Shape Evolution in Neutron-Rich Krypton Isotopes Beyond N=60: First Spectroscopy of ^{98,100}Kr

We report on the first γ-ray spectroscopy of low-lying states in neutron-rich ^{98,100}Kr isotopes obtained from ^{99,101}Rb(p,2p) reactions at ∼220  MeV/nucleon. A reduction of the 2_{1}^{+} state energies beyond N=60 demonstrates a significant increase of deformation, shifted in neutron number compared to the sharper transition observed in strontium and zirconium isotopes. State-of-the-art beyond-mean-field calculations using the Gogny D1S interaction predict level energies in good agreement with experimental results. The identification of a low-lying (0_{2}^{+}, 2_{2}^{+}) state in ^{98}Kr provides the first experimental evidence of a competing configuration at low energy in neutron-rich krypton isotopes consistent with the oblate-prolate shape coexistence picture suggested by theory.

Gamma Decay of Unbound Neutron-Hole States in ^{133}Sn

Excited states in the nucleus ^{133}Sn, with one neutron outside the double magic ^{132}Sn core, were populated following one-neutron knockout from a ^{134}Sn beam on a carbon target at relativistic energies at the Radioactive Isotope Beam Factory at RIKEN. Besides the γ rays emitted in the decay of the known neutron single-particle states in ^{133}Sn additional γ strength in the energy range 3.5-5.5 MeV was observed for the first time. Since the neutron-separation energy of ^{133}Sn is low, S_{n}=2.402(4)  MeV, this observation provides direct evidence for the radiative decay of neutron-unbound states in this nucleus. The ability of electromagnetic decay to compete successfully with neutron emission at energies as high as 3 MeV above threshold is attributed to a mismatch between the wave functions of the initial and final states in the latter case. These findings suggest that in the region southeast of ^{132}Sn nuclear structure effects may play a significant role in the neutron versus γ competition in the decay of unbound states. As a consequence, the common neglect of such effects in the evaluation of the neutron-emission probabilities in calculations of global β-decay properties for astrophysical simulations may have to be reconsidered.

Re-evaluating Cut-off Points for the Expansion of Deceased Donor Criteria for Kidney Transplantation in Japan

BACKGROUND

A shortage of donors poses a serious problem for organ transplantation around the world. In response, the concept of the expanded criteria donor (ECD) has been defined to include donors with traditionally less favorable characteristics. That definition has now been accepted and is being applied in kidney transplantation in the United States and Europe. However, the ECD has not yet been defined for deceased donor kidney transplantation in Japan.

PATIENTS AND METHODS

We analyzed data on graft survival and relevant risk factors in patients who received deceased donor kidney transplants through the East Japan Branch of the Japan Organ Transplant network (n = 1051). Recipients were divided into two groups: the standard-function group (estimated glomerular filtration rate [eGFR] ≥20 mL/min/1.73 m²; n = 906) and the poor-function group (eGFR <20 mL/min/1.73 m²; n = 145; Cox proportional hazards regression analysis; P < .0001).

RESULTS

The 10-year survival rate was significantly lower in the poor-function group than in the standard-function group (85.5% vs 22.5%; P < .0001). The two groups differed significantly in recipient and donor risk for graft failure. Recipient risk factors were length of time on dialysis before renal transplantation and incidence of acute rejection after transplantation. Donor risk factors were donor category (heart death), age, history of hypertension, presence of cerebrovascular disease, mean urine output, and donor creatinine level immediately before donor nephrectomy, total ischemic time, and warm ischemic time.

CONCLUSION

Data from deceased donor transplantation should be analyzed in depth to determine which factors influence renal function after transplantation. In addition, ECD standards should be reconsidered for use in a Japanese context.

Abstract P4-02-13: Breast ultrasound surveillance with image fusion technique in a short-interval follow-up for BI-RADS category 3 mass lesions

PURPOSE: Breast ultrasound (US) is a diagnostic imaging modality that is now widely used as an adjunct to mammography for evaluation of breast abnormalities. In the Breast Imaging-Reporting and Data System (BI-RADS) lexicon, a solid mass with an oval shape, well-circumscribed margins and parallel orientation is classified as category 3 (BI-RADS category 3 mass lesions) . This mass should have a risk of malignancy of &lt; 2%. Surveillance breast US in short-interval follow-up for BI-RADS category 3 mass lesions is an acceptable alternative to biopsy. The surveillance US is recommended 6 month after initial lesion identification and then every year for at least 2 y. However, inconsistent reproducibility for US due to operator dependence is still a clinical issue. The aim of our study was to verify the utility of US using real-time virtual sonography (RVS) - to coordinate present US images with past US images reconstructed from previously acquired US volume data using magnetic tracking system – in a short-interval follow--up for BI-RADS category 3 mass lesions.

METHOD AND MATERIALS: We enrolled 20 women (23 lesions) with more than 24 months of follow-up after classification as BI-RADS category 3 during initial US. US surveillance was scheduled at 6, 12 and 24 months. Three-dimensional assessment of morphologic features was performed while serially checking past US volume data corresponding to the present US probe position. Measurement of the target lesion diameter was performed after the probe was adjusted to include the maximum diameter of a past US image at each visit.

