The new record of Philodina gregaria from Sôya Coast and life history of the species

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

A braided stent becomes flattened inside a curved catheter tube: A micro-CT imaging study

BACKGROUND: The braided stent is a widely accepted endovascular treatment device consisting of woven metal wires. One of the unsolved issues for the braided stent is the stent flattening phenomena when deployed into highly curved arteries. Although a recent computational study highlighted that the mechanical state of the stent inside the catheter before the deployment plays an essential role in causing stent flattening, there is no experimental observation for the stent inside the curved catheter. OBJECTIVE: We investigated braided stent shapes in curved catheter tubes with various curvatures by micro-computed tomography (CT). METHODS: A braided stent was deployed into catheter tubes and set in rectangular cases with constant curvature. The three-dimensional shape of the stent was imaged by micro-CT, and its cross-sectional flatness was quantitatively assessed. RESULTS: Stent flattening occurred in cases of high curvatures of the outer side of the tube curvature, and the degree of flatness increased with increasing tube curvature. This demonstrates that stent flattening can be caused inside the highly curved catheter before deployment. CONCLUSIONS: This preliminary and first observational report provides new insight into the mechanism of stent flattening and emphasizes the importance of the geometrical and mechanical state of the stent inside the catheter.The definitive, peer reviewed and edited version of this article is published in Bio-Medical Materials and Engineering, vol. 31, no. 6, pp. 373-380, 2020, https://doi.org/10.3233/BME-206011

The Surgical Benefits of Repeat Hepatectomy for Colorectal Liver Metastasis

The most common site of distant metastasis from colorectal cancer is the liver, and hepatectomy presents the best curative treatment for recurrence of colorectal liver metastasis （CRLM）. This study aimed to identify factors of prognostic value for repeat hepatectomy for CRLM and to determine whether a third such procedure could similarly produce favourable outcomes for CRLM. We analyzed data for 161 patients in our department with colorectal metastasis. Of these, 22 patients underwent repeat hepatectomy for recurrent metastasis, with 16 undergoing a second hepatectomy and 6 a third hepatectomy. We analyzed patient characteristics, tumor status, operation-related variables, and short- and long-term outcomes. Univariate analysis for repeat hepatectomy identified the following five prognostic risk factors: T factor （＞SE） of the primary cancer, number of tumors involved in the initial hepatectomy （＞5）, interval from first to second hepatectomy （＜1year）, number of tumors involved in second hepatectomy （＞3）, and post-operation time （＞30days）. By multivariate analysis, T factor （＞SE） of the primary cancer, number of tumors in the initial hepatectomy （＞5）, and number of tumors in the second hepatectomy （＞3） were independently associated with a worse survival after surgery for CRLM. Although surgical outcomes of the third hepatectomy were not compared with those of the first and second hepatectomy, there were no obvious differences, nor did the 1-, 3-, and 5-year survival rates differ significantly among the three groups. Repeat hepatectomy for CRLM could improve long-term survival. In addition, patients undergoing a third hepatectomy showed a similar survival benefit to those having one or two resections

Clinicopathological Significance of FOXP3 Expression in Esophageal Squamous Cell Carcinoma

The expression of transcription factor forkhead box protein 3 (FOXP3), a master control gene for regulatory T cells, has been reported to influence patient survival. However, there have been few reports of the relationship between FOXP3 positive cells and esophageal squamous cell carcinoma (ESCC). The aim of this study was to clarify the prognostic value of FOXP3 expression in ESCC. Ninety-five patients who were diagnosed with primary ESCC and underwent subtotal esophagectomy during 2009 and 2010 were retrospectively analyzed. Deepest sections from each tumor were selected for immunohistochemistry and the number of FOXP3 positive cells was counted. The median number was used as a cutoff to divide into FOXP3 positive and FOXP3 negative subgroups. Relationships between FOXP3 expression and clinicopathological features, disease-free survival (DFS) and overall survival (OS) were determined. Statistical values of p < 0.05 were considered significant. FOXP3 positive cells were found in all 95 cases and the number of FOXP3 positive cells was significantly higher in the peri-tumor compartment than in the intra-tumor compartment (p = 0.0006). For this reason, the peri-tumor compartment numbers were used for all of the association studies. Results showed that the FOXP3 positive group had a significantly larger mean tumor size (43.8 ± 4.1mm vs 29.1 ± 4.0mm, p = 0.0055), and the FOXP3 negative group had a significantly higher percentage of deep invasion (T2, T3, T4)(p = 0.0399). There was no significant association for DFS, however, for OS the FOXP3 positive group demonstrated a significantly better prognosis (p = 0.0024). Multivariate analysis showed that peri-tumor FOXP3 expression is an independent prognostic factor for OS (p = 0.0035). Peri-tumoral FOXP3 expression is an independent and favorable prognostic factor for ESCC

