Genomic drivers in craniopharyngiomas: Analysis of the AACR project GENIE database.

PURPOSE: Craniopharyngiomas are rare tumors originating in the sellar region, with limited information on their somatic mutational landscape. In this study, we utilized a publicly available genomic database to profile the somatic mutational landscape of craniopharyngioma patients and interrogate differences based on histologic subtype. METHODS: We utilized the American Association for Cancer Research (AACR) Project Genomics Evidence Neoplasia Information Exchange (GENIE)® database accessed from cBioPortal (v13.1-public) to query all patients with craniopharyngiomas. RESULTS: Of the 336 patients with sellar tumors, 51 (15.2%) had craniopharyngiomas. Of these 51 patients, 42 (82.4%) were adamantinomatous subtype and 9 (17.6%) were papillary subtype. In this cohort, 32 (62.7%) patients were pediatric, while 19 (37.3%) were adult. The top mutations in the cohort were: CTNNB1 (n = 37; 73%), BRAF (n = 7; 14%), ARID1B (n = 5; 10%), KMT2D (n = 4; 8%), FANCA (n = 4; 8%), ATM (n = 4; 8%), and TERT (n = 3; 8%). Of the 37 patients with CTNNB1 mutations, 8 (21.6%) had S33X, 9 (24.3%) had S37X, 7 (18.9%) had T41X, and 5 (13.5%) had D32X. In this cohort, CTNNB1 mutations tended to co-occur with ATM (n = 4; 10.8%), KMT2C (n = 4; 10.8%), TERT (n = 3; 8.1%), BLM (n = 3; 8.1%), and ERBB2/3 (n = 3; 8.1%), suggesting CTNNB1 mutations tended to co-occur with mutations in genes important in cell growth and survival, chromatin accessibility, and DNA damage response pathways. CONCLUSIONS: CTNNB1 mutations account for a large proportion of somatic mutations in craniopharyngiomas. Identification of specific point mutations and secondary drivers may advance development of novel craniopharyngioma preclinical models for targeted therapy testing.

Can serum IgE or blood eosinophil count predict postoperative oral corticosteroid response in chronic rhinosinusitis with nasal polyps?

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterised by inflammatory mucosa and polyp formation in the paranasal sinuses. The study's primary objective was to evaluate the outcomes of postoperative oral corticosteroid (OCS) in treating patients with bilateral CRSwNP. The secondary objective was to determine whether preoperative serum IgE levels (sIgE)and/or blood eosinophil count (BEC) correlate with postoperative outcomes following OCS use. METHODS: Patients with bilateral CRSwNP (n=236) who underwent endoscopic sinus surgery (ESS) were randomly assigned to receive 15 mg OCS twice daily or a placebo for 2 weeks. We investigated the treatment effects based on the subjective visual analogue scale (VAS), Sino-Nasal Outcome Test 22 (SNOT-22), and objective Lund-Kennedy Endoscopy Score (LKES) over 6 months; subgroups were stratified preoperatively as follows: sIgE <150 IU/mL, sIgE>=150 IU/mL, BEC <0.39x10(9) cells/L, and BEC>=0.39x10(9) cells/L. RESULTS: A total of 193 participants completed the study up to the 6-month follow-up; no apparent linear relationship was noted between sIgE and BEC. No significant differences in scores were noted upon assessment of the VAS, SNOT-22, and LKES among the follow-up timepoints in the primary analysis. However, in the primary or subgroup analyses with sIgE or BEC, significant differences in the longitudinal scores of sleep dysfunction were observed at the 1-month follow-up. CONCLUSION: Postoperative OCS did not significantly affect bilateral CRSwNP outcomes. sIgE levels and BEC may not be surrogate predictive biomarkers to assess the role of postoperative OCS use. OCS may increase the risk of transient sleep disturbance.

Application of a Physiologically Based Pharmacokinetic Model to Predict Cefazolin and Cefuroxime Disposition in Obese Pregnant Women Undergoing Caesarean Section.

