The eCura system as a novel indicator for the necessity of salvage surgery after non-curative ESD for gastric cancer: A case-control study

Endoscopic submucosal dissection (ESD) for early gastric cancer does not always lead to complete cancer resection. The aim of this study was to determine indicators for cancer residue (CR) status in cases of non-curative ESD. We analyzed 47 cases of non-curative ESD followed by salvage surgery and collected data regarding the rates of CR, which included both local CR and lymph node metastasis (LNM). To elucidate the risk factors for CR status, we compared the CR positive and the CR negative groups among surgical specimens according to the following variables obtained from ESD findings: tumor location, tumor size, depth of invasion, lympho-vascular invasion, histological margin, and histological diagnosis. The eCura system, which is an LNM risk scoring system, was also applied and scores were calculated in each case as follows: 3 points for lymphatic invasion and 1 point each for tumor size >30 mm, positive vertical margin, venous invasion, and submucosal invasion ≥500 μm. There were 9 (19%) CR positive cases, which included 6 cases of local CR and 4 cases of LNM; no cancer was detected in over 80% of the patients. The eCura scoring system was the only significant factor for CR status: the higher the eCura score, the greater the CR positivity (p = 0.0128). In particular, all patients in the low-risk group (score = 0-1 point) had no CR. Although no cancer recurrence was observed during a median follow-up of 4 years, 2 patients died of pneumonia. In conclusion, the eCura system might make it possible to select appropriate cases for salvage surgery.

SurePath® LBC improves the diagnostic accuracy of intrahepatic and hilar cholangiocarcinoma

INTRODUCTION

The current study aimed to compare cytology using SurePath^® (SP)-LBC and biliary tissue histology (BTH) for the diagnosis of biliary disease.

METHODS

Between January 2014 and December 2016, 57 patients underwent endoscopic retrograde cholangiopancreatography for the diagnosis of biliary disease. Biliary cytological samples were processed using SP-LBC and subsequently BTH was performed. A final diagnosis was confirmed by surgery (23 malignant cases) and clinical follow-up (34 benign and malignant cases): 18 extrahepatic cholangiocarcinoma; 17 intrahepatic/hilar cholangiocarcinoma (intra/H-CC); eight other malignant disease; and 14 benign biliary disease. The diagnoses made using SP-LBC and BTH were classified into four categories: (1) benign; (2) indeterminate; (3) suspicious for malignancy/malignant; and (4) inadequate. In addition, diagnostic accuracy was compared between SP-LBC and BTH.

RESULTS

Although 23% (13/57) of BTH samples were classified as inadequate, all SP-LBC cases were classified as adequate. Among 43 malignant cases, 11 normal, four indeterminate and 28 suspicious for malignancy/malignant were found using SP-LBC (26%, 9% and 65%, respectively), in contrast to 10 inadequate, nine normal, 10 indeterminate and 14 suspicious for malignancy/malignant observed using BTH (23%, 21%, 23%, and 33%, respectively). The identification of malignant cells was strikingly different between SP-LBC and BTH. Furthermore, limited to intra/H-CC, accuracy was significantly higher using SP-LBC than using BTH (P < .001).

CONCLUSIONS

SP-LBC of the biliary tract is a useful and reliable method for diagnosing biliary malignant disease and has an advantage over BTH for detecting malignant cells and accurately diagnosing intra/H-CC.

Functions to map photoelectron distributions in a variety of setups in angle-resolved photoemission spectroscopy

The distribution of photoelectrons acquired in angle-resolved photoemission spectroscopy can be mapped onto the energy-momentum space of the Bloch electrons in the crystal. The explicit forms of the mapping function f depend on the configuration of the apparatus as well as on the type of the photoelectron analyzer. We show that the existence of the analytic forms of f^-1 is guaranteed in a variety of setups. The variety includes the case when the analyzer is equipped with a photoelectron deflector. Thereby, we provide a demonstrative mapping program implemented by an algorithm that utilizes both f and f^-1. The mapping methodology is also usable in other spectroscopic methods such as momentum-resolved electron-energy loss spectroscopy.

