Sirt6-Mediated Cell Death Associated with Sirt1 Suppression in Gastric Cancer.

BACKGROUND: Gastric cancer, one of the leading causes of cancer-related death, is strongly associated with H. pylori infection, although other risk factors have been identified. The sirtuin (Sirt) family is involved in the tumorigenesis of gastric cancer, and sirtuins can have pro- or anti-tumorigenic effects. METHODS: After determining the overall survival rate of gastric cancer patients with or without Sirt6 expression, the effect of Sirt6 upregulation was also tested using a xenograft mouse model. The regulation of Sirt6 and Sirt1, leading to the induction of mouse double minute 2 homolog (MDM2) and reactive oxygen species (ROS), was mainly analyzed using Western blotting and immunofluorescence staining, and gastric cancer cell (SNU-638) death associated with these proteins was measured using flow cytometric analysis. RESULTS: Sirt6 overexpression led to Sirt1 suppression in gastric cancer cells, resulting in a higher level of gastric cancer cell death in vitro and a reduced tumor volume. ROS and MDM2 expression levels were upregulated by Sirt6 overexpression and/or Sirt1 suppression according to Western blot analysis. The upregulated ROS ultimately led to gastric cancer cell death as determined via Western blot and flow cytometric analysis. CONCLUSION: We found that the upregulation of Sirt6 suppressed Sirt1, and Sirt6- and Sirt1-induced gastric cancer cell death was mediated by ROS production. These findings highlight the potential of Sirt6 and Sirt1 as therapeutic targets for treating gastric cancer.

Visual outcomes after three different surgical procedures for correction of refractive error in patients with thin corneas.

AIM: To investigate and compare the visual and refractive outcomes of small incision lenticule extraction (SMILE), laser assisted sub-epithelial keratomileusis (LASEK), and LASEK combined with corneal collagen cross-linking (LASEK-CXL) surgery in patients with less than 500 µm of central corneal thickness (CCT). METHODS: The retrospective medical records review was conducted on the patients with CCT less than 500 µm treated with SMILE, LASEK, and LASEK-CXL. There was a total of 172 eyes, 76 eyes were in the SMILE group, 53 eyes in the LASEK group, and 43 eyes in the LASEK-CXL group. Uncorrected distance visual acuity (UDVA), spherical equivalent refraction (SE), and corneal haze were followed up in the three groups for 12mo. RESULTS: At 12mo postoperatively, there were no statistically significant differences in UDVA and in the absolute value of SE between the three groups. The predictability within ±0.50 D in the SMILE group (85.5%) was significantly higher than in both the LASEK group (64.2%, P<0.01) and the LASEK-CXL group (69.8%, P=0.04). The efficacy index and safety index were not significantly different among the three groups. Corneal haze at 12mo postoperatively was higher in the LASEK-CXL group (27.9%) than in the SMILE group (2.6%, P<0.01) and in the LASEK group (7.5%, P<0.01). CONCLUSION: In patients with CCT less than 500 µm, SMILE, LASEK, and LASEK-CXL appear to be effective for myopic correction. Among them, SMILE surgery shows the highest predictability.

Resectability of Rectal Neuroendocrine Tumors Using Endoscopic Mucosal Resection with a Ligation Band Device and Endoscopic Submucosal Dissection.

BACKGROUND: Rectal neuroendocrine tumors (NETs) < 10 mm in diameter, limited to the submucosa without local or distant metastasis, can be treated endoscopically. Endoscopic mucosal resection with a ligation band device (EMR-L) and endoscopic submucosal dissection (ESD) have been employed to resect rectal NETs. We evaluated and compared the clinical outcomes of EMR-L and ESD for endoscopic resection of rectal NETs G1 < 10 mm in diameter. METHODS: We conducted a retrospective study of 82 rectal NETs in 82 patients who underwent either EMR-L or ESD. Therapeutic outcomes (en bloc resection and complete resection rates), procedure time, and procedure-related adverse events were evaluated. Additionally, we measured the distance of the lateral and vertical margins from the border of the tumor in pathologic specimens and compared the resectability between EMR-L and ESD. RESULTS: Sixty-six lesions were treated using EMR-L and 16 using ESD. En bloc resection was achieved in all patients. The complete resection rate with EMR-L was significantly higher than that with ESD (95.5% vs.75.0%, p = 0.025). The prevalence of vertical margin involvement was significantly higher in the ESD group than in the EMR-L group (12.5% vs. 0%, p = 0.036), and ESD was more time consuming than EMR-L (24.21 ± 12.18 vs. 7.05 ± 4.53 min, p < 0.001). The lateral and vertical margins were more distant in the EMR-L group than in the ESD group (lateral margin distance, 1661 ± 849 vs. 1514 ± 948 µm; vertical margin distance, 277 ± 308 vs. 202 ± 171 µm). CONCLUSIONS: EMR-L is more favorable for small rectal NETs with respect to therapeutic outcomes, procedure time, and technical difficulties. Additionally, EMR-L enables achievement of sufficient vertical margin distances.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: short- and long-term outcomes.

BACKGROUND AND AIMS: Application of endoscopic submucosal dissection (ESD) for undifferentiated-type early gastric cancers (EGCs) remains controversial owing to limited data regarding long-term outcomes. We aimed to evaluate the feasibility of ESD for undifferentiated-type EGCs that meet the expanded criteria (EC). METHODS: We performed a retrospective analysis of 66 patients who underwent ESD for undifferentiated-type EGC between January 2005 and December 2014. We evaluated the rates of en bloc, complete, and curative resections along with overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS). RESULTS: Of the 66 patients, the EC group included 38 patients and the beyond-EC group included 28 patients. The overall rates of en bloc, complete, and curative resection of the 66 lesions were 92.4% (61/66), 65.2% (43/66), and 48.5% (32/66), respectively. Of the 34 patients with non-curative resection, 18 underwent additional surgery. Local remnant cancer was detected in 1 patient (1/18, 5.6%), and none of the 18 patients had lymph node metastasis. On multivariate analysis, tumors > 2 cm [odd ratio (OR) 6.183, 95% confidence interval (CI) 1.279-29.880, p = 0.023) and submucosal invasion depth (OR 6.226, 95% CI 1.881-20.606, p = 0.003) were independent predictors of incomplete resection. All 26 patients with more than 1 year of follow-up after curative resection survived without any evidence of local or distant recurrences over a median follow-up period of 36 months. The OS, DSS, and RFS rates of patients with curative ESD were 93.8, 100, and 100%, respectively. CONCLUSIONS: ESD may have favorable long-term outcomes in patients with undifferentiated-type EGC after curative resection.

[A Case of Hemorrhage of an Esophageal Duplication Cyst Improved by Endoscopic Drainage].

Esophageal duplication cyst is a rare congenital gastrointestinal malformation. It is the second most common duplication cyst following small bowel duplication cyst in the gastrointestinal tract. Patients with an esophageal duplication cyst are generally asymptomatic; however, some patients may present the following symptoms: dysphagia, chest pain, stridor, unproductive cough, and epigastric discomfort by compression of the surrounding structures. Surgical removal is the treatment of choice in symptomatic cases and can be considered in asymptomatic cases if they are at risk for developing complications, such as ulceration or perforation. Herein, we report a case of hemorrhage of an esophageal duplication cyst, which was improved by endoscopic drainage.

Primary Follicular Lymphoma in the Rectum Incidentally Found on Screening Colonoscopy.

The gastrointestinal tract is the most common site of extra-nodal non-Hodgkin lymphoma. However, the incidence of primary rectal lymphoma is extremely rare. Among the primary gastrointestinal lymphomas, follicular lymphoma has been described as a rare disease. It is difficult to diagnose rectal lymphoma due to its variable growth patterns and inadequate biopsies. Majority of patients with rectal lymphoma have non-specific symptoms or negative biopsies, often delaying the diagnosis. Our patient is a 62-year-old female. Two sessile and smooth subepithelial lesions with a yellowish normal mucosa were found on a screening colonoscopy. The initial mucosal biopsy finding was chronic inflammation, but we were highly suspicion of malignancy; we performed an endoscopic mucosal resection. Herein, we present a rare case of rectal follicular lymphoma diagnosed by endoscopic mucosal resection with a literature review.

Positively-charged reduced graphene oxide as an adhesion promoter for preparing a highly-stable silver nanowire film.

An ultrathin conductive adhesion promoter using positively charged reduced graphene oxide (rGO-NH3(+)) has been demonstrated for preparing highly stable silver nanowire transparent conductive electrodes (AgNW TCEs). The adhesion promoter rGO-NH3(+), spray coated between the substrate and AgNWs, significantly enhances the chemical and mechanical stabilities of the AgNW TCEs. Besides, the ultrathin thickness of the rGO-NH3(+) ensures excellent optical transparency and mechanical flexibility for TCEs. The AgNW films prepared using the adhesion promoter are extremely stable under harsh conditions, including ultrasonication in a variety of solvents, 3M Scotch tape detachment test, mechanical bending up to 0.3% strain, or fatigue over 1000 cycles. The greatly enhanced adhesion force is attributed to the ionic interactions between the positively charged protonated amine groups in rGO-NH3(+) and the negatively charged hydroxo- and oxo-groups on the AgNWs. The positively charged GO-NH3(+) and commercial polycationic polymer (poly allylamine hydrochloride) are also prepared as adhesion promoters for comparison with rGO-NH3(+). Notably, the closely packed hexagonal atomic structure of rGO offers better barrier properties to water permeation and demonstrates promising utility in durable waterproof electronics. This work offers a simple method to prepare high-quality TCEs and is believed to have great potential application in flexible waterproof electronics.

