[Eight mm Port-Site Hernia Following Robot-Assisted Abdominoperineal Resection for Rectal Cancer-A Case Report].

A 70s woman with a history of asthma and dyslipidemia underwent a robot-assisted abdominoperineal resection for rectal cancer. The ports were placed as per the method of Shizuoka Cancer Center and no intraoperative complications were observed. The colostomy was constructed in the left lower abdomen by the retroperitoneal route. The 12-mm port part was closed in 2 layers, the fascia and dermis, and the 8-mm port part was closed only in the dermis. The postoperative course was good; however, the patient vomited 10 days after surgery. Abdominal computed tomography revealed an incarcerated small intestine in the 8-mm port of the left abdomen, and it was diagnosed as port-site hernia incarceration. Emergency laparotomy hernia repair was performed on the day. A part of the 8-mm port was incised to 30-mm and the fascia dilatation to 30-mm was observed. The color tone of the incarcerated small intestine was good. Only adhesion peeling was performed, the small intestine was returned, and the fascia was closed. The postoperative course was uneventful and the patient was discharged 17 days after the second surgery. At the 1 year postoperative follow-up, recurrence of hernia or rectal cancer was not observed.

[Long-Term Survival of a Patient with Hepatocellular Carcinoma after Surgical Resection of Metachronous Hilar Lymph Node Metastases].

The recurrence of hepatocellular carcinoma(HCC)is primarily due to intrahepatic metastases. Additionally, extrahepatic HCC metastases most commonly occurs in the lungs, lymph nodes, adrenal glands, and bones. Systemic chemotherapy is the standard treatment for extrahepatic metastases. Although several reports on surgical resection of lymph node metastases (LNM) in patients with HCC have been published, its clinical benefits remain controversial. We report a case in which surgical resection of LNM was performed in a patient with HCC. The patient was a 74-year-old woman diagnosed with HCC and non-B non-C chronic hepatitis, for which she underwent a laparoscopic partial hepatectomy. The pathological diagnosis was St-A, 1.6×1.4 cm, confluent multinodular type, pT1N0M0, fStage Ⅰ. Nine months later, 2 LNM on the liver hilum were detected and managed with sorafenib. Sorafenib was discontinued after 2 months due to the development of Grade 3 hand-foot syndrome. Since no new lesions were detected on follow-up, lymph node resection was performed. The patient remains disease-free 4.5 years postoperatively.

Impact of Lymph Node Ratio on Survival Outcome in Esophageal Squamous Cell Carcinoma After Minimally Invasive Esophagectomy.

BACKGROUND: Esophageal squamous cell cancer (ESCC) is one of the deadliest cancers in the world. Esophagectomy remains the principal treatment, and minimally invasive esophagectomy (MIE) has been performed worldwide. This study aimed to clarify whether the lymph node ratio (LNR), defined as the ratio of metastatic lymph nodes (LNs) to examined, is a prognostic factor for ESCC after MIE. METHODS: This study included 327 MIEs with the patient in the prone position at two institutions from 2010 to 2015. Cox proportional hazards regression analyses using clinicopathologic characteristics and the LNR were performed for the pN1 patients and the whole cohort. RESULTS: In the multivariate analysis for all stages, independent prognostic factors were depth of tumor invasion (P < 0.0001), LNR (P = 0.014), operative time (P = 0.003), and pneumonia (P = 0.012). In the analysis of the pN1 subgroup, the optimum LNR cutoff level for overall survival (OS) was 9 based on receiver operation characteristic analysis. The LNR was significantly associated with depth of tumor invasion (P = 0.004) and number of metastatic LNs (P < 0.0001). The OS curve for the group with an LNR of 9 or higher was significantly worse than for the group with an LNR lower than 9 (P < 0.001). Multivariate analyses demonstrated that the LNR is a unique independent prognostic factor for the pN1 subgroup (hazard ratio, 6.811; 95% confidence interval, 2.009-23.087; P = 0.002). CONCLUSIONS: The LNR is an independent prognostic factor in ESCC after MIE. Especially for patients with pN1 status, the LNR is more useful than the number of metastatic LNs for predicting survival outcome.

