Search

Static and dynamic frictional properties of rock discontinuities are of great importance in the evaluation of the initiation of failure and post-failure motions of rock engineering structures as well as the rupture and strong motions induced by earthquake faults in earthquake science. Nevertheless, experiments on static and dynamic frictional properties of rock discontinuities are very rare. In this study, the authors describe tilting and stick–slip experiments on various natural rock discontinuities and saw-cut surfaces to determine their static and dynamic frictional properties. Furthermore, these experimental results are compared with each other to discuss the static and dynamic frictional properties of rock discontinuities from tilting and stick–slip tests. Experimental results show that peak (static) friction angle for discontinuity surfaces obtained from tilting tests and stick–slip experiments are very close to each other. Highlights: In this paper, it is demonstrated that the static and dynamic frictional properties of rock discontinuities can be determined from tilting and stick-slip tests. Experimental results confirm that peak (static) friction angle for discontinuity surfaces obtained from tilting tests are very close to those obtained from stick-slip experiments. The experimental results could be useful for researchers dealing with the estimation of post-failure motions of failed bodies in Rock Mechanics and Rock Engineering as well as strong motion simulations in Earthquake Science and Engineering. [ABSTRACT FROM AUTHOR]

Purpose: Follow-up examinations after flow diverter (FD) treatment for cerebral aneurysms typically involve magnetic resonance imaging (MRI) or digital subtraction angiography (DSA). However, MRI is prone to vascular defects due to metal artifacts from FD, and DSA carries a risk of ischemic complications. In the context of computed tomography angiography (CTA), this study compares the efficacy of ultra-high-resolution CT (UHRCT) and novel reconstruction techniques, such as model-based iterative reconstruction (MBIR), against conventional methods such as filtered back projection (FBP) and hybrid iterative reconstruction (IR), to determine if they are a viable alternative to DSA in clinical settings. Materials and methods: A phantom study was conducted with the full-width half-maximum considered as the FD thickness. This study compared three reconstruction methods: MBIR, FBP, and hybrid IR. A clinical study was also conducted with 21 patients who underwent follow-up CTA after FD treatment. The FD's visibility was assessed using a 4-point scale in FBP, hybrid IR, and MBIR compared to cone-beam CT (CBCT) with angiographic systems. Results: In the phantom study, FBP, hybrid IR, and MBIR visualized thinner FD thicknesses and improved detail rendering in that order. MBIR proved to be significantly superior in both the phantom and clinical study. Conclusion: UHRCT with MBIR is highly effective for follow-up evaluations after FD treatment and may become the first-choice modality in the future. [ABSTRACT FROM AUTHOR]

Background: Challenges to our understanding the molecular mechanisms of the progression of gastric cancer (GC) must be overcome to facilitate the identification of novel biomarkers and therapeutic targets. In this article, we analyzed the expression of the gene encoding F-box-only 50 (FBXO50) and determined whether it contributes to the malignant phenotype of GC. Methods: FBXO50 messenger RNA (mRNA) levels and copy numbers of the FBXO50 locus were determined in 10 GC cell lines and a nontumorigenic epithelial cell line. Polymerase chain reaction array analysis was performed to identify genes coordinately expressed with FBXO50. The effects of inhibiting FBXO50 on GC cell proliferation, adhesion, invasiveness, and migration were evaluated using a small interfering RNA targeted to FBXO50 mRNA. To evaluate the clinical significance of FBXO50 expression, we determined the levels of FBXO50 mRNA in tissues acquired from 200 patients with GC. Results: The levels of FBXO50 mRNA were increased in five GC cell lines and positively correlated with those of ITGA5, ITGB1, MMP2, MSN, COL5A2, GNG11, and WNT5A. Copy number gain of the FBXO50 locus was detected in four GC cell lines. Inhibition of FBXO50 expression significantly decreased the proliferation, adhesion, migration, and invasiveness of GC cell lines. In clinical samples, high FBXO50 expression correlated with increased pT4, invasive growth, lymph node metastasis, and positive peritoneal lavage cytology. Patients with high FBXO50 expression had a significantly higher prevalence of recurrence after curative gastrectomy and were more likely to experience shorter overall survival. Conclusions: FBXO50 may represent a biomarker for GC phenotypes and as a target for therapy. [ABSTRACT FROM AUTHOR]