Evaluation of the Function of Primary Human Hepatocytes Co-Cultured with the Human Hepatic Stellate Cell (HSC) Line LI90

Most bioartificial liver devices utilise primary hepatocytes alone although some have considered the use of non parenchymal cells in addition. However the effects of co-culture of human hepatocytes with different sinusoidal cell types has not been fully investigated. In this study we have examined the influence of co-culturing primary human hepatocytes with the human hepatic stellate cell (HSC) line, LI90. Cultures were monitored by light microscopy and on days 4, 8 and 14 urea synthesis and cytochrome P450 activity were measured. Morphologically LI90 cells proliferated to fill spaces between and into adjacent islands of hepatocytes. On day 14 cytochrome P450 activity in co-culture was significantly improved compared to hepatocytes cultured alone. By contrast, urea synthesis in hepatocytes was unaffected by single or co-culture. Therefore it can be concluded that a combination of primary human hepatocytes with LI90 cells is beneficial for growth and some stability of hepatocytes and may therefore be appropriate for seeding bioartificial liver devices.

Perceptions of dental students in Japanese national universities about studying abroad

PURPOSE

Dental faculties in Japan have organised many short-term international exchange programs to enable their undergraduates to study abroad. However, not many students apply for those programs. In this present study, we attempted to clarify the factors that discourage undergraduate dental students from studying abroad.

METHODS

We administered a questionnaire survey to 512 undergraduate dental students in three national universities located in different areas in Japan.

RESULTS

Although 61.7% of the participants expressed interest in studying abroad, only 19.1% of them had prior experiences of study abroad or plans to do so. Their main worries were about lack of sufficient language ability in academic fields. Comparing those who were interested in studying abroad with those who were not revealed significant differences regarding their concern about lack of language ability and lack of specialised knowledge in dentistry. Participants who did not want to study abroad indicated that they did not perceive a purpose in doing so and cited not having foreign friends as a problem. Household income was significantly correlated with concerns about overall expenses.

CONCLUSION

Overall, language ability and academic knowledge appeared to be the two strongest factors affecting dental students' consideration of studying abroad. Dental schools in Japan can use the findings of this study to improve their undergraduate exchange programs in such a way as to stimulate greater interest amongst their students.

[A Case of Locally Advanced Gastric Cancer - R0 Resection Was Performed by Pancreaticoduodenectomy with Portal Vein Resection Following Neoadjuvant Therapy]

A 76-year-old woman, complained of weight loss, was admitted in our hospital. After investigation, she was diagnosed with clinical Stage III B gastric cancer with invasion into the pancreas and transverse colon. After performing the staging laparoscopy and gastrojejunostomy for pyloric stenosis, she was treated with 2 courses of SOX therapy as neoadjuvant therapy, and subsequently underwent pancreaticoduodenectomy and right hemicolectomy combined with portal vein resection due to severe adhesion by the tumor. The pathological diagnosis was pT4b(colon), pN0(0/22), pM0, pStage III B. There were no findings of tumor invasion into the pancreas or the portal vein. She was discharged without any complications. She did not receive the adjuvant chemotherapy, and died of other illness at 10 months after surgery. For the locally advanced gastric cancer such as invasion to the pancreas, the extended resection as an R0 resection could be achieved more safely, by evaluating accurately the incurable factors and planning an effective strategy according to the patient's condition.

Prolonged duration of nonequilibrated Dirac fermions in neutral topological insulators

Topological insulators (TIs) possess spin-polarized Dirac fermions on their surface but their unique properties are often masked by residual carriers in the bulk. Recently, (Sb_1−xBi_x)₂Te₃ was introduced as a non-metallic TI whose carrier type can be tuned from n to p across the charge neutrality point. By using time- and angle-resolved photoemission spectroscopy, we investigate the ultrafast carrier dynamics in the series of (Sb_1−xBi_x)₂Te₃. The Dirac electronic recovery of ∼10 ps at most in the bulk-metallic regime elongated to >400 ps when the charge neutrality point was approached. The prolonged nonequilibration is attributed to the closeness of the Fermi level to the Dirac point and to the high insulation of the bulk. We also discuss the feasibility of observing excitonic instability of (Sb_1−xBi_x)₂Te₃.

Universalization of the operative strategy by systematic mesogastric excision for stomach cancer with that for total mesorectal excision and complete mesocolic excision colorectal counterparts

Gastrointestinal cancer surgery aims at en bloc removal of the primary tumor with its lymphatic drainage by excising organ-specific mesentery as an "intact package". This concept was advocated in colorectal cancer surgery as total mesorectal excision (TME) or complete mesocolic excision (CME) procedures, but is not directly applicable to stomach cancer as a result of the morphological complexities of the gastric mesentery. In this review, we discuss the unique anatomical features of the mesogastrium by introducing its embryology, disclose its similarity to the mesosigmoid, and then propose a theoretical concept to mesentery-based D2 gastrectomy, namely systematic mesogastric excision, which can universalize the operative strategy of stomach cancer with that of TME and CME colorectal counterparts.

