Discovery of ^{60}Ca and Implications For the Stability of ^{70}Ca

The discovery of the important neutron-rich nucleus _{20}^{60}Ca_{40} and seven others near the limits of nuclear stability is reported from the fragmentation of a 345  MeV/u ^{70}Zn projectile beam on ^{9}Be targets at the radioactive ion-beam factory of the RIKEN Nishina Center. The produced fragments were analyzed and unambiguously identified using the BigRIPS two-stage in-flight separator. The eight new neutron-rich nuclei discovered, ^{47}P, ^{49}S, ^{52}Cl, ^{54}Ar, ^{57}K, ^{59,60}Ca, and ^{62}Sc, are the most neutron-rich isotopes of the respective elements. In addition, one event consistent with ^{59}K was registered. The results are compared with the drip lines predicted by a variety of mass models and it is found that the models in best agreement with the observed limits of existence in the explored region tend to predict the even-mass Ca isotopes to be bound out to at least ^{70}Ca.

Prevention of Late-Onset Cytomegalovirus Infection and Disease in Donor-Positive/Recipient-Negative Kidney Transplant Recipients Using Low-Dose Valganciclovir

BACKGROUND

The main challenge with cytomegalovirus (CMV) prophylaxis in IgG donor-positive/recipient-negative (D+/R-) kidney transplant recipients is late-onset CMV disease. We evaluated a novel protocol for the prevention of late-onset CMV infection and disease in D+/R- organ recipients.

METHODS

Our prospective, observational, cohort study included 100 adult kidney transplant recipients. Prophylaxis with low-dose valganciclovir (450 mg/d, 3 times a week for 6 months) was administered to D+/R- recipients. Risk factors for CMV infection and disease were identified. Renal function and the outcomes of CMV infection and disease were compared between D+/R- (n = 15) and recipient-positive (R+; n = 81) organ recipients.

RESULTS

D+/R- recipients showed significant independent risk factors with high hazard ratios for CMV infection (2.04) and disease (10.3). The proportion of CMV infection in D+/R- and R+ recipients was 80% and 46% (P = .023), and that of CMV disease was 33% and 6.2% (P = .008), repectively. D+/R- recipients developed CMV infection and disease within 6 months after transplantation. However, both CMV infection- and disease-free survival rates beyond 1 year post-transplantation defined as late-onset were stable in D+/R- recipients. Moreover, serum creatinine levels at 1 year post-transplantation were comparable between D+/R- and R+ recipients (1.45 ± 0.71 vs 1.16 ± 0.35 mg/dL, P = .26).

CONCLUSION

Our novel protocol prevented late-onset CMV infection and disease beyond 1 year post-transplantation in D+/R- recipients.

Excitation of the Isovector Spin Monopole Resonance via the Exothermic ^{90}Zr(^{12}N,^{12}C) Reaction at 175 MeV/u

The (^{12}N, ^{12}C) charge-exchange reaction at 175  MeV/u was developed as a novel probe for studying the isovector spin giant monopole resonance (IVSMR), whose properties are important for better understanding the bulk properties of nuclei and asymmetric nuclear matter. This probe, now available through the production of ^{12}N as a secondary rare-isotope beam, is exothermic, is strongly absorbed at the surface of the target nucleus, and provides selectivity for spin-transfer excitations. All three properties enhance the excitation of the IVSMR compared to other, primarily light-ion, probes, which have been used to study the IVSMR thus far. The ^{90}Zr(^{12}N,^{12}C) reaction was measured and the excitation energy spectra up to about 70 MeV for both the spin-transfer and non-spin-transfer channels were deduced separately by tagging the decay by γ emission from the ^{12}C ejectile. Besides the well-known Gamow-Teller and isobaric analog transitions, a clear signature of the IVSMR was identified. By comparing with the results from light-ion reactions on the same target nucleus and theoretical predictions, the suitability of this new probe for studying the IVSMR was confirmed.