Background: Gastric cancer (GC) relapse can occur even if curative resection is achieved. Biomarkers predicting recurrence are needed to provide appropriate postoperative surveillance and perioperative therapeutic strategy. Methods: A global expression profiling was performed using tissues from GC patients with synchronous liver-confined metastasis. Family with sequence similarity 46, member C ( FAM46C), was identified as a candidate biomarker. mRNA expression analysis, direct nucleotide sequencing, bisulfite sequencing and copy number assays for FAM46C were performed with eleven GC cell lines. Expression levels of FAM46C in primary GC tissues from 129 patients who underwent curative GC resection were determined and correlated with clinicopathological factors, including postoperative outcome. Results: Levels of FAM46C mRNA differed among GC cell lines. Point mutations in FAM46C were detected in five GC cell lines accompanied with reduced FAM46C transcription. No hypermethylation was found in the promoter region of FAM46C. Copy number alterations were found in six GC cell lines with differing FAM46C transcription levels. Reduced FAM46C mRNA expression levels were detected in 117 (91 %) GC specimens compared with adjacent noncancerous tissues. Low FAM46C expression levels were significantly associated with larger macroscopic GC tumor sizes. The low FAM46C expression group was likely to have shorter disease-free survival than the high group and low FAM46C level was identified as an independent risk factor for recurrence after curative resection. FAM46C expression levels were low in all cases that were later found to have hepatic recurrence. Conclusions: Reduced GC expression of FAM46C is a potential biomarker to predict hepatic recurrence after curative gastrectomy. [ABSTRACT FROM AUTHOR]

Background: Gastrectomy with systemic lymphadenectomy is the standard of care for resectable gastric cancer (GC), but it is sometimes associated with postoperative morbidity. Predicting complications is therefore an essential part of risk management in clinical practice. The renal function is routinely evaluated before surgery by blood examinations to determine dose of medication and infusion. However, the value of various parameters of renal function in prediction of postoperative complications remain unclear. Methods: We included 315 patients who underwent curative D2 gastrectomy for clinical T2-T4 GC without preoperative treatment, and evaluated the correlation between the incidence of postoperative complications and the indicators of renal function. Results: Forty-three patients experienced clinically relevant postoperative complications. Estimated glomerular filtration rate (eGFR) showed a higher area under the curve for predicting complications compared with urea nitrogen, creatinine, and creatinine clearance. The optimal eGFR cutoff value was 63.2 ml/min/1.73 m, and eGFR < 63.2 was an independent risk factor for postoperative complications in multivariable analysis (odds ratio 4.67; 95 % confidence interval 2.16-10.5; p < 0.001). Particularly, the incidence of anastomotic leakage was significantly higher in patients with eGFR < 63.2 than those with eGFR ≥ 63.2 (9.4 % vs. 3.5 %). eGFR < 63.2 was also associated with a higher incidence of postoperative complications independent of age, body mass index, operative procedure, and clinical disease stage. Postoperative hospital stay was significantly longer in the eGFR < 63.2 group. Conclusions: Preoperative eGFR is a simple and useful predictor for complications after gastrectomy in patients with GC and may improve clinical care and the process of obtaining informed consent. [ABSTRACT FROM AUTHOR]

