TOF-Cuff® measurements in patients.

Dietary Iron Restriction Protects against Aneurysm Rupture in a Mouse Model of Intracranial Aneurysm

INTRODUCTION

Iron accumulation in vessel walls induces oxidative stress and inflammation, which can cause cerebrovascular damage, vascular wall degeneration, and intracranial aneurysmal formation, growth, and rupture. Subarachnoid hemorrhage from intracranial aneurysm rupture results in significant morbidity and mortality. This study used a mouse model of intracranial aneurysm to evaluate the effect of dietary iron restriction on aneurysm formation and rupture.

METHODS

Intracranial aneurysms were induced using deoxycorticosterone acetate-salt-induced hypertension and a single injection of elastase into the cerebrospinal fluid of the basal cistern. Mice were fed an iron-restricted diet (n = 23) or a normal diet (n = 25). Aneurysm rupture was detected by neurological symptoms, while the presence of intracranial aneurysm with subarachnoid hemorrhage was confirmed by post-mortem examination.

RESULTS

The aneurysmal rupture rate was significantly lower in iron-restricted diet mice (37%) compared with normal diet mice (76%; p < 0.05). Serum oxidative stress, iron accumulation, macrophage infiltration, and 8-hydroxy-2'-deoxyguanosine in the vascular wall were lower in iron-restricted diet mice (p < 0.01). The areas of iron positivity were similar to the areas of CD68 positivity and 8-hydroxy-2'-deoxyguanosine in both normal diet and iron-restricted diet mouse aneurysms.

CONCLUSIONS

These findings suggest that iron is involved in intracranial aneurysm rupture via vascular inflammation and oxidative stress. Dietary iron restriction may have a promising role in preventing intracranial aneurysm rupture.

Development of Low-Molecular-Weight Organogelators from Cyclic β-Amino Acid: Effect of Stereochemistry and their Application on Visual Chiral Recognition of Amines

This study reports the formation of low-molecular-weight gelators based on carboxylic acids derived from chiral cyclicβ-amino acids. The effect of their stereochemistry on the gelation of organic solvents was investigated, and their assemblies with the intermolecular interactions in the xerogels were proposed via infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and crystallographic details of the related model compounds. The effect of the alkyl chain length on the gelators was studied, and they were applied to the chiral recognition of amines. Only one diastereomeric salt with amines afforded gels, whereas the others resulted in precipitates. Chiral recognition was also achieved in the gel state, and the appearance of the as-prepared gel changed upon the addition of each amine enantiomer, thus enabling the visual detection of their chirality.

Abstract TP256: The Role Of Dietary Iron Restriction In The Pathophysiology Of Intracranial Aneurysm Rupture

Background: Iron is an essential element for maintaining vascular wall, however iron depositions in vascular wall cause tissue damage by oxidative stress via Fenton/Haber-Weiss reaction. We hypothesized that iron promotes intracranial aneurysmal formation and rupture through oxidative stress and vascular inflammation. Using a mouse model of intracranial aneurysm, we examined whether iron restriction reduces aneurysm formation and rupture.

Methods: To induce aneurysm, we combined induced systemic hypertension (deoxycorticosterone acetate-salt hypertension) and a single injection of elastase (35mU) into the cerebrospinal fluid at the right basal cistern. The mice were divided into two groups and fed with iron restricted diet (IRD) (0.32mg/100g) or normal diet (ND) (600mg/100g) for 5 weeks.

Results: IRD significantly reduced the aneurysmal rupture compared to ND (ND versus IRD: 76% versus 37%; P < 0.05). Whereas, there was no significant difference in the overall incidence of aneurysms between the ND and IRD groups (ND versus IRD: 68% versus 69%; P =1.00).

Conclusion: Our data demonstrate that iron restriction reduces intracranial aneurysm rupture.

Treatment-resistant venous thrombosis and pulmonary embolism in a patient with granulomatosis with polyangiitis: a case report

BACKGROUND

We herein present a case of venous thrombosis that developed more than 20 years after diagnosis of granulomatosis with polyangiitis (GPA), although many reports of GPA have described venous thrombosis within 1 year of diagnosis.

CASE PRESENTATION

A 73-year-old man with GPA was admitted for lower extremity swelling and diagnosed with venous thrombosis and pulmonary embolism. On the second day, catheter-based thrombolysis was unsuccessful, and inferior vena cava filter insertion and anticoagulation were performed. On the third day, respiratory disturbance and loss of consciousness appeared and progressed. The patient died on the fifth day. The autopsy revealed a large thrombus in the inferior vena cava filter, and death of progressive venous thrombosis was suspected.

CONCLUSIONS

We experienced a case of venous thrombosis that developed 20 years after diagnosis of GPA, although GPA is frequently associated with venous thrombosis immediately after diagnosis. The thrombosis progressed rapidly and was resistant to treatment.

74 Analysis of chromosomal abnormality of bovine IVF embryos based on next-generation sequencing

It has been suggested that bovine IVF embryos have a higher frequency of occurrence of chromosomal abnormalities than invivo-fertilised embryos, which may explain low pregnancy success, but the details have not been clarified (Yao et al. 2018 Sci. Rep. 8, 7460). In this study, chromosomal aneuploidy in blastocysts of bovine IVF and invivo-fertilised was analysed by copy number variations (CNVs) based on next-generation sequencing. The IVF bovine embryos were cultured in well of-the-well culture dishes (LinKID micro25: Dai Nippon Printing) containing 125µL of CR1aa supplemented with 5% calf serum at 38.5°C in 5% O2 and 5% CO2 for 8 days after insemination. Invitro development of embryos was monitored using time-lapse cinematography (Sugimura et al. 2010 Biol. Reprod. 83, 970-78). Invivo embryos were produced by collection of a superstimulated Japanese Black cow. Embryos that reached the blastocyst stage were divided into inner cell mass (ICM) and trophectoderm (TE) fractions by a micromanipulator with a blade. The TE and ICM samples were biopsied individually from 10 IVF and 4 invivo-derived embryos, and extracted DNA was amplified using the SurePlex DNA amplification System (Illumina). The whole-genome amplified DNA libraries were sequenced using MiSeq (Illumina). The sequencing reads were mapped onto the Bos taurus reference genome ARS-UCD1.2, obtained from the National Center for Biotechnology Information. In all 29 autosomal chromosomes and the X chromosome, CNV analysis was performed by CNV-seq (Xie and Tammi 2009 BMC Bioinformatics 10, 80). Male or female Japanese Black cattle DNA sequence was used for the reference genome. The parameter of CNV-seq was run with P-value=0.001, log2=0.6, and window size=1M. Four IVF embryos showed chromosomal duplications or deletions in either ICM- or TE-cell samples (4/10, 40%). The CNV loci between ICM and TE cells were relatively similar in each embryo. One of them was a code 1-expanded blastocyst with normal cleavage. Interestingly, CNV was not identified in another code 1-expanded blastocyst that underwent direct cleavage from 1 cell to 3 or more cells. In invivo embryos, only one embryo had a CNV (1/4, 25%). Observed CNVs in both IVF and invivo embryos were segmental duplication or deletion in each chromosome. Hence, to improve pregnancy success in bovine IVF embryos, cytogenetic evaluation may be useful for quality evaluation of embryos that are prone to chromosomal abnormalities, as well as morphological scoring.

Effects of 5-aminolevulinic acid supplementation on milk production, iron status, and immune response of dairy cows

The objective of this study was to investigate the effect of 5-aminolevulinic acid (5-ALA) as a dietary supplement on milk yield and composition as well as iron status and immune response in lactating dairy cows. In this study 13 lactating Holstein cows were randomly assigned to either a control group or a treatment group supplemented with 10 mg of 5-ALA per kilogram of dry matter. During feeding, 5-ALA was mixed with a small amount of the total mixed ration and top-dressed. The experiments followed a crossover design with 2 periods. Each period consisted of an adaptation period of 12 d and a test period of 2 d. Dairy cows fed the diet supplemented with 5-ALA exhibited increased counts of white blood cells and granulocytes compared with the control group. The rate of phagocytosis and mitogen-induced proliferation of peripheral blood mononuclear cells in cows fed 5-ALA were higher than in cows fed a basal diet. However, 5-ALA did not affect iron status or plasma biochemical composition. Supplementation with 5-ALA improved milk protein and milk casein contents; however, it had no effect on milk production, milk fat, lactose, total solids, or solids-not-fat, compared with the control. We conclude that dietary supplementation of 5-ALA to lactating dairy cows may have a positive effect on milk protein synthesis and the immune response.

