Photonic Topological Spin Pump in Synthetic Frequency Dimensions.

Reducing geometrical complexity while preserving desired wave properties is critical for proof-of-concept studies in wave physics, as evidenced by recent efforts to realize photonic synthetic dimensions, isospectrality, and hyperbolic lattices. Laughlin's topological pump, which elucidates quantum Hall states in cylindrical geometry with a radial magnetic field and a time-varying axial magnetic flux, is a prime example of these efforts. Here we propose a two-dimensional dynamical photonic system for the topological pumping of pseudospin modes by exploiting synthetic frequency dimensions. The system provides the independent control of pseudomagnetic fields and electromotive forces achieved by the interplay between mode-dependent and mode-independent gauge fields. To address the axial open boundaries and azimuthal periodicity of the system, we define the adjusted local Chern marker with rotating azimuthal coordinates, proving the nontrivial topology of the system. We demonstrate the adiabatic pumping for crosstalk-free frequency conversion with wave front molding. Our approach allows for reproducing Laughlin's thought experiment at room temperature with a scalable setup.

Incidence, Morbidity, and Mortality of Achalasia: A Nationwide, Population-Based Cohort Study in South Korea.

Background/Aims: Although an association between achalasia and esophageal cancer has been reported, whether achalasia confers a substantial increase in mortality is unknown. Moreover, the causes of death related to achalasia have not been investigated. We performed this nationwide, population-based cohort study on achalasia because no such study has been performed since the introduction of high-resolution manometry in 2008. Methods: This study was performed using data extracted from the Korean National Health Insurance Service database, covering a 9-year period from 2009 to 2017. Control participants without a diagnostic code for achalasia were randomly selected and matched by sex and birth year at a case-to-control ratio of 1:4. Data on the cause of death from Statistics Korea were also analyzed. Results: The overall incidence of achalasia was 0.68 per 100,000 person-years, and the prevalence was 6.46 per 100,000 population. Patients with achalasia (n=3,063) had significantly higher adjusted hazard ratio (aHR) for esophageal cancer (aHR, 3.40; 95% confidence interval [CI], 1.25 to 9.22; p=0.017), pneumonia (aHR, 2.30; 95% CI, 1.89 to 2.81; p<0.001), aspiration pneumonia (aHR, 3.92; 95% CI, 2.38 to 6.48; p<0.001), and mortality (aHR, 1.68; 95% CI, 1.44 to 1.94; p<0.001). Esophageal cancer carried the highest mortality risk (aHR, 8.82; 95% CI, 2.35 to 33.16; p=0.001), while pneumonia had the highest non-cancer mortality risk (aHR, 2.28; 95% CI, 1.31 to 3.96; p=0.004). Conclusions: In this nationwide study, achalasia was associated with increased risk of mortality. Esophageal cancer and pneumonia were the most common comorbidities and the major causes of death in patients with achalasia.

Reliability of endoscopic ultrasonography and endoscopy in measurement of gastric subepithelial tumor size.

BACKGROUND: Subepithelial tumor (SET) size is important in determining the treatment plan; however, size estimation for gastric SETs has not been well investigated. We aimed to investigate which method predicts SET size most accurately by retrospectively analyzing surgically removed SETs. METHODS: From January 2015 through June 2020, patients who underwent surgical gastric SET removal at Asan Medical Center, Seoul, Korea, were enrolled. SET sizes measured by pathologists and endoscopists were retrospectively reviewed. The reliability of SET size measurement by endoscopic ultrasonography (EUS) and endoscopy was calculated using intraclass correlation coefficient (ICC), with pathologic size as the gold standard. RESULTS: Overall, EUS was highly reliable (ICC 0.86, P < 0.001), and endoscopy was moderately reliable (ICC 0.75, P < 0.001). When analyzed according to SET location, endoscopy was highly reliable in the lesser curvature's lower third (ICC 0.86, P = 0.014), middle third (ICC 0.88, P < 0.001), and upper third (ICC 0.90, P < 0.001); as well as the anterior wall's middle third (0.84, P < 0.001) and the posterior wall's upper third (ICC 0.80, P < 0.001). EUS (ICC 0.96, P = 0.005) and endoscopy (ICC 0.95, P = 0.008) both were most reliable for lower-third posterior wall lesions, whereas endoscopy was unreliable for middle-third greater curvature lesions (ICC 0.41, P = 0.05). CONCLUSIONS: Both EUS and endoscopy were reliable methods for measuring gastric SET size, and overall, EUS was more reliable than endoscopy. In terms of SET location, EUS was consistently reliable, whereas endoscopy showed variable reliability. When measuring SET size by endoscopy, additional size measurements with EUS should be considered in certain locations.