Survival of Nigral Grafts within the Striatum of Marmosets with 6-Ohda Lesions Depends Critically on Donor Embryo Age

The study examined the importance of embryonic donor age for the survival of nigral grafts in 6-OHDA–lesioned marmosets. The issue as to whether donor age is critical for the survival of nigral grafts in primates is controversial, because several early reports suggested that relatively old tissue could survive transplantation and produce functional benefits in monkeys, in contrast to the restrictive time dependence observed in rodents. Embryonic marmoset donors embryos of three different ages were employed: 1) E74 (Carnegie stage 18-19); 2) E83-84 (Carnegie stage 23+); 3) E92-93 (foetal period). The nigral neurons derived from the ventral mesencephalon in the two older donor age groups did not survive well when grafted to the striatum of adult marmosets with unilateral 6-OHDA lesions. Although a few tyrosine hydroxylase (TH+) neurons could be identified by immunohistochemistry at graft sites in all recipients in older donor age groups, the numbers of surviving neurons in these were small, on average typically less than 100 TH+ cells. These small grafts were not sufficient to affect amphetamine-induced rotation. In contrast, many more TH+ cells typically survived transplantation in the recipients; of graft tissue derived from the youngest donors and amphetamine-induced rotation was significantly reduced in this group alone. The time course and extent of the reduction in rotation was remarkably similar to that observed in previous marmoset nigral graft studies, confirming the utility of amphetamine-induced rotation as a sensitive and reliable indicator of nigral graft function in this species. Considering these results and other recent evidence from monkey to monkey, human to rat, and human to human graft studies, the survival of embryonic nigral tissues derived from primate donors transplanted into the striatum does appear to be critically dependent on the age of the donor tissue.

Significance of Portal Venous Velocity in Short-term Graft Function in Living Donor Liver Transplantation

BACKGROUND

Graft regeneration and functional recovery after reperfusion of transplanted graft are very important for successful living donor liver transplantation (LDLT). The aim of this study was to evaluate the significance of postoperative portal venous velocity (PVV) in short-term recovery of graft function in LDLT.

PATIENTS AND METHODS

From February 2007 through December 2015, we performed 17 primary LDLTs, which were included in the present study. The patients ranged in age from 12 to 65 years (mean: 50 years), and 11 were female patients. Postoperatively, Doppler ultrasonography was performed daily to measure PVV (cm/s), and liver function parameters were measured daily. The change in PVV (ΔPVV) was defined as follows: ΔPVV = PVV on postoperative day (POD) 1 - PVV on POD 7. Maximal value of serum aspartate aminotransferase (ASTmax) and maximal value of serum alanine transaminase (ALTmax) at 24 hours after graft reperfusion were used as parameters of reperfusion injury. Correlation analyses were performed as follows: (1) correlation of ΔPVV and PVV on POD 1 (PVV-POD 1) with the values such as ASTmax, ALTmax, other liver function parameters on POD 7 and graft regeneration rate; (2) correlation of ASTmax and ALTmax with other liver function parameters on POD 7.

RESULTS

ΔPVV significantly correlated with the values of serum total bilirubin (P < .01), prothrombin time (P < .01), and platelet count (P < .05), and PVV-POD 1 significantly correlated with the values of serum total bilirubin (P < .05) and prothrombin time (P < .05).

CONCLUSION

ΔPVV and PVV-POD 1 may be useful parameters of short-term functional recovery of the transplant liver in LDLT.

Laparoscopic subtotal gastrectomy for advanced gastric cancer: technical aspects and surgical, nutritional and oncological outcomes

BACKGROUND

Higher morbidity in total gastrectomy than in distal gastrectomy has been reported, but laparoscopic subtotal gastrectomy (LsTG) has been reported to be safe and feasible in early gastric cancer (GC). We determined the surgical, nutritional and oncological outcomes of LsTG for advanced gastric cancer (AGC).