77 Monozygotic Twin Calves Production by Blastomere Separation Technique with Commercial Well-of-the-Well Culture Dish

Monozygotic twin bovine embryos can be produced by blastomere separation of 2-cell embryos and commercial well-of-the-well (WOW) culture dish (Hashiyada et al. 2016 Reprod. Fertil. Dev. 28, 178) obtaining 60% and 48% of blastocyst formation and monozygotic blastocyst pairs, respectively. The present study was conducted to evaluate the fertility of blastocysts derived from this production system in Japanese Black beef cattle. Embryos were produced using oocytes collected by ovum pick-up technique. TCM-199 supplemented with 5% calf serum (CS), Brackett-Oliphant solution supplemented with 10 mg mL−1 BSA, and CR1aa containing 5% CS, were used for each culture step: in vitro maturation, fertilization, and culture (IVM,IVF, and IVC). Two-cell stage embryos were obtained 24 to 27 h post-insemination. Zonae pellucidae were removed by exposure to 0.25% pronase. Then, embryos were separated into blastomeres by gentle pipetting in IVC medium. Each blastomere was introduced into a single conical microwell of 25 wells, each having a diameter and depth of ~287 μm and 168 μm (Dai Nippon Printing, Tokyo, Japan). Blastomeres in wells were cultured covered with a droplet of 2.5 μL of IVC medium/well. The developed blastocysts in pairs on 7 days post-insemination were used for transfer. Single embryos of monozygotic twin embryos were transferred to Japanese Black cattle with a generally small body frame to produce twin calves from a set of recipients. Twin embryos were transferred in pairs to unilateral of uterus of non-lactating Holstein cows. Pregnancy and twin pregnancy were determined at 30 days of gestation by ultrasonography and were reconfirmed at 60 days with detection of fetal loss. Statistical significance was analysed by Fisher’s exact test. There was no significant difference in pregnancy rate or twin pregnancy rate between single embryo transfer (7/14, 50% and 2/7, 28.6%) and twin embryo transfer (9/21, 42.9% and 4/21, 19%). In either transfer method, fetal loss was not observed in diagnosis carried out at 60 days by ultrasonography. To date, 2 pairs of twin calves have been obtained from twin pregnant cows by twin embryo transfer within the normal range of gestation length (286 and 288 days) and birth weight (31-40 kg). These results indicate that blastocysts developed from blastomeres separated from 2-cell embryos by culturing with commercial WOW culture dish had fertility similar to that of intact embryos derived from standard in vitro culture and further demonstrate the possibility of production of normal twin calves.

143 EFFECT OF FSH OR EPIDERMAL-GROWTH-FACTOR-LIKE PEPTIDE SUPPLEMENTATION TO MATURATION MEDIUM ON DEVELOPMENTAL COMPETENCE OF BOVINE OOCYTES DERIVED FROM FULLY DEVELOPED FOLLICLES INDUCED BY SUPER-STIMULATION

Bovine oocytes obtained by ovum-pick-up (OPU) following follicle growth treatment (FGT) have improved quality and competence (Imai et al. 2008 Reprod. Fertil. Dev. 20, 182). However, the effect of the presence of FSH or epidermal growth factor (EGF) like peptide during in vitro maturation (IVM) on the developmental competence of FGT oocytes has not been well known. This study was undertaken to examine the developmental competence of FGT oocytes following IVM in the presence of FSH (recombinant human FSH) or EGF-like peptide (amphiregulin; Areg) and IVF. Japanese Black cows (n = 17) were used as donors. Five days after arbitrary OPU (opu group), follicles ≥8 mm in diameter were aspirated again, a controlled internal drug release (CIDR) was inserted into the vagina, and then pFSH was injected twice a day from the evening of Day 6 to the morning of Day 10 with decreasing doses (total of 20 AU; 4, 4, 3, 3, 2, 2, 1, 1 AU/day). On the evening of Day 8, PGF2α (0.5 mg of cloprostenol) was administered. On Day 11, oocytes were aspirated from follicles with ≥5 mm in diameter of the treated donors by OPU (fgt group). The cumulus-oocyte complexes (COC) were cultured in the absence (opu-cont and fgt-cont groups) or presence of 0.1 IU mL−1 FSH (opu-fsh and fgt-fsh groups) or 100 ng mL−1 Areg (opu-areg and fgt-areg groups) in IVM medium (mTCM199 containing 5 mg mL−1 BSA) for 20 to 22 h (1 COC/5 µL, total of 162–171 COC per group), and then co-cultured with 3 × 106 sperm/mL for 6 h. The presumptive zygotes were continued to culture in mCR1aa supplemented with 5% newborn calf serum for 216 h (1 zygote/5 µL) using micro-well culture dishes (Dai-Nippon-Print). When repeating this opu-fgt session in the same cow, an interval at least for 50 days was kept, and the session was performed 28 times. Statistical analysis was carried out by Mann-Whitney’s U-test (between opu and fgt groups) or Steel-Dwass test after Kruskal-Wallis test (among all groups). The number of follicles ≥5 mm increased in the fgt than opu group (17.8 v. 2.9; P < 0.01). The number of COC collected was not different between the opu and fgt groups (23.1 v. 19.6; P > 0.05). The blastocyst formation rate was higher in the fgt than opu group (36.9 v. 23.1%; P < 0.01). Within 6 groups, the blastocyst formation rate was higher in the fgt-fsh (43.3%; P < 0.01) and fgt-areg (39.5%; P < 0.05) groups than the opu-cont (16.3%) group. The rate in the fgt-fsh group was also higher than that in the opu-fsh group (43.3 v. 18.7%; P < 0.01). These results suggested that FGT improved the developmental competence of bovine oocytes, probably through improving the ability of the COC to react against FSH/Areg.

Oocyte maturation and quality: role of cyclic nucleotides

The cyclic nucleotides, cAMP and cGMP, are the key molecules controlling mammalian oocyte meiosis. Their roles in oocyte biology have been at the forefront of oocyte research for decades, and many of the long-standing controversies in relation to the regulation of oocyte meiotic maturation are now resolved. It is now clear that the follicle prevents meiotic resumption through the actions of natriuretic peptides and cGMP - inhibiting the hydrolysis of intra-oocyte cAMP - and that the pre-ovulatory gonadotrophin surge reverses these processes. The gonadotrophin surge also leads to a transient spike in cAMP in the somatic compartment of the follicle. Research over the past two decades has conclusively demonstrated that this surge in cAMP is important for the subsequent developmental capacity of the oocyte. This is important, as oocyte in vitro maturation (IVM) systems practised clinically do not recapitulate this cAMP surge in vitro, possibly accounting for the lower efficiency of IVM compared with clinical IVF. This review particularly focuses on this latter aspect - the role of cAMP/cGMP in the regulation of oocyte quality. We conclude that clinical practice of IVM should reflect this new understanding of the role of cyclic nucleotides, thereby creating a new generation of ART and fertility treatment options.

Extending prematuration with cAMP modulators enhances the cumulus contribution to oocyte antioxidant defence and oocyte quality via gap junctions

STUDY QUESTION

Can bovine oocyte antioxidant defence and oocyte quality be improved by extending the duration of pre-in vitro maturation (IVM) with cyclic adenosine mono-phosphate (cAMP) modulators?

SUMMARY ANSWER

Lengthening the duration of cAMP-modulated pre-IVM elevates intra-oocyte reduced glutathione (GSH) content and reduces hydrogen peroxide (H2O2) via increased cumulus cell-oocyte gap-junctional communication (GJC), associated with an improvement in subsequent embryo development and quality.

WHAT IS KNOWN ALREADY

Oocytes are susceptible to oxidative stress and the oocyte's most important antioxidant glutathione is supplied, at least in part, by cumulus cells. A temporary inhibition of spontaneous meiotic resumption in oocytes can be achieved by preventing a fall in cAMP, and cyclic AMP-modulated pre-IVM maintains cumulus-oocyte GJC and improves subsequent embryo development.

STUDY DESIGN, SIZE, DURATION

This study consisted of a series of 10 experiments using bovine oocytes in vitro, each with multiple replicates. A range of pre-IVM durations were examined as the key study treatments which were compared with a control. The study was designed to examine if one of the oocyte's major antioxidant defences can be enhanced by pre-IVM with cAMP modulators, and to examine the contribution of cumulus-oocyte GJC on these processes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Immature bovine cumulus-oocyte complexes were treated in vitro without (control) or with the cAMP modulators; 100 µM forskolin (FSK) and 500 µM 3-isobutyl-1-methyxanthine (IBMX), for 0, 2, 4 or 6 h (pre-IVM phase) prior to IVM. Oocyte developmental competence was assessed by embryo development and quality post-IVM/IVF. Cumulus-oocyte GJC, intra-oocyte GSH and H2O2 were quantified at various time points during pre-IVM and IVM, in the presence and the absence of functional inhibitors: carbenoxolone (CBX) to block GJC and buthionine sulfoximide (BSO) to inhibit glutathione synthesis.

MAIN RESULTS AND THE ROLE OF CHANCE

Pre-IVM with FSK + IBMX increased subsequent blastocyst formation rate and quality compared with standard IVM (P < 0.05), regardless of pre-IVM duration. The final blastocyst yields (proportion of blastocysts/immature oocyte) were 26.3% for the control, compared with 39.2, 35.2 and 34.2%, for the 2, 4 and 6 h pre-IVM FSK + IBMX treatments, respectively. In contrast to standard IVM (control), pre-IVM with cAMP modulators maintained open gap junctions between cumulus cells and oocytes for the duration (6 h) of pre-IVM examined, and persisted for a further 8 h in the IVM phase. Cyclic AMP-modulated pre-IVM increased intra-oocyte GSH levels at the completion of both pre-IVM and IVM, in a pre-IVM duration-dependent manner (P < 0.05), which was ablated when GJC was blocked using CBX (P < 0.05). By 4 h of pre-IVM treatment with cAMP modulators, oocyte H2O2 levels were reduced compared the control (P < 0.05), although this beneficial effect was lost when oocytes were co-treated with BSO. Inhibiting glutathione synthesis with BSO during pre-IVM ablated any positive benefits of cAMP-mediated pre-IVM on oocyte developmental competence (P < 0.01).