Effective and Safe Reduction of Conventional Immunosuppressants Using Everolimus in Maintenance Kidney Transplant Recipients

BACKGROUND

Adverse events due to conventional immunosuppressive therapy decrease both graft and patient survival. We aimed to establish a new protocol using everolimus (EVR) to safely minimize conventional immunosuppressants in maintenance kidney transplant recipients.

METHODS

A total of 86 consecutive kidney transplant recipients with no complications were maintained with triple-drug combination therapy (conventional group). In case of complications, the administration of very low-dose tacrolimus (C₀: 5.0 to <3.0 ng/mL), reduced mycophenolate mofetil (1000-1500 to 500-1000 mg), and EVR (C₀: 3.0-5.0 ng/mL) and methylprednisolone withdrawal (2-4 to 0 mg) were simultaneously conducted (EVR group). Graft survival and acute rejection rate were compared between groups. Within the EVR group, the dose of conventional immunosuppressants was compared between pre- and post-EVR administration. Renal function was evaluated 1 year post-EVR administration.

RESULTS

All grafts survived in the conventional (n = 50) and EVR (n = 36) groups, and biopsy-proven acute rejection rate exhibited no significant difference between these groups (12% vs 17%; P = .55). Furthermore, no acute rejection occurred post-EVR administration. In the EVR group, all immunosuppressants significantly decreased post-EVR administration compared with those pre-EVR administration (P < .01), and serum creatinine significantly improved at postoperative year 1 (P = .031).

CONCLUSIONS

EVR administration enables very low-dose tacrolimus administration, helps reduce mycophenolate mofetil and steroid withdrawal, and ameliorates renal function in maintenance kidney transplant recipients experiencing complications associated with conventional immunosuppressive therapy.

Spectroscopy of Pionic Atoms in ^{122}Sn(d,^{3}He) Reaction and Angular Dependence of the Formation Cross Sections

We observed the atomic 1s and 2p states of π^{-} bound to ^{121}Sn nuclei as distinct peak structures in the missing mass spectra of the ^{122}Sn(d,^{3}He) nuclear reaction. A very intense deuteron beam and a spectrometer with a large angular acceptance let us achieve a potential of discovery, which includes the capability of determining the angle-dependent cross sections with high statistics. The 2p state in a Sn nucleus was observed for the first time. The binding energies and widths of the pionic states are determined and found to be consistent with previous experimental results of other Sn isotopes. The spectrum is measured at finite reaction angles for the first time. The formation cross sections at the reaction angles between 0° and 2° are determined. The observed reaction-angle dependence of each state is reproduced by theoretical calculations. However, the quantitative comparison with our high-precision data reveals a significant discrepancy between the measured and calculated formation cross sections of the pionic 1s state.

Steroid Withdrawal Using Everolimus in ABO-Incompatible Kidney Transplant Recipients With Post-Transplant Diabetes Mellitus

BACKGROUND

The effectiveness of everolimus (EVR) for ABO-incompatible (ABOi) kidney transplantation is unknown. We evaluated outcomes of conversion from steroid to EVR in ABOi kidney transplant recipients.

METHODS

We performed a retrospective observational cohort study of 33 de novo consecutive adult ABOi living donor kidney transplant recipients. Desensitization was performed using 0 to 4 sessions of plasmapheresis and 1 to 2 doses of 100 mg rituximab according to the anti-A/B antibody titer. ABOi recipients were administered a combination of tacrolimus, mycophenolate mofetil, and methylprednisolone. Diabetic patients were converted from methylprednisolone to EVR at 1 to 15 months post-transplantation to prevent diabetes progression. Graft outcomes, hemoglobin A1c (HbA1c) levels, and cytomegalovirus infection rates were compared between the EVR (n = 11) and steroid (n = 22) groups.

RESULTS

Mean postoperative duration was 814 and 727 days in the EVR and steroid groups, respectively (P = .65). Between the 2 groups, graft survival rate (100% vs 95.5%, P > .99), acute rejection rate (9.1% vs 18.2%, P = .64), and serum creatinine levels (1.46 mg/dL vs 1.68 mg/dL, P = .66) were comparable. Although HbA1c levels were elevated in the steroid group (5.47%, 5.87%; P = .003), no significant deterioration was observed in the EVR group without additional insulin administration (6.10%, 6.47%; P = .21). Cytomegalovirus infection rate was significantly lower in the EVR group than in the steroid group (18.2% vs 63.6%, P = .026).

