20 GENERATION AND CHARACTERIZATION OF TRANSGENIC-CLONED PIGS EXPRESSING THE FAR-RED FLUORESCENT PROTEIN MONOMERIC PLUM

Transgenic (Tg) pigs expressing a fluorescent protein are extremely useful for research into transplantation and regenerative medicine. This study aimed to create Tg pigs expressing monomeric Plum (mPlum), a far-red fluorescent protein with a longer wavelength than enhanced green fluorescent protein (EGFP) and humanized Kusabira Orange (huKO), the two fluorescent proteins that have been used previously for Tg pig production. A linearized CAG-mPlum transgene construct was transferred into porcine fetal fibroblasts (PFF) by electroporation. mPlum fluorescence-positive cells were collected using a cell sorter and used as nuclear donors (mPlum-PFF) for somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were obtained from porcine cumulus–oocyte complexes cultured in NCSU23-based medium and were used to obtain recipient oocytes for SCNT after enucleation. Then, SCNT was performed as reported previously (Matsunari et al., 2008). The reconstructed embryos were cultured for 7 days in porcine zygote medium-5 (PZM-5). mPlum fluorescence expression was screened during the early development of the embryos. After 5 or 6 days of culture, the SCNT embryos were surgically transferred to the uterus of a recipient gilt. We first obtained fetuses on Day 36 or 37 of gestation by Caesarean section and the PFF were retrieved from their skin. Fluorescence expression was analysed using fluorescence microscope, and the number of transgene copies in each fetus was determined by Southern blot analysis. We also analysed whether unique spectral properties of mPlum are suitable for multicolor imaging using confocal microscope and flow cytometer. The identification of mPlum-expressing PFF under the mixed culture of PFF expressing EGFP and huKO was examined. The 2 cell lines of PFF expressing EGFP and huKO were previously generated in our laboratory. Rates of normal cleavage and blastocyst formation occurred in the SCNT embryos generated with mPlum-PFF (mPlum embryos) were equivalent to those of SCNT embryos derived from nontransgenic PFF (34/42, 81.0%; 33/42, 78.6% v. 37/40, 92.5%; 30/40, 75.0%). Total cell numbers in mPlum and control blastocysts did not differ significantly (88.3 ± 6.0 v. 99.9 ± 8.8). Fluorescence expression in the mPlum embryos began at the 8-cell stage and became brighter from the morula stage. The gilt into which 103 mPlum embryos were transferred produced 3 fetuses. These fetuses expressed mPlum fluorescence systemically and had 1 to 5 copies of the transgene. Multicolor fluorescence imaging and flow cytometric analyses of a mixed culture of mPlum PFF and PFF expressing EGFP and huKO showed that clear identification and isolation of cells displaying each of the 3 fluorescence signals was possible. These observations demonstrate that the transfer of CAG-mPlum did not interfere with the development of porcine SCNT embryos and resulted in the successful generation of Tg cloned pigs that systemically expressed mPlum. This work was supported by JSPS KAKENHI Grant Number 25293279.