LIMITATIONS, REASONS FOR CAUTION

It is unclear if the improvement in oocyte antioxidant defence and developmental competence reported here is due to direct transfer of total and/or reduced glutathione from cumulus cells to the oocyte via gap junctions, or whether a GSH synthesis signal and/or amino acid substrates are supplied to the oocyte via gap junctions. Embryo transfer experiments are required to determine if the cAMP-mediated improvement in blastocyst rates leads to improved live birth rates.

WIDER IMPLICATIONS OF THE FINDINGS

IVM offers significant benefits to infertile and cancer patients and has the potential to significantly alter ART practice, if IVM efficiency in embryo production could be improved closer to that of conventional IVF (using ovarian hyperstimulation). Pre-IVM with cAMP modulators is a simple and reliable means to improve IVM outcomes.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants and fellowships from the National Health and Medical Research Council of Australia (1007551, 627007, 1008137, 1023210) and by scholarships from the Chinese Scholarship Council (CSC) awarded to H.J.L. and the Japanese Society for the Promotion of Science Postdoctoral Fellowship for Research Abroad awarded to S.S. The Fluoview FV10i confocal microscope was purchased as part of the Sensing Technologies for Advanced Reproductive Research (STARR) facility, funded by the South Australian Premier's Science and Research Fund. We acknowledge partial support from the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics (CE140100003). We declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

96 EFFICIENT PRODUCTION OF MONOZYGOTIC TWIN BOVINE EMBRYOS USING BLASTOMERE SEPARATION TECHNIQUE WITH COMMERCIAL WELL OF THE WELL CULTURE DISH

Monozygotic twin embryos can be produced using the technique of blastomere separation and well of the well (WOW) dish having handmade micro-wells by the needle depression (Tagawa et al. 2008). We have recently reported that developed commercial WOW dish enhances embryo competence in individual culture (Sugimura et al. 2010). The present study was conducted to evaluate the availability of commercial WOW dish for production of monozygotic twin embryos in bovine. Embryos were produced using oocytes from ovaries collected at an abattoir by IVM, IVF, and IVC. For each culture, TCM-199 supplemented with 5% calf serum (CS), Brackett-Oliphant solution supplemented with 10 mg mL–1 BSA, and CR1aa containing 5% CS were used. To evaluate the adaptability of dishes on culture of isolated blastomeres from different cell stage, 2- (n = 63), 4- (n = 94), 8- (n = 137), and 10- to 14- (n = 116) cell stages were obtained on 24–27 h, 30–36 h, 48–54 h, and 48–54 h from the beginning of fertilization, respectively. The zona pellucida was removed by exposure of 0.25% pronase, followed by gentle pipetting by inspiration and expiration in the IVC medium. Then, two halves separated from the original number of blastomeres were randomly allocated to the conical micro-wells of commercial dish (Dai Nippon Printing, Tokyo, Japan) or created micro-wells by pressing the bottom of the dish with an eyeleteer (control). The approximate diameter and depth of each 25 wells in a commercial dish was 287 and 168 μm, and each 20 wells in the control were 800 and 600 μm. The blastomeres were cultured in wells covered with a droplet of 2.5 μL well–1 IVC medium until Day 8 (IVF = Day 0). Expanded blastocysts (n = 28) derived from tetra-blastomeres of 8-cell stage were stained to determine the number of the inner cell mass (ICM) and trophectoderm (TE) in each group. Statistical significance of the blastocyst formation rates and the number of cells were analysed by the chi-square test and the Student’s t-test, respectively. In the 2-cell stage, blastocyst formation rate in commercial dish tended to be higher than that in the control (60.0% v. 46.1%). The rate of monozygotic blastocyst pairs in commercial dish was higher compared with the control (48.0% v. 26.3%, P < 0.05). In the 4-cell stage, rates of blastocyst formation (50.0% v. 33.0%, P < 0.05) and the pairs (39.5% v. 12.5%, P < 0.01) in the commercial dish, both were higher compared with the control. In the 8-cell stage, there were no differences between two groups in rates of blastocyst formation (53.1% v. 59.0%) and the pairs (41.8% v. 48.7%), similarly in the 10- to 14-cell stage (47.9% v. 56.8% and 36.2% v. 40.9%, respectively). The ICM, TE, and total cell numbers were not different between the commercial and the control dish (28.0 ± 3.2 v. 26.0 ± 3.8, 64.6 ± 4.3 v. 76.0 ± 7.9, and 92.6 ± 6.2 v. 102.0 ± 11.0, respectively). These results indicate that separated blastomeres could be developed to blastocysts efficiently and stably regardless of embryo cell stage with a commercial WOW culture dish.

138 COMPARISON OF KINETICS AND PATTERNS OF THE FIRST CLEAVAGE OF IN VIVO AND IN VITRO-MATURED HOLSTEIN OOCYTES AFTER IN VITRO FERTILIZATION WITH X-SORTED SPERM

Previously, it was reported that a high rate of good quality blastocysts were produced by IVF of in vivo-matured oocytes, obtained by ovum pick up (OPU) after superstimulation in Holstein cows, using X-sorted sperm (Matoba et al. 2012 Reprod. Domest. Anim. 47, 515). In this system, an early first cleavage within 28 h after IVF was found to be a potent marker for the selection of embryos with high developmental competence (Matoba et al. 2013 Reprod. Fertil. Dev. 25, 266). However, we have limited knowledge on the timing and normality of embryonic cleavages in in vitro-matured oocytes after IVF. The purpose of the present study was to compare the kinetics and patterns of the first cleavage of in vivo- and in vitro-matured bovine oocytes after IVF with X-sorted sperm. In vivo-matured oocytes (Group A) were collected by OPU from non-lactating Holstein cows just before ovulation after superstimulation. Immature oocytes were either collected by OPU without hormonal treatment or by aspiration of ovaries at the local abattoir and matured in vitro (Group B or C). All the oocytes were inseminated with 5 × 106 sperm mL–1 of X-sorted sperm, except half of oocytes in Group C inseminated by non-sorted sperm (Group D) and cultured in CR1aa supplemented with 5% calf serum and 0.25 mg mL–1 of linoleic acid albumin at 38.5°C in 5% CO2, 5% O2, and 90% N2 for 216 h. Embryo kinetics were observed individually using a microwell culture dish and time-lapse cinematography (Sugimura et al. 2010 Biol. Reprod. 83, 970–978). Photographs of each embryo were taken in every 15 min during the IVC period and analysed by time-lapse cinematography software. Cleavage pattern was categorized as normal (2 even blastomeres without fragment or protrusion) or abnormal (2 uneven blastomeres, with fragment or protrusion and those dividing into 3–5 blastomeres) at the first cleavage. Data were analysed by ANOVA, chi-squared, or discriminant function. A total of 268 cleaved embryos were used. The blastocyst rate in Group A was higher than in Groups B and C (61.3 v. 40.0 and 25.0%, respectively; P < 0.05). The timing of first cleavage was longer in Group A compared with Groups C and D (28.3 ± 3.8 v. 27.6 ± 3.8 and 26.7 ± 1.9 h, respectively) and in Group B (28.1 ± 4.0 h) compared with in Group D (P < 0.05). Higher rates of normal cleavage were observed in Groups A, B, and D than in Group C (53.5, 44.4, and 54.8 v. 16.7%, respectively; P < 0.01). The frequency of blastocysts derived from the early (28.3 h) and normal pattern cleaving oocytes were greater in Groups A and B than in Group C (29.0 and 20.0 v. 8.3%, respectively; P < 0.05) and similar in Group D (22.6%). Our results reveal that IVF embryos produced from in vivo-matured oocytes with sex-sorted sperm had superior normality than those produced from in vitro-matured oocytes and similar normality to embryos inseminated with non-sorted sperm. Supported by the Research and Development projects for application in promoting new policy of agriculture, forestry and fisheries (22016) and by JSPS and HAS under the Japan-Hungary Research Cooperative Program.

