Stereotactic Ablative Radiotherapy for the Treatment of Glandular Metastases from Renal Cell Carcinoma

PURPOSE/OBJECTIVE(S)

Glandular metastases including pancreatic and adrenal sites of disease are associated with renal cell carcinoma (RCC) of indolent biology. Adrenal and pancreatic metastases may develop in isolation or involve other organs and are associated with prolonged survival. Glandular metastases can be treated with systemic therapy, stereotactic ablative radiotherapy (SAbR) or surgical resection and the optimal management of these patients is unknown. There is paucity of data on SAbR for RCC glandular metastases. We hypothesize that ablative doses of radiation therapy utilizing SAbR are associated with high rates of local control greater than 90%, with minimal or no acute grade 3 toxicities or higher with this approach. Here, we report local control (LC), progression-free survival (PFS), overall survival (OS) rates as well as toxicities related to SAbR for RCC metastases to the pancreatic and adrenal glands.

MATERIALS/METHODS

This IRB-approved, single-institution, retrospective study included patients with RCC metastases to the adrenal glands and pancreas treated with SAbR. Data on patient demographics, functional status, tumor characteristics, International Metastatic RCC Database Consortium (IMDC) risk category, local and systemic treatments, toxicities, and outcomes were collected and analyzed. RECIST 1.1 principals were utilized to determine LC rates and PFS. PFS was determined from the initiation of SAbR to progression (at SAbR-treated or other sites), or death. OS was defined from the start of SAbR to death. Two independent reviewers assessed these measures and analyzed patient electronic health records for toxicities using CTCAE v5 and relatedness scores.

RESULTS

A total of 50 RCC patients were included in this study with 36 adrenal and 20 pancreatic metastases treated with SAbR. Median dose fractionation used was 40 Gray delivered in 5 fractions. Sixteen patients (32%) were treatment naïve with oligometastatic disease, and thirty-four (68%) were oligo-progressive on systemic therapy with 1-3 prior lines of systemic therapy. For treated adrenal metastatic lesions at 1 year, patients demonstrated a 75.3% OS, 46.7% PFS, and LC of 93.3%. For treated pancreatic metastatic lesions at 1 year, patients demonstrated a 100% OS, 48.6% PFS, and LC of 100%. At 1 year, there was an OS of 82.2%, PFS of 48.2%, and LC of 95.9 % in the combined cohort. The percentage of patients experiencing an acute grade 2 or 3 toxicity attributed to adrenal or pancreatic gland SAbR was 7.4%. There were no acute grade >3 toxicities. The percentage of patients experiencing a late grade 2 or 3 toxicity was 9.3%. Median time to late adverse events was 37.4 months.

CONCLUSION

SAbR of RCC metastases to the pancreas and adrenal glands is feasible, safe and appears to be effective. Median PFS and OS in this cohort compared favorably to those reported in historical cohorts and is consistent with indolent disease.

The Number of Positive Lymph Nodes as Prognostic Factor in ypN1 Breast Cancer with Neoadjuvant Chemotherapy

PURPOSE/OBJECTIVE(S)

This study aimed to assess the ability of the number of positive lymph nodes (LNP) after neoadjuvant chemotherapy (NAC) to stratify prognosis even within the same ypN stage in breast cancer patients.

MATERIALS/METHODS

A 6,443 non-metastatic breast cancer patients with ypN1 disease after NAC following primary surgery were identified using the stage, stage evaluation field, treatment fields from Surveillance Epidemiology and End Results (SEER) database. Survival analysis was performed for overall survival (OS) using Kaplan-Meier plot and Cox proportional hazard models.