Intravenous (IV) cefuroxime and cefazolin are used prophylactically in caesarean sections (CS). Currently, there are concerns regarding sub-optimal dosing in obese pregnant women compared to lean pregnant women prior to CS. The current study used a physiologically based pharmacokinetic (PBPK) approach to predict cefazolin and cefuroxime pharmacokinetics in obese pregnant women at the time of CS as well as the duration that these drug concentrations remain above a target concentration (2, 4 or 8 µg/mL or µg/g) in plasma or adipose tissue. Cefazolin and cefuroxime PBPK models were first built using clinical data in lean and in obese non-pregnant populations. Models were then used to predict cefazolin and cefuroxime pharmacokinetics data in lean and obese pregnant populations. Both cefazolin and cefuroxime models sufficiently described their total and free levels in the plasma and in the adipose interstitial fluid (ISF) in non-pregnant and pregnant populations. The obese pregnant cefazolin model predicted adipose exposure adequately at different reference time points and indicated that an IV dose of 2000 mg can maintain unbound plasma and adipose ISF concentration above 8 µg/mL for 3.5 h post dose. Predictions indicated that an IV 1500 mg cefuroxime dose can achieve unbound plasma and unbound ISF cefuroxime concentration of ≥8 µg/mL up to 2 h post dose in obese pregnant women. Re-dosing should be considered if CS was not completed within 2 h post cefuroxime administration for both lean or obese pregnant if cefuroxime concentrations of ≥8 µg/mL is required. A clinical study to measure cefuroxime adipose concentration in pregnant and obese pregnant women is warranted.

Effects of Ticagrelor and Clopidogrel on Coronary Microcirculation in Patients with Acute Myocardial Infarction.

INTRODUCTION: Clopidogrel has been demonstrated to be effective in improving coronary microcirculation (CM) among patients with ST-elevation myocardial infarction (STEMI) treated with fibrinolytics. Ticagrelor is a more potent adenosine diphosphate (ADP) receptor blocker proven to be superior to clopidogrel among patients with acute coronary syndromes. The present study aimed to compare the effects of ticagrelor and clopidogrel on CM in patients with STEMI treated with fibrinolytics. METHODS: The present study prospectively included 48 patients participating in the TREAT trial, which randomly assigned patients with STEMI undergoing fibrinolysis to ticagrelor versus clopidogrel. The primary endpoint of this study was the evaluation of the CM using the global myocardial perfusion score index (global MPSI) obtained by myocardial contrast echocardiography (MCE). Platelet aggregation to ADP was evaluated by Multiplate® and expressed as area under the curve (AUC). RESULTS: The global MPSI demonstrated no differences between the groups [mean 1.4 (1.2-1.5) in the ticagrelor group and 1.2 (1.2-1.5) in the clopidogrel group (p = 0.41)]. Platelet aggregability was lower in the ticagrelor group (18.1 ± 9.7 AUC), compared to the clopidogrel group (26.1 ± 12.5 AUC, p = 0.01). CONCLUSION: We found no improvement in coronary microcirculation with ticagrelor compared to clopidogrel among patients with STEMI treated with fibrinolytics, despite the fact that platelet aggregation to ADP was lower with ticagrelor. CLINICAL TRIALS REGISTRATION: NCT03104062.

Recommendations for the diagnosis and management of vaccine-induced immune thrombotic thrombocytopenia.

There have recently been safety concerns regarding an increased risk of vaccine-induced immune thrombotic thrombocytopenia (VITT) following administration of SARS-CoV-2 adenoviral vector vaccines. The Southern African Society of Thrombosis and Haemostasis reviewed the emerging literature on this idiosyncratic complication. A draft document was produced and revised by consensus agreement by a panel of professionals from various specialties. The recommendations were adjudicated by independent international experts to avoid local bias. We present concise, practical guidelines for the clinical management of VITT.

Prophylactic perioperative cefuroxime levels in plasma and adipose tissue at the time of caesarean section (C-LACE): a protocol for a pilot experimental, prospective study with non-probability sampling to determine interpatient variability.

BACKGROUND: The aim of the C-LACE study is to measure cefuroxime concentration in plasma and adipose tissue of non-obese and obese pregnant women undergoing caesarean section. METHODS: This study plans to compare maternal cefuroxime concentrations (plasma and adipose tissue), at the time of skin incision and time of skin closure during a caesarean section from non-obese (body mass index BMI < 30 kg/m2) and obese (BMI ≥ 30 kg/m2) pregnant women. The incidence of post-surgical site infection will also be measured. At least 15 participants are required for each arm (non-obese vs obese) with a total of 30 participants. The study participants will be followed up between 30 and 40 days post-caesarean section to record details of any post-caesarean surgical infection to explore correlations between BMI, measured cefuroxime concentrations and post-caesarean infection rates. DISCUSSION: This pilot study will allow the development of a model testing the inter-patient variability in plasma and adipose tissue concentrations of cefuroxime. The results will facilitate the development of a larger study to determine whether differences in cefuroxime plasma and tissue concentration in obese and non-obese women can support the development of a physiologically based pharmacokinetic model. This model can then be used to propose dosing adjustments that can be used in a further trial to optimise cefuroxime dosing for women undergoing caesarean section. TRIAL REGISTRATION: ISRCTN Registry , ISRCTN17527512 . Registered on 26 October 2020.