252 EFFECT OF SUPERSTIMULATORY TREATMENT TO DONOR COWS IN OXYGEN CONSUMPTION OF MATURED OOCYTES

We previously reported that follicular wave synchronization and follicular growth treatment (FGT) before ovum pick-up (OPU) were effective in improving oocyte competence, which was associated with an increase in related embryos obtained by somatic cell nuclear transfer (Sugimura et al. 2012 Cell. Reprogram. 14, 29–37). However, oxygen consumption in oocytes remained unknown. The present study was designed to examine the differences in oxygen consumption between bovine oocytes obtained by OPU with or without FGT after in vitro maturation. Holstein dry cows (n = 8) were reared under the same feeding and environmental conditions. Two OPU sessions were conducted in each cow to collect immature oocytes, as described by Sugimura et al. (2012). The first OPU session (OPU group) was performed in cows on arbitrary days of the oestrous cycle, using a 7.5-MHz linear transducer with the needle connected to an ultrasound scanner. Follicles larger than 8 mm in diameter were then aspirated and a controlled internal drug release device (CIDR) was inserted on Day 5 (the day of the first OPU session = Day 0). Then 30 Armour units (AU) of FSH (Antrin, Kyoritsu Seiyaku, Tokyo, Japan) was administrated to cows twice a day from Day 7 to 10 in decreasing doses (6, 6, 4, 4, 3, 3, 2, 2 AU day–1). Cloprostenol (prostaglandin F2α; 0.75 mg) was administered in the morning of Day 9. The second OPU session (FGT-OPU group) was performed 48 h after prostaglandin F2α administration (Day 11), and only follicles larger than 5 mm in diameter were aspirated. The CIDR was removed from the cows just before OPU. Collected cumulus–oocyte complexes in the OPU and FGT-OPU groups were matured in vitro as described by Imai et al. [2006 J. Reprod. Dev. 52(Suppl.), S19–S29]. To collect in vivo-matured oocytes (control group), the CIDR was inserted into the cows on arbitrary days of the oestrous cycle (= Day 0), and oestradiol benzoate (0.8 mg) was administered on Day 1. The cows received the FGT treatment (as described above) from Day 6 to 10; however, the CIDR was removed in the evening of Day 8. Buserelin (gonadotropin-releasing hormone; 200 µg) was then administrated in the morning of Day 10, and OPU was performed at 24 h after gonadotropin-releasing hormone administration (Day 11). Oxygen consumption of matured oocytes was measured noninvasively with a scanning electron microscopy system (HV-405SP; Hokuto Denko Co., Tokyo, Japan). Data were analysed by ANOVA followed by a Tukey-Kramer test. There was no difference in the mean oxygen consumption between the FGT-OPU group (0.34 ± 0.02 × 10–14 mol–1, mean ± SEM) and control group (0.40 ± 0.01 × 10–14 mol–1). However, oxygen consumption in the FGT-OPU and control groups was significantly lower (P < 0.01) than that in the OPU group (0.50 ± 0.02 × 10–14 mol–1). These results revealed significantly lower oxygen consumption in OPU-derived in vitro-matured bovine oocytes after FGT treatment compared with those obtained without FGT treatment. Oxygen consumption of oocytes obtained from FGT-OPU was similar to that of in vivo-matured oocytes, which may reflect their cytoplasmic maturation status with high developmental competence.

236 KINETICS AND PATTERN OF THE FIRST CLEAVAGE OF IN VITRO-FERTILIZED EMBRYOS BY IN VIVO-MATURED OOCYTES AND X-SORTED SPERMATOZOA IN DAIRY CATTLE

Recently, we reported that high rates of good-quality blastocysts can be produced by IVF of in vivo-matured oocytes, obtained by ovum pick-up (OPU) after superstimulation in Holstein cows, with X-sorted sperm [Matoba et al. 2012 Reprod. Domest. Anim. 47(Suppl. 4), 515]. However, we have limited knowledge concerning the normality of embryonic cleavages in such embryos. The present study examined their kinetics and pattern of the first cell cycle. In vivo-matured oocytes were collected by OPU from non-lactating Holstein cows just before ovulation after superstimulation and ovulation induction by gonadotropin-releasing hormone. The oocytes were inseminated with 5 × 106 sperm mL–1 of X-sorted sperm and cultured in CR1aa supplemented with 5% newborn calf serum and 0.25 mg mL–1 of linoleic acid albumin at 38.5°C in 5% CO2, 5% O2, and 90% N2 for 216 h. Embryo kinetics were observed individually using a microwell culture dish and time-lapse cinematography (CCM-1.4MZS, Astec, Fukuoka, Japan) (Sugimura et al. 2010 Biol. Reprod. 83, 970–978). Photographs of each embryo were taken every 15 min during the in vitro culture period, and images were analysed by CCM-1.4 software (Astec). The cleavage pattern was categorised into normal cleavage (2 even blastomeres without fragment or protrusion) or abnormal cleavage (those with 2 uneven blastomeres, with fragments or protrusions and those dividing into 3 to 5 blastomeres at the first cleavage). Data were analysed by ANOVA, chi-square, and discriminant function. A total of 117 embryos were examined; of this number, 63.2% developed to the blastocyst stage and the rest were degenerated. A high rate of normal cleavage and a low rate of abnormal cleavage, including those with 2 uneven blastomeres and those with fragments or protrusions in the first cleavage pattern, were recorded in embryos that could develop to blastocysts compared with degenerated ones (P < 0.01 or P < 0.05, respectively; Table 1). No significant difference was found in those dividing into 3 to 5 blastomeres between the blastocysts and degenerated embryos (Table 1). Embryos developing to the blastocyst stage had a shorter duration of the first cell cycle [27.2 ± 2.3 h post-insemination (hpi)] compared with those undergoing degeneration (30.6 ± 5.7 hpi; P < 0.001). The threshold of duration of the first cell cycle was calculated by (X – 27.2)/2.3 = (30.6 – X)/5.7, resulting in X = 28.2. Blastocysts with a short duration of the first cell cleavage (≤28.2 hpi) showed a higher frequency of the normal cleavage pattern than those with a duration of the first cell cleavage longer than 28.2 hpi (71.7 and 53.6%, respectively; P < 0.05). Our results revealed that those IVF embryos that finished their first cleavage before 28.2 h of IVF and showed a normal cleavage pattern had superior developmental competence. Table 1.The first cleavege pattern reflects the developmental competence: blastocysts versus degenerated embryos This work was supported by the Research and Development Projects for Application in Promoting New Policy of Agriculture, Forestry and Fisheries (22016).

159 RELATIONSHIP BETWEEN CLEAVAGE PATTERNS OF FIRST CELL CYCLE AND POST-TRANSFER VIABILITY IN BOVINE EMBRYOS OBTAINED BY OVUM PICKUP AND IN VITRO FERTILIZATION

More than 300 000 embryos have been transferred all over the world (Stroud 2010 IETS Newsl. 27(4), 11–21). We have reported that embryos that showed the abnormal cleavage pattern at the first cell division can develop to the blastocyst stage (Somfai et al. 2010 J. Reprod. Dev. 56, 200–207). However, we have limited knowledge about the consequences of the pattern of first embryonic cleavage on their post-transfer developmental competence. The present study was conducted to determine the developmental competence of bovine blastocysts showing different cleavage patterns at their first cell division. Cumulus–oocyte complexes were collected by ovum pickup from Japanese Black cows and were subjected to in vitro maturation and IVF as reported previously (Imai et al. 2006 J. Reprod. Dev. 52, S19–S29 suppl). Inseminated oocytes were cultured in CR1aa medium supplemented with 5% calf serum covered by mineral oil at 38.5°C in 5% CO2 in air with micro-droplets or 5% CO2, 5% O2 and 90% N2. The kinetics of embryo development were analysed by time-lapse cinematography for 168 h after IVF by using a Cultured Cell Monitoring System (CCM-M1.4ZS, Astec, Fukuoka, Japan). A total of 673 photographs of each embryo were taken (1 photograph in every 15 min) during in vitro culture. Image stacks were analysed by the CCM-M1.4 software. Embryos were classified in 5 groups according to the pattern of first cleavage as normal cleavage (NC), direct cleavage from 1 cell to 3 to 4 blastomeres (3–4BL), unequal blastomeres (UB), multiple fragments (MF) and protrusion formation (PT). Blastocysts developing from each group were transferred into the ipsilateral uterine horn of each synchronized recipient on Day 7 or 8 after oestrus. Data on conception at Day 60, abortion and delivery were then recorded. Data were analysed by chi-square test and Student's t-test. In total, 43 embryos were transferred, 17 conceptions (39.5%) were established and 16 recipients (94.1%) were delivered. Only 1 abortion was detected at Day 223 in the NC group. The highest conception rate was observed in the NC group (55%, n = 20) and the 3–4BL (n = 12), UB (n = 6) and PT (n = 3) groups showed similar conception rates of 33.3% (1 implanted embryo belonged to 2 classes in UB and PT) and none of the embryos derived from the MF group (n = 3) could cause conception. There was a significant difference (P < 0.05) in conception rates between the NC group and totals of each of the other cleavage groups. No significant difference was found in gestation lengths and birth weights between the NC group (282.2 ± 4.4 days, 30.6 ± 3.8 kg, respectively) and totals of each of the other cleavage groups (282.8 ± 5.3 days, 30.3 ± 1.9 kg, respectively). These results indicate that embryos showing abnormal cleavage patterns at first cell division can develop to normal calves with normal gestation lengths and birth weights; however, their post-transfer viability is lower than for NC embryos. This work was supported by the Research and Development Program for New Bio-industry Initiatives.

158 RELATIONSHIP BETWEEN FOURTH CELL CYCLE DURATION AND POST-TRANSFER VIABILITY IN IN VITRO-FERTILIZED BOVINE EMBRYOS

In cattle, the prediction of embryonic viability after embryo transfer is an important research target. A previous study has indicated that the duration of the fourth cell cycle at the time of maternal-zygotic transition, which is involved in in vitro embryonic development, may be an indicator of blastocyst formation; this study showed that embryos with a short fourth cell cycle have a better potential of developing into blastocysts than those with a long fourth cell cycle (Lequarre et al. 2003 Biol. Reprod. 69, 1707–1713). However, the relationship between the fourth cell cycle duration and post-transfer viability of embryos is unclear. The aim of the present study was to examine the effect of the fourth cell cycle duration on embryo development after embryo transfer. Twenty-five IVF bovine embryos were cultured in well-of-the-well culture dishes contained 125 μ of CR1aa supplemented with 5% calf serum at 38.5°C in 5% O2 and 5% CO2 for 168 h after insemination. In vitro development of the embryos was monitored using time-lapse cinematography (Sugimura et al. 2010 Biol. Reprod. 83, 970–978). We found that 61% of the blastocysts had a long fourth cell cycle (41.5 ± 5.9 h), which is commonly referred to as the lag phase, whereas the remaining embryos had a short fourth cell cycle (7.4 ± 4.5 h). All the embryos with a short fourth cell cycle exhibited a lag phase in the next cell cycle (32.9 ± 6.6 h). Moreover, embryos with a short fourth cell cycle were found to have a higher blastocyst rate (75.8%) than those with a long fourth cell cycle (48.1%; Student's t-test, P < 0.01). However, embryonic cell number, apoptosis incidence, chromosomal abnormality and O2 consumption were found to be identical between the 2 groups (Student's t-test, P > 0.05). Real-time reverse-transcription PCR results of the individual blastocysts showed that the relative expression of 5 genes related to pregnancy reorganization, placentation and fetal growth—namely, CDX2, IFN-τ, PLAC8, AKR1B1 and IGF2R—did not differ between the 2 groups (Student's t-test, P > 0.05). Furthermore, blastocysts derived from embryos with long (n = 30) and short (n = 19) fourth cell cycles were transferred into 49 recipient cows; we did not observe any difference between the long and short fourth cell cycles on the rates of pregnancy (long vs short fourth cell cycle, 30.0 vs 52.6%) and delivery (long vs short fourth cell cycle, 30.0 vs 47.4%; Yates' corrected chi-square test, P > 0.10). These results show that blastocysts derived from embryos with either long or short fourth cell cycles have identical developmental competence after embryo transfer. Therefore, the fourth cell cycle duration during maternal-zygotic transition appears to be unavailable as the indicator of post-transfer viability of IVF bovine embryos. This work was supported by the Research and Developmental Program for New Bio-Industry Initiatives.

138 TIME-LAPSE CINEMATOGRAPHY-COMPATIBLE INJECTION-MOLDED MICROWELL CULTURE SYSTEM FOR TRACKING THE DEVELOPMENT OF INDIVIDUAL BOVINE EMBRYOS

We have developed a polystyrene-based well of-the-well system (WOW) using injection moulding to track individual embryos throughout culture using time-lapse cinematography (TLC). The WOW-cultured bovine embryos following in vitro fertilization (IVF) were compared with conventional droplet (control)-cultured embryos on in vitro and in vivo development. Twenty-five of zygotes were cultured in each culture system containing 125 μL of CR1aa medium supplemented with 5% calf serum for 168 h after IVF. No differences between control- and WOW-cultured embryos were observed during development to the blastocyst stage. Morphological quality, inner cell mass (ICM), and trophectoderm (TE) cell numbers and post-vitrification survival rates were not different between control- and WOW-derived blastocysts; however, incidence of apoptosis in the ICM and TE cells was reduced in WOW culture (P < 0.01). Oxygen consumption in WOW-derived blastocysts was closer to physiological level than that of control-derived blastocysts. Moreover, WOW culture improved embryo viability, as indicated by increased pregnancy rates at days 30 and 60 after embryo transfer (P < 0.05). The TLC monitoring was performed to evaluate the cleavage pattern and the duration of the first cell cycle of embryos from oocytes collected by ovum pick-up; correlations with success of pregnancy were determined. Logistic regression analysis indicated that the cleavage pattern correlated with success of pregnancy (P < 0.05), but cell cycle length did not. Higher pregnancy rates (66.7%) were observed for animals in which transferred blastocysts had undergone normal cleavage, identified by the presence of 2 blastomeres of the same size without fragmentation, than among those with abnormal cleavage (33.3%). These results suggest that our microwell culture system is a powerful tool for producing and selecting healthy embryos and for identifying viability biomarkers. This work was supported by the Research and Developmental Program for New Bio-Industry Initiatives.

212 EFFECT OF CONSECUTIVE SUPERSTIMULATORY TREATMENT-INDUCED FOLLICULAR WAVE SYNCHRONIZATION TO OPTIMIZE OOCYTE RETRIEVAL AND EMBRYO PRODUCTION BY OVUM PICKUP AND IN VITRO FERTILIZATION IN COWS

We previously reported that superstimulatory (SS) treatment-induced follicular wave synchronization after ovum pickup (OPU) was effective in enhancing the quality of obtained oocytes and blastocysts derived from in vitro maturation (IVM) and fertilization (IVF; Imai et al. 2010 Reprod. Fertil. Dev. 22, 296). The present study was designed to examine the efficiency of embryo production by 4 sessions of OPU-IVF using a series of the SS treatment-induced follicular wave synchronizations. For the SS protocols, 3 consecutive SS (3CSS) and 2 separated SS (2SSS) were used. In the 3CSS group, the first OPU was performed on random days of the oestrous cycle (Day 0) and all follicles larger than 2 mm in diameter were aspirated. On Day 5, follicles larger than 8 mm in diameter were aspirated and a CIDR (InterAg, Hamilton, New Zealand) was inserted. The cows then received 20 armour units of FSH (Kawasaki-Seiyaku, Kawasaki, Japan) in twice-daily decreasing doses by IM injection from Day 7 to 10. Cloprostenol (PGF; 0.75 mg, Fujita-Pharm, Tokyo, Japan) was administered on the morning of Day 9. The second OPU was performed 48 h after PGF administration on Day 11; the CIDR was removed from the cows just before OPU. After the second OPU, donors were treated consecutively with the SS protocol mentioned above for the third and fourth OPU sessions. In the 2SSS group, donors received 2 sets of the SS treatment mentioned above, with an interval of 11 days between the second and the third OPU session. Four OPU sessions were performed every 11 days on all cows. In this study, 8 Japanese Black cows were divided into the 3CSS and 2SSS groups, and the treatment for each group was reversed after a 65-day interval as crossover trials. After OPU, Grade 1 and 2 oocytes were used for IVM and IVF, and putative zygotes were cultured as described by (Imai et al. 2006 J. Reprod. Dev. 52, S19–S29 suppl.). A part of the zygotes were cultured in a micro-well system. Data were analysed by Student’s t-test and chi-square test. There were differences (P < 0.05) in the mean (±SD) number of follicles, collected oocytes, and cultured oocytes in the 3CSS (35.0 ± 8.6 and 24.4 ± 11.2, respectively) and 2SSS (30.8 ± 10.5 and 20.2 ± 9.0, respectively) groups. There were no differences in mean percentage of blastocyst formation and Grade 1 blastocyst rates between the 3CSS (38.5 and 55.8%, respectively) and 2SSS (34.8 and 54.8%, respectively) groups. However, the mean number of blastocysts produced per OPU session was significantly (P < 0.05) higher in the 3CSS group (8.1 ± 6.3) compared with the 2SSS group (5.8 ± 4.4). These results indicate that a series of 3 consecutive SS treatments had greater efficiency in producing OPU-IVF embryos. This work was supported in part by the Research and Development Program for New Bio-industry Initiatives.

154 THE EFFECT OF OXYGEN TENSION ON IN VITRO DEVELOPMENT OF BOVINE EMBRYOS IN POLYDIMETHYLSILOXANE-BASED WELL OF THE WELL DISHES PREPARED UNDER ATMOSPHERIC OR REDUCED AIR PRESSURE

Polydimethylsiloxane (PDMS) is a non-toxic silicon compound. Its excellent optical characteristics and easy preparation make it a good candidate material for the molding of custom-shaped dishes for embryo culture. We investigated the feasibility of PDMS-based well of the well (WOW) dishes for in vitro culture of bovine embryos under different oxygen tensions. The WOW dishes with 25 micro-wells (each of 175 μm depth and 250 μm width in diameter arranged in 5 columns and 5 rows) were molded from PDMS prepared either under atmospheric (Experiment 1) or reduced (0.1 MPa) (Experiment 2) air pressure to remove air bubbles. Presumptive zygotes obtained by the in vitro maturation and fertilization of follicular oocytes were placed and cultured for 7 days in traditional micro-drops of culture medium (Control) or in the micro-wells of PDMS-based WOW dishes (PDMS-WOW), both covered by paraffin oil. The culture medium was CR1aa supplemented with 5% calf serum. The culture drop size was 125 μL (5 μL/oocyte) in both groups. Embryo development and blastocyst cell numbers between Control and PDMS-WOW groups were compared either under 20% or 5% O2 tensions. There was no statistical difference in cleavage and blastocyst rates (ranging between 82.3-86.4% and 34.0-45.8%, respectively) between Control and PDMS-WOW embryos irrespective of oxygen tension and dish production method. In Experiment 1, the mean total cell numbers in blastocysts were lower in the PDMS-WOW group than that in Control under 20% O2 (105.0 ± 5.5 and 130.4 ± 9.9, respectively) (P < 0.05, ANOVA); however, the application of 5% O2 significantly improved the cell numbers and eliminated the difference between the PDMS-WOW and Control groups (135.4 ± 6.2 and 148.0 ± 9.0, respectively). In Experiment 2, there was no significant difference in mean total cell numbers in blastocysts between the PDMS-WOW and Control either under 20% O2 (97.2 ± 5.7 and 103.9 ± 8.9, respectively) or 5% O2 (147.5 ± 12.1 and 157.3 ± 3.9, respectively). The numbers and rates of inner cell mass and trophectoderm cells did not differ between the Control and PDMS-WOW groups, irrespective of O2 tension and production method. Our results demonstrate that bovine embryos can develop to the blastocyst stage in PDMS-based WOW dishes; however, it may express detrimental effects on embryonic cell numbers, which can be neutralized by the application of low O2 tension during culture or reduced air pressure during the PDMS preparation. This work was supported by the Research and Development Program for New Bio-Industry Initiatives.