[A Case of Complete Resection Using the Liver-First Approach after Systemic Chemotherapy in a Patient with Synchronous Colorectal Liver and Lung Metastases].

Conversion surgery for patients with initially unresectable colorectal liver metastases is increasingly being performed because of effective systemic chemotherapy. Additionally, many studies have reported the benefit of the liver-first approach for advanced liver metastasis. We report a case of an initially unresectable advanced colon cancer with multiple liver and lung metastases that was successfully treated with the liver-first approach following chemotherapy. The patient was a 36-year- old woman who was diagnosed with advanced rectal cancer, cT4aN2aM1b, cStage Ⅳb. After a temporary transverse colostomy, she was administered systemic chemotherapy for 9 months. The primary tumor and liver metastases showed partial response while the lung metastases showed complete response. Since it was considered that liver metastases were the main prognostic factors, we performed a right hemihepatectomy plus S3 partial hepatectomy, followed by laparoscopic high anterior resection. A partial pneumonectomy was also performed because of the regrowth of the lung metastases, and we succeeded in complete resection. The liver-first approach was a beneficial treatment option for this patient with unresectable colorectal liver metastases.

Correction to: Thoracic Duct Resection During Esophagectomy Does Not Contribute to Improved Prognosis in Esophageal Squamous Cell Carcinoma: A Propensity Score Matched-Cohort Study.

In the original article, there are errors in Fig. 1. Following is the corrected figure.

Development of a new gene expression vector for Thermus thermophilus using a silica-inducible promoter.

BACKGROUND: Thermostable enzymes are commonly produced in mesophilic hosts for research and bioengineering purposes. However, these hosts do not overexpress the active forms of some biologically functional thermoenzymes. Therefore, an efficient thermophilic expression system is needed. Thermus thermophilus contains an easily manipulable genome and is therefore among the best candidate microbes for a "hot" expression system. We previously identified a strong and inducible promoter that was active in T. thermophilus under supersaturated silica conditions. Here, we report a new heterologous gene expression system based on a silica-inducible promoter in T. thermophilus. RESULTS: A Thermus sp. A4 gene encoding thermostable ß-galactosidase was cloned as a reporter gene into the expression vector pSix1, which contains a selection marker that confers thermostable resistance to hygromycin and a 600 bp DNA region containing a putative silica-inducible promoter. ß-galactosidase activity was 11-fold higher in the presence than in the absence of 10 mM silicic acid. SDS-PAGE revealed a prominent band corresponding to 73 kDa of ß-galactosidase, and this enzyme was expressed as an active and soluble protein (yield: 27 mg/L) in Thermus but as an inclusion body in Escherichia coli. Truncation of the putative silica-inducible promoter region in Thermus expression vector improved the yield of the target protein, possibly by avoiding plasmid instability due to homologous recombination. Finally, we developed an expression vector containing the pSix1 backbone and a 100 bp DNA region corresponding to the silica-inducible promoter. We used this vector to successfully express the active form of glutamate dehydrogenase from Pyrobaculum islandicum (PisGDH) without additional treatment (yield: 9.5 mg/L), whereas the expression of active PisGDH in E. coli required heat treatment. CONCLUSION: We successfully expressed the thermostable ß-galactosidase and PisGDH in T. thermophilus as active and soluble forms and achieved with our system the highest known protein expression levels in this species. These thermoenzymes were expressed in active and soluble forms. Our results validate the use of our silica-inducible expression system as a novel strategy for the intracellular overexpression of thermostable proteins.

Prophylactic Cervical Lymph Node Dissection in Thoracoscopic Esophagectomy for Esophageal Cancer Increases Postoperative Complications and Does Not Improve Survival.