Status of Constipation and Its Association with Sarcopenia in Older Adults: A Population-Based Cohort Study.

(1) Background: As the clinical relevance of constipation and sarcopenia is not well studied, we aimed to investigate the association between them in older adults. (2) Methods: A cross-sectional study was conducted on 1278 community-dwelling older adults in South Korea. The Rome IV criteria were used to identify patients with clinically defined constipation, while sarcopenia was defined by the Asian Working Group for Sarcopenia consensus. The cohort was classified into three groups: no constipation, self-reported constipation only, and clinically defined constipation. (3) Results: The presence of constipation was associated with sarcopenia and slow gait speed (p < 0.001). After adjustment for possible covariates, the association with sarcopenia attenuated, while that for slow gait speed persisted. In terms of geriatric parameters, both groups with clinically defined and self-reported constipation had a higher burden of cognitive impairment, IADL disability, and lower QOL scores (p < 0.05) compared with those without constipation. (4) Conclusions: Sarcopenia and slow gait speed associated with constipation in community-dwelling older adults. Individuals with self-reported constipation symptoms alone showed comparable sarcopenic and geriatric burden to those with clinically defined constipation. Clinical suspicion for possible co-existing sarcopenia is warranted in older patients with constipation.

The Aging Study of Pyeongchang Rural Area (ASPRA): Findings and Perspectives for Human Aging, Frailty, and Disability.

The Aging Study of Pyeongchang Rural Area (ASPRA) is a population-based, prospective cohort study of older adults in Pyeongchang, South Korea. Since the initial enrollment of 382 participants, the ASPRA has been maintained and has conducted comprehensive geriatric assessments annually, gradually expanding its population and coverage area. As a cohort study of aging-related conditions and their functional consequences, the ASPRA leveraged Pyeongchang's relatively low annual population movement rate and its healthcare delivery system, which was largely maintained by community health posts. Since its establishment, the ASPRA has reported numerous observational and multicomponent intervention studies on functional decline, geriatric syndrome, and frailty. Here, we discuss the findings and perspectives of ASPRA studies. We hope that the ASPRA enables the further implementation of a longitudinal study design on geriatric parameters and the development of public health strategies targeting aging-related conditions, especially in resource-limited community settings.

Longitudinal impact of oral health on geriatric syndromes and clinical outcomes in community-dwelling older adults.

BACKGROUND: Oral health is essential for daily living and plays a pivotal role in overall health conditions and well-being. This study evaluated the impact of self-reported oral health on geriatric conditions, institutionalization, and mortality. METHODS: This study analyzed the population of the Aging Study of Pyeongchang Rural Area that had undergone geriatric assessments between 2016 and 2017. The oral health status of the participants was determined using three items from the General Oral Health Assessment Index, and the participants were classified into three groups according to the total sum of the scores as good (3), fair (4-7), or poor (8-15). The outcomes were the incidence of geriatric syndromes at 2 years and the composite outcome of mortality and institutionalization. RESULTS: Among the 1189 participants, 44.1 % were women, and the mean age of the study population was 75.0 years. Good, fair, and poor oral health were observed in 597 (50.2 %), 406 (34.1 %), and 186 (15.6 %) individuals, respectively. Worsening oral health status was associated with the incidences of various geriatric syndromes at follow-up, and these associations were attenuated after adjusting for baseline demographic and geriatric parameters. Similarly, the significant association between baseline oral health status and the incidence of the composite outcome was attenuated after adjusting for demographic and geriatric parameters. CONCLUSIONS: Oral health affected the geriatric health conditions in this prospective, longitudinal cohort of community-dwelling older adults. The correlations and interactions of oral health status with other functional parameters may deserve consideration as a geriatric domain.

Higher frailty burden in older adults with chronic constipation.

