Analytically Tractable Models for Decision Making under Present Bias

Time-inconsistency is a characteristic of human behavior in which people plan for long-term benefits but take actions that differ from the plan due to conflicts with short-term benefits. Such time-inconsistent behavior is believed to be caused by present bias, a tendency to overestimate immediate rewards and underestimate future rewards. It is essential in behavioral economics to investigate the relationship between present bias and time-inconsistency. In this paper, we propose a model for analyzing agent behavior with present bias in tasks to make progress toward a goal over a specific period. Unlike previous models, the state sequence of the agent can be described analytically in our model. Based on this property, we analyze three crucial problems related to agents under present bias: task abandonment, optimal goal setting, and optimal reward scheduling. Extensive analysis reveals how present bias affects the condition under which task abandonment occurs and optimal intervention strategies. Our findings are meaningful for preventing task abandonment and intervening through incentives in the real world

Optimal Transport with Cyclic Symmetry

We propose novel fast algorithms for optimal transport (OT) utilizing a cyclic symmetry structure of input data. Such OT with cyclic symmetry appears universally in various real-world examples: image processing, urban planning, and graph processing. Our main idea is to reduce OT to a small optimization problem that has significantly fewer variables by utilizing cyclic symmetry and various optimization techniques. On the basis of this reduction, our algorithms solve the small optimization problem instead of the original OT. As a result, our algorithms obtain the optimal solution and the objective function value of the original OT faster than solving the original OT directly. In this paper, our focus is on two crucial OT formulations: the linear programming OT (LOT) and the strongly convex-regularized OT, which includes the well-known entropy-regularized OT (EROT). Experiments show the effectiveness of our algorithms for LOT and EROT in synthetic/real-world data that has a strict/approximate cyclic symmetry structure. Through theoretical and experimental results, this paper successfully introduces the concept of symmetry into the OT research field for the first time

Prostate Biopsy May Not Be Indicated Early after Bacillus Calmette Guérin Treatment

Bacillus Calmette-Guérin (BCG) treatment for non-muscle-invasive bladder cancer frequently causes an intraprostatic BCG granuloma. We investigated the optimal timing for a prostate biopsy after BCG treatment by retrospectively analyzing the cases of 22 patients with non-muscle-invasive bladder cancer who underwent a prostate biopsy after BCG treatment at our institute (2013-2017). Biopsies were indicated for a rising prostate-specific antigen (PSA) level, positive digital rectal examination findings, or the appearance of de novo low apparent diffusion coefficient lesions on MRI. The control group was comprised of 28 age- and PSA-matched patients. The relationships among the cancer detection rate and the patients’ PSA levels and MRI findings were analyzed. Prostate cancer was detected by biopsy in only 13.9% (3/22) of the patients in the BCG group but in 78.5% (22/28) of the control patients (p=0.0001). The three patients in the BCG group in whom prostate cancer was detected had all undergone the biopsy > 1 year after their BCG treatment. The remaining biopsies were performed within 1 year after BCG treatment and resulted in no diagnoses of prostate cancer. We suggest that performing a prostate biopsy early after BCG treatment is not informative or useful

Long-Term Outcome of Proton Therapy and Carbon-Ion Therapy for Large (T2a–T2bN0M0) Non–Small-Cell Lung Cancer