Three-dimensional measurement of radiographic bone-implant contact lengths of zygomatic implants in zygomatic bone: a retrospective study of 66 implants in 28 patients.

Zygomatic implant treatment is widely applied for severe maxillary atrophy to help rehabilitate the maxillary dentition. This retrospective study was performed to evaluate the actual radiographic bone-implant contact (rBIC) lengths of zygomatic implants. The records of 28 patients who underwent zygomatic implant surgery and subsequent follow-up examinations between August 2013 and September 2018 in the Department of Oral and Maxillofacial Surgery, Taipei Tzu Chi Hospital were reviewed. The surgeries were performed by a single surgeon using the same treatment protocol. All patients had a computed tomography scan at 1year after the surgery. Using three-dimensional imaging software, an investigator measured the rBIC lengths of 66 implants and documented their clinical status. The implant survival rate was 100%. The mean rBIC length was significantly longer in male patients than in female patients (20.80±5.88mm versus 17.79±6.34mm; P=0.028). The mean rBIC length of double zygomatic implants was significantly longer when compared to that of single implants (21.11±6.23mm versus 17.75±5.85mm; P=0.027). This article is novel in reporting the exact rBIC lengths of zygomatic implants in a clinical setting. The results showed that zygomatic implants are a viable treatment modality for full-mouth rehabilitation.

Usefulness of speckle tracking echocardiography and biomarkers for detecting acute cellular rejection after heart transplantation.

BACKGROUND: Acute cellular rejection (ACR) is a major complication after heart transplantation. Endomyocardial biopsy (EMB) remains the gold standard for its diagnosis, but it has concerning complications. We evaluated the usefulness of speckle tracking echocardiography (STE) and biomarkers for detecting ACR after heart transplantation. METHODS: We prospectively studied 60 transplant patients with normal left and right ventricular systolic function who underwent EMB for surveillance 6 months after transplantation. Sixty age- and sex-matched healthy individuals constituted the control group. Conventional echocardiographic parameters, left ventricular global longitudinal, radial and circumferential strain (LV-GLS, LV-GRS and LV-GCS, respectively), left ventricular systolic twist (LV-twist) and right ventricular free wall longitudinal strain (RV-FWLS) were analyzed just before the procedure. We also measured biomarkers at the same moment. RESULTS: Among the 60 studied patients, 17 (28%) had severe ACR (grade ≥ 2R), and 43 (72%) had no significant ACR (grade 0 - 1R). The absolute values of LV-GLS, LV-twist and RV-FWLS were lower in transplant patients with ACR degree ≥ 2 R than in those without ACR (12.5% ± 2.9% vs 14.8% ± 2.3%, p=0.002; 13.9° ± 4.8° vs 17.1° ± 3.2°, p=0.048; 16.6% ± 2.9% vs 21.4%± 3.2%, p < 0.001; respectively), while no differences were observed between the LV-GRS or LV-GCS. All of these parameters were lower in the transplant group without ACR than in the nontransplant control group, except for the LV-twist. Cardiac troponin I levels were significantly higher in patients with significant ACR than in patients without significant ACR [0.19 ng/mL (0.09-1.31) vs 0.05 ng/mL (0.01-0.18), p=0.007]. The combination of troponin with LV-GLS, RV-FWLS and LV-Twist had an area under curve for the detection of ACR of 0.80 (0.68-0.92), 0.89 (0.81-0.93) and 0.79 (0.66-0.92), respectively. CONCLUSION: Heart transplant patients have altered left ventricular dynamics compared with control individuals. The combination of troponin with strain parameters had higher accuracy for the detection of ACR than the isolated variables and this association might select patients with a higher risk for ACR who will benefit from an EMB procedure in the first year after heart transplantation.

Sonothrombolysis Improves Myocardial Dynamics and Microvascular Obstruction Preventing Left Ventricular Remodeling in Patients With ST Elevation Myocardial Infarction.