BACKGROUND: Despite constipation being a common clinical condition in older adults, the clinical relevance of constipation related to frailty is less studied. Hence, we aimed to investigate the association between chronic constipation (CC) and frailty in older adults. METHODS: This is a cross-sectional analysis of a population-based, prospective cohort study of 1278 community-dwelling older adults in South Korea. We used the Rome criteria to identify patients with irritable bowel syndrome with predominant constipation (IBS-C) and functional constipation (FC). We investigated whether participants consistent with the criteria for IBS-C and FC had CC. Frailty was assessed using the Cardiovascular Health Study (CHS) frailty phenotype. RESULTS: In the study population with a mean age of 75.3 ± 6.3 years, 136 (10.7%) had CC. The participants with CC were older, had higher medication burdens, and had worse physical performances compared to those without CC (All P < .05). By association analysis, the prevalence of CC was associated with frailty by the CHS criteria (P < .001). The CHS frailty score was associated with the presence of CC by the univariate logistic regression analysis and the multivariate analysis adjusted for age, sex, and multimorbidity. CONCLUSIONS: Frailty was associated with CC in community-dwelling older people, suggesting that constipation should be considered as an important geriatric syndrome in clinical practice concerning frail older adults.

Sarcopenia is associated with severe erectile dysfunction in older adults: a population-based cohort study.

BACKGROUND/AIMS: Sarcopenia and erectile dysfunction (ED) are associated with poor health and quality of life in older men. We investigate the association between sarcopenia and severe ED in community-dwelling older men. METHODS: We prospectively assessed sarcopenia and ED in 519, community-dwelling, older men (mean age, 74.0) in Pyeongchang, Korea, in 2016 to 2017. Sarcopenia was based on muscle mass, grip strength, and gait speed according to the Asian Working Group consensus algorithm. Severe ED was defined as 5-item International Index of Erectile Function questionnaire score under 8. Logistic regressions were used to study associations between incident severe ED and sarcopenia, after adjusting age, cardiovascular risk factors, depression, and polypharmacy. RESULTS: The prevalence of severe ED was 52.4% and that of sarcopenia was 31.6%. At baseline, the prevalence of severe ED was higher in men with sarcopenia than in those without (73.2% vs. 42.8%; adjusted odds ratio [aOR], 1.89; 95% confidence interval [CI], 1.18 to 3.03; p = 0.008). Slow gait speed (aOR, 2.80; 95% CI, 1.18 to 6.62; p = 0.019) and decreased muscle mass (aOR, 2.54; 95% CI, 1.11 to 5.81; p = 0.027) were associated with the incidence of severe ED, while decreased grip strength (aOR, 0.76; 95% CI, 0.30 to 1.91; p = 0.564) was not. CONCLUSION: Sarcopenia was associated with severe ED. Slow gait speed, and decreased muscle mass was independently associated with incident severe ED at 1 year. Further research is warranted to examine whether an intervention targeting these components can prevent severe ED.

Evaluation of Clinically Meaningful Changes in Measures of Frailty.

BACKGROUND: To determine the clinically meaningful changes and responsiveness of widely used frailty measures. METHODS: We analyzed data from a prospective cohort study of 1,135 community-dwelling older adults who underwent assessments of frailty and health-related quality of life using the EuroQol-5D at baseline and 1 year later. Frailty measures included deficit-accumulation frailty index (FI); frailty phenotype; Fatigue, Resistance, Ambulation, Illness, and Loss of Weight scale; and the Study of Osteoporotic Fracture (SOF) index. We determined the clinically meaningful changes by the distribution-based method and the anchor-based method using the EuroQol-5D score and responsiveness indices. RESULTS: Frailty measures were available in 925 participants at 1 year (81.5%). Based on the distribution-based method, small and large clinically meaningful changes were 0.019 and 0.057 for FI, 0.249 and 0.623 for frailty phenotype, 0.235 and 0.587 for FRAIL scale, and 0.116 and 0.289 for SOF index, respectively. The anchor-based estimates of small and large changes were 0.028 and 0.076 for FI, 0.097 and 0.607 for frailty phenotype, 0.269 and 0.368 for FRAIL scale, and 0.023 and 0.287 for SOF index, respectively. Based on the responsiveness index, per-group sample sizes to achieve 80% power in clinical trials, ranged from 51 (FI) to 7,272 (SOF index) for a small change and 9 (FI) to 133 (FRAIL scale) for a large change. CONCLUSIONS: The estimates of clinically meaningful change of frailty measures can inform the choice of frailty measures to track longitudinal changes of frailty in clinical trials and clinical care of community-dwelling older adults.