IntroductionAlthough many reports have shown the safety and efficacy of stereotactic body radiotherapy (SBRT) for T1N0M0 non–small-cell lung cancer (NSCLC), it is rather difficult to treat T2N0M0 NSCLC, especially T2b (>5 cm) tumor, with SBRT. Our hypothesis was that particle therapy might be superior to SBRT in T2 patients. We evaluated the clinical outcome of particle therapy for T2a/bN0M0 NSCLC staged according to the 7th edition of the International Union Against Cancer (UICC) tumor, node, metastasis classification.MethodsFrom April 2003 to December 2009, 70 histologically confirmed patients were treated with proton (n = 43) or carbon-ion (n = 27) therapy according to institutional protocols. Forty-seven patients had a T2a tumor and 23 had a T2b tumor. The total dose and fraction (fr) number were 60 (Gray equivalent) GyE/10 fr in 20 patients, 52.8 GyE/4 fr in 16, 66 GyE/10 fr in 16, 80 GyE/20 fr in 14, and other in four patients, respectively. Toxicities were scored according to the Common Terminology Criteria for Adverse Events, Version 4.0.ResultsThe median follow-up period for living patients was 51 months (range, 24–103). For all 70 patients, the 4-year overall survival, local control, and progression-free survival rates were 58% (T2a, 53%; T2b, 67%), 75% (T2a, 70%; T2b, 84%), and 46% (T2a, 43%; T2b, 52%), respectively, with no significant differences between the two groups. The 4-year regional recurrence rate was 17%. Grade 3 pulmonary toxicity was observed in only two patients.ConclusionParticle therapy is well tolerated and effective for T2a/bN0M0 NSCLC. To further improve treatment outcome, adjuvant chemotherapy seems a reasonable option, whenever possible

A case with difficulty in airway management nevertheless switching from emergency tracheostomy to cricothyrotomy

深頸部膿瘍は時に急速な喉頭浮腫を来たし窒息に至ることもある救急疾患である．深夜に救急外来を受診し手術室にて気道確保中に窒息をきたし，院内コードブルー発動を経て救命し得た深頸部膿瘍の1例を経験したので報告する．症例は60代男性．増悪する咽頭痛，軽度の呼吸苦を主訴に当院へ救急搬送された来院後より次第に呼吸苦が増悪し，甲状軟骨内側の膿瘍および高度の喉頭浮腫を認め，気管切開による気道確保を計画した．術中，窒息が切迫した状態となり迅速に気道を確保するために輪状甲状膜切開に術式を切り替えた．しかし，呼吸苦から体動が多く不穏となりまた体動・出血に伴い窒息に至り，徐々に血中酸素飽和度が低下していった通常の手術続行が不可能となった段階で院内コードブルーを要請し，人員を集め，輪状甲状間膜切開・気道確保に成功した最終的には後遺症なく救命が可能であった

Retinol Supplements Antiviral Action of Interferon in Patients with Chronic Hepatitis C: A Prospective Pilot Study

Sustained virologic response with peg-interferon and ribavirin combination therapy for 48 weeks is still inadequate. Our study examined whether short-term administration of retinol clinically influences the anti-viral activity of interferon early during interferon and ribavirin combination therapy. The control group received 6 MIU of interferon α-2b every day for two weeks and then 3 times a week for 22 weeks intramuscularly plus 600 mg or 800 mg per day of ribavirin orally for 24 weeks. The retinol group, in addition to above treatment, received retinol 30,000 units per day orally for 3 weeks from one week before the start of interferon α-2b plus ribavirin combination therapy. The hepatitis C virus (HCV) RNA negativity rate at 1 week after the end of interferon α-2b and ribavirin combination therapy was 46.7% (28/60) for the retinol group and 31.7% (19/60) for the control group, which was significantly higher for the retinol group. The level of serum HCV RNA in the retinol group was significantly lower at 1 week after beginning treatment as compared to the control group (p<0.01). Furthermore, serum 2,5'AS protein at 1 week after beginning treatment was significantly higher in the retinol group (p = 0.0002). The results suggest that retinol supplement increases the antiviral effect of interferon α-2b plus ribavirin only during the administration of IFN α-2b, ribavirin and retinol in patients with chronic hepatitis C

A case report on refractory ulcerative stomatitis associated with acute lymphoblastic leukemia