Acute ectopic pancreatitis occurring after endoscopic biopsy in a gastric ectopic pancreas.

Ectopic pancreas is a congenital anomaly and the most common type of ectopic tissue in the gastrointestinal tract. Most patients with an ectopic pancreas are asymptomatic and rarely have complications. Ectopic pancreatitis after an endoscopic biopsy has not been reported. We report a patient who developed acute ectopic pancreatitis in the stomach after an endoscopic biopsy. A 71-year-old male patient presented with a subepithelial tumor (SET) in the stomach and had no symptoms. Endoscopic ultrasonography demonstrated a 30-mm hypoechoic mural mass, lobulated margins, and anechoic duct-like lesions. To obtain proper tissue specimen, endoscopic biopsy was performed through the opening on the surface of the mass. The pathologic results confirmed an ectopic pancreas. One day after the endoscopic biopsy, he developed persistent epigastric pain. His serum amylase and lipase elevated. Computed tomography of the abdomen showed swelling of the SET and diffuse edema of the gastric wall. His condition was diagnosed as acute ectopic pancreatitis occurring after endoscopic biopsy.

A roll-to-roll welding process for planarized silver nanowire electrodes.

We demonstrate continuous roll-to-roll production of highly conductive silver network films on a plastic substrate via mechanical and chemical welding processes. This process included three essential steps: (i) solvent spraying, (ii) roll compression, and (iii) salt treatment and washing. The sheet resistance of the resulting AgNW film was 5 Ω sq(-1) at 92% transmittance, which was the lowest sheet resistance and the highest transparency among the values reported previously for solution-processed AgNW electrodes. Moreover, the strong contacts among the AgNWs dramatically enhanced the mechanical stability of the network film. The resulting AgNW film was successfully applied to various organic electronic devices, such as organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs), and organic solar cells (OSCs).

Synthesis of diethylamino-curcumin mimics with substituted triazolyl groups and their sensitization effect of TRAIL against brain cancer cells.

A newly designed curcumin mimic library (11a-11k) with 2-ethylamino groups in a chalcone structure and variously substituted triazole groups as side chains was synthesized using the Huisgen 1,3-cycloaddition reaction between various alkynes (a-k) and an intermediate (10), with CuSO4 and sodium ascorbate in a solution mixture of chloroform, ethanol, and water (5:3:1) at room temperature for 5h. In the lactate dehydrogenase (LDH) release assay involving co-treatment with tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and/or synthetic curcumin derivatives using TRAIL-resistant human CRT-MG astroglioma cells, the novel curcumin mimic library was found to effectively stimulate the cytotoxicity of TRAIL, causing mild cytotoxicity when administered alone. In particular, 11a and 11j are promising candidates for TRAIL-sensitizers with potential use in combination chemotherapy for brain tumors.

Clinical characteristics, pathological distribution, and prognostic factors in non-Hodgkin lymphoma of Waldeyer's ring: nationwide Korean study.

BACKGROUND/AIMS: In Asia, the incidence of non-Hodgkin lymphoma (NHL) has increased in recent decades. Waldeyer's ring (WR) is the most common site of NHL involving the head and neck. In this study, the pathological distribution of WR-NHL and its clinical features were analyzed retrospectively. METHODS: From January 2000 through December 2010, we analyzed the medical records of 328 patients from nine Korean institutions who were diagnosed with WR-NHL. RESULTS: The study group comprised 197 male and 131 female patients with a median age of 58 years (range, 14 to 89). The rate of localized disease (stage I/II) was 64.9%, and that of low-risk disease (low/low-intermediate, as defined by the International Prognostic Index) was 76.8%. Diffuse large B-cell lymphoma (DLBCL; 240 patients, 73.2%) was the most common pathologic subtype, followed by peripheral T-cell lymphoma (14 patients, 4.3%) and nasal NK/T-cell lymphoma (14 patients, 4.3%). WR-NHL occurred most frequently in the tonsils (199 patients, 60.6%). Extranodal involvement was greater with the T-cell subtype (20 patients, 42.5%) compared with the B-cell subtype (69 patients, 24.5%). Multivariate analyses showed that age ≥ 62 years, T-cell subtype, and failure to achieve complete remission were significant risk factors for overall survival. CONCLUSIONS: DLBCL was found to have a higher incidence in Korea than those incidences reported by other WR-NHL studies. T-cell lymphoma occurred more frequently than did follicular lymphoma. T-cell subtype, age ≥ 62 years, and complete remission failure after first-line treatment were significant poor prognostic factors for overall survival according to the multivariate analysis.