BACKGROUND: Esophagectomy with three-field lymph node dissection is common, but the effects of cervical lymph node dissection on overall survival in patients with thoracic esophageal cancer remain controversial. Recently, we performed thoracoscopic esophagectomy and superior mediastinum and paracervical esophageal lymph nodes could have been effectively dissected from the thoracic cavity. This study assessed the risks and benefits of prophylactic supraclavicular lymph node dissection in patients who underwent thoracoscopic esophagectomy. METHODS: This retrospective study included 294 patients who underwent thoracoscopic esophagectomy at Kobe University Hospital and Hyogo Cancer Center between April 2010 and December 2015. Patients in the two-field (paracervical esophageal lymph nodes were dissected from the thoracic cavity) and three-field lymph node dissection groups were matched using propensity score matching. We compared overall survival and the incidence of postoperative complications in the matched cohort and assessed the estimated efficacy of additional lymphadenectomy for supraclavicular lymph node recurrence in the entire cohort. RESULTS: In the matched cohort, overall survival was not significantly different between the two groups, but the incidence of recurrent laryngeal nerve palsy was significantly higher in the 3FL group than in the 2FL group. In the entire cohort, 162 patients underwent a two-field lymph node dissection; 11 experienced supraclavicular nodal recurrence. We performed additional supraclavicular lymph node dissection in three patients without systemic metastasis, all of whom are alive without any other recurrence. CONCLUSIONS: Prophylactic cervical lymph nodes dissection in thoracoscopic esophagectomy does not improve long-term survival but does increase the risk of postoperative complications.

Thoracic Duct Resection During Esophagectomy Does Not Contribute to Improved Prognosis in Esophageal Squamous Cell Carcinoma: A Propensity Score Matched-Cohort Study.

PURPOSE: Esophagectomy with extended lymphadenectomy remains the mainstay of treatment for localized esophageal squamous cell carcinoma (ESCC). Thoracic duct (TD) resection has been recommended as part of extended lymphadenectomy, although its merits are unclear. The aim of this two-institutional, matched-cohort study is to clarify whether TD resection improves prognosis in esophagectomy for ESCC. PATIENTS AND METHODS: In this two-institutional, matched-cohort study of 399 patients with ESCC who underwent McKeown esophagectomy between 2010 and 2014, the primary outcomes were overall survival (OS), disease-free survival (DFS), and cause-specific survival (CSS). Secondary outcomes were perioperative results and recurrence patterns. RESULTS: Based on a propensity score, 122 TD-resected or 122 TD-preserved patients in all stages were selected (median follow-up 4.5 years). The 5-year OS, DFS, and CSS rates in the TD-resected versus TD-preserved groups were 49% versus 60%, 53% versus 57%, and 58% versus 70%, respectively, without any significant differences. Operative time for the thoracic procedure was significantly longer and the number of retrieved mediastinal nodes was significantly higher in the TD-resected group (P = 0.009 and 0.005, respectively). The rates of chylothorax and left recurrent laryngeal nerve (RLN) palsy were significantly higher in the TD-resected group (P = 0.041 and 0.018, respectively). There were no significant differences in rates of local or distant metastases between the two groups. CONCLUSIONS: TD resection does not contribute to improve OS, DFS, or CSS in ESCC but increases incidence of chylothorax and left RLN palsy. Prophylactic TD resection should be avoided in esophagectomy for ESCC.

Comparison of total versus subtotal gastrectomy for remnant gastric cancer.

PURPOSE: Completion gastrectomy (CG) is a common procedure for remnant gastric cancer (RGC). However, partial gastrectomy for gastric cancer has several benefits compared to total gastrectomy in terms of the quality of life. In this study, we evaluated the feasibility and advantage of subtotal resection of the remnant stomach (SR) for clinical stage IA RGC. METHODS: A total of 43 patients who underwent gastrectomy for clinical stage IA RGC were included. CG and SR were performed on 27 (62.8%) and 16 patients (37.2%), respectively. The short- and long-term outcomes, including the nutritional status, after CG and SR for clinical stage IA RGC were compared between the two groups. RESULTS: There were no significant differences in pathological stage or incidence of postoperative complications between the two groups. The decrease in body weight, body mass index, and serum albumin level was significantly lower in the SR group than in the CG group (P < 0.001, P = 0.025, and 0.008). In the SR group, there was no recurrence at the remaining lymph nodes or gastric stump. The 5-year overall survival rate was 87.8% in the CG group and 86.1% in the SR group, without a significant difference between the two groups (P = 0.959). CONCLUSIONS: The present study showed the noninferiority of SR to CG based on surgical and oncological outcomes for clinical stage IA RGC. Furthermore, SR has an advantage over CG in terms of postoperative nutritional status. Therefore, SR could be an alternative elective treatment option for early RGC located around the anastomotic site.