RESULTS

Of patients, 1,132(17.6%) had 3 positive lymph nodes (LNP3), 4,363 (67.7%) patients were T1/2 stage and 538 (8.35%) patients were downstage after treatment. LNP3 group had a significantly worse OS than LNP1/2 group (5yr OS, 74.2% vs. 80.9%, p <0.001). Similar results were observed in cause specific survival analysis (5yr OS, 79.8% vs. 85.2%, p <0.001). In subgroup analysis, there was a significant difference in OS between LNP1/2 and LNP3 group for HER2 or triple negative subtype, (p <0.001), T1/2 stage (p <0.001) and stable/downstage of N stage (p <0.001 and 0.019, respectively), but not for luminal A/B subtype and T3/4 (p = 0.126, 0.629 and 0.154, respectively). Regarding the number of examined lymph node (LNE), OS was significantly decreased in patients with LNE ≤5 in LNP3 group (p <0.001) but not in LNP1/2 group. In multivariable analysis, the prognostic significance of LNP3 remained (p <0.001) and the following factors were significantly related to the prolonged OS; Luminal A/B (p<0.001 and 0.001, respectively), T1/2 stage (p <0.001), N1 stage (p <0.001), LNE (≤5 vs. >5, p = 0.001) and receipt of radiotherapy (p = 0.012). Even when PS matching was performed, the OS of LNP was worse than that of LNP1/2.

CONCLUSION

LNP could more stratify the patients with ypN1 breast cancer after NAC. LNP3 is significantly associated with OS even after adjusting for other prognosticators. In particular, since there is a potential difference in the magnitude of the impact of LNP3 according to LNE, it is necessary to consider both of them together for decision-making.

CRITICAL CURRENT DENSITIES AND N-VALUES OF MGB2 CONDUCTORS FOR SMES, MRI, AND LOW AC LOSS APPLICATIONS

Multifilamentary MgB 2 strands (filament numbers 36 to 114) prepared by the in-situ power-in-tube (PIT) route with carbon doping contents of 0, 2, and 3.2% were wound on barrels for transport J c and n -value measurement at 4.2 K in fields of up to 12 T. The strand and gauge lengths were 1 m and 0.5 m. Heat treatments at 675 °C and 650 °C centered around the melting point of Mg (650 °C) and both utilized the liquid-solid reaction. A pair of strands, with and without 2% C doping exhibited the J c (B) crossover effect. Studied were the dependencies of J c on field strength, dopant concentration, and cabling and the dependence of n -value on field strength.

Prediction of atrial fibrillation in patients with embolic stroke with undetermined source using electrocardiogram deep learning algorithm and clinical risk factors

Background

Combining the artificial intelligence algorithm with the known clinical risk factors may provide enhanced accuracy for prediction of the hidden atrial fibrillation (AF) in patients with embolic stroke with undetermined source (ESUS).

Purpose

We aimed to develop enhanced prediction models for AF with deep learning algorithm (DLA) and clinical predictors in patients with ESUS. The DLA was created to identify the patients with paroxysmal AF based on their electrocardiograms (ECG) during sinus rhythm.

Methods

We analyzed the 221 patients who underwent insertable cardiac monitor (ICM) for AF detection following ESUS. The DLA was previously developed with sinus rhythm ECGs of 10,605 paroxysmal AF patients and 50,522 non-AF patients. The convolutional neural network was used for the DLA. The primary endpoint was defined as any AF episode lasting over 5 min by ICM. The atrial ectopic burden (AEB) was calculated as the percentage of the number of conducted QRS by atrial ectopy on Holter monitoring.

Results

AF (≥5 min) was detected by ICM in 32 patients (14.5%) during follow-up period of 15.1±8.6 months. AF patients had higher AEB (0.199% vs 0.023%, p&lt;0.001), larger left atrial diameters (LAD, 41.2 mm vs 35.7 mm, p&lt;0.001), and larger left atrial volume index (LAVI, 46.4 ml/m2 vs 32.3 ml/m2, p&lt;0.001) than those without AF. The means of calculated probabilities of AF by DLA were higher in patients with AF than those without AF (63.8% vs 40.2%, p&lt;0.001). In the receiver operating characteristic curve analysis, the areas under the curve (AUC) were the highest in DLA (0.824) followed by AEB (0.784), LAVI (0.780), and LAD (0.768). The multivariable model with AEB, LAVI, and DLA demonstrated excellent prediction accuracy for paroxysmal AF (AUC: 0.902, Figure 1)

Conclusions

In patients with ESUS, the DLA outperformed other clinical risk factors for prediction of AF. Combining DLA with AEB, LAD and LAVI could is a potential useful tool to predict AF in ESUS patients.

Funding Acknowledgement

Type of funding sources: None.