Background: Systemic hemostasis and thrombosis activation has been implicated in tumor progression and metastasis. This study aimed to investigate the use of coagulation factors as a novel prediction method for postoperative outcomes after curative gastrectomy in patients with stage II/III gastric cancer (GC). Methods: Overall, 126 patients with stage II/III GC who underwent gastrectomy between May 2003 and February 2016 were eligible for inclusion in the study. We retrospectively evaluated the predictive value of preoperative platelet count and plasma fibrinogen and d-dimer levels, and coagulation score (0: fibrinogen and d-dimer both below upper limits; 1: either fibrinogen or d-dimer over upper limits; 2: both fibrinogen and d-dimer over upper limits) for short- and long-term outcomes. Results: Postoperative complications were significantly more frequent in patients with elevated preoperative d-dimer levels compared with those with normal d-dimer levels (26 vs. 10 %; p = 0.032). The prevalence of postoperative complications showed a stepwise increase in proportion to the coagulation score. Patients with a coagulation score of 2 had significantly larger tumors ( p = 0.013) and significantly greater intraoperative blood loss ( p = 0.004) than those who scored 0 or 1. Coagulation score showed the highest values distinguished high-risk patients in overall and disease-free survival, and a coagulation score of 2 was an independent prognostic factor for recurrence. Patients with a coagulation score of 2 experienced a significantly higher prevalence of liver metastasis as an initial recurrence than those who scored 0 or 1 ( p = 0.019). Conclusions: The coagulation score is a simple and promising predictor for postoperative complications and recurrence after gastrectomy in stage II/III GC patients. [ABSTRACT FROM AUTHOR]

Background: Laparoscopic (assisted) distal gastrectomy (LDG) with radical lymphadenectomy for gastric cancer has been widely conducted, particularly in the Far East. Peripancreatic inflammatory fluid collection (PIFC) is a serious and frequent postoperative complication after LDG for gastric cancer. The aim of this study was to evaluate the diagnostic performance of drain amylase content (D-AMY) for clinically relevant PIFC after LDG.Methods: Two hundred and sixty-four patients who underwent LDG with prophylactic drains were enrolled. The predictive value of D-AMY on postoperative day (POD) 1 and POD 3 in the diagnosis of PIFC was evaluated.Results: Twenty (7.6 %) patients experienced postoperative PIFC. Area under the curve in terms of receiver operating characteristics curve analysis of D-AMY on POD 1 was 0.801, and the optimal cutoff value for prediction of PIFC was 904 IU/l, with 98.2 % negative predictive value. Another cutoff was proposed as 4078 IU/l, with 92.2 % specificity. Multivariable analyses identified D-AMY on POD 1 ≥900 and ≥4000 IU/l as independent diagnostic factors for PIFC. Among patients at high risk of PIFC (D-AMY on POD 1 ≥900 IU/l), those who on POD 3 retained D-AMY value in excess of 31.2 % of the D-AMY value on POD 1 were more likely to experience PIFC compared with those with a pronounced decrease in D-AMY.Conclusions: D-AMY on POD 1 serves as a predictive factor for clinically relevant PIFC after LDG. Time-dependent changes in D-AMY can also be used for determining management of drains in patients at high risk of PIFC. [ABSTRACT FROM AUTHOR]

Background: Identification of novel molecules implicated in the malignancy of gastric cancer (GC) is key to the development of personalized treatments and the improvement of patient outcome. Neurotrophin receptor-interacting melanoma antigen-encoding protein ( NRAGE) regulates apoptosis and metastasis via interactions with various genes. This study aimed to evaluate the function and clinical significance of NRAGE in GC. Methods: The expression of NRAGE and its putative interacting genes apoptosis antagonizing transcription factor ( AATF), p75 neurotrophin receptor ( p75NTR), and proliferating cell nuclear antigen ( PCNA) were determined in GC cell lines using reverse transcription-polymerase chain reaction (RT-PCR). The effect of NRAGE knockdown by small interfering RNA (siRNA) on GC cell behavior also was evaluated. In addition, NRAGE expression was determined in 179 pairs of resected gastric tissues. Results: Expression of NRAGE mRNA positively correlated with that of AATF, and NRAGE knockdown significantly decreased the proliferation, migration, and invasion of GC cells. The mean level of NRAGE mRNA expression was significantly higher in GC tissues than in corresponding adjacent normal tissues. The expression patterns of NRAGE mRNA and protein were closely correlated. A stepwise elevation in NRAGE mRNA expression in GC tissues was observed with increasing Union for International Cancer Control (UICC) stage. High NRAGE expression in GCs was associated with shortened recurrence-free survival and identified as an independent prognostic factor (hazard ratio, 1.83; 95 % CI, 1.12-3.02, p = 0.017). Conclusions: The results indicate that NRAGE represents a putative oncogene associated with a malignant phenotype of GC. In GC, NRAGE may serve as a predictive biomarker and a target of molecular therapy. [ABSTRACT FROM AUTHOR]