Medial approach for subcarinal lymphadenectomy during thoracoscopic esophagectomy in the prone position.

PURPOSE: In esophageal squamous cell carcinoma (ESCC), lymph nodes (LNs) around the subcarina and main bronchi are thought to be highly involved. Therefore, complete dissection of these LNs with preservation of the pulmonary branches of the vagus nerves, which control important pulmonary functions, is recommended. The aim of this retrospective study was to investigate the feasibility of reliable method for lymphadenectomy around the subcarina and main bronchi, named the medial approach, during thoracoscopic esophagectomy in the prone position (TEP). METHODS: This was a case-matched control study of patients who underwent TEP for ESCC. The fundamental concept in this method is to first exfoliate the LNs around the subcarina and main bronchi from the pericardium. Developing the operative field contributes to visualizing and preserving the pulmonary branches of the right vagus nerve. Twenty-three patients who underwent the medial approach and 23 patients who underwent the conventional approach were selected by the use of propensity score matching to compare the operative outcomes. RESULTS: The medial approach significantly reduced operative time for procedure (16 ± 3 vs 30 ± 6 min, p < 0.0001) and operative blood loss (123 ± 108 vs 207 ± 162 ml, p = 0.046) comparing with conventional approach. The incidence of postoperative pneumonia was lower in the medial approach group (4%) than in the conventional approach group (15%) (p = 0.069). CONCLUSIONS: The medial approach for lymphadenectomy around the subcarina and both main bronchi during TEP is technically safe and feasible in shorting the operative time with possibility to reduce postoperative pneumonia.

The Depth from the Skin to the Celiac Artery Measured Using Computed Tomography is a Simple Predictive Index for Longer Operation Time During Laparoscopic Distal Gastrectomy.

BACKGROUND: Body mass index (BMI) is commonly used to classify obesity. However, BMI does not always reflect the degree of visceral fat. This study aimed to clarify the usefulness of measuring the depth from the skin to the celiac artery using computed tomography, as a simple predictive index for longer operation time during laparoscopic distal gastrectomy (LDG). METHODS: From September 2012 to March 2016, 66 patients who underwent LDG with D1+ lymph node dissection were included. The depth from the skin to the bifurcation of the celiac artery was defined as 'skin-to-celiac artery distance (SCD).' The patients were divided into two groups based on the median operation time. [Time scenarios from omentum incision to specimen extirpation and infrapyloric and suprapancreatic lymph node dissections (I-LND, S-LND) were assessed.] The factors eliciting a longer operation time than the median operation time were investigated. RESULTS: From omentum incision to specimen extirpation, BMI, thickness of subcutaneous fat (TSF), and SCD (P = 0.002, P = 0.039, P < 0.001) were the factors associated with longer operation time. Furthermore, BMI, TSF, and SCD in I-LND (P = 0.008, P = 0.022, P < 0.001) and BMI and SCD in S-LND (P < 0.001, P < 0.001) were associated with longer operation time. The multivariate analysis showed that a long SCD was the only significant independent factor to predict an operation time longer than the median operation time (P = 0.001). The best cutoff level of SCD calculated using the receiver operating characteristic curve was 88 mm. CONCLUSIONS: This study demonstrated that SCD is a simple predictive index for longer operation time during LDG.

Standardizing procedures improves and homogenizes short-term outcomes after minimally invasive esophagectomy.