Relationship between iliac screw loosening and proximal junctional kyphosis after long thoracolumbar instrumented fusion for adult spinal deformity.

PURPOSE: Authors assumed that the stability of iliac screw (IS) fixation could affect the development of proximal junctional kyphosis (PJK). The purpose of this study was to analyze the relationship between IS loosening and PJK after long fusion surgery for adult spinal deformity (ASD). METHODS: Sixty-eight ASD patients (6 males, 62 females; mean age, 68.1 years) who underwent long fusion surgery with IS fixation were reviewed. The incidence and risk factors of IS loosening were investigated. The relationship between IS loosening and PJK was also analyzed. RESULTS: IS loosening and PJK appeared in 33 and 19 patients, respectively. The median time for IS loosening and PJK to develop was 6.0 months (range 1.3-59.2) and 9.1 months (range 1.3-73.2), respectively. PJK developed in patients without IS loosening more frequently than in patients with IS loosening. PJK did not develop in 28 patients who presented with IS loosening first. IS loosening developed 5 months postoperatively in those 28 patients, whereas IS loosening was present 11 months postoperatively in 4 patients who presented with PJK first. Preoperative PT (OR = 1.091) and IS loosening (OR = 0.343) were significantly related with the development of PJK. IS loosening was significantly associated with postoperative PI-LL > 10° (OR = 0.957), postoperative SVA (OR = 1.023), and postoperative PT (OR = 1.072). CONCLUSION: Postoperative sagittal malalignment should be avoided to prevent IS loosening and PJK. IS loosening occurred earlier than PJK and seemed to affect the development of PJK. This relationship supports the hypothesis that distal stability of long constructs may increase proximal junctional stress. LEVEL OF EVIDENCE: III. These slides can be retrieved under Electronic Supplementary Material.

Characteristics of sarcopenia by European consensuses and a phenotype score.

BACKGROUND: We aimed to assess the clinical characteristics of sarcopenia by the original and revised European Working Group on Sarcopenia in Older People (EWGSOP 1 and 2), and to propose a new sarcopenia phenotype score (SPS) to improve relevance of clinical outcomes. METHODS: Analyses were performed in 1408 older adults of the Aging Study of PyeongChang Rural Area, a community-based cohort in Korea. For sarcopenia definitions, we used EWGSOP 1, EWGSOP 2, and SPS, a new index counting number of abnormal domains among components of grip strength, gait speed, or muscle mass. Frailty status by the frailty index and the Cardiovascular Health Study frailty score was compared with sarcopenia measures. Prediction ability for composite outcome combining death and institutionalization due to functional decline was assessed among sarcopenia measures. RESULTS: Generally, sarcopenia spectrum by both EWGSOP 1 and 2 was associated with worse functional status in parameters of geriatric assessments. However, population who were considered as sarcopenic by EWGSOP 1, but not by EWGSOP 2, showed increased risk of composite outcome and worse frailty status, compared with people who were classified as not sarcopenic by both EWGSOP 1 and 2. With SPS, dose-response relationship was observed with both frailty status and outcome prediction. Prediction for composite outcome was better in SPS than in EWGSOP 2 classification. CONCLUSIONS: A new SPS might be used to classify sarcopenic burden in older adults to resolve possible inconsistencies in phenotype correlation and outcome prediction of EWGSOP 2 criteria.

Screening Value of Social Frailty and Its Association with Physical Frailty and Disability in Community-Dwelling Older Koreans: Aging Study of PyeongChang Rural Area.