Decreased fasting serum glucogenic amino acids with a higher compared to normal protein diet during energy restriction in women: a randomized controlled trial

Dietary protein alters circulating amino acid (AAs) levels and higher protein intake (HP) is one means of losing weight. We examined 34 overweight and obese women (57 ± 4 years) during 6 months of energy restriction (7.3 ± 3.8% weight loss) divided into groups consuming either normal protein (NP; 18.6 energy% protein) or HP (24.3 energy% protein). There was a reduction in fasting serum glucogenic AAs (p = 0.015) that also associated with greater weight loss (p < 0.05) in the HP group, but not in the NP group. These findings have implications for nutrient prioritization during energy restriction.

Thermal neutron transmutation doping of GaN semiconductors

High quality Ge doping of GaN is demonstrated using primarily thermal neutrons for the first time. In this study, GaN was doped with Ge to concentrations from 10¹⁶ Ge atoms/cm³ to 10¹⁸ Ge atoms/cm³. The doping concentrations were measured using gamma-ray spectroscopy and confirmed using SIMS analysis. The data from SIMS analysis also show consistent Ge doping concentration throughout the depth of the GaN wafers. After irradiation, the GaN was annealed in a nitrogen environment at 950 °C for 30 min. The neutron doping process turns out to produce spatially uniform doping throughout the whole volume of the GaN substrate.

Laparoscopic treatment of gastrointestinal stromal tumors located at the duodenojejunal junction

Gastrointestinal stromal tumors are the most common subepithelial tumors of the gastrointestinal tract. Gastrointestinal stromal tumors are commonly detected in the stomach followed by the small intestine. Surgery for gastrointestinal stromal tumors affecting the duodenojejunal junction is technically challenging because of the anatomical complexity of this area. A 56-year-old woman visited the outpatient clinic with the chief complaint of melena associated with dizziness from 5 days ago. Abdominal computed tomography revealed an enhancing small bowel mass measuring 4 cm × 5 cm in the left upper abdomen abutting the duodenojejunal junction. She underwent successful laparoscopic small bowel segmental resection of the duodenojejunal junction area. Laparoscopic segmental resection with side-to-side duodenojejunostomy for a gastrointestinal stromal tumor at the duodenojejunal junction is an advanced and challenging procedure requiring experience and a good surgical technique.

Rectal perforations caused by cleansing enemas in chronically constipated patients: Two case reports

Constipation is a common disease that is frequently treated with cleansing enemas. Enemas are considered as effective and in some cases may cause serious adverse events. Iatrogenic perforations due to enemas lead to adverse outcomes in elderly patients with a poor general condition. Perforation remains an infrequent and rarely reported complication. In this work, we describe the cases of two patients with rectal perforation caused by a cleansing enema. The first patient had rectal perforation that led to a para-rectal abscess and the second patient had generalized peritonitis caused by rectal perforation.

Vessel-specific coronary perfusion territories using a CT angiogram with a minimum cost path technique and its direct comparison to the American Heart Association 17-segment model

OBJECTIVES

This study compared the accuracy of an automated, vessel-specific minimum cost path (MCP) myocardial perfusion territory assignment technique as compared with the standard American Heart Association 17-segment (AHA) model.

METHODS

Six swine (42 ± 9 kg) were used to evaluate the accuracy of the MCP technique and the AHA method. In each swine, a dynamic acquisition, comprised of twenty consecutive whole heart volume scans, was acquired with a computed tomography scanner, following peripheral injection of contrast material. From this acquisition, MCP and AHA perfusion territories were determined, for the left (LCA) and right (RCA) coronary arteries. Each animal underwent additional dynamic acquisitions, consisting of twenty consecutive volume scans, following direct intracoronary contrast injection into the LCA or RCA. These images were used as the reference standard (REF) LCA and RCA perfusion territories. The MCP and AHA techniques' perfusion territories were then quantitatively compared with the REF perfusion territories.

RESULTS

The myocardial mass of MCP perfusion territories (M_MCP) was related to the mass of reference standard perfusion territories (M_REF) by M_MCP = 0.99M_REF + 0.39 g (r = 1.00; R² = 1.00). The mass of AHA perfusion territories (M_AHA) was related to M_REF by M_AHA = 0.81M_REF + 5.03 g (r = 0.99; R² = 0.98).

CONCLUSION

The vessel-specific MCP myocardial perfusion territory assignment technique more accurately quantifies LCA and RCA perfusion territories as compared with the current standard AHA 17-segment model. Therefore, it can potentially provide a more comprehensive and patient-specific evaluation of coronary artery disease.