CONCLUSION

Conversion from steroid to EVR in ABOi kidney transplant recipients maintained excellent graft outcomes and avoided diabetes progression and cytomegalovirus infection.

Natural history of gastric cancer from a retrospective review of endoscopic images of older patients with interval gastric cancer

AIM

Interval gastric cancers (IGC) are defined as those diagnosed after negative results of endoscopy carried out within the past 10 years. We aimed to investigate the characteristics of IGC and the natural history of gastric cancer (GC) from a retrospective view of endoscopic images of older patients with IGC.

METHODS

We retrospectively reviewed endoscopic images of 240 patients with GC who were aged >60 years. We compared past endoscopic images with newer ones, in which GC was diagnosed. IGC were classified into two categories: missed cancers and new cancers.

RESULTS

Of the 240 patients with GC, 32 had past endoscopic images that qualified for a precise review. A total of 14 cases involved new cancers, whereas 18 involved missed cancers. Most of the IGC were stage I for at least 2 years; however, a small subset was unresectable at >2 years after a negative endoscopy. Furthermore, the rate of endoscopic treatment was significantly higher for IGC compared with that for non-IGC.

CONCLUSIONS

In people aged >60 years, most IGC remain in an early stage for at least 2 years; however, at >2 years after a negative endoscopy, some are unresectable. These results suggest that most early-stage GC will not develop into advanced cancers within 2 years; thus, a 2-year interval might be within the permissible range for patients with negative endoscopy results for any lesions. Geriatr Gerontol Int 2018; 18: 997-1002.

A case of nodal malignant lymphoma presenting with arterial bleeding related to its duodenal penetration

A 62-year-old man with a chief complaint of dysphagia visited our hospital. Enhanced computed tomography showed the tumor near the duodenal wall and lymphadenopathy in the left supraclavicular fossa and para-aortic lymph node. Upper gastrointestinal endoscopy showed an ulcer accompanied with a fistula in the anterior wall of duodenal bulb, suggesting that the tumor penetrated into duodenal wall. Biopsy from the lymph node in the left supraclavicular fossa indicated diffuse large B-cell lymphoma. Although chemotherapy was planned, massive arterial bleeding occurred from the part of duodenal penetration. Endoscopic hemostasis was unsuccessfully performed. Therefore, we performed transcathether arterial embolization for hemostasis. After the procedure, the patient received six cycles of chemotherapy, and he achieved complete response. He has been alive 5 years without recurrence. There were many cases of gastrointestinal bleeding from primary gastrointestinal lymphomas, while there were few cases with nodal involvement by malignant lymphoma resulting in bleeding from gastrointestinal tract. We herein report a case of duodenal bleeding by nodal involvement of diffuse large B-cell lymphoma with review of literature.

A case of a rectal stricture related to ischemic proctitis following rupture of an aortic aneurysm

Background and study aims  Ischemic proctitis is a rare disease and comprises 2 % to 5 % of cases of ischemic colitis, because the rectum has abundant blood supply and rich collaterals. Herein, we report a case of a 73-year-old male patient with a pronounced rectal stricture caused by ischemic proctitis resulting from an abdominal aortic rupture and treated by endoscopic balloon dilation therapy. To date, only 3 cases of rectal stricture related to ischemic proctitis including our case have been reported, and this is the first case of rectal stricture related to ischemic proctitis, which was successfully treated by endoscopic balloon dilation.

Hepatic portal venous gas due to polystyrene sulfonate-induced enteritis

A 78-year-old man with acute right lower abdominal pain and nausea was referred to our hospital. Computed tomography (CT) demonstrated hepatic portal venous gas and a thickened wall of the terminal ileum, and colonoscopy demonstrated ulcers and erosions of the ileocecal region. Histological examination of biopsy samples revealed basophilic crystals consistent with the component of calcium polystyrene sulfonate (CPS). This patient started taking CPS 2 months prior for chronic hyperkalemia. The symptoms resolved soon after ceasing CPS, and subsequent imaging studies confirmed the disappearance of the portal venous gas and ileocolitis.