Population aging is a challenge, therefore efficient frailty screening has been increasingly emphasized for mass older populations. This study aimed to evaluate the prevalence of social frailty and its association with physical frailty, geriatric syndromes and activity of daily living (ADL) disability in community-dwelling older adults. A cross-sectional study was conducted with 408 older adults (mean age, 75 years; 58% female) in the Aging Study of PyeongChang Rural Area. A five-item social frailty index was administered (range: 0-5); (1) going out less frequently; (2) rarely visiting the homes of friends; (3) feeling unhelpful to friends and family; (4) being alone; and (5) not talking with someone every day. Social frailty was defined as ≥2 positive responses. Physical frailty was assessed according to the Cardiovascular Health Study frailty phenotype criteria. We used logistic regression to examine whether social frailty can identify older adults with common geriatric syndromes including ADL disability, independently of age, gender, and physical frailty. Social frailty was present in 20.5% (14.5% in male and 25.0% in female) and 11.5% was not overlapped with physical frailty. Social frailty increased risk of ADL disability (odds ratio, 2.53; 95% confidence interval, 1.26-5.09) and depressed mood (odds ratio, 4.01; 95% confidence interval, 1.30-12.39) independently of age, gender, and physical frailty. The predictive power for disability was maximized by using both frailty indices (C statistic 0.73) compared with either frailty index alone (C statistic: 0.71 for social frailty and 0.68 for physical frailty). Social frailty screening is important as it can identify frail older adults who are not captured by demographic characteristics and physical frailty. Moreover, assessment of both social frailty and physical frailty can better detect disability and geriatric syndromes.

Validation of a novel endoscopic program for measuring the size of gastrointestinal lesions.

BACKGROUND: Valid and reliable methods for measurement of lesion sizes during endoscopy have not been established. METHODS: We developed a novel software program (ENDOVER; Poinbionics, Seoul, Republic of Korea) to measure lesions sizes and assessed its validity and reliability. To validate the program, we measured standard coin sizes and estimated measurement errors. To assess program reliability, 32 pictures of endoscopically resected specimens were used to measure tissue sizes six times in a 24-h interval by two examiners. Intraclass correlation coefficients (ICCs) were used to assess intraobserver and interobserver agreements. Agreement between the program and pathological measurements was assessed by absolute differences. RESULTS: The nominal standard sizes of 10-won, 100-won, and 500-won coins were 18.0, 24.0, and 26.5 mm, and the calculated sizes were 18.09, 24.48, and 26.31 mm, respectively. ICCs of the long and short diameters were, respectively, 0.92 [95% confidence interval (CI) 0.87-0.95] and 0.93 (CI 0.89-0.96) for examiner 1 and 0.88 (CI 0.81-0.93) and 0.92 (CI 0.87-0.95) for examiner 2. Interobserver ICCs of the long and short diameters were 0.97 (CI 0.94-0.99) and 0.97 (CI 0.94-0.99), respectively. The mean absolute differences between the program and pathological measurements were 4.4 and 4.7 mm for the long and short diameters, respectively. CONCLUSIONS: Our findings indicate that the novel measurement program is a valid and reliable method for estimation of lesion sizes from endoscopic findings during and after examination.

Can Endoscopic Bleeding Control Improve the Prognosis of Advanced Gastric Cancer Patients?: A Retrospective Case-Control Study.

BACKGROUND: Gastric bleeding is not rare and difficult to treat in gastric cancer patients. We investigated whether this affects survival and if successful bleeding control improves the prognosis. PATIENTS/MATERIAL AND METHODS: We retrospectively reviewed medical records for 64 subjects who underwent endoscopic therapy for gastric cancer bleeding at Asan Medical Center from January 2012 to December 2014 (bleeding group). Each subject was matched 1:2 by age, sex, and American Joint Committee on Cancer staging with 128 randomly selected patients treated for stomach cancer during the same period (control group). Median survival, bleeding treatment methods, successful bleeding control, and rebleeding rate were investigated. RESULTS: The median age was 58.5 years, the male to female ratio 4.3:1. The initial hemostasis rate was 73.4%. Most patients were treated with a single method (37 patients, 57.8%); the coagrasper (32/95 cases, 33.7%) was the most frequently used treatment. Among the 47 patients in which successful bleeding control was achieved, 17 (36.2%) experienced rebleeding after 3 days. The median survival was longer in the control than in the bleeding group (18.5 vs. 6.5 mo), and in the successful bleeding control than in the failed bleeding control group (8.5 vs. 1.8 mo). However, the successful bleeding control group had lower survival than the control group (18.5 vs. 8.5 mo). Multivariate analysis showed that the risk of bleeding was lower in Borrmann type II, IV cancer, but was higher in the patients using antiplatelet or anticoagulant. CONCLUSIONS: Successful bleeding control is essential for improving survival in bleeding gastric cancer patients.