KEY POINTS

• The minimum cost path (MCP) technique accurately determines left and right coronary artery perfusion territories, as compared with the American Heart Association 17-segment (AHA) model. • The minimum cost path (MCP) technique could be applied to cardiac computed-tomography angiography images to accurately determine patient-specific left and right coronary artery perfusion territories. • The American Heart Association 17-segment (AHA) model often fails to accurately determine left and right coronary artery perfusion territories, especially in the inferior and inferoseptal walls of the left ventricular myocardium.

Humeral shaft fracture and radial nerve palsy in Korean soldiers: focus on arm wrestling related injury

INTRODUCTION

Humeral shaft fractures can lead to radial nerve injury and may require surgery and rehabilitation. We determined the causative events of humeral fracture, including arm wrestling, in young Korean soldiers and examined whether humeral fracture is related to demographic characteristics and the presence of radial nerve palsy.

METHODS

We reviewed 7.5 years (July 2012 to June 2019) of medical records covering patients who had experienced a humeral shaft fracture after entering military service and had received surgery for open reduction and internal fixation. Data were obtained on basic demographics, initial event provoking the fracture, presence of radial nerve palsy, initial and follow-up severity of the weakness, and any discharge from military service because of prolonged radial nerve palsy.

RESULTS

Of 123 cases, arm wrestling was the leading cause (52.8%). A high energy injury, such as falling from a height (11.4%), and sports related slips (10.6%) were other causes. All humeral shaft fractures caused by forceful contraction were spiral, while 40% of the fractures caused by external force related events were of a transverse type. The percentage of left-sided fractures was significantly higher for fractures arising from an external force than in those caused by forceful contraction related events. Radial nerve palsy was found in 34 patients (27.6%), and 16 were discharged from the military because of prolonged radial nerve palsy 6 months after the fracture. The causative events and other factors did not affect the presence of radial nerve palsy.

CONCLUSION

Arm wrestling was the leading cause of humeral fracture in young Korean soldiers but the chance of developing comorbid radial nerve palsy did not differ from that of other causes. These epidemiologic findings in this young active group may help in understanding the causes of humeral shaft fracture in soldiers and in the wider young population.

FeSe quantum dots for in vivo multiphoton biomedical imaging

An immense demand in biomedical imaging is to develop efficient photoluminescent probes with high biocompatibility and quantum yield, as well as multiphoton absorption performance to improve penetration depth and spatial resolution. Here, iron selenide (FeSe) quantum dots (QDs) are reported to meet these criteria. The synthesized QDs exhibit two- and three-photon excitation property at 800- and 1080-nm wavelengths and high quantum yield (ca. 40%), which are suitable for second-window imaging. To verify their biosuitability, poly(ethylene glycol)-conjugated QDs were linked with human epidermal growth factor receptor 2 (HER2) antibodies for in vitro/in vivo two-photon imaging in HER2-overexpressed MCF7 cells and a xenograft breast tumor model in mice. Imaging was successfully carried out at a depth of up to 500 μm from the skin using a nonlinear femtosecond laser at an excitation wavelength of 800 nm. These findings may open up a way to apply biocompatible FeSe QDs to multiphoton cancer imaging.

P4580The effect of anesthetic techniques on cardiac troponin-T after non-cardiac surgery

Background

The effects of anesthetics on cardiac protection and clinical outcomes have shown conflicting results in patients undergoing non-cardiac surgery. Unlike cardiac surgeries in which cardio-protective effects of anesthetic techniques have been reported, it lacks evidence and reproducibility in non-cardiac surgery. A current generation high-sensitivity cardiac troponin (hs-cTnI) is known to detect perioperative myocardial injury in non-cardiac surgery which is closely related to clinical outcomes. In this study, we hypothesized that balanced anesthesia using both remifentanil and volatile agents is the most effective in reducing postoperative myocardial injury, and compared the incidence of postoperative myocardial injury among different types of general anesthesia.