278 EFFECT OF FOLLICULAR WAVE SYNCHRONIZATION AND SUPERSTIMULATION ON THE NORMALITY OF BOVINE EMBRYOS PRODUCED IN VITRO

We previously reported that follicular wave synchronization by dominant follicle removal on Day 5 and the start of a superstimulatory treatment on Day 7 after ovum pick-up (OPU) was effective to increase oocyte quality (Imai et al. 2008 Reprod. Fertil. Dev. 20, 182). The present study was designed to examine the effect of superstimulatory treatment-induced follicular wave synchronization on quality of embryos obtained by OPU and in vitro production. Japanese Black cows were reared under the same feeding and environmental conditions and 2 OPU sessions were conducted in each cow. The first OPU session was performed in 7 cows at arbitrary days of estrous cycle using a 7.5-MHz linear transducer with needle connected to an ultrasound scanner. Then, follicles larger than 8 mm in diameter were aspirated and CIDR was inserted on Day 5 (the day of first OPU session = Day 0). The cows then received 30 mg of FSH twice a day from Days 7 to 10 in decreasing doses (4, 4, 3, 3, 2, 2, 1, 1 mg per shot) by i.m. injections. Cloprostenol (PGF; 0.75 mg) was administered in the morning of Day 9. The second OPU session was performed 48 h after PGF administration (Day 11) and only follicles larger than 5 mm in diameter were aspirated. The CIDR was removed from the cows just before OPU. Grade 1 and 2 cumulus oocyte complexes were in vitro matured, fertilized (IVF), and cultured as described by Imai et al. (2006 J. Reprod. Dev. 52, Suppl. S19-29). Some zygotes were fixed and stained to check their sperm penetration. Embryo development was monitored by time-lapse cinematography for 168 h after IVF. Cleavage pattern of embryos was classified morphologically into normal and abnormal (including those with multiple fragments, protrusions, 3 to 4 blastomeres, and uneven cell division) groups at their first cleavage. Normal penetration rate of second OPU session was significantly (P < 0.05) higher than that of the first OPU session. There were no differences in the mean percentage of total blastocyst and grade 1 blastocyst rates between the first (45.2 and 46.9%, respectively) and second (47.5 and 41.8%, respectively) OPU sessions. However, the rates of blastocysts developing from embryos that were beyond the 4-cell stage at 48 h after IVF was significantly (P < 0.05) higher after the second OPU session (81.2%) than after the first OPU session (67.4%). Furthermore, a significant difference (P < 0.05) was found in the rates of normal cleavage at the first cell division in embryos that developed to the blastocyst stage between the first and second OPU sessions (53.3% and 73.9%, respectively). These results indicate that superstimulatory treatment-induced follicular wave synchronization improved the normality of fertilization and development of cattle oocytes obtained by OPU. This work was supported by the Research and Development Program for New Bio-industry Initiatives.

87 EVALUATION OF MITOCHONDRIAL FUNCTION IN SINGLE CLONED MINIATURE PIG EMBRYOS BY MEASURING OXYGEN CONSUMPTION

Mitochondria are organelles that produce energy for embryogensis. Their function [oxidative phosphorylation (OXPHOS) and electron transport] is regulated by intercommunication with the nucleus. In somatic cell nuclear transfer (SCNT) embryos, incomplete reprogramming may lead to dysfunction of the intercommunication before or after embryonic activation, or both, although it is unknown whether reprogramming for energy synthesis is required. In the previous report (Abe et al. 2004 J. Mamm. Ova Rec. 21, 22), we developed a noninvasive method using a scanning electrochemical microscopy (SECM) for measurement of oxygen consumption that provides more direct information about mitochondrial function (Trimarch et al. 2000 Biol. Reprod. 62, 1866–1874). In the present study to evaluate mitochondrial function in individual miniature pig SCNT embryos, we measured oxygen consumption by SECM. Oocytes in pig ovaries collected from the local slaughterhouse were matured for 44 h in NCSU23 and used as recipient. After SCNT with fetal miniature pig fibroblasts, reconstructed embryos were cultured in vitro in NCSU23 or PZM-3. Oxygen consumption in single 2- and 4-cell-stage embryos, morulae, and blastocysts were measured, and the values were compared with those derived from IVF. All data were analyzed by ANOVA. In IVF embryos, oxygen consumption was lowest at the 2- and 4-cell stages, and reached a peak at the blastocyst stage on Day 5. However, there were significant differences (P &lt; 0.05) in blastocysts between NCSU23 and PZM-3: 0.61 � 0.14 vs. 0.83 � 0.18 at Day 5, 0.53 � 0.14 vs. 0.70 � 0.24 at Day 6, 0.47 � 0.11 vs. 0.73 � 0.20 � 10-14 mol s-1 at Day 7, respectively. In contrast, SCNT embryos showed no increase in oxygen consumption during pre-implantation stages in the 2 media, but there was a significant difference (P &lt; 0.05) at the 2-cell stage between NCSU23 and PZM-3 (0.35 � 0.09 vs. 0.43 � 0.10, respectively). Comparison of the Day 5 IVF and SCNT blastocysts cultured in PZM-3 showed no difference in total cell numbers but significantly (P &lt; 0.05) lower oxygen consumption in SCNT (0.83 � 0.18 vs. 0.40 � 0.13 � 10-14 mol s-1, respectively). After treatment with 1 �M CCCP (mitochondrial uncoupler) or 1 mM NaCN (mitochondrial electron transporter inhibitor), oxygen consumption in IVF and SCNT blastocysts at Day 5 increased (112 � 18 and 51 � 44%, respectively) or decreased (50 � 20 and 21 � 32%, respectively) compared with those of nontreated embryos. Sensitivity to these reagents differed significantly (P &lt; 0.05) between IVF and SCNT, indicating that the SCNT blastocysts had a lower OXPHOS capacity than those from IVF. These results suggest that reprogramming for sustaining mitochondrial function during pre-implantation development may be required in miniature pig SCNT embryos.

78 EFFECTS OF DIFFERENT ACTIVATION PROTOCOLS ON ACTIN FILAMENT DISTRIBUTION AND IN VITRO DEVELOPMENT OF MINIATURE PIG NT EMBRYOS

In the process of producing reconstructed oocytes nuclear transfer (NT) embryos by somatic cell nuclear transfer, in vitro-matured oocytes can be used as recipient ones. It, however, has been well documented that after IVF porcine embryos derived from in vitro-matured oocytes have a small number of cells and low viability compared from those in vivo. As one possible reason, abnormal actin filament distribution has been detected in abnormal embryo cleavage and small cell numbers (Wang et al. 1999 Biol. Reprod. 60, 1020-1028). Artificial activation, which is necessary for development of NT embryos, can affect actin filament distribution of porcine oocytes matured in vitro, resulting in fragmentation (Kawahara et al. 2002 Theriogenology 58, 1081-1095). In the present study, we investigated effects of different activation protocols on actin filament distribution and in vitro development of miniature pig NT embryos. Porcine oocytes collected from ovaries were matured in vitro for 40 to 44 h in NCSU-23. First, we compared different activation protocols in development rates to blastocysts of oocytes activated. We used three activation methods (15 �M ionomycin treatment for 20 min (I), double DC pulses of 1.2 kV/cm for 60 ms in intervals of 5 s (E), and 5 mg/mL cycloheximide treatment for 5 h (C)) to prepare seven activation protocols (I, E, C, I + C, I + E, E + C, and I + E + C). Second, we examined effects of different activation protocols on actin filament distribution and subsequent development of NT embryos activated by the different activation protocols. Matured oocytes were enucleated, and fused with miniature pig fetal fibroblasts in calcium-free medium; approximately 3 h later, the resultant NT embryos were activated with three activation protocols (E, I + C, or I + E + C). All data were analyzed by chi-square test. The developmental rates to blastocysts in the I, E, C, I + C, I + E, E + C, and I + E + C groups were 5.6, 11.1, 0.0, 36.1, 20.7, 14.6, and 24.7%, respectively, showing that the rate in oocytes activated with I + C was significantly higher (P < 0.05) than the rates in oocytes activated by other treatments. In NT embryos, the developmental rates to blastocysts in the E, I + C, or I + E + C groups were 4.1, 14.3, and 4.6%, respectively, showing that the rate in NT embryos activated with I + C was significantly higher (P < 0.05) than the rate in NT embryos activated with other treatments. The abnormal rate of actin filament distribution in NT embryos activated with E or I + E + C was significantly higher (P < 0.05) than that in NT embryos activated with I + C (26.7% or 33.3% vs. 6.7%). The present results suggest that in miniature pig NT embryos an activation protocol by ionomycin combined with cycloheximide treatments may avoid physical damage to actin filaments with the resultant improvement of subsequent development.