Background: In East Asia, the tumor infiltrative pattern (INF) has been routinely evaluated by hematoxylin and eosin-stained sections as a pathologic characteristic of surgically resected specimens. Methods: The infiltrative pattern of gastric cancer (GC) has been histopathologically classified as INFa (expansive growth), INFb (intermediate type) and INFc (infiltrative growth) according to the Japanese Classification of Gastric Carcinoma. The prognostic value and characteristics of the disease recurrence pattern for each INF type were assessed in 785 patients with various stages of GC and also in 243 patients with stages 2 and 3 GC. Results: Comparison of the overall survival experienced by patients independently of stage showed that INF was significantly associated with prognosis. Specifically, peritoneal metastasis was present in 91 % of stage 4 patients in the INFc group, whereas hepatic metastasis was present in 39 % of stage 4 patients in the INFa and INFb group. After curative gastrectomy of patients with stages 2 or 3 GC, INF was not significantly associated with survival. The prevalence of peritoneal recurrence was significantly higher in the INFc group than in the INFa and INFb group, whereas the prevalence of hepatic recurrence was significantly higher in the INFa and INFb group than in the INFc group. Multivariate analysis identified INFc as an independent risk factor for peritoneal recurrence after curative gastrectomy. The association of the INF type with the incidence of peritoneal recurrence was observed with all disease stages regardless whether the patient was given adjuvant chemotherapy or not. Conclusions: Evaluation of the INF type shows promise for its role as a predictor of postoperative recurrence sites in patients with GC. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to evaluate the prognostic relevance of subcarinal lymph node dissection in patients with esophageal squamous cell carcinoma (ESCC) and to identify a subset of patients in whom subcarinal lymph node dissection can be omitted. Methods: We retrospectively analyzed 342 consecutive patients with thoracic ESCC who underwent R0 subtotal esophagectomy. All patients underwent subcarinal lymph node dissection. The efficacy index (frequency of metastasis to a particular lymph node station multiplied by the 5-year disease-specific survival rate of patients with metastasis to the station) was calculated for the subcarinal lymph node station, and the prognostic impact of dissecting this station was estimated with reference to the main tumor location. Independent predictive factors for pathological subcarinal lymph node metastasis were analyzed using a proportional hazards model. Results: The overall frequency of metastasis to the subcarinal lymph nodes was 7.0 % (2.4, 8.9, and 5.8 % in patients with upper, middle, and lower thoracic ESCC, respectively). The efficacy index for the middle thoracic esophagus was 2.9, and that for the upper and lower thoracic esophagus was 0.0. The 5-year disease-free survival rate was significantly lower in patients with pathological subcarinal lymph node metastasis than those without (23.1 vs. 67.5 %, respectively; log-rank p < 0.0001). In multivariate analysis, clinical T stage (T2-T4) was the independent predictive factor for pathological subcarinal lymph node metastasis ( p = 0.021). Conclusions: Subcarinal lymph node dissection might have little value in patients with upper and lower thoracic ESCC and could be omitted, especially for superficial carcinoma. [ABSTRACT FROM AUTHOR]

Background: We conducted paravertebral block (PVB) for thoracotomy, with epidural anesthesia carried out as usual for laparotomy. To date, there has been no report of combining continuous PVB for thoracotomy and epidural anesthesia for laparotomy after esophagectomy. The aim of this historical study was to evaluate the efficacy of the combination. Methods: This is a retrospective analysis of 105 patients who underwent transthoracic esophagectomy at our institution from April 2012 to July 2014. Fifty-three patients underwent two epidural catheter placements for thoracotomy and laparotomy from April 2012 to March 2013 (EP group), and 52 underwent PVB for thoracotomy and epidural catheter for laparotomy from April 2013 to July 2014 (PVB group). In both groups, an anesthetic agent was continuously infused until postoperative day 7. PVB was placed by the surgical team at the end of the operation under direct vision. Results: There was no significant difference between the two groups regarding dosage of an additional analgesic agent. Only one catheter-related complication occurred, in the EP group. The frequency of hypotension in the PVB group was significantly lower than that in the EP group (9.6 and 30.2 %, respectively; P = 0.008). The time to ambulation in the PVB group was significantly shorter than that in the EP group (1.5 ± 0.5 days vs. 1.9 ± 0.9 days; P = 0.007). Conclusions: Combined PVB for thoracotomy and epidural anesthesia for laparotomy is safe and effective. This method should be considered a useful option for postoperative pain control after esophagectomy. [ABSTRACT FROM AUTHOR]