Helicobacter pylori Eradication Therapy Is Effective as the Initial Treatment for Patients with H. pylori-Negative and Disseminated Gastric Mucosa-Associated Lymphoid Tissue Lymphoma.

BACKGROUND/AIMS: We investigated the effectiveness of Helicobacter pylori eradication therapy for gastric mucosaassociated lymphoid tissue (MALT) lymphoma regardless of the H. pylori infection status or disease stage. METHODS: From November 1995 to September 2014, 345 subjects who were diagnosed with gastric MALT lymphoma and had received eradication therapy as their first-line treatment were eligible for inclusion in this study. A retrospective review was performed using the medical records. RESULTS: Of the 345 patients, H. pylori infection was detected in 317 patients (91.9%). The complete remission (CR) rate after eradication therapy was 82.3%, which was higher in H. pylori -positive patients than in H. pylori-negative patients (84.5% vs 57.1%, p=0.001). CR rates after eradication did not present significant differences between stages, and the CR rate was 83.3% for stage IE1 and 74.4% for stage IE2 or above (p=0.167). The overall CR rate was 87.2% after additional treatment, and neither H. pylori infection status nor stage showed differences according to the treatment response. CONCLUSIONS: Eradication therapy led to CR in 57.1% of H. pylori-negative patients and in 74.4% of patients with stage IE2 or above. Eradication therapy is worthwhile as an initial treatment for gastric MALT lymphoma regardless of the H. pylori infection status and stage.

Myeloid cell leukemia-1 promotes epithelial-mesenchymal transition of human gastric cancer cells.

Epithelial-mesenchymal transition (EMT) is a critical process that occurs during cancer progression, and cancer stem cells have been shown to acquire the EMT phenotype. Myeloid cell leukemia-1 (Mcl-1) has been implicated in cancer progression and is overexpressed in a variety of human cancers. However, the interaction between Mcl-1 and EMT in human gastric cancer (GC) is unclear. We investigated the impact of Mcl-1 expression levels on EMT and the underlying signaling pathways in human GC cells. We used the human GC cell lines, AGS and SNU638, and small interfering RNAs (siRNAs) to evaluate the effects of Mcl-1 knockdown on cell adhesion, migration and invasion. Expression of Mcl-1 and other target genes was determined using reverse transcription-polymerase chain reaction assays and western blotting. The results revealed that expression levels of Mcl-1 mRNA and protein in the AGS and SNU638 cells were reduced following transfection with Mcl-1 siRNAs. Knockdown of Mcl-1 led to increased cellular adhesion to fibronectin and collagen. Expression levels of vimentin, MMP-2, MMP-9 and Snail protein were decreased following knockdown of Mcl-1. However, expression of E-cadherin was increased in the AGS cells following knockdown of Mcl-1. The expression of cancer stemness markers, such as CD44 and CD133, was not altered by knockdown of Mcl-1. Knockdown of Mcl-1 suppressed tumor cell migration and invasion in both human GC cell lines. Signaling cascades, including the ß-catenin, MEK1/2, ERK1/2 and p38 pathways, were significantly blocked by knockdown of Mcl-1. Our results indicate that Mcl-1 expression induces EMT via ß-catenin, MEK1/2 and MAPK signaling pathways, which subsequently stimulates the invasive and migratory capacity of human GC cells.

Association between interleukin-18 gene polymorphism and Helicobacter pylori infection in the Korean population.

Interleukin-18 (IL-18) is a pleiotropic, pro-inflammatory cytokine that is capable of promoting the Th1 response. A predominant Th1 response induces chronic and persistent inflammatory changes in the gastric mucosa in response to Helicobacter pylori (H. pylori) infection. The aim of this study was to investigate the potential association between IL-18 gene polymorphisms and susceptibility to H. pylori infection in the Korean population. A total of 678 subjects who underwent a routine health check-up were enrolled. The IL-18 gene polymorphisms at positions -656, -607, -137, +113, and +127 were genotyped. H. pylori positivity was demonstrated in 456 subjects (67.3%). The allele frequencies of IL-18 gene polymorphisms at position -137 (rs187238) were different based on the status of H. pylori infection (G vs. C, adjusted OR 0.64 CI: 0.47-0.87, P = 0.005). The results indicate that the genetic variants in the IL-18 gene may be associated with susceptibility to H. pylori infection in the Korean population, suggesting that IL-18 plays a role in the pathogenesis of H. pylori-associated diseases. However, this finding requires further replication and validation.