症例は難治性潰瘍性口内炎を契機に判明した急性リンパ性白血病の 1 例である．患者は 60 歳台，女性．下口唇に難治性潰瘍を認め紹介となった．血液検査にて汎血球減少を認めたため，血液疾患を疑った．骨髄検査にて，Ph 染色体陰性急性 B 細胞性リンパ性白血病と診断され，初診の 4 日後からステロイド療法が開始された．なお，下口唇生検の病理組織には明らかな白血病細胞の浸潤は認めなかった．口腔症状が白血病の初発症状となることがあり，これを主訴に受診した白血病患者を早期診断することは大変重要である．しかし，口腔病変の原因は多彩であり，さまざまな科が対応することが多く，各科が連携して診療にあたることが重要と考える．We herein report a case on refractory ulcerative stomatitis associated with acute lymphoblastic leukemia. The female patient in her 60s showed refractory ulcer on her lower lip ; and the referral was made. Since pancytopenia was found by a blood test, hematologic disease was suspected. Bone marrow examination presented the diagnosis of Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia. Based on this diagnosis, steroid therapy had been initiated from four days after the first visit. On biopsy of lower lip, the pathological tissue did not show obvious infiltration of leukemia cells. Since oral manifestation may sometimes be an initial symptom of leukemia, an early diagnosis on leukemia patient with main complaint of oral symptom is critically important. Oral lesions, however, have various causes, and it thus often requires care of various clinical department. Based on this, it is considered to be important to implement treatment with cooperation among each clinical department

Computed Tomography Findings for Diagnosing Follicular Thyroid Neoplasms

Since no diagnostic method has been established to distinguish follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA), surgery has been the only way to reach a diagnosis of follicular neoplasm. Here we investigated the computed tomography (CT) features of follicular neoplasms, toward the goal of being able to identify specific CT features allowing the preoperative differentiation of FTC from FTA. We retrospectively analyzed the cases of 205 patients who underwent preoperative CT of the neck and were histopathologically diagnosed with FTC (n=31) or FTA (n=174) after surgery between January 2002 and June 2016 at several hospitals in Japan. In each of these 205 cases, non-enhanced and contrast-enhanced CT images were obtained, and we analyzed the CT features. On univariate analysis, inhomogeneous features of tumor lesions on contrast-enhanced CT were more frequently observed in FTC than in FTA (p=0.0032). A multivariate analysis identified inhomogeneous features of tumor lesions on contrast-enhanced CT images as an independent variable indicative of FTC (p=0.0023). CT thus offers diagnostic assistance in distinguishing FTC from FTA

SH3BP2 Deficiency Ameliorates Murine Systemic Lupus Erythematosus

Background: The adaptor protein Src homology 3 domain-binding protein 2 (SH3BP2) is widely expressed in immune cells. It controls intracellular signaling pathways. The present study was undertaken to investigate the role of SH3BP2 in a murine systemic lupus erythematosus model. Methods: For the lupus model, we used Faslpr/lpr mice. Clinical and immunological phenotypes were compared between Faslpr/lpr and SH3BP2-deficient Faslpr/lpr mice. Splenomegaly and renal involvement were assessed. Lymphocyte subsets in the spleen were analyzed by flow cytometry. To examine the role of SH3BP2 in specific cells, B cell-specific SH3BP2-deficient lupus mice were analyzed; T cells and bone marrow-derived dendritic cells and macrophages were analyzed in vitro. Results: SH3BP2 deficiency significantly reduced lupus-like phenotypes, presented as splenomegaly, renal involvement, elevated serum anti-dsDNA antibody, and increased splenic B220+CD4−CD8− T cells. Notably, SH3BP2 deficiency in B cells did not rescue the lupus-like phenotypes. Furthermore, SH3BP2 deficiency did not substantially affect the characteristics of T cells and macrophages in vitro. Interestingly, SH3BP2 deficiency suppressed the differentiation of dendritic cells in vitro and reduced the number of dendritic cells in the spleen of the lupus-prone mice. Conclusions: SH3BP2 deficiency ameliorated lupus-like manifestations. Modulating SH3BP2 expression could thus provide a novel therapeutic approach to autoimmune diseases