Background: Allogeneic blood transfusions (BTFs) are sometimes required for radical gastrectomy with regional lymph node dissection for advanced gastric cancer (GC). The prognostic impact of perioperative BTF in GC is controversial. Methods: Clinical data were collected retrospectively from 250 consecutive patients who underwent curative gastric resection for stage II/III GC. The prognostic impact of BTF on patient survival was evaluated. Subgroup analysis was performed according to units of blood transfused, timing of BTF, type of gastrectomy, splenectomy, intraoperative estimated blood loss, and year of surgery. Results: Fifty-seven (22.8 %) patients underwent perioperative BTF. Patients who received BTF experienced a significantly shorter disease-specific survival after curative surgery, and multivariable analysis identified perioperative BTF as an independent prognostic factor for cancer-related death (hazard ratio, 1.80; 95 % confidence interval, 1.05-3.02; p = 0.032). The BTF group experienced significantly lower recurrence-free survival rate and a higher rate of initial peritoneal recurrence. The amount of blood cells transfused had less impact on prognosis. Pre- or postoperative BTF without intraoperative BTF had limited influence on postoperative prognosis. Prognosis of patients was affected by splenectomy. Even when intraoperative blood loss exceeded 800 ml, the prognosis of the non-BTF group was more favorable. The prognostic impact of BTF became less clear after introduction of adjuvant chemotherapy with S-1. Conclusions: BTF was an independent prognostic factor in patients with stage II/III GC after curative gastrectomy. To improve prognosis, BTF should be avoided when possible, particularly during surgery. [ABSTRACT FROM AUTHOR]

Introduction: The present study compares the applicability of CT carotid plaque imaging using effective Z maps using gemstone spectral imaging (GSI) with that of conventional extracorporeal carotid ultrasound (US) and virtual histology-intravascular ultrasound (VH-IVUS). Methods: We assessed stenosis in 31 carotid arteries of 30 patients. All patients underwent carotid CTA using GSI (Discovery CT750 HD, GE Healthcare). US and IVUS were examined with 25 and 8 vessels, respectively. We compared the effective Z values at noncalcified carotid plaque with the plaque components identified by US. We defined the plaque with low or low to iso intensity on US as vulnerable plaque and the plaque with iso, iso to high, and high intensity on US as stable plaque. We also performed visual assessment of color-coded effective Z maps in comparison with VH-IVUS and compared effective Z values with plaque components generated by VH-IVUS. Results: The effective Z values at noncalcified carotid plaque were significantly lower for a group with vulnerable plaque, than with stable plaque on US ( p < 0.05). Receiver operating curve analysis showed that AUC of effective Z values was 0.882 concerning the differentiation of these two groups on US. The interpretation of color-coded effective Z maps was essentially compatible with that of VH-IVUS for carotid plaque in all vessels. Effective Z values at noncalcified plaque showed significant negative correlation with the areas of fibro-fatty components generated by VH-IVUS ( ρ = −0.874, p < 0.05). Conclusion: Effective Z maps generated by GSI can detect vulnerable carotid plaque materials. [ABSTRACT FROM AUTHOR]