Methods

We analyzed the data of 3555 patients who underwent general anesthesia for non-cardiac surgery in our hospital between February 2010 and December 2016. In all patients, hs-cTnI was detected in preoperative period and postoperative period within 48 hours. Major exclusion criteria was troponin elevation before surgery. Patients were stratified into three groups; 661 patients who were received propofol-remifentanil total intravenous anesthesia (TIVA group), 1279 patients who were received volatile anesthesia without remifentanil (Volatile group) and 1622 patients who were received volatile anesthesia with remifentanil (Balanced group). The Primary outcome was troponin elevation [hs-cTnI≥0.04 ng/mL] within post-operative within 48 hours, and the incidence of postoperative complications such as postoperative acute kidney injury, new-onset atrial fibrillation and in-hospital mortality were also compared.

Results

The occurrence of myocaridial injury were significant difference between three groups. The occurrence of myocardial injury was significantly lower in the Balanced group than in Volatile group after adjustment (Odds ratio (OR) = 0.727; 95% confidence interval (CI) = 0.59–0.89; P-value = 0.002). Balanced group and TIVA group showed comparable results in risk of postoperative troponin elevation after adjustment (OR 1.131; 95% CI 0.96–1.33; P-value = 0.133). The incidence of troponin elevation was significantly higher in Volatile group than TIVA group after adjustment (OR 1.6; 95% CI 0.52–0.96; P-value = 0.005). The incidence of AKI was significantly lower in Balanced group than Volatile group after adjustment (OR 0.637; 95% CI 0.49–0.81; P-value <0.001).

Conclusion

The remifentanil combination during general anesthesia may be associated with myocardial protection effect in patients undergoing non-cardiac surgery. Whether this impact leads to adverse long-term outcome remains unclear, and requires further investigation.

Abstract OT2-04-02: A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress

Background

In patients with early stage breast cancer, regional nodal irradiation (RNI) is added to whole breast irradiation (WBI) in order to control microscopic regional disease and to prevent systemic spread of cancer. According to recent randomized trials (MA.20 and EORTC 22922-10925), prophylactic RNI was associated with improvement in disease-free survival (DFS) in the patients with high-risk node negative or pN1 breast cancer. However, systemic agents now known to improve loco-regional control, such as taxane or endocrine therapy, were prescribed to a small percentage of patients in the studies. The benefit of RNI found in the previous studies might be attributed to incorporation of less effective systemic treatments. The impact of prophylactic RNI in pN1 breast cancer should be evaluated in the patients receiving modern systemic treatment. The current study was conducted to compare the effect of post-lumpectomy WBI vs WBI plus RNI on DFS in pN1 breast cancer patients who received adjuvant taxane-based chemotherapy.

Methods

This study is a multicenter, phase 3, randomized controlled non-inferiority trial (NCT03269981). Eligibility criteria are ≥ 20 years female; pathologically proven invasive carcinoma of the breast; one to three positive axillary lymph nodes (pN1) in pathologic specimen; receiving breast-conserving surgery followed by taxane-based chemotherapy; having adjuvant endocrine therapy or anti-HER2 treatment according to molecular subtype of tumor. Patients are randomly assigned in a 1:1 ratio to receive WBI or WBI plus RNI. Patient randomization was stratified by molecular subtype of tumor (i.e. luminal A/luminal B/luminal HER2/HER2-enriched/triple-negative) and methods of axillary management (i.e. sentinel lymph node biopsy/axillary lymph node dissection). The primary outcome is DFS. The secondary outcomes include DFS according to molecular subtype, treatment-related toxicity, and patient's quality of life per EORTC QLQ-C30 and QLQ-BR23. Patients will be followed for survival and disease recurrence for seven years. A total of 1,926 patients are planned to be enrolled, with recruitment initiated in April 2017. As of June 2018, a total of 236 patients were enrolled.

Acknowledgement

This study was supported by a grant from the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (grant number: HA17C0043010018).

Citation Format: Kim H, Park W, Choi DH, Ahn SJ, Kim SS, Kim ES, Lee JH, Lee KC, Kim JH, Lee H-S, Kim JH, Kim MY, Park HJ, Kim K, Song SH, Kwon J, Lee IJ, Kim TH, Kim TG, Chang AR, Cho O, Jeong BK, Ha B, Lee J, Ki Y. A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-04-02.

Quantification of vessel-specific coronary perfusion territories using minimum-cost path assignment and computed tomography angiography: Validation in a swine model

BACKGROUND

As combined morphological and physiological assessment of coronary artery disease (CAD) is necessary to reliably resolve CAD severity, the objective of this study was to validate an automated minimum-cost path assignment (MCP) technique which enables accurate, vessel-specific assignment of the left (LCA) and right (RCA) coronary perfusion territories using computed tomography (CT) angiography data for both left and right ventricles.

