Exact and fixed-parameter algorithms for metro-line crossing minimization problems

A metro-line crossing minimization problem is to draw multiple lines on an underlying graph that models stations and rail tracks so that the number of crossings of lines becomes minimum. It has several variations by adding restrictions on how lines are drawn. Among those, there is one with a restriction that line terminals have to be drawn at a verge of a station, and it is known to be NP-hard even when underlying graphs are paths. This paper studies the problem in this setting, and propose new exact algorithms. We first show that a problem to decide if lines can be drawn without crossings is solved in polynomial time, and propose a fast exponential algorithm to solve a crossing minimization problem. We then propose a fixed-parameter algorithm with respect to the multiplicity of lines, which implies that the problem is FPT.Comment: 19 pages, 15 figure

Postoperative recurrence and the role of adjuvant chemotherapy in patients with pulmonary large-cell neuroendocrine carcinoma

ObjectivesThe prognosis for patients with large-cell neuroendocrine carcinoma is generally very poor. In this study, we describe the clinical features of recurrent tumors of large-cell neuroendocrine carcinoma and discuss the role of adjuvant chemotherapy and management of recurrence in patients with large-cell neuroendocrine carcinoma.MethodsWe retrospectively analyzed clinical data from 79 patients and evaluated the prognosis of patients with platinum-based adjuvant chemotherapy, recurrence patterns, patient response to chemotherapy or radiation therapy, and prognosis in patients who experienced relapse.ResultsOf 72 patients, 36 had confirmed recurrent tumors upon follow-up examinations. Of those with recurrent tumors, 33 patients (91.7%) had their first recurrent tumors within 3 years. Patients who underwent platinum-based adjuvant chemotherapy had a significantly lower rate of tumor recurrence and a higher rate of disease-free survival than those who had non–platinum-based adjuvant chemotherapy or no adjuvant chemotherapy. Multivariate analyses revealed that platinum-based adjuvant chemotherapy, pathologic stage, and the presence of second cancer are independent prognostic factors. Three patients with limited resection of the primary tumor had poor prognosis with recurrence. Postoperatively, 11 of the 36 patients without recurrence (30.6%) had metachronous second primary cancers, of which 4 patients had more than 1 site.ConclusionsPatients with large-cell neuroendocrine carcinoma had frequent recurrence following resection of the primary tumor, and those without recurrence often developed metachronous second primary cancers. Platinum-based adjuvant chemotherapy after surgery may be useful for preventing recurrence in patients with large-cell neuroendocrine carcinoma

Ocular Changes --Cataract And Retinal Lesion-- In Spontaneously Diabetic Torii (SDT) Fatty Rats, An Obese Type 2 Diabetic Model

Cataract and retinopathy remain the preventable cause of blindness worldwide, and many pharmacological strategies have been proposed for the treatment of these eye diseases. Animal models play an important role in understanding the pathophysiological features of eye disease and developing for a new therapy. In this study, we investigated the development of cataract and retinal lesion with diabetes using an obese type 2 diabetic models SDT fatty rat. Macroscopic analysis in eyes was performed from 16 to 24 weeks of age and histological analysis was performed at 24 weeks of age. As a result, the lens cloudiness was observed from 19 weeks of age and the degree of the cloudiness was more progressed until 24 weeks of age. Histopathological findings, such as degeneration of lens fiber and shortening and irregular arrangement of cone and rod in retinal tissue, were observed at 24 weeks of age. In conclusion, SDT fatty rats may be useful to understand the pathological features in diabetic cataract and retinopathy develop a new therapy for the disease

Radiosensitization by telomerase-dependent oncolytic adenovirus

DNA修復機能阻害は放射線感受性を増強させるため，DNA修復に関与する因子の阻害剤は放射線増感剤となり得る．我々の開発したテロメラーゼ依存的腫瘍融解アデノウイルス製剤OBP-301（テロメライシン）は，アデノウイルスE1B55kDaタンパクを介して細胞のDNA修復に重要な役割を果たすMRN複合体（Mre11，Rad50，NBS1）を分解する機能を有する．このMRN複合体の分解によりATM（ataxia-telangiectasia mutated）の活性化が抑制され結果的にDNA修復機構が阻害される．我々はOBP-301と放射線との併用が強力な相乗効果を生み出すことをマウスの皮下腫瘍モデルおよび食道癌同所性モデルにおいて証明した．これらの結果はOBP-301が将来有望な放射線増感剤となり得ることだけでなく，E1B55kDaタンパクを産生する腫瘍融解アデノウイルス製剤と放射線との併用が悪性腫瘍に対する有力な治療戦略となり得ることを示す

CLICK:One-step generation of conditional knockout mice

Abstract Background CRISPR/Cas9 enables the targeting of genes in zygotes; however, efficient approaches to create loxP-flanked (floxed) alleles remain elusive. Results Here, we show that the electroporation of Cas9, two gRNAs, and long single-stranded DNA (lssDNA) into zygotes, termed CLICK (CRISPR with lssDNA inducing conditional knockout alleles), enables the quick generation of floxed alleles in mice and rats. Conclusions The high efficiency of CLICK provides homozygous knock-ins in oocytes carrying tissue-specific Cre, which allows the one-step generation of conditional knockouts in founder (F0) mice