PURPOSE: Esophageal cancer is one of the deadliest cancers worldwide. Esophagectomy with lymphadenectomy is regarded as the only curative option for resectable esophageal cancer, but it is associated with high morbidity and mortality. Multidisciplinary team (MDT) management was recently associated with improved outcomes after surgery for esophageal cancer. The aim of this study was to investigate the effect of standardizing procedures for minimally invasive esophagectomy (MIE) in the MDT setting. METHODS: This was a case-matched control study of 154 patients with esophageal cancer who underwent thoracoscopic esophagectomy in the prone position (TEP) between 2012 and 2016. Surgery was performed by two attending surgeons (surgeons A and B) who began working together in the same MDT in 2015. At that time, the following surgical procedures were standardized between surgeons A and B: mediastinal lymphadenectomy, abdominal procedures, and estimation of the blood supply of the gastric conduit. Short-term outcomes were compared between the following paired groups using propensity scores: surgeon A's pre- and post-standardization groups, surgeon B's pre- and post-standardization groups, and surgeon A's post-standardization group and surgeon B's post-standardization group. RESULTS: Concerning surgeon A, the estimated total blood loss in the post-standardization group (142 ± 87 mL) was significantly lower than that in the pre-standardization group (376 ± 215 mL, P = 0.006). The rate of left recurrent laryngeal nerve palsy in the post-standardization group (13%) was significantly lower than that in the pre-standardization group (47%, P = 0.046). Concerning surgeon B, the rate of anastomotic leakage in the post-standardization group (0%) was significantly lower than that in the pre-standardization group (11%, P = 0.039). Comparing the post-standardization groups of surgeons A and B, there were no significant differences in operative outcomes or morbidity. CONCLUSIONS: Standardizing procedures for MIE improved and homogenized surgical short-term outcomes.

Effect of acetamiprid on the immature murine testes.

Neonicotinoids, such as acetamiprid (ACE), a pesticide used worldwide, are believed to be safe for human use. These molecules are structurally similar to nicotine, act as nicotinic acetylcholine receptor (nAChR) agonists, and were shown to be associated with neuromuscular and reproductive disorders, but these experiments were primarily performed in mature animals. In this study, the effects of ACE on the testes of immature mice were examined. The exposure of 3-week-old mice to ACE-containing water for 180 days led to a decrease in body weight and mildly affected spermatogenesis. Additionally, the expression of testosterone-metabolism genes, nAChR subunit genes, and proliferation-associated genes decreased in the testes of ACE-treated mice. Our results show that immature rodents may be less sensitive to ACE than mature ones, that mice may be more likely to accumulate ACE than rats, and that the development of disorders may be affected by the accumulation of ACE in the testes.

Comparison of two- and three-dimensional display for performance of laparoscopic total gastrectomy for gastric cancer.

PURPOSE: Introduction of three-dimensional (3D) display might remove technical obstacles of laparoscopic surgery and improve laparoscopic skills. We analyzed the effect of 3D technology on operative performance during laparoscopic total gastrectomy (LTG) for gastric cancer and assessed its advantages over two-dimensional (2D) laparoscopy. METHODS: This study included 30 consecutive surgeries of LTG with esophagojejunostomy by the overlap method performed (3D group, n = 15, 2D group, n = 15). The surgical outcomes were compared between the 3D and 2D groups. Further, we compared the performance time, the frequency of bleeding requiring hemostasis, and the frequency of remaking the surgical view by the assistant's forceps in each laparoscopic scene between the 3D and 2D groups. RESULTS: All surgeries were completed without any complications. The total time of pure laparoscopic scenes was shorter in the 3D than 2D group (154.2 vs. 182.7 min, P = 0.026), and total blood loss was almost the same (10 vs. 20 g, P = 0.195). The operative time during lymphadenectomy in scenes 6 and 7 were significantly shorter in the 3D than the 2D group (scene 6, 13.5 vs. 17.5 min, P = 0.003, and scene 7, 12.4 vs. 18.4, P = 0.025) and esophagojejunostomy (30.3 vs. 39.4 min, P = 0.008). The frequency of tissue exposure by the assistant was significantly less in the 3D group than the 2D group in scenes 6 and 7 (scene 6, n = 3.0 vs. 4.0, P = 0.006, and scene 7, n = 3.0 vs. 4.0, P = 0.017). CONCLUSIONS: 3D display is useful due to improvement of surgical skill during difficult situations such as lymphadenectomy around the celiac artery, which requires handling in the tangential view, and reconstruction using the suturing technique in a narrow space.

Short-term outcomes and one surgeon's learning curve for thoracoscopic esophagectomy performed with the patient in the prone position.