METHODS

Six swine were used to validate the MCP technique. In each swine, a dynamic acquisition comprised of twenty consecutive volume scans was acquired with a 320-slice CT scanner following peripheral injection of contrast material. From this acquisition the MCP technique was used to automatically assign LCA and RCA perfusion territories for the left and right ventricles, independently. Each animal underwent another dynamic CT acquisition following direct injection of contrast material into the LCA or RCA. Using this acquisition, reference standard LCA and RCA perfusion territories were isolated from the myocardial blush. The accuracy of the MCP technique was evaluated by quantitatively comparing the MCP-derived LCA and RCA perfusion territories to these reference standard territories.

RESULTS

All MCP perfusion territory masses (Mass_MCP) and all reference standard perfusion territory masses (Mass_RS) in the left ventricle were related by Mass_MCP = 0.99Mass_RS+0.35 g (r = 1.00). Mass_MCP and Mass_RS in the right ventricle were related by Mass_MCP = 0.94Mass_RS+0.39 g (r = 0.96).

CONCLUSION

The MCP technique was validated in a swine animal model and has the potential to be used for accurate, vessel-specific assignment of LCA and RCA perfusion territories in both the left and right ventricular myocardium using CT angiography data.

Would intravitreal bevacizumab injection increase risk of cerebral infarction?

BACKGROUND AND PURPOSE

Although studies have evaluated the relationship between intravitreal bevacizumab (IVB) injection and cerebral infarction (CI), the effects of IVB on CI are still not clear. The aim of this study was to investigate the effects of IVB injection on patients with CI with age-related macular degeneration (AMD).

METHODS

We retrospectively reviewed patients with AMD who received IVB injections for 1 year and determined the incidence of CI within 60 days after IVB injection to analyze the possible association between IVB and CI.

RESULTS

A total of 263 patients were enrolled over a 12-month period. Six patients (2.28%) were diagnosed with CI within 2 months after receiving an IVB injection. The incidence of CI in patients of 75-84 years of age was 6.38%. These results showed a higher incidence for patients with IVB injections than the results of previous epidemiological studies (0.13% for all age groups, 1.68% for patients of 75-84 years of age). All CIs occurred 21-53 days after the IVB injection (mean: 39.33 ± 14.65 days). Logistic regression analyses showed that age and CI history were factors associated with CI.

CONCLUSIONS

Treatment with IVB might be an independent risk factor for CI. These results are useful for planning treatment strategies for patients with AMD and for prevention of CI.

Laparoscopic management of massive intraperitoneal haemorrhage caused by an acute gallbladder perforation

Laparoscopic cholecystectomy is the gold standard for managing the treatment of patients with symptomatic gallstone disease. Certain patients with acute cholecystitis will develop gallbladder perforation (GP). Furthermore, massive intraperitoneal haemorrhage following perforation is a rare complication. The high morbidity and mortality rates associated with this condition are due to delays in the diagnosis and treatment since signs and symptoms of perforation do not differ significantly from those of uncomplicated cholecystitis. Severe inflammation and haemodynamic instability necessitate exploratory laparotomy in many patients. To the best of our knowledge, no study had described laparoscopic completion cholecystectomy for massive intraperitoneal haemorrhage caused by an acute GP. Laparoscopy can be an option for the management of these patients, in selected cases and with available expertise.

Spin-Orbit Coupling and Interband Transitions in the Optical Conductivity of Sr_{2}RhO_{4}

The prototypical correlated metal Sr_{2}RhO_{4} was studied using optical and photoemission spectroscopy. At low energies and temperatures, the optical data reveal a complex, multicomponent response that on the surface points to an unconventional metallic state in this material. Via a comparison with photoemission, the anomalous optical response may be attributed to an unexpectedly strong interband transition near 180 meV between spin-orbit coupled bands that are nearly parallel along ΓX. This spin-orbit coupling effect is shown to occur in a number of related metallic ruthenates and explains the previously puzzling optical properties reported for these materials.