49 PRACTICAL APPLICATION OF THE HOLLOW FIBER VITRIFICATION METHOD FOR CRYOPRESERVATION OF MAMMALIAN EMBRYOS

We recently developed the hollow fibro vitrification (HFV) method, which is a novel, high-performance embryo cryopreservation method (Matsunari et al., 2012). In this study, we aimed to verify the applicability of the HFV method for cryopreserving various types of embryos; BDF1 mouse embryos at the 2-cell stage, porcine parthenogenetic morulae derived from in vitro-matured oocytes, bovine morulae produced by in vitro maturation/fertilization (LIAJ Animal Biotechnology Center, Tokyo, Japan), and in vivo-derived blastocysts of common marmosets were vitrified, and their survival was assessed by culture or transfer. The embryos were vitrified using 20 mM HEPES-buffered TCM-199 containing 20% calf serum as a base medium. Cellulose acetate hollow fibres (25 mm) containing 1 to 20 embryos were placed in an equilibration solution containing 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for 5 to 7 min, followed by incubation for 1 min in vitrification solution containing 15% EG, 15% DMSO, and 0.5 M sucrose. The embryos were then vitrified by immersion in LN. The embryos were devitrified by immersing the hollow fibre in a 1 M sucrose solution at 38.5°C, which was followed by stepwise dilution of the cryoprotectants and washing. For a subset of the vitrified mouse embryos, rewarming in a non-ultra-rapid manner by melting a hollow fibre in air at room temperature for 5 s was tested. Embryo transfer was performed to assess the viability of the vitrified mouse embryos. For porcine embryos, vitrification in LN vapor (–150°C) was tested. Development of the vitrified mouse embryos to blastocysts was equal to that of the non-vitrified embryos [105/110 (95.5%) v. 109/110 (99.1%)]. Post-transfer development to fetuses was also equal between the vitrified and non-vitrified embryos [pregnancy rates: 4/4 v. 2/2; developmental rates: 55/80 (68.8%) v. 35/40 (87.5%)]. Non-ultra-rapid rewarming did not decrease the survival of the vitrified mouse embryos [blastocysts: 94/100 (94.0%); pregnancy: 4/4; fetuses: 55/80 (68.8%)]. Blastocyst formation was equivalent for vitrification of porcine embryos in LN vapor [27/34 (79.4%)], direct immersion into LN [28/35 (80.0%)], and the non-vitrified control [31/32 (96.9%)]. Vitrification of 191 bovine morulae resulted in 153 (80.1%) blastocysts. In preliminary experiments, survival of marmoset blastocysts was 100% (n = 6). These data demonstrate that the HFV method is (1) effective for embryos of various species and production methods; (2) effective even for porcine in vitro-derived morulae, which are highly cryosensitive; and (3) amenable to modifications such as non-ultra-rapid warming and cooling in LN vapor, increasing the potential applicability of the HFV method. For instance, vitrification in LN vapor may allow embryo cryopreservation with high hygienic standards. This study was supported by JST, ERATO, Nakauchi Stem Cell and Organ Regeneration Project.

A randomized phase III trial of postoperative adjuvant therapy for completely resected stage IA-IIIA lung cancer using an anti‑angiogenetic agent: irsogladine maleate

AIM

Although angiogenesis plays an important role in the invasion and metastasis of solid tumors, very few anti-angiogenetic drugs have been developed. Reexamining the anti-angiogenetic effects of existing drugs such as Thalidomide is another possible strategy for drug discovery. Irsogladine maleate (IM) is a drug invented to treat gastric ulcers; however, several reports have shown that IM also exerts anti-angiogenetic effects in vitro, in vivo and in humans. In order to elucidate whether treatment with IM would improve the prognoses of patients with resected lung cancer, we conducted a randomized trial.

METHODS

In the control group, uracil-tegafur (250 mg/m2/day) was administered for two years to patients with resected stage IB - IIIA lung cancer, and no adjuvant therapy was administered to those with stage IA disease. In the study group, IM (4 mg/body/day) was additionally administered for two years.

RESULTS

No significant differences were observed in the major prognostic factors among 305 eligible patients between the study and control groups. Adverse effects were minimal. The overall survival of the patients in the study and control groups were not statistically different. When the analysis was stratified by regimen, among the patients with resected stage IA disease, disease-specific survival in the study group was slightly higher than that in the control group; however, the difference was not significant (p=0.07).

CONCLUSION

Although it could not be proven that IM improves the prognoses of resected lung cancer patients, IM might have some effect on resected stage IA disease, and another trial should be conducted.

Synovial chondromatosis of the temporomandibular joint with calcium pyrophosphate dihydrate crystal deposition disease (pseudogout)

This report describes a very rare case of synovial chondromatosis with deposition of calcium pyrophosphate dihydrate (CPPD) crystals (pseudogout) in the temporomandibular joint (TMJ) of a 46-year-old male patient. Synovial chondromatosis is a non-neoplastic disease characterized by metaplasia of the connective tissue leading to chondrogenesis in the synovial membrane. Pseudogout is an inflammatory disease of the joints caused by the deposition of CPPD, producing similar symptoms to those observed in gout but not hyperuricaemia. Both diseases commonly affect the knee, hip and elbow joints, but rarely affect the TMJ.

67 A HOLLOW FIBER VITRIFICATION METHOD ENABLES CRYOBANKING OF IN VITRO-MATURATION/IN VITRO-FERTILIZATION-DERIVED TRANSGENIC PIG EMBRYOS

We have recently developed a novel high-performance embryo cryopreservation method: the hollow fiber vitrification (HFV) method (Matsunari et al. 2012 J. Reprod. Dev., in press). In this study, we aimed to demonstrate the utility of the HFV method for the cryopreservation of transgenic pig embryos produced by in vitro oocyte maturation/fertilization (IVM/IVF). In vitro-matured oocytes were inseminated with cryopreserved epididymal sperm (Kikuchi et al. 1998 Theriogenology 50, 615–623) from a transgenic pig carrying the humanized Kusabira-Orange gene (Matsunari et al. 2008 Cloning Stem Cell 10, 313–323) and then cultured for 96 h. Morulae with normal morphology were divided into the vitrification and nonvitrification groups. The vitrification of embryos was performed by the HFV method using 20-mM HEPES-buffered TCM199 containing 20% calf serum as a base medium. Cellulose acetate hollow fibers (25 mm), each containing 10 to 20 embryos, were placed in an equilibration solution containing 7.5% ethylene glycol and 7.5% dimethyl sulfoxide for 5 to 7 min and were then placed for 1 min in the vitrification solution containing 15% ethylene glycol, 15% dimethyl sulfoxide, and 0.5 M sucrose. The embryos were then vitrified by immersion in liquid nitrogen and held there for 5 to 10 min. The embryos were warmed by immersing the hollow fiber in a 1-M sucrose solution at 38.5°C, followed by a stepwise dilution of the cryoprotectants using 0.5-M sucrose solution (3 min) and the base medium (10 min). Vitrified and nonvitrified embryos were cultured for 40 h, and their development into blastocysts was evaluated. The in vitro development of vitrified embryos to the blastocyst stage was compared with that of the nonvitrified controls on Day 6. In the embryo-transfer experiments, blastocysts at either Day 5 or Day 6 from both the vitrification and nonvitrification groups were transferred to 3 recipient gilts per group (25–32 blastocysts/gilt), and their development through farrowing was compared. To test long-term preservation, some of the vitrified morulae were kept in liquid nitrogen for 43 days, and their development to Day 30 fetuses was evaluated after transfer to an additional recipient. The differences in proportional data between the 2 groups were analyzed with the χ2-test. Of the 393 putative zygotes obtained by IVM/IVF, 169 (43.0%) developed into morulae. In vitro development of the vitrified morulae to blastocysts (66/85, 77.6%) was comparable with that of the nonvitrified morulae (67/84, 79.8%, not significant: NS). The embryo-transfer experiments resulted in pregnancy in all 6 of the recipients. The production efficiency of piglets (piglets/embryos transferred) was 17/88 (19.3%) for the vitrification group and 27/88 (27.7%, NS) for the nonvitrification group. Approximately 50% of the offspring in both groups were transgenic. Long-term cryopreservation using the HFV method resulted in similar piglet production efficiency (7 piglets produced out of 32 embryos transferred). This study demonstrated for the first time that the HFV method effectively cryopreserves IVM/IVF-derived transgenic pig embryos. Supported by the JST CREST program.

Regional dissemination of Acinetobacter species harbouring metallo-β-lactamase genes in Japan

Metallo-β-lactamase (MBL) producers have been reported among the various Acinetobacter species worldwide. In this study, the epidemiology and molecular characteristics of carbapenemase-encoding genes and mobile elements were studied to analyse the regional dissemination of MBL genes in Acinetobacter species. From January 2001 to December 2006, 48 Acinetobacter isolates harbouring MBL genes identified from five hospitals in Kyoto and Shiga Prefecture, Japan were collected and analysed. The partial rpoB gene or the 16S-23S ribosomal RNA intergenic spacer region was sequenced to obtain a species-level identification. Molecular typing using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) was performed. Twenty-five Acinetobacter pittii isolates were divided into eight PFGE types and five sequence types (STs) using MLST. Nine Acinetobacter bereziniae isolates belonged to five PFGE types. Five Acinetobacter nosocomialis isolates were divided into two PFGE types and two STs. Three unclassified Acinetobacter species isolates were divided into two PFGE types. Eighteen of the 25 A. pittii isolates belonged to ST119 and were identified from four hospitals. The bla(IMP-19) gene was detected in 41 of 48 isolates, including all of the A. pittii ST119 isolates. The bla(IMP-1) and bla(IMP-11) genes were detected in four and three isolates, respectively. The MBL genes were all embedded within a class 1 integron as a gene cassette array: bla(IMP-19) -aac(6')-31-bla(OXA-21) -aadA1, catB8-like/aacA4-bla(IMP-1) and bla(IMP-11). This study is the first report demonstrating the regional dissemination of MBL-producing Acinetobacter species. A. pittii ST119 harbouring blaIMP-19 was widely spread throughout the Kyoto-Shiga region.

A new approach for posterior mediastinal tumors: thoracoscopic resection in the prone position

Video-assisted thoracoscopic surgery in the lateral position has been the standard surgical approach for posterior mediastinal tumors. Herein, we report the successful thoracoscopic resection of a posterior mediastinal tumor with the patient in the prone position. The patient was a 62-year-old man with a posterior mediastinal mass. We were able to completely extirpate the posterior mediastinal tumor by means of thoracoscopic resection, with the patient in the prone position, much in the manner of solo surgery. The prone position has the potential to become the standard thoracoscopic surgical approach for posterior mediastinal tumors because it provides excellent exposure of the posterior mediastinum.

Molecular and clinical characterization of plasmid-mediated AmpC β-lactamase-producing Escherichia coli bacteraemia: a comparison with extended-spectrum β-lactamase-producing and non-resistant E. coli bacteraemia

Plasmid-mediated AmpC β-lactamase-producing Escherichia coli (AmpC-E) bacteraemia was characterized by comparison with bacteraemia caused by extended-spectrum β-lactamase (ESBL)-producing E. coli (ESBL-E) and non-resistant E. coli (NR-E) in the era of the worldwide spread of the CTX-M-15-producing O25b-ST131-B2 clone. Of 706 bloodstream E. coli isolates collected between 2005 and 2010 in three Japanese university hospitals, 111 ESBL screening-positive isolates were analysed for AmpC and ESBL genes by PCR. A case-control study was performed in which the cases consisted of all of the patients with AmpC-E bacteraemia. Phylogenetic groups, sequence types and O25b serotype were determined. Twenty-seven AmpC-E isolates (26 of which were of the CMY-2 type) were identified, and 54 ESBL-E and 54 NR-E isolates were selected for the controls. Nineteen AmpC-E isolates were also positive for ESBL. CTX-M-14 was the most prevalent ESBL type among both the AmpC-E and ESBL-E isolates. The O25b-ST131-B2 clone was the most prevalent among the ESBL-E isolates (26%) and the second most prevalent among the NR-E isolates (13%), but only one O25b-ST131-B2 clone was found among the AmpC-E isolates. Twenty-three different sequence types were identified among the AmpC-E isolates. When compared with bacteraemia with ESBL-E, previous isolation of multidrug-resistant bacteria and intravascular catheterization were independently associated with a lower risk for AmpC-E. When compared with NR-E bacteraemia, prior use of antibiotics was the only significant risk factor for AmpC-E. Unlike the spread of the O25b-ST131-B2 clone between ESBL-E and NR-E, the AmpC-E isolates were not dominated by any specific clone.

Regional spread and control of vancomycin-resistant Enterococcus faecium and Enterococcus faecalis in Kyoto, Japan

The purpose of this investigation was to control the post-outbreak prevalence of vancomycin-resistant enterococci (VRE) in the affected Kyoto region. The study period was from 2005 to 2010. Faecal samples were subjected to VRE screening, and vancomycin resistance genes were detected by polymerase chain reaction (PCR). The genotype was determined by pulsed-field gel electrophoresis (PFGE) of genomic DNA digested with SmaI and by multilocus sequence typing (MLST). A VRE control programme was established in 2006, consisting of a laboratory-based faecal VRE screening system, annual surveillance of hospital inpatients and the promotion of adequate infection control measures. vanA-Enterococcus faecium, vanB-E. faecium and vanB-E. faecalis were detected at 35, 12 and 5 hospitals, respectively. Genotype analysis revealed that all of the vancomycin-resistant E. faecium isolates obtained since 2005 belonged to ST78, and that clonally related vanB-E. faecalis of ST64 had spread to three hospitals. The rate of faecal VRE carriage among the patients enrolled in the annual surveillance increased until 2007, when it reached 24 (1.2%) of the 2,035 enrolled patients. The rate began to decrease in 2008 and, by 2010, reached a low of 4 (0.17%) of the 2,408 enrolled patients. While VRE did spread within the Kyoto region, the VRE control programme succeeded in controlling the overall VRE spread.