β-γ and isomeric decay spectroscopy of 168Dy

This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.

Discovery of ^{72}Rb: A Nuclear Sandbank Beyond the Proton Drip Line

In this Letter, the observation of two previously unknown isotopes is presented for the first time: ^{72}Rb with 14 observed events and ^{77}Zr with one observed event. From the nonobservation of the less proton-rich nucleus ^{73}Rb, we derive an upper limit for the ground-state half-life of 81 ns, consistent with the previous upper limit of 30 ns. For ^{72}Rb, we have measured a half-life of 103(22) ns. This observation of a relatively long-lived odd-odd nucleus, ^{72}Rb, with a less exotic odd-even neighbor, ^{73}Rb, being unbound shows the diffuseness of the proton drip line and the possibility of sandbanks to exist beyond it. The ^{72}Rb half-life is consistent with a 5^{+}→5/2^{-} proton decay with an energy of 800-900 keV, in agreement with the atomic mass evaluation proton-separation energy as well as results from the finite-range droplet model and shell model calculations using the GXPF1A interaction. However, we cannot explicitly exclude the possibility of a proton transition between 9^{+}(^{72}Rb)→9/2^{+}(^{71}Kr) isomeric states with a broken mirror symmetry. These results imply that ^{72}Kr is a strong waiting point in x-ray burst rp-process scenarios.

Shell Evolution towards ^{78}Ni: Low-Lying States in ^{77}Cu

The level structure of the neutron-rich ^{77}Cu nucleus is investigated through β-delayed γ-ray spectroscopy at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. Ions of ^{77}Ni are produced by in-flight fission, separated and identified in the BigRIPS fragment separator, and implanted in the WAS3ABi silicon detector array, surrounded by Ge cluster detectors of the EURICA array. A large number of excited states in ^{77}Cu are identified for the first time by correlating γ rays with the β decay of ^{77}Ni, and a level scheme is constructed by utilizing their coincidence relationships. The good agreement between large-scale Monte Carlo shell model calculations and experimental results allows for the evaluation of the single-particle structure near ^{78}Ni and suggests a single-particle nature for both the 5/2_{1}^{-} and 3/2_{1}^{-} states in ^{77}Cu, leading to doubly magic ^{78}Ni.

Selection Criteria for Kidney Laterality in Retroperitoneoscopic Living Donor Nephrectomy and the Usefulness of Pretransplant Intervention

OBJECTIVES

To evaluate the selection criteria for kidney laterality and the usefulness of pretransplant intervention in living donor nephrectomy.

METHODS

We compared conventional and revised criteria. The conventional criteria were that left kidneys were chosen in preference and provided the kidney with the fewest structural abnormalities and lowest functional decline and that most renal arteries remained in the donor. From April 2013, we allowed the use of left kidneys with double renal arteries. Patient characteristics and surgical outcomes were retrospectively compared between right and left retroperitoneoscopic living donor nephrectomies.

RESULTS

We compared data for 30 right kidney and 222 left kidney nephrectomies. Right kidneys were selected because of multiple renal arteries (n = 18), structural abnormalities (n = 10) of the left kidney, or functional decline (n = 2) of the right kidney. Right retroperitoneoscopic nephrectomies were associated with significantly longer operating times (267 minutes vs 241 minutes), larger blood losses (240 g vs 55 g), and higher open conversion rates (10% vs 0.9%). Pretransplant intervention was necessary for structural abnormalities in right kidneys, but the amended selection criteria resulted in fewer right nephrectomies. Pretransplant intervention was still necessary by ex vivo arterial anastomosis for multiple left renal arteries, which increased the total ischemia time (94 minutes vs 64 minutes); however, post-transplantation renal function was not significantly different.

CONCLUSIONS

Pretransplant intervention was beneficial both for repairing structural abnormalities and for reducing the difficulties of retroperitoneoscopic living donor nephrectomy.