Rapidly growing primary cardiac leiomyosarcoma: report of a case

Primary cardiac leiomyosarcomas are very rare. A 19-year-old man was admitted to a local hospital with dyspnea and hemoptysis. He was later transferred to our hospital because of his worsening dyspnea. An enhanced chest computed tomography scan demonstrated a large mass in the left atrium. A transthoracic echocardiogram showed a large mobile mass in the left atrium. The tumor was totally resected. The pathohistological examination showed leiomyosarcoma. The tumor rapidly recurred. and a second and third operation were performed. After the third operation, the patient was treated with radiotherapy. There was no local recurrence but multiple distant metastases were found 2 months after completion of radiation therapy.

[Processes underlying young children's spatial orientation]

The purpose of this study was to investigate the processes underlying spatial orientation in 3-year-old children. After the subjects had seen the experimenter hide an object in one of the two hiding locations on a turntable, they were asked to indicate the location of the object under three conditions: (a) only the table is rotated up to 180 degrees by 45 degrees steps, (b) only the subject is moved to an opposite side by 45 degrees steps, and (c) both the table and the subject were moved simultaneously up to 180 degrees by 45 degrees steps. The results showed that the discrepancy between the locations subjects indicated and the correct locations increased with the degree of rotation in all conditions although there were no significant differences among the conditions. Some of the individual patterns, however, indicated abrupt increases of the discrepancy. These findings suggest that the spatial orientation consists of perceptual and representational processes.

Disruption in the intrathoracic trachea due to blunt trauma

Intrathoracic tracheal disruption by blunt trauma is rare and potentially life threatening. Here report 3 cases of intrathoracic tracheal disruption due to blunt trauma. Two cases, each 43 year old, involved an unrestrained male driver who suffered a head-on crash, while the other, 63 year old, involved a male who suffered compression. Chest roentgenograms on admission showed remarkable deep cervical and mediastinal emphysema in Cases 1 and 2 and mediastinal emphysema alone in Case 3. Bronchoscopy revealed disruption in the trachea. Primary repair was performed through a right posterolateral thoracotomy in Cases 1 and 3 and through a median sternotomy in Case 2. In all cases the postoperative course was uneventful.

Intrapulmonary sequestration with arterial supply from the left internal thoracic artery: a case report

Pulmonary sequestration is uncommon in the upper lobe. Its arterial supply from the internal thoracic artery is very rare. Reported here is a case of a 20-year-old male whose presenting symptom was recurrent pneumonia. Helical computed tomography (CT) and three-dimensional reconstruction images showed that aberrant arteries arising from the left internal thoracic artery were supplying the area of sequestration and draining into the pulmonary vein. Selective intra-arterial digital substraction angiogram also showed left internal thoracic artery supplying the area of the sequestration. Helical three-dimensional CT is noninvasive and provides as accurate three-dimensional information of the aberrant vascular supply in intrapulmonary sequestration as the angiography.

Primary cardiac sarcoma: two case reports

Two case reports of primary cardiac sarcoma, which is uncommon, are presented. The first case, a 38-year-old male, complained of chest tightness. Chest roentgenograms showed enlargement of the cardiac shadow and left pleural effusion. Transthoracic echocardiography and chest magnetic resonance imaging showed a tumor in the right atrium, and pericardial effusion. The tumor involved the right atrial wall and interatrial septum, and was partially resected. Pathohistological examination revealed angiosarcoma. He died 1 month later. The second case, a 19-year-old male complained of dyspnea and orthopnea. Chest roentgenograms showed pulmonary congestion. Transthoracic echocardiography showed a large mobile mass in the left atrium. An emergency operation was performed and the tumor was totally resected. Pathohistological examination demonstrated leiomyosarcoma. The postoperative course was uneventful, but the tumor rapidly recurred. Second and third operations were performed at intervals of 2 months. After the third operation, he was treated with radiotherapy. Local recurrence was not found but multiple distant metastases were found 2 months after completion of radiation therapy.

[Blunt rupture of the intrapericardial inferior vena cava: report of two cases]

Blunt rupture of the intrapericardial inferior vena cava is rare. Our experience in recent two cases is presented. Case 1: A 52-year-old male was admitted following a traffic accident. Chest CT demonstrated cardiac tamponade and mediastinal hematoma. Ruptures of the right and left atria across the caudal aspect of the atrial septum, and a separate laceration of intrapericardial IVC were found in the emergency operation. Case 2: A 35-year-old male jumped from the fourth floor of a building. Chest CT revealed descending aortic rupture and the patient was taken to surgery. He died of massive hemorrhage from the aortic rupture. Exploration revealed a rupture of intrapericardial IVC. Recent literatures were reviewed and the mechanism of IVC rupture is discussed.

Terminal warm blood cardioplegia improves the recovery of myocardial electrical activity. A retrospective and comparative study

OBJECTIVE

The effect of terminal warm blood cardioplegia was analyzed in 191 patients undergoing either coronary artery bypass grafting (CABG) or prosthetic heart valve replacement between Jan. 1990 and Dec. 1995.

METHODS

Patients were subdivided into 3 historical cohorts based on the method of myocardial protection: Group A (n = 106), multidose cold crystalloid glucose-potassium cardioplegia, alone; Group B (n = 37), cold crystalloid glucose-potassium cardioplegia plus terminal warm blood cardioplegia, Group C (n = 48), cardioplegia induction with cold crystalloid glucose-potassium cardioplegia, maintenance with multidose cold blood cardioplegia, and terminal warm blood cardioplegia.

RESULTS

Of patients undergoing CABG, 5.6% of group A, 70.4% of group B, and 86.7% of group C spontaneously resumed sinus rhythm after aortic declamping, as did 9.1% of group A, 60.0% of group B, and 55.6% of group C of patients undergoing prosthetic heart valve replacement. The incidence of spontaneous recovery was significantly better in groups B and C than in group A (p < 0.05). Over 90% of patients without terminal warm blood cardioplegia developed ventricular fibrillation or tachycardia requiring electrical cardioversion (p < 0.05). Postoperatively, patients without terminal warm blood cardioplegia required temporary epicardial pacing more frequently than those with terminal warm blood cardioplegia (p < 0.05). In patients undergoing prosthetic heart valve replacement, groups B and C, the incidence of postoperative atrial fibrillation was significantly lower than in group A.

CONCLUSION

Terminal warm blood cardioplegia thus promoted better postoperative electrophysiological cardiac recovery.

Hepatocellular carcinoma with spontaneous regression of multiple lung metastases

Spontaneously regressed lung metastasis of hepatocellular carcinoma (HCC) in a 82-year-old Japanese man with liver cirrhosis was recorded. Multiple nodular lesions of both lungs, up to 1 cm across, were shown on chest X-ray when the clinical diagnosis of HCC was made because of the presence of a liver mass on abdominal computed tomography (CT) scan and high serum alpha-fetoprotein (AFP) value. The lung lesions which were regarded clinically as metastasis of HCC decreased in number and size 7 months later, and subsequently disappeared a further 7 months radiographically. However, the liver mass revealed no reduction on abdominal CT, despite normalization of the serum AFP value, and the patient died 7 months after the disappearance of the lung lesions. The patient refused biopsy for the liver mass and anticancerous treatment during the course of the disease. At autopsy, the liver mass, 13 cm in diameter, histologically featured moderately differentiated HCC. Only one metastasis, 0.5 cm across, was obvious in the left lower lung lobe. In addition, there were 14 minute lesions in both lungs, up to 0.2 cm across, including three with complete necrosis and 11 with histocytic reaction and fibrosis. The necrotic tissue was filled with large ghostly cells that appeared to be debris from a neoplastic tissue, regardless of no viable tumor cells among them. The clinical and autopsy findings highly suggested that the patient developed spontaneous regression of multiple lung metastases of HCC and subsequently left the very small lesions as the vestige. Thus, the histology of these lesions may exhibit a process of the regression as the sequence of events, i.e., a transition from necrosis of the metastatic HCC to its fibrosis. Presence of an effective factor(s) in relation to the regression was unclarified. There has been no reported cases with regression of the only metastasis of HCC in the literature to date.

[Dumbbell type schwannoma of the posterior mediastinum: a report of two cases with different surgical approaches]

Two cases of dumbbell type schwannoma of the posterior mediastinum are reported. Case 1 involved a 16-year-old man and case 2, a 48-year-old woman. They were asymptomatic, and in both cases an abnormal mass shadow of the left mediastinum was incidentally detected on a routine chest roentogenogram. In these cases, CT and MRI revealed that dumbbell type tumors extended to the spinal canal. The operations were performed with thoracic approach cooperated with a neurosurgeon in case 1 and with combined posterior and thoracic approach cooperated with an orthopedic surgeon in case 2. Histopathologic findings indicated all benign schwannomas. The reported 25 cases in Japan sofar are reviewed.

Acute traumatic dissection and blunt rupture of the thoracic descending aorta: A case report

Rupture of the thoracic aorta following blunt trauma is increasing in incidence and remains a highly lethal injury. Blunt traumatic rupture and acute dissection of the thoracic aorta is very rare. A 50-year-old man involved in a motor vehicle accident on March 3, 1998 was admitted to our hospital one and a half hours following the accident. On admission, he was alert and his hemodynamics were stable. Chest roentgenogram demonstrated a widened mediastinum and multiple left-sided rib fractures. Enhanced chest CT revealed a periaortic hematoma just distal to the isthmus, dissection of the descending thoracic aorta and mediastinal hematoma. With the diagnosis of thoracic aortic rupture and acute DeBakey type IIIB dissection, an emergency operation was performed. Intraoperative transesophageal echocardiogram showed a mobile intimal flap and diminished caliber of the proximal descending aorta. Disruption and dissection of the descending thoracic aorta were found. Prosthetic graft interposition was accomplished with the aid of left atrium-left femoral artery bypass using a centrifugal pump and heparin-coated circuits and a blood collection device for blood conservation. The weak dissected aortic wall was glued and reapproximated with Gelatine-Resorcine-Formol glue. The postoperative course was uneventful.

[Human parvovirus B19-induced aplastic crisis in a case with spherocytosis]

A 43-year-old female with spherocytosis was admitted to the hospital because of fever, headache, and rapidly progressive anemia. On admission, she had severe anemia (Hb 3.9 g/dl) with marked decrease in reticulocytes (0.3%). Some premature leukocytes, such as promyerocyte, were observed in the peripheral blood. Bone marrow smear revealed normocellular marrow with normal presence of erythroid cells. Anti-human parvovirus B19 IgM and IgG antibody was positive in the serum on admission. The DNA of the virus was also detected in the peripheral blood by PCR assay. Thus, this case was diagnosed as acute aplastic crisis caused by human parvovirus B19 infection. Blood transfusion was performed on day 1 and day 2. The symptoms gradually disappeared and increase in reticulocyte (11.5%) was observed on day 5. Premature leukocytes in the peripheral blood disappeared on day 2. She recovered from anemia and was discharged on day 7.

[High-dose methylprednisolone-containing chemotherapy in advanced invasive thymoma--report of three cases]

During the period from May, 1995 to August, 1996, three patients with Stage III or IVa invasive thymoma received chemotherapy consisting of cisplatin, doxorubicin and methylprednisolone (1000 mg on days 1 through 5, and 500 mg on days 6 and 7). The first case, a 55-year-old woman, who underwent extended thymectomy 7 years ago, was found to have a recurrent tumor in the left pleural cavity. The second case, a 38-year-old man, who had first operation 3 years ago, developed recurrent tumor in the right pleural cavity. These two patients were treated with the above regimen as the primary mode of therapy. The third case, a 61-year-old woman, had a thymoma with direct invasion to right upper lobe. The same chemotherapy regimen was employed as the induction chemotherapy. All patients showed a major response to treatment with only a small amount of tumor remaining. The effectiveness of chemotherapy in the treatment of malignant tumors has been recently reported to be at least partly due to induction of apoptosis. Steroids are known to induce apoptosis in normal thymic cells, and thus steroid in chemotherapy regimen against invasive thymoma may enhance the effect of anti-cancer drugs through the induction of apoptosis.

[Pedicled aortic wall flap for the reconstruction of aortico-ventricular discontinuity--a case report]

A 55-year-old man was operated on urgently for aortic valve endocarditis complicated by an annular abscess at the base of the non-coronary leaflet extending down to the left ventricle. Rapidly progressive heart failure and presence of a friable-appearing vegetation on echocardiography were the indications for urgent operation. Preoperative electrocardiogram showed first degree A-V block. At operation the aortic valve was generally thickened with mild calcification about the commissures. Non-coronary cusp was severely deformed and was nearly detached at its base due to annular abscess formation. Native valve was completely excised and the abscess was debrided. A club or a tongue-shaped pedicled aortic wall flap was prepared to the left of the oblique aortotomy incision with its free end to the distal side of the aorta. The flap was folded inward at its pedicle about 1 cm above the non-coronary annulus and was used to patch the abscess cavity. The aortic valve was replaced with a SJM 23 mm aortic valve prosthesis. The remaining defect of the aortic wall was repaired with a patch of woven-dacron vascular prosthesis. Post-operative hemodynamics of the patient was uneventful and he was given a 6-week course of parenteral antibiotics. He developed complete A-V block during the operation, and a permanent pacemaker was implanted on the 6th postoperative day. One year after operation he has not had recurrent infection and is leading a normal life. When used in the repair of ventriculo-aortic discontinuity created by infective endocarditis, the pedicled aortic wall flap has several advantages. It is easily obtainable and can cover abscesses of almost any shape and size. Unlike aortic root homograft, there is no problem of availability. Technically it is relatively simple to prepare a flap, bring it down through the non-coronary sinus and suture over the abscess. Aortic wall has just appropriate thickness and strength to reinforce the weakened periannular area, and if the debrided cavity is deep, the flap can be folded to obtain double thickness. By using this flap, potentially infected cavity is covered and packed by autologous tissue alone, and the synthetic patch to repair the aortic wall defect is placed well away from the site of possible contamination. In addition to the use in infective endocarditis, the aortic wall flap can predictably be used in the repair of aortic annular defect created by over-zealous removal of calcium in the surgery of calcific aortic stenosis, and in intracardiac patching in aortic annular enlargement operation such as Manouguian operation. To our knowledge, the use of pedicled aortic wall flap for aortic annular reconstruction has not been reported in the literature.

[A case of acute mediastinitis with pyothorax secondary to peritonsillar abscess]

A 41-year-old man was admitted to a hospital elsewhere because of tonsillitis with high grade fever. On the 9th day of hospitalization, the patient complained of dysphagia and dyspnea. A chest X-ray film and a CT scan showed right pleural effusion and pericardial effusion, and he was referred to our hospital. Immediately after admission, he underwent pericardiotomy to relieve cardiac tamponade, and a right thoracic tube was inserted for pyothorax. Next day, mediastinal drainage was accomplished through a cervical incision and a right thoracotomy. Eight drainage tubes were left in place. Cultures revealed alpha-Streptococcus, Neisseria and group F Streptococci. Continuous closed irrigation with diluted Isodine (povidone iodine) solution was performed. The last extubation of the drainage tube was done on the 140th day after operation. He was cured and discharged on the 162nd day after operation. In patients with extensive acute mediastinitis secondary to deep cervical infection, early complete mediastinal drainage via a cervical and a transthoracic incision is essential.

[Mobile right atrial thrombus: a case report of surgical removal]

A 71-year-old man was admitted due to brain infarction. An abnormal floating mass was found in the right atrium by echocardiography. The mass was assumed to be a thrombus. The patient was failed to be in danger of pulmonary embolism, so it was decided to remove surgically. The thrombus was removed under cardiopulmonary bypass including the atrial wall where it was attached, because it was difficult to rule out the possibility of cardiac tumor macroscopically. The tumor showed pathological findings of thrombus. Postoperative course was uneventful.

[A case of aortic valve rupture due to blunt chest trauma]

A case of aortic valve rupture due to blunt chest trauma is presented. 19-year-old man was in good health until he sustained traumatic injury in a traffic accident. He was admitted to a hospital elsewhere because of blunt chest trauma and fractures of the bilateral lower extremities. A heart murmur was detected and echocardiogram revealed marked aortic regurgitation. Then he was referred to our hospital. Progressive congestive heart failure developed. He underwent aortic valve replacement with 25 mm SJM prosthesis 9 days after the injury. The noncoronary cusp was found to be ruptured parallel to and 2 mm from its attachment. His postoperative course was uneventful and he is doing well 4 years and 6 months after operation.

[A case of tricuspid regurgitation due to blunt chest trauma]

A case of tricuspid regurgitation due to blunt chest trauma is presented. A 35-year-old man was in good health until he sustained blunt chest trauma in a traffic accident 17 years ago (in 1972). After that easy fatiguability developed. In 1977, slight tricuspid regurgitation was detected, but he was clinically well and no treatment seemed necessary. In October 1989, he was admitted due to right heart failure. The chest X-ray film showed marked cardiomegaly and ECG revealed atrial fibrillation and complete right bundle branch block. Two-dimensional echocardiogram showed a flail anterior leaflet of the tricuspid valve and severe tricuspid regurgitation. In December 1989, he underwent tricuspid valve replacement with Carpentier-Edwards bioprosthesis. The chordae tendineae to the anterior leaflet of the tricuspid valve were ruptured. Furthermore, an artificial cardiac pacemaker was implanted because of slow atrial fibrillation. His postoperative course was uneventful.

[A case report of corrected TGA with ventricular septal defect, tricuspid valve regurgitation and atrioventricular block]

A 61-year-old woman was admitted for heart failure. She was diagnosed as corrected TGA with tricuspid regurgitation, perimembronous ventricular septal defect and atrioventricular block by echocardiography and cardiac catheterization. We chose tricuspid valve replacement with preservation of valve leaflet and subvalvular apparatus, direct closure of ventricular septal defect and implantation of permanent pacemaker (myocardial lead). Although IABP was needed for 24 hours, after that postoperative course was uneventful. It is preferable that tricuspid valve replacement with preservation of valve leaflet and subvalvular apparatus is applied to similar adult cases from standpoint of morphological structure.