Clinical impact of prophylactic antibiotic treatment for self-expandable metallic stent insertion in patients with malignant colorectal obstruction.

Purpose. The aim of this study was to determine the efficacy of prophylactic antibiotics (PA) for reducing the infectious complications and the potential risk factors responsible for the infectious complications after stent insertion for malignant colorectal obstruction. Methods. We performed a retrospective review of 224 patients who underwent self-expandable metallic stent (SEMS) insertion for malignant colorectal obstruction from May 2004 to December 2012. Results. There were 145 patients in the PA group and 79 in non-PA group. The CRP level in PA group was significantly higher than that in non-PA. Abdominal tenderness and mechanical ileus were significantly more frequent in PA group than those in non-PA. The frequency of post-SEMS insertion fever, systemic inflammatory response syndrome (SIRS), and bacteremia was not significantly different between PA and non-PA groups. In multivariate analysis, the CRP level was risk factor related to post-SEMS insertion SIRS. However, in propensity score matching analysis, there was no independent risk factor related to post-SEMS insertion fever, SIRS, and bacteremia. Conclusion. The use of PA in patients with malignant colorectal obstruction may be not effective to prevent the development of infectious complications after SEMS insertion.

Bronchiolitis obliterans associated with Stevens-Johnson syndrome: a case report.

We report a case of bronchiolitis obliterans associated with Stevens-Johnson syndrome. A 59-year-old man presented with respiratory distress that gradually worsened over 3 months. He had been diagnosed with Stevens-Johnson syndrome 3 months before admission. He had no history of previous airway disease. On physical examination, expiratory breathing sounds were not audible, and a chest X-ray revealed a hyperinflated lung. A pulmonary function test indicated a severe obstructive pattern. Computed tomography scans of inspiratory and expiratory phases of respiration showed oligemia and air trapping, and both were more prominent on expiration view than on inspiration view. The pathogenesis of bronchiolitis obliterans associated with Stevens-Johnson syndrome is largely unknown.

Myeloid cell leukemia-1 regulates the cell growth and predicts prognosis in gastric cancer.

The expression of myeloid cell leukemia-1 (Mcl­1), a member of the anti-apoptotic Bcl-2 protein family, has been associated with tumor progression and adverse patient outcome. The aims of current study were to evaluate whether Mcl-1 affects the survival or death of gastric cancer cells, and to investigate the prognostic value of its expression in gastric cancer. PcDNA3.1-Mcl-1 expression and Mcl-1 siRNA vectors were used to overexpress and silence Mcl-1 expression in gastric cancer cell lines including SNU638 and TMK1, respectively. Immunohistochemistry was used to determine the expression of Mcl-1 in gastric cancer tissues. Apoptosis was determined by the TUNEL assay, and cell proliferation was determined by immunostaining with a Ki-67 antibody. Mcl-1 knockdown induced apoptosis through the upregulation of caspase-3, and -7, and PARP activity, and the release of Smac/DIABLO and Omi/HtrA2 into the cytoplasm. Additionally, cell cycle arrest occurred due to decrease of cyclin D1, cell division cycle gene 2 (cdc2), and cyclin-dependent kinase 4 and 6. In contrast, overexpression of Mcl-1 inhibited apoptosis and cell cycle arrest. Mcl-1 knockdown did not suppress tumor cell proliferation in gastric cancer cells, whereas overexpression of Mcl-1 enhanced tumor cell proliferation. The JAK2 and STAT3 signaling cascades were significantly blocked by Mcl-1 knockdown. The mean Ki-67 labeling index (KI) value of Mcl-1 positive tumors was significantly lower than that of Mcl-1 negative tumors. However, there was no significant difference between Mcl-1 expression and the apoptotic index (AI). Mcl-1 expression was significantly increased in gastric cancer tissues compared to normal gastric mucosa tissues, and was associated with age, tumor size, stage, depth of invasion, lymph node metastasis and poor survival. Our study showed that Mcl-1 regulates the cell growth and might be a potential prognostic marker for gastric cancer.