RESULTS: RVS was technically successful in 100% of patients. All target lesions were detected, including two iso-echoic lesions. The mean target lesion diameters at baseline and at 6, 12 and 24 months were 8.2+4.2, 8.4+4.5, 8.1+4.5 and 8.3+5.0 mm, respectively . Statistical analysis using a Friedman test with multiple comparisons revealed no significant difference between the diameters at each time point (p = 0.785). RVS was used to directly compare the US morphologic characteristics and sized of lesions. Furthermore, the RVS data can be reproduced in their entirety for independent review at a later date by using stored US volume data.

CONCLUSION:Our results suggest that RVS is reproducible, operator-independent technique for comparison of US images of BI-RADS category 3 mass lesions obtained at different time points.

Citation Format: Nakano S, Fujii K, Kousaka J, Mouri Y, Ando T. Breast ultrasound surveillance with image fusion technique in a short-interval follow-up for BI-RADS category 3 mass lesions [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-02-13.

Induction of humoral and cellular immune response to hepatitis B virus (HBV) vaccine can be upregulated by CpG oligonucleotides complexed with Dectin-1 ligand

A persistent hepatitis B virus (HBV) infection is characterized by a lack of or a weak immune response to HBV, which may be reflective of tolerance to HBV. Efficient induction of HBV-specific immune response leads to the clearance of HBV in patients with a chronic HBV infection. CpG oligodeoxynucleotides (ODN) has a powerful adjuvant effect in HBV vaccination. A recent report demonstrated that the immunization by B/K CpG ODN (K3) wrapped by the nonagonistic Dectin-1 ligand, schizophyllan (SPG), namely K3-SPG, was more effective in the induction of antigen-specific immune response than that by K3. In this study, we examined the efficacy of K3-SPG as a HBV vaccine adjuvant. Wild-type (WT) mice and HBV transgenic (HBV-Tg) mice were subcutaneously immunized with hepatitis B surface antigen (HBsAg) alone, HBsAg and K3, or HBsAg and K3-SPG. The vaccination with HBsAg and K3-SPG significantly enhanced humoral and cellular immune response to HBV antigen compared to the other vaccinations in WT and HBV-Tg mice. K3-SPG induced the accumulation of dendritic cells (DCs) into draining lymph node and the activation of DCs. The expression of cytokines and chemokines related to Th1 and Th2 responses was upregulated after the vaccination including with K3-SPG. In conclusion, these results indicated that the vaccination using K3-SPG may overcome tolerance even in patients with chronic HBV infection.

Are There Signatures of Harmonic Oscillator Shells Far from Stability? First Spectroscopy of ^{110}Zr

The first measurement of the low-lying states of the neutron-rich ^{110}Zr and ^{112}Mo was performed via in-beam γ-ray spectroscopy after one proton removal on hydrogen at ∼200  MeV/nucleon. The 2_{1}^{+} excitation energies were found at 185(11) keV in ^{110}Zr, and 235(7) keV in ^{112}Mo, while the R_{42}=E(4_{1}^{+})/E(2_{1}^{+}) ratios are 3.1(2), close to the rigid rotor value, and 2.7(1), respectively. These results are compared to modern energy density functional based configuration mixing models using Gogny and Skyrme effective interactions. We conclude that first levels of ^{110}Zr exhibit a rotational behavior, in agreement with previous observations of lighter zirconium isotopes as well as with the most advanced Monte Carlo shell model predictions. The data, therefore, do not support a harmonic oscillator shell stabilization scenario at Z=40 and N=70. The present data also invalidate predictions for a tetrahedral ground state symmetry in ^{110}Zr.

52 CRYOPRESERVATION OF BOVINE SOMATIC CELL USING ANTIFREEZE POLYAMINO-ACID (CARBOXYLATED POLY-L-LYSINE)

Cryopreservation is used for long-term preservation of biological materials containing cell and tissue, somatic cells are important to commercial application in gene bank and medical engineer. For cell cryopreservation, dimethyl sulfoxide (DMSO) have been used widely as cryoprotective material for long time. Carboxylated poly-l-lysine (CPLL) is an ampholytic polymer compound obtained by converting 65% amino groups to carboxyl groups after synthesising ε-poly-l-lysine aqueous solution and succinic anhydride. It is reported that the addition of CPLL into cryopreservation medium improves the post-thaw survival rate of murine L929 cells, human induced pluripotent stem cells and murine embryo. In this research, the effectiveness of CPLL as bovine somatic cell cryoprotective material was examined. In experiment 1, using bovine fibroblast cells from skin, the cryopreservation media were prepared as follows: 10% (vol/vol) DMSO, 5% (vol/vol) DMSO + 5% (wt/vol) CPLL, 5% (wt/vol) CPLL, 7.5% (wt/vol) CPLL, 10% (wt/vol) CPLL and 20% (wt/vol) CPLL were dissolved in DMEM and pH was adjusted to 7.4. Cells were resuspended in 1 mL of cryopreservation medium at a cell density of 5 × 105 and stored in a −80°C freezer. After storage for at least 1 wk, cells were thawed. The 5% CPLL showed significantly higher post-thaw survival rate than 10% DMSO (96.5% v. 86.7%; P < 0.05), and 7.5% CPLL and 20% CPLL showed significantly higher proliferation rates than 10% DMSO at 72 h after thawing (10% DMSO v. 7.5% CPLL v. 20% CPLL ; 99.4% v. 173.6% v. 207.4%; P < 0.05). Although it is necessary to remove the cryoprotective material after thawing, the proliferation rate at 72 h after thawing of 5% CPLL and 10% CPLL without removal of cryoprotective material were significantly higher than that when removing cryoprotective material (111.2% v. 269.6%, 113.0% v. 210.0%). In addition, there was no difference between the removal treatment of CPLL and the NOT removal treatment of CPLL at the thawing. In experiment 2, using bovine cumulus cells, the cryopreservation media were prepared as follows: 10% (vol/vol) DMSO, 5% (vol/vol) DMSO + 5% (wt/vol) CPLL, 5% (wt/vol) CPLL, 10% (wt/vol) CPLL, 20% (wt/vol) CPLL, 25% (wt/vol) CPLL, and 30% (wt/vol) CPLL were dissolved in DMEM and other conditions were the same as experiment 1. There was no significant difference for post-thaw survival rate (93.7, 91.8, 89.2, 89.2, 95.3, 91.6, and 90.2%). At 72 h after thawing, 10% DMSO, 5% DMSO + 5% CPLL and 25% CPLL showed higher proliferation rate (10% DMSO v. 5% DMSO + 5% CPLL v. 25% CPLL; 258.4% v. 281.4% v. 257.4%). The significant differences in survival rate were determined by chi-squared test, and in proliferation were determined by ANOVA. In bovine somatic cells, it was possible to cryopreserve cells using CPLL without DMSO. The cryoprotective effect of CPLL is equal or superior to that of DMSO, the conventional cryoprotective material. Further, when using CPLL, it was possible to culture without removing the cryopreservation medium after thawing. These results suggest that CPLL has promise as a new cryoprotective material for bovine somatic cells.

47 CRYOPRESERVATION OF BOVINE GERM CELL USING ANTIFREEZE POLYAMINO-ACID (CARBOXYLATED POLY-L-LYSINE)

Carboxylated poly-l-lysine (CPLL) is an ampholytic polymer compound, and it is obtained by converting 65% amino groups to carboxyl groups after synthesising ε-poly-l-lysine aqueous solution and succinic anhydride. CPLL has cryoprotective property similar to antifreeze protein, and addition of CPLL into cryopreservation medium improves the post-thaw survival rate of cells and embryos. In this research, we examined the effectiveness of CPLL as a bovine germ cell cryoprotective material. In experiment 1 (in sperm), the conventional cryopreservation medium used for control group was consisted of 6.5% (vol/vol) glycerin, and the cryopreservation medium used for CPLL group was consisted of 3.25% (vol/vol) glycerin and 0.5% CPLL (wt/vol). The post-thaw survival and motility were assessed by using Sperm Motility Analysis System (DITECT Corp., Tokyo, Japan). There was no significant difference for post-thaw survival rate and motility (control v. CPLL; 98.8% v. 96.6% and 69.7% v. 62.2%, respectively). Artificial insemination was carried out in 65 cows (control v. CPLL; 34 v. 31), and the conception rate of the CPLL group was higher than that of the control group (80.6% v. 67.6%; P = 0.23). In experiment 2 (embryos), the conventional cryopreservation medium used for control group was consisted of 5% (vol/vol) ethylene glycol and 6% (vol/vol) propylene glycol in PBS. In the CPLL group, 7% (wt/vol) CPLL was added to the conventional medium. In vitro fertilization embryos were cryopreserved at Day 7 and Day 8. There was no significant difference in survival rate at 0, 24, and 48 h and hatched rate until 72 h after thawing (control v. CPLL: 93.6% v. 93.2%, 69.0% v. 64.7%, 56.1% v. 56.3%, 12.9% v. 10.2%, respectively). Embryos obtained by superovulation treatment and in vivo fertilization at Day 7 were cryopreserved using above 2 media, and transferred non-surgically into synchronized recipient cows (1 embryo per animal). Embryo transfer (ET) was carried out in 81 cows (control v. CPLL: 31 v. 50), and recipients were diagnosed for pregnancy ultrasonically 50 days after embryo transfer. Conception rate of CPLL group was higher than control group (50.0% v. 29.0%; P = 0.063). In both experiments, the significant differences between control group and CPLL group were determined by chi-squared test. The effectiveness of CPLL in cells and embryos has been reported; however, there is no report using CPLL in bovine germ cells. In this research, CPLL improved the conception rate of AI and ET, probably due to its low toxicity and protection of the cell membrane. These results suggest that CPLL is available as a new cryoprotective material for bovine sperm and embryo in slow freezing methods.