Increased frequency of osteoporosis and BMD below the expected range for age among South Korean women with rheumatoid arthritis.

OBJECTIVE: To compare the frequency of osteoporosis and bone mineral density (BMD) below the expected range for age between female patients with rheumatoid arthritis (RA) and healthy subjects and to determine risk factors for bone loss in female patients with RA. METHOD: Two hundred and ninety-nine patients with RA and 246 age-matched healthy subjects were included in this study. BMD in the lumbar spine, femoral neck and total hip were measured with dual-energy X-ray absorptiometry. A T-score of -2.5 or lower in postmenopausal women was defined as osteoporosis, and a Z-score -2.0 or lower in females prior to menopause was defined as below the expected range for age. RESULT: The frequency of osteoporosis in the RA patients (22.1%) was significantly higher than in healthy subjects (11.4%) at either the spine or hip (P = 0.014). The occurrence of BMD below the expected range for age in RA patients (7.8%) was also significantly higher than in healthy subjects (1.0%, P = 0.015). In 299 female patients with RA, higher age, lower body mass index and postmenopausal status were significantly associated with the lumbar spine and hip BMD reduction. Of disease-related variables, glucocorticoid use was independently associated with reduction of hip BMD. CONCLUSION: The prevalence of osteoporosis in the RA patients was 1.9 times higher than in healthy subjects. Glucocorticoid use was a risk factor for generalized bone loss in female RA patients.

Positional isomerization of butene-2 over nanoporous MCM-48 catalysts.

Positional isomerization of butene-2 to butene-1 was investigated over nanoporous MCM-48 catalysts. The effects of the method and the amount of aluminum incorporation into MCM-48 on the catalyst characteristics were studied, with respect to the butene-2 isomerization reaction. Incorporation of aluminum into MCM-48 using a post-synthetic grafting method (P) or direct sol-gel method (D) increases the total acid amount due to the increase in the Lewis acidity level. From the results of butene-2 isomerization, the yield of butene-1 was increased although the selectivity of butene-1 was decreased due to an increase of byproducts such as i-butene, cracked fraction, and C5+ hydrocarbons. This trend is nearly identical over both catalyst preparation methods; the effect of Al incorporation method on the butene-1 yield and the selectivity appeared negligible. The maximum yield of butene-1 was 27.1 wt% by feeding pure butene-2 in the reaction condition as follows: a temperature of 450 degrees C, atmospheric pressure, and with the WHSV at 70 h(-1).

Stenosis of the proximal external carotid artery in an adult with moyamoya disease: moyamoya or atherosclerotic change?

A 55-year-old woman presented with moyamoya disease manifesting as recurrent transient ischemic attacks despite taking aspirin and antihypertensive agent. Angiography showed the characteristic angiographic appearance with bilateral internal carotid artery occlusion and abnormal collateral vessels. Left external carotid angiography demonstrated moderate stenosis of the proximal external carotid artery (ECA). A self-expandable stent was successfully placed in the left ECA to improve ipsilateral cerebral perfusion. The patient had an uneventful outcome after a 1-year follow up. Involvement of the proximal ECA is very unusual in moyamoya disease, and might result from hemodynamic stress or degenerative atherosclerosis. Revascularization procedures for stenoses of proximal ECA may improve cerebral perfusion in patients with moyamoya disease.

Aspergillosis presenting as an optic neuritis.

A 59-year-old woman was referred to our clinic with sudden visual loss in her right eye after she was treated with 40 mg/day of oral prednisolone for 2 weeks under the diagnosis of idiopathic optic neuritis. At that time, computerized tomography (CT) of the brain showed no evidence of optic nerve or brain pathology. However, there was progressive diminution of right visual acuity associated with a limitation of adduction and abduction in the right eye. On magnetic resonance imaging and repeated CT, a malignant lesion was suggested, and was confirmed as an Aspergillus fungus colony by histopathologic examination. Postoperatively, she was treated with intravenous administration of amphotericin B for 13 weeks. However, her condition continued to deteriorate. She developed ptosis and total ophthalmoplegia in the right eye and blindness in both eyes. After discharge, she was given itraconazole for 20 weeks. She has shown no recovery of visual acuity or extraocular motion during a two-year follow-up period. The clinical features of our case suggest that early diagnosis in a case of aspergilloma presenting with visual loss is difficult and that a high index of suspicion, repeated radiological examination and adequate biopsy may be required for diagnosis.