Feasibility of Precoagulation Without the Pringle Maneuver for Endoscopic Hepatectomy of Cirrhotic Liver

Various methods, devices, and techniques have been developed to improve safety during laparoscopic hepatectomy procedures. Among these, the Pringle maneuver （PM） is widely used to minimize blood loss during liver transections; however, the risk of ischemic injury associated with this technique is increased by poor hepatic reserve and regeneration dysfunction secondary to liver cirrhosis. This retrospective study evaluated the short-term outcomes and feasibility of precoagulation for endoscopic hepatectomy without PM in patients with liver cirrhosis. Eleven patients with liver cirrhosis who also underwent endoscopic hepatectomy for hepatocellular carcinoma were recruited to undergo either microwave tissue coagulation or radiofrequency ablation for precoagulation before liver transection. A wedge resection without the PM was performed in all patients, with seven patients selected for bipolar radiofrequency ablation and four patients for microwave coagulation therapy. The procedures included video-assisted thoracoscopic hepatectomy in two patients and laparoscopic hepatectomy in nine patients. One patient who underwent radiofrequency ablation developed postoperative bleeding （Clavien-Dindo grade Ⅲ）. In conclusion, precoagulation can help to minimize intraoperative blood loss without the PM, contributing to effective resection of liver tumors. We propose that precoagulation could serve as a standard technique for endoscopic hepatectomy in patients with cirrhosis

Efficacy and Safety of an Ultrasonically Activated Device for Sealing the Bile Ducts During Liver Resection

The use of ultrasonically activated devices (USADs) in hepatic resections may be associated with an increased rate of complications, such as postoperative bile leaks. Nonetheless, the safety of USADs for sealing bile ducts during liver surgery has not yet been established. The purpose of this study was to assess the efficacy of a USAD for sealing bile ducts. In animal experiments, the common bile duct of ten anesthetized dogs was individually occluded using a USAD. Additionally, using the prospective liver surgery database from a single institution, we identified 45 consecutive patients who underwent hepatic resection using a USAD (USAD group) and 45 similar patients who underwent hepatic resection without the use of a USAD (NUSAD group). In the occluded and harvested canine bile ducts, the mean burst pressure was 280mmHg, and the lumen of the bile duct was completely sealed morphologically. In the clinical study, there was no significant difference in postoperative mortality or complications between the two groups, and biliary leakage was observed in only one patient (0.7%) in the USAD group. These data demonstrate that the USAD is a safe, efficient, and practical instrument for use during liver surgery to achieve complete hemobiliary stasis

エイセイ ハッシンキ ニ ヨリ スイテイ シタ ホッカイドウ レブントウ ニ セイソク スル ゴマフアザラシ（Phoca largha） ノ ハンショクキ オヨビ ハンショクジョウ

礼文島を上陸場として利用するゴマフアザラシの繁殖期および繁殖場の推定を目的に，2009年～2014年に当島で本種の成獣（メス3個体およびオス1個体）と亜成獣（メス・オス各2個体）に衛星発信器を装着・放獣し，行動を追跡した。その結果，成獣はメス・オス共にタタール（間宮）海峡の海氷域に3月を中心に滞在し，その分布域も重複する傾向が見られた。また，上陸割合を算出できた成獣メス1個体においては，その3月に海氷上での上陸割合も高い値（日中：56.7%，夜間：23.9%）を示した。それ以外の成獣メス2個体の海氷上利用時期は2月～4月であった。成獣オス1個体の上陸割合も3月に最高値（日中：47.2%，夜間：15.1%）を示しており，その時期が当個体の交尾期であったと推定された。以上の結果と，本種の繁殖は一般的に海氷上で行われるとの既往知見から，礼文島を利用するゴマフアザラシの繁殖場は当海域であり，繁殖期は2月～4月と推定された。さらに，成獣に装着した発信器は4月以降にタタール海峡で脱落したことから，成獣は換毛期までタタール海峡を利用していたと推測された。一方，亜成獣は4月に礼文海域で発信器が脱落したことに加え，上陸割合も最大となったことから，換毛期は4月と推定された。To determine the breeding period and area of spotted seals hauling out at Rebun Island, a total of 8 seals (4 adults and 4 sub adults) were equipped with satellite transmitters and were tracked. All of the adults stayed in the Tatar Strait during the sea-ice period for up to 4 months, and did not enter into the Okhotsk Sea. Of these, 3 adult females were distributed in the sea-ice area between January and April, and they often co-occurred within a relatively narrow distance (ca. 28 km). The distribution of an adult male overlapped well with the adult females during March, suggesting that mating of this male occurred during this month in the Tatar Strait. Daytime and night haul-out ratios obtained from an adult female were both highest during March. From the result of haul-out ratio, it was considered that the adult female gave birth and nursed in March. Thus, it has been concluded that the spotted seals occurring on Rebun Island breed during February through April in the Tatar Strait. In addition, the fact that the transmission of the satellite tags disconnected after April indicated that the molting of the seals occurs after April

Development of a New Bioartificial Liver Support System Using a Radial-flow Bioreactor

There is an increasing number of patients with severe liver disease that requires whole organ transplantation or living-related split liver transplantation. This has resulted in a shortage of donor organs, which is particularly problematic and still awaits resolution. Bioartificial liver (BAL) support systems have been developed with the aim of supporting patients with life-threatening liver disease until their liver recovers. Here, we describe a high performance three-dimensional rat hepatocyte culture system using a radial-flow bioreactor (RFB) with a polyvinyl alcohol (PVA) membrane as a small-scale BAL support system. Hepatocytes from male Sprague-Dawley rat livers were isolated and divided into two groups as follows. Group A: isolated hepatocytes were maintained in culture medium as controls; and group B: isolated hepatocytes were injected into the medium chamber of the RFB-PVA culture system. Sampling was carried out every 48 h to analyze the concentrations of ammonia and albumin in the medium. Light and electron microscopic examination of hepatocytes explanted from the PVA membrane was also performed. Albumin production and urea synthesis by cells in group B were both significantly higher than in group A. Hematoxylin-Eosin staining of the cells in group B showed that three-dimensional cell masses were attached to the PVA membrane. It also showed that the cells were stably proliferating in the porous spaces of the PVA. Scanning electron microscopic images of group B also showed clusters of hepatocytes attached to the PVA membrane. Hepatocyte clusters growing in the RFB-PVA culture system retained their biological function and were stable in the porous spaces of the PVA membrane. This cell culture system may be useful for the development of new BAL support systems

Targeted transcriptomic study of the implication of central metabolic pathways in mannosylerythritol lipids biosynthesis in Pseudozyma antarctica T-34.

Pseudozyma antarctica is a nonpathogenic phyllosphere yeast known as an excellent producer of industrial lipases and mannosylerythritol lipids (MELs), which are multi-functional glycolipids. The fungus produces a much higher amount of MELs from vegetable oil than from glucose, whereas its close relative, Ustilago maydis UM521, produces a lower amount of MELs from vegetable oil. In the present study, we used previous gene expression profiles measured by DNA microarray analyses after culturing on two carbon sources, glucose and soybean oil, to further characterize MEL biosynthesis in P. antarctica T-34. A total of 264 genes were found with induction ratios and expression intensities under oily conditions with similar tendencies to those of MEL cluster genes. Of these, 93 were categorized as metabolic genes using the Eukaryotic Orthologous Groups classification. Within this metabolic category, amino acids, carbohydrates, inorganic ions, and secondary metabolite metabolism, as well as energy production and conversion, but not lipid metabolism, were enriched. Furthermore, genes involved in central metabolic pathways, such as glycolysis and the tricarboxylic acid cycle, were highly induced in P. antarctica T-34 under oily conditions, whereas they were suppressed in U. maydis UM521. These results suggest that the central metabolism of P. antarctica T-34 under oily conditions contributes to its excellent oil utilization and extracellular glycolipid production