Background: Treatment of peritoneal carcinomatosis arising from gastric cancer remains a considerable challenge. In recent years, the anticancer effect of nonequilibrium atmospheric pressure plasma (NEAPP) has been reported in several cancer cell lines. Use of NEAPP may develop into a new class of anticancer therapy that augments surgery, chemotherapy, and radiotherapy. Method: Gastric cancer cells were assessed for changes in cell morphology and rate of proliferation after treatment with NEAPP-exposed medium (PAM). To explore the functional mechanism, caspase 3/7, annexin V, and uptake of reactive oxygen species (ROS) were evaluated, along with the effect of the ROS scavenger N-acetylcysteine (NAC). Results: PAM treatment for 24 h affected cell morphology, suggestive of induction of apoptosis. PAM cytotoxicity was influenced by the time of exposure to PAM, the type of cell line, and the number of cells seeded. Cells treated with PAM for 2 h demonstrated activated caspase 3/7 and an increased proportion of annexin V-positive cells compared with untreated cells. Additionally, ROS uptake was observed in PAM-treated cells, whereas NAC reduced the cytotoxicity induced by PAM presumably through reduction of ROS uptake. Furthermore, CD44 variant 9, which reportedly leads to glutathione synthesis and suppresses stress signaling of ROS, was overexpressed in PAM-resistant cells. Conclusions: PAM treatment induced apoptosis of gastric cancer cells through generation and uptake of ROS. Local administration of PAM could develop into an option to treat peritoneal carcinomatosis. [ABSTRACT FROM AUTHOR]

Introduction: Follow-up CT angiography (CTA) is routinely performed for post-procedure management after carotid artery stenting (CAS). However, the stent lumen tends to be underestimated because of stent artifacts on CTA reconstructed with the filtered back projection (FBP) technique. We assessed the utility of new iterative reconstruction techniques, such as adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR), for CTA after CAS in comparison with FBP. Methods: In a phantom study, we evaluated the differences among the three reconstruction techniques with regard to the relationship between the stent luminal diameter and the degree of underestimation of stent luminal diameter. In a clinical study, 34 patients who underwent follow-up CTA after CAS were included. We compared the stent luminal diameters among FBP, ASIR, and MBIR, and performed visual assessment of low attenuation area (LAA) in the stent lumen using a three-point scale. Results: In the phantom study, stent luminal diameter was increasingly underestimated as luminal diameter became smaller in all CTA images. Stent luminal diameter was larger with MBIR than with the other reconstruction techniques. Similarly, in the clinical study, stent luminal diameter was larger with MBIR than with the other reconstruction techniques. LAA detectability scores of MBIR were greater than or equal to those of FBP and ASIR in all cases. Conclusion: MBIR improved the accuracy of assessment of stent luminal diameter and LAA detectability in the stent lumen when compared with FBP and ASIR. We conclude that MBIR is a useful reconstruction technique for CTA after CAS. [ABSTRACT FROM AUTHOR]

Background: A combination of fluorouracil and leucovorin (5-FU/LV) with oxaliplatin (FOLFOX) is an established first-line therapy for metastatic colorectal cancer (mCRC). However, the cumulative neurotoxicity of oxaliplatin often requires therapy to be discontinued while the patient is still responding. A strategy to stop FOLFOX, deliver 5-FU/LV as a maintenance therapy and reintroduce FOLFOX was found to be equivalent in terms of efficacy while neurotoxicity was substantially reduced. The aim of this study was to evaluate feasibility of a stop-and-go strategy with S-1, an oral fluoropyrimidine derivative, as a maintenance therapy administered between modified FOLFOX6 (mFOLFOX6) as a first-line treatment of mCRC. Methods: Thirty patients with untreated mCRC were treated with six cycles of mFOLFOX6 followed by maintenance therapy with oral S-1. Reintroduction of mFOLFOX6 was scheduled after four cycles of S-1 or upon tumor progression. The primary endpoint was duration of disease control (DDC). Results: Twenty-one of the 30 patients who achieved responses or stabilizations received S-1 maintenance therapy. mFOLFOX6 was reintroduced in 15 patients. Median DDC and progression-free survival were 9.3 and 7.9 months, respectively. The response rates and disease control rates were 40.0 and 86.6% for the initial mFOLFOX6, 23.8 and 57.1% for S-1 maintenance therapy and 20.0 and 73.3% for mFOLFOX6 reintroduction, respectively. Twenty-eight patients (93.3%) had peripheral neuropathy, but grade 3 neurotoxicity was observed in only 1 patient (3.3%). Conclusion: The planned oxaliplatin stop-and-go strategy with oral S-1 maintenance therapy was feasible as a first-line treatment for Japanese mCRC patients. Further prospective randomized control study is warranted. [ABSTRACT FROM AUTHOR]

Background: Laparoscopic surgery requires fundamental skills peculiar to endoscopic procedures such as eye-hand coordination. Acquisition of such skills prior to performing actual surgery is highly desirable for favorable outcome. Virtual-reality simulators have been developed for both surgical training and assessment of performance. The aim of the current study is to show construct validity of a novel simulator, LapVR (Immersion Medical, San Jose, CA, USA), for Japanese surgeons and surgical residents. Methods: Forty-four subjects were divided into the following three groups according to their experience in laparoscopic surgery: 14 residents (RE) with no experience in laparoscopic surgery, 14 junior surgeons (JR) with little experience, and 16 experienced surgeons (EX). All subjects executed 'essential task 1' programmed in the LapVR, which consists of six tasks, resulting in automatic measurement of 100 parameters indicating various aspects of laparoscopic skills. Results: Time required for each task tended to be inversely correlated with experience in laparoscopic surgery. For the peg transfer skill, statistically significant differences were observed between EX and RE in three parameters, including total time and average time taken to complete the procedure and path length for the nondominant hand. For the cutting skill, similar differences were observed between EX and RE in total time, number of unsuccessful cutting attempts, and path length for the nondominant hand. According to the programmed comprehensive evaluation, performance in terms of successful completion of the task and actual experience of the participants in laparoscopic surgery correlated significantly for the peg transfer ( P = 0.007) and cutting skills ( P = 0.026). Conclusions: The peg transfer and cutting skills could best distinguish between EX and RE. This study is the first to provide evidence that LapVR has construct validity to discriminate between novice and experienced laparoscopic surgeons. [ABSTRACT FROM AUTHOR]

The prognosis of patients with gastric cancer (GC) with hematogenous metastasis is dismal. Identification of biomarkers specific for hematogenous metastasis is required to develop personalized treatments that improve patients' outcomes. Global expression profiling of GC tissues with synchronous hepatic metastasis without metastasis to the peritoneal cavity or distant lymph nodes was conducted using next-generation sequencing and identified the G protein-coupled receptor 155 (GPR155) as a candidate biomarker. GPR155 transcription was suppressed in GC cell lines compared with a nontumorigenic cell line. DNA methylation of the GPR155 promoter region was not detected, albeit 20% of GC cell lines harbored copy number loss at GPR155 locus. The expression levels of GPR155 mRNA correlated inversely with those of TWIST1 and WNT5B. Inhibition of GPR155 expression increased the levels of p-ERK1/2 and p-STAT1, significantly increased cell proliferation, and increased the invasiveness of a GC cell lines. GPR155 mRNA levels in GC clinical samples correlated with hematogenous metastasis and recurrence. Multivariate analysis revealed that reduced expression of GPR155 mRNA was an independent predictive marker of hematogenous metastasis. GPR155 may represent a biomarker for diagnosing and predicting hematogenous metastasis of GC. [ABSTRACT FROM AUTHOR]

Anisotropic materials form inside living tissue and are widely applied in engineered structures, where sophisticated structural and functional design principles are essential to employing these materials. This paper presents a candidate laminated open-cell framework, which is an anisotropic material that shows remarkable mechanical performance. Using additive manufacturing, artificial frameworks are fabricated by lamination of in-plane orthotropic microstructures made of elbowed beam and column members; this fabricated structure features orthogonal anisotropy in three-dimensional space. Uniaxial loading tests reveal strong auxeticity (high negative Poisson's ratios) in the out-of-plane direction, which is retained reproducibly up to the nonlinear elastic region, and is equal under tensile and compressive loading. Finite element simulations support the observed auxetic behaviors for a unit cell in the periodic framework, which preserve the theoretical elastic properties of an orthogonal solid. These findings open the possibility of conceptual materials design based on geometry. [ABSTRACT FROM AUTHOR]