PURPOSE: Thoracoscopic esophagectomy with the patient in the prone position (TEP) is now being performed as minimally invasive esophagectomy for esophageal cancer. This study examines the short-term outcomes and the learning curve associated with TEP. METHODS: One surgeon ("Surgeon A") performed TEP on 100 consecutive patients assigned to three periods based on treatment order. Each group consisted of 33 or 34 patients. The outcomes of the three groups were compared to define the influence of surgeon expertise. RESULTS: Outcomes improved as Surgeon A gained experience in performing this operation, as evidenced by reduced thoracic operative times between periods 1 and 2, and then between periods 2 and 3 (p = 0.0033 and p = 0.0326, respectively); an increased number of retrieved chest nodes between periods 1 and 2 (p = 0.0070); and a decline in recurrent laryngeal nerve (RLN) palsy between periods 2 and 3 (p = 0.0450). Period 2 was the pivotal period for each learning curve. CONCLUSIONS: An individual surgeon's learning curve over the course of 100 TEP procedures had three outcomes: a shortened operative time, a higher number of retrieved chest nodes, and a decreased rate of RLN palsy. Approximately 30-60 cases were needed to reach a plateau in the TEP procedure and a reduction in the morbidity rate.

Silica-Induced Protein (Sip) in Thermophilic Bacterium Thermus thermophilus Responds to Low Iron Availability.

UNLABELLED: Thermus thermophilus HB8 expresses silica-induced protein (Sip) when cultured in medium containing supersaturated silicic acids. Using genomic information, Sip was identified as a Fe(3+)-binding ABC transporter. Detection of a 1-kb hybridized band in Northern analysis revealed that sip transcription is monocistronic and that sip has its own terminator and promoter. The sequence of the sip promoter showed homology with that of the σ(A)-dependent promoter, which is known as a housekeeping promoter in HB8. Considering that sip is transcribed when supersaturated silicic acids are added, the existence of a repressor is presumed. DNA microarray analysis suggested that supersaturated silicic acids and iron deficiency affect Thermus cells similarly, and enhanced sip transcription was detected under both conditions. This suggested that sip transcription was initiated by iron deficiency and that the ferric uptake regulator (Fur) controlled the transcription. Three Fur gene homologues (TTHA0255, TTHA0344, and TTHA1292) have been annotated in the HB8 genome, and electrophoretic mobility shift assays revealed that the TTHA0344 product interacts with the sip promoter region. In medium containing supersaturated silicic acids, free Fe(3+) levels were decreased due to Fe(3+) immobilization on colloidal silica. This suggests that, because Fe(3+) ions are captured by colloidal silica in geothermal water, Thermus cells are continuously exposed to the risk of iron deficiency. Considering that Sip is involved in iron acquisition, Sip production may be a strategy to survive under conditions of low iron availability in geothermal water. IMPORTANCE: The thermophilic bacterium Thermus thermophilus HB8 produces silica-induced protein (Sip) in the presence of supersaturated silicic acids. Sip has homology with iron-binding ABC transporter; however, the mechanism by which Sip expression is induced by silicic acids remains unexplained. We demonstrate that Sip captures iron and its transcription is regulated by the repressor ferric uptake regulator (Fur). This implies that Sip is expressed with iron deficiency. In addition, it is suggested that negatively charged colloidal silica in supersaturated solution absorbs Fe(3+) ions and decreases iron availability. Considering that geothermal water contains ample silicic acids, it is suggested that thermophilic bacteria are always facing iron starvation. Sip production may be a strategy for surviving under conditions of low iron availability in geothermal water.

Trainee competence in thoracoscopic esophagectomy in the prone position: evaluation using cumulative sum techniques.

PURPOSE: Minimally invasive esophagectomy (MIE) has less morbidity than the open approach. In particular, thoracoscopic esophagectomy in the prone position (TEP) has been performed worldwide. Using the cumulative sum control chart (CUSUM) method, this study aimed to confirm whether a trainee surgeon who learned established standards would become skilled in TEP with a shorter learning curve than that of the mentoring surgeon. METHODS: Surgeon A performed TEP in 100 patients; the first 22 patients comprised period 1. His learning curve, defined based on the operation time (OT) of the thoracic procedure, was evaluated using the CUSUM method, and short-term outcomes were assessed. Another 22 patients underwent TEP performed by surgeon B, with outcomes compared to those of surgeon A's period 1. RESULTS: Using the CUSUM chart, the peak point of the thoracic procedure OT occurred at the 44th case in surgeon A's experience of 100 cases. With surgeon A's first 22 cases (period 1), the peak point of the thoracic procedure OT could not be confirmed and graph is expanding soaring at CUSUM chart. The CUSUM chart of surgeon B's experience of 22 cases clearly indicated that the peak point of the thoracic procedure OT occurred at the 17th case. The rate of recurrent laryngeal nerve palsy for surgeon B (9 %) was significantly lower than for surgeon A in period 1 (36 %) (p = 0.0266). CONCLUSIONS: There is some possibility for a trainee surgeon to attain the required basic skills to perform TEP in a relatively short period of time using a standardized procedure developed by a mentoring surgeon. The CUSUM method should be useful in evaluating trainee competence during an initial series of procedures, by assessing the learning curve defined by OT.

A tightly regulated expression system for E. coli using supersaturated silicic acid.

OBJECTIVE: To develop a new expression system regulated by a ferric uptake regulator in which silicic acid is used as an inducer. RESULTS: Fur box (binding site for Fur) was substituted for the lac operator to regulate the expression of GFP with the lac promoter. Since the addition of supersaturated silicic acid invokes iron deficiency, supersaturated silicic acids were used as an inducer. GFP expression was dependent on silica concentration, and the expression level without silica was negligible. Basal expression level of this lac-Fur system was extremely low and, hence, lytic enzyme gene E from bacteriophage ϕX174 could be retained in this system. Furthermore, the expression of genes of interest was spontaneously initiated as the cell density increased and the costs of the inducer are considerably less than IPTG. CONCLUSION: The combination of lac promoter and Ferric uptake repressor allowed the protein expression by supersaturated silicic acid as an inducer in an easy and cost-effective way.

Can the intraoperative leak test prevent postoperative leakage of esophagojejunal anastomosis after total gastrectomy?

PURPOSE: Anastomotic failures that cannot be detected during surgery often lead to postoperative leakage. There have been no detailed reports on the intraoperative leak test for esophagojejunal anastomosis. Our purpose was to investigate the utility of routine intraoperative leak testing to prevent postoperative anastomotic leakage after performing esophagojejunostomy. METHODS: We prospectively performed routine air leak tests and reviewed the records of 185 consecutive patients with gastric cancer who underwent open total gastrectomy followed by esophagojejunostomy. RESULTS: A positive leak test was found for six patients (3.2 %). These patients with positive leak tests were subsequently treated with additional suturing, and they developed no postoperative anastomotic leakage. However, anastomotic leakage occurred in nine patients (4.9 %) with negative leak tests. A multivariate analysis demonstrated that a patient age >75 years and the surgeon's experience <30 cases were risk factors for anastomotic leakage. CONCLUSION: Intraoperative leak testing can detect some physical dehiscence, and additional suturing may prevent anastomotic leakage. However, it cannot prevent all anastomotic leakage caused by other factors, such as the surgeons' experience and patients' age.

PURE ribosome display and its application in antibody technology.

Ribosome display utilizes formation of the mRNA-ribosome-polypeptide ternary complex in a cell-free protein synthesis system to link genotype (mRNA) to phenotype (polypeptide). However, the presence of intrinsic components, such as nucleases in the cell-extract-based cell-free protein synthesis system, reduces the stability of the ternary complex, which would prevent attainment of reliable results. We have developed an efficient and highly controllable ribosome display system using the PURE (Protein synthesis Using Recombinant Elements) system. The mRNA-ribosome-polypeptide ternary complex is highly stable in the PURE system, and the selected mRNA can be easily recovered because activities of nucleases and other inhibitory factors are very low in the PURE system. We have applied the PURE ribosome display to antibody engineering approaches, such as epitope mapping and affinity maturation of antibodies, and obtained results showing that the PURE ribosome display is more efficient than the conventional method. We believe that the PURE ribosome display can contribute to the development of useful antibodies. This article is part of a Special Issue entitled: Recent advances in molecular engineering of antibody.