Peritoneal Simple Mesothelial Cyst Misdiagnosed as a Gastric Subepithelial Tumor

Peritoneal simple mesothelial cysts are very rare mesenteric cysts of mesothelial origin. A peritoneal simple mesothelial cyst may be misdiagnosed, even by advanced diagnostic tools, as a gastric subepithelial tumor. A few cases that were misdiagnosed as a regarding peritoneal simple mesothelial cysts. To the best of our knowledge, there are no reports regarding peritoneal simple mesothelial cysts.

Prognostic relevance of lymph node status for patients with ampullary adenocarcinoma after radical resection followed by adjuvant treatment

PURPOSE

Attempts have been made to revise the nodal stage due to simplicity of current N staging system in ampullary adenocarcinoma. However, because of the disease rarity, there have only been a few studies assessing the prognostic impact of lymph node (LN) parameters.

METHODS

We retrospectively analyzed 120 patients who underwent radical resection followed by adjuvant chemoradiotherapy for ampullary adenocarcinoma. The effect of LN parameters (number of total harvest LNs, number of metastatic LN (MLN), lymph node ratio (LNR), and log odds of positive LNs (LODDS)) on overall survival (OS), locoregional relapse-free survival (LRFS) and distant metastasis-free survival were evaluated. Cutoff points of MLN, LNR and LODDs were determined using maximal χ² method.

RESULTS

Fifty-seven patients (48%) were staged as pN1 and their survival was not significantly decreased compared with pN0 patients. There was also no significant difference between patients with MLN 0 vs. 1. In univariate analyses, MLN (0-1 vs. ≥2), LNR (≤17% vs. >17%) and perineural invasion were common prognosticators for OS and LRFS. Distant metastasis-free survival was not influenced by LN status. In addition, multivariate analysis revealed that among the LN parameters, LNR was able to independently predict both OS and LRFS.

CONCLUSIONS

LNR performs better than other LN related parameters for predicting survival. After radical resection followed by adjuvant treatment, survival of patients with one positive LN does not seem to differ from patients without LN metastasis.

Overexpression of HSP47 in esophageal squamous cell carcinoma: clinical implications and functional analysis

Several biomarkers of esophageal squamous cell carcinoma (ESCC) have been explored to improve the prognosis of this disease. One of these, the 47-kDa heat shock protein (HSP47), has been screened as a potential biomarker by genomic profiling and is known to be overexpressed in some malignant diseases. In this study, we explored the role and evaluated the prognostic value of HSP47 expression in ESCC. The function of this protein was analyzed by assaying proliferation, wound healing, and colony formation in an HSP47-knockdown ESCC line. The prognostic implication of HSP47 expression was analyzed by immunohistochemical staining in 157 surgical specimens. HSP47 expression level and other clinical variables were analyzed using multivariate Cox proportional hazards models. Silencing of the HSP47 gene in the ESCC cell line inhibited cell proliferation and colony formation. HSP47 was highly expressed in ESCC tissue samples, compared with normal esophageal tissues. The level of immunohistochemical staining of HSP47 and pathologic stage were significantly correlated with overall and recurrence-free survival, as shown by multivariate analysis (P = 0.014 and 0.044, respectively). We found that overexpression of HSP47 is associated with poor prognosis in patients with ESCC and that this is consistent with the function of HSP47 in terms of increased cell proliferation and colony formation. These results suggest that HSP47 is a potential prognostic biomarker for ESCC and merits further research for novel diagnostic and therapeutic applications.

Terahertz Dynamics of a Topologically Protected State: Quantum Hall Effect Plateaus near the Cyclotron Resonance of a Two-Dimensional Electron Gas

We measure the Hall conductivity of a two-dimensional electron gas formed at a GaAs/AlGaAs heterojunction in the terahertz regime close to the cyclotron resonance frequency using highly sensitive Faraday rotation measurements. The sample is electrically gated, allowing the electron density to be changed continuously by more than a factor of 3. We observe clear plateaulike and steplike features in the Faraday rotation angle vs electron density and magnetic field (Landau-level filling factor) even at fields or frequencies very close to cyclotron resonance absorption. These features are the high frequency manifestation of quantum Hall plateaus-a signature of topologically protected edge states. We observe both odd and even filling factor plateaus and explore the temperature dependence of these plateaus. Although dynamical scaling theory begins to break down in the frequency region of our measurements, we find good agreement with theory.