BACKGROUND: It has recently been demonstrated that high-energy diagnostic transthoracic ultrasound and intravenous microbubbles dissolve thrombi (sonothrombolysis) and increase angiographic recanalization rates in patients with ST-segment-elevation myocardial infarction. We aimed to study the effect of sonothrombolysis on the myocardial dynamics and infarct size obtained by real-time myocardial perfusion echocardiography and their value in preventing left ventricular remodeling. METHODS: One hundred patients with ST-segment-elevation myocardial infarction were randomized to therapy (50 patients treated with sonothrombolysis and percutaneous coronary intervention) or control (50 patients treated with percutaneous coronary intervention only). Left ventricular volumes, ejection fraction, risk area (before treatment), myocardial perfusion defect over time (infarct size), and global longitudinal strain were determined by quantitative real-time myocardial perfusion echocardiography and speckle tracking echocardiography imaging. RESULTS: Risk area was similar in the control and therapy groups (19.2±10.1% versus 20.7±8.9%; P=0.56) before treatment. The therapy group presented a behavior significantly different than control group over time (P<0.001). The perfusion defect was smaller in the therapy at 48 to 72 hours even in the subgroup of patients with no recanalization at first angiography (12.9±6.5% therapy versus 18.8±9.9% control; P=0.015). The left ventricular global longitudinal strain was higher in the therapy than control immediately after percutaneous coronary intervention (14.1±4.1% versus 12.0±3.3%; P=0.012), and this difference was maintained until 6 months (17.1±3.5% versus 13.6±3.6%; P<0.001). The only predictor of left ventricular remodeling was treatment with sonothrombolysis: the control group was more likely to exhibit left ventricular remodeling with an odds ratio of 2.79 ([95% CI, 0.13-6.86]; P=0.026). CONCLUSIONS: Sonothrombolysis reduces microvascular obstruction and improves myocardial dynamics in patients with ST-segment-elevation myocardial infarction and is an independent predictor of left ventricular remodeling over time.

Prognostic impact of circumferential resection margin in esophageal cancer with or without neoadjuvant chemoradiotherapy.

The prognostic impact of circumferential resection margin (CRM) in surgically resected esophageal squamous cell carcinoma (ESCC) has been controversial. This investigation assessed the prognostic impact of CRM in surgically resected pathologic T3 ESCC patients with or without neoadjuvant chemoradiotherapy (nCRT). We reviewed consecutive p/yp T3 ESCC patients undergoing esophagectomy from two medical centers between January 2009 and December 2016. The cohort was divided into two groups: upfront esophagectomy (upfront surgery) and nCRT followed by esophagectomy (nCRT + surgery). CRM status was assessed and divided into CRM > 1 mm, 0 < CRM < 1 mm, and tumor at CRM. A total of 217 p/yp T3 ESCC patients undergoing esophagectomy (138 patients in the upfront surgery group and 79 in the nCRT + surgery group) were enrolled. In the upfront surgery group, patients with 0 < CRM < 1 mm showed equivalent overall survival to those with CRM > 1 mm (log-rank P = 0.817) and significantly outlived those with tumor at CRM (log-rank P < 0.001). However, in the nCRT + surgery group, CRM > 1 mm failed to show survival superiority to CRM between 0 and 1 mm or involved by cancer (log-rank P = 0.390). In conclusion, a negative CRM, even though being <1 mm, is adequate for pT3 ESCC patients undergoing upfront esophagectomy. In contrast, the CRM status is less prognostic in ypT3 ESCC patients undergoing nCRT followed by esophagectomy.

Efficacy of perioperative cefuroxime as a prophylactic antibiotic in women requiring caesarean section: A systematic review.

Intravenous (IV) Cefuroxime (CFX) is widely used in Caesarean Section (CS) as a prophylactic antibiotic. The objective of this systematic review to compare CFX concentration in maternal blood and adipose tissue with the incidence of surgical site infection (SSI) following IV CFX in non-obese and obese women undergoing CS. A search in Medline, EMBASE, Cochrane, Web of Science, CINHAL Plus, Scopus and Google Scholar was conducted without language or date restrictions. Published articles or abstracts reporting CFX concentration or rates of SSI following CFX IV administration in adult women requiring CS were included. Studies were screened by title and abstract. Quality of studies was assessed via the ClinPK Statement checklist (Pharmacokinetics studies), or Joanna Briggs Institute Critical Appraisal Tools (SSI studies). The Cochrane Effective Practice and Organisation of Care checklist evaluated the risk of bias (SSI studies). There were no studies evaluating CFX concentrations in obese women undergoing CS. For non-obese women, CFX plasma concentrations ranged from 9.85 to 95.25 mg/L within 30-60 min of administration (1500 mg dose; 4 articles, n = 108 women). Plasma CFX concentrations were above the minimum inhibitory concentration (8 mg/L) for up to 3 h post-dose. No studies reported on CFX concentration in adipose tissue. Reported rates of SSI were 4.7% and 6.8% after administration of a single 1500 mg dose of CFX administrated after cord clamping (n = 144 women). There is limited data on pharmacokinetics of CFX for CS. There were no studies that reported CFX concentrations or SSI in obese women.