METHODS

Of the 816 consecutive patients with GC who underwent radical gastrectomy at our institution between 2008 and 2012, 253 who underwent curative laparoscopic gastrectomy (LG) for AGC were enrolled. LsTG was indicated for patients with upper stomach third tumors, who hoped to avoid total gastrectomy, <4 cm to the esophagogastric junction and a 2-cm proximal margin with cut end negative in frozen section, whereas laparoscopic conventional distal gastrectomy (LcDG) and laparoscopic total gastrectomy (LTG) were performed otherwise. Surgical outcomes and postoperative nutritional status were primarily assessed.

RESULTS

Of 253 patients, the morbidity (Clavien-Dindo classification grade ≥ III) was 17.0% (43 patients). The 3-year overall survival and 3-year recurrence-free survival rates were 80.2 and 73.5%, respectively. LcDG, LsTG and LTG were performed in 121, 27 and 105 patients, individually. Morbidity was strongly associated with LTG (P = 0.001). Postoperative loss of body weight was significantly greater after LTG in comparison with LcDG or LsTG (P < 0.001). No difference in morbidity and postoperative loss of body weight were observed between LcDG and LsTG group.

CONCLUSIONS

LG for AGC was feasible and safe surgically and oncologically. LsTG for AGC may be safer than LTG from surgical and postoperative nutritional point of view.

Topologically Entangled Rashba-Split Shockley States on the Surface of Grey Arsenic

We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and that the crossing of the pair at Γ[over ¯] is topologically unavoidable. First-principles calculations well reproduce the bands and their nontrivial topology; the calculations also support that the surface states are of Shockley type because they arise from a band inversion caused by crystal field. The results provide compelling evidence that topological Shockley states are realized on As(111).

High repetition pump-and-probe photoemission spectroscopy based on a compact fiber laser system

The paper describes a time-resolved photoemission (TRPES) apparatus equipped with a Yb-doped fiber laser system delivering 1.2-eV pump and 5.9-eV probe pulses at the repetition rate of 95 MHz. Time and energy resolutions are 11.3 meV and ∼310 fs, respectively, the latter is estimated by performing TRPES on a highly oriented pyrolytic graphite (HOPG). The high repetition rate is suited for achieving high signal-to-noise ratio in TRPES spectra, thereby facilitating investigations of ultrafast electronic dynamics in the low pump fluence (p) region. TRPES of polycrystalline bismuth (Bi) at p as low as 30 nJ/mm² is demonstrated. The laser source is compact and is docked to an existing TRPES apparatus based on a 250-kHz Ti:sapphire laser system. The 95-MHz system is less prone to space-charge broadening effects compared to the 250-kHz system, which we explicitly show in a systematic probe-power dependency of the Fermi cutoff of polycrystalline gold. We also describe that the TRPES response of an oriented Bi(111)/HOPG sample is useful for fine-tuning the spatial overlap of the pump and probe beams even when p is as low as 30 nJ/mm².

TNF-α-induced IL-6 and MMP-9 expression in immortalized ameloblastoma cell line established by hTERT

OBJECTIVE

Ameloblastoma (AM) shows locally invasive behaviour. However, biological investigations regarding regulation of gene expression associated with AM pathological features are difficult to perform, because AM cells can be passaged for a few generations due to senescence. We report a newly established immortalized AM cell line, AMB cells, by transfection with human telomerase reverse transcriptase (hTERT). Furthermore, we examined whether TNF-α modulates bone resorption-related genes, IL-6 and MMP-9 in cooperation with TGF-β or IFN-γ.

MATERIALS AND METHODS

Following transfection of an hTERT expression vector into AM cells using a non-viral method, the effects of cytokines on the expressions of IL-6 and MMP-9 mRNA were examined using real-time PCR. TNF-α-induced NF-κB activity was examined by western blotting and transcription factor assays.

RESULTS

AMB cells continued to grow for more than 100 population doublings. Stimulation with TNF-α increased IL-6 and MMP-9 mRNA expressions, as well as NF-κB activation. Furthermore, TGF-β and IFN-γ dramatically increased TNF-α-mediated expressions of MMP-9 and IL-6 mRNA, respectively, while those responses were suppressed by NF-κB inhibitor.

CONCLUSION

We established an immortalized AM cell line by hTERT transfection. TNF-α-mediated regulation of MMP-9 and IL-6 via NF-κB may play an important role in the pathological behaviour of AMs, such as bone resorption.