Prenatal chromosomal microarray testing of fetuses with ultrasound structural anomalies: A prospective cohort study of over 1000 consecutive cases.

OBJECTIVE: Evaluate the diagnostic yield of prenatal submicroscopic chromosome anomalies using prenatal array comparative genomic hybridisation (aCGH). METHOD: Prospective cohort study conducted between March 2013 and June 2017 including fetuses where an elevated nuchal translucency (NT) or structural anomaly was identified on ultrasound and common aneuploidy testing was negative. aCGH was performed using an 8-plex oligonucleotide platform with a genome wide backbone resolution of greater than 200 kb and interpretation in line with American College of Medical Genetics guidance. RESULTS: One thousand one hundred twenty-nine fetuses were included; 371 fetuses with an increased NT (32.9%) and 758 with a structural anomaly (67.1%). The rate of pathogenic copy number variants (CNVs) and variant of uncertain significance (VUS) was 5.9% (n = 22) and 0.5% (n = 2) in the elevated NT group and 7.3% (n = 55) and 0.8% (n = 6) in the mid-trimester anomaly group. No pathogenic CNVs were identified in fetuses with an NT less than 4.0 mm. Multisystem and cardiac anomalies had the greatest yield of pathogenic CNV with a 22q11.2 microdeletion present in 40% (12/30). CONCLUSION: Prenatal aCGH is a useful diagnostic tool in the investigation of fetuses with a significantly elevated NT or structural anomaly. With time and experience, rates of pathogenic CNVs have increased, and VUS have reduced, supporting the prenatal application of increasingly high resolution aCGH platforms.

TRAIL suppresses gut inflammation and inhibits colitogeic T-cell activation in experimental colitis via an apoptosis-independent pathway.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces cell apoptosis by transducing apoptosis signals. Recently, accumulating evidence demonstrated that TRAIL regulates autoimmune inflammation and immune cell homeostasis in several autoimmune animal models, suggesting a novel immunoregulatory role of TRAIL in autoimmune diseases. However, the impact of TRAIL in inflammatory bowel disease is yet undefined. This study is to address the therapeutic effects and immunoregulatory role of TRAIL in autoimmune gut inflammation. We demonstrated herein that TRAIL significantly suppressed gut inflammation and reduced the severity of colitis in a dextran sodium sulfate (DSS)-induced colitis model. Suppression of gut inflammation was not due to induction of apoptosis in colonic T cells, dendritic cells, or epithelium cells by TRAIL. In contrast, TRAIL directly inhibited activation of colitogenic T cells and development of gut inflammation in an adoptive transfer-induced colitis model. The anti-inflammatory effects of TRAIL on colitis were abolished when T cells from TRAIL receptor (TRAIL-R) knockout mice were adoptively transferred, suggesting that TRAIL regulates autoreactive colitogenic T-cell activation in the development of gut inflammation. Our results demonstrate that TRAIL effectively inhibited colonic T-cell activation and suppressed autoimmune colitis, suggesting a potential therapeutic application of TRAIL in human inflammatory bowel disease.

On the representation of effective stress for computing hemolysis.

Hemolysis is a major concern in blood-circulating devices, which arises due to hydrodynamic loading on red blood cells from ambient flow environment. Hemolysis estimation models have often been used to aid hemocompatibility design. The preponderance of hemolysis models was formulated on the basis of laminar flows. However, flows in blood-circulating devices are rather complex and can be laminar, transitional or turbulent. It is an extrapolation to apply these models to turbulent flows. For the commonly used power-law models, effective stress has often been represented using Reynolds stresses for estimating hemolysis in turbulent flows. This practice tends to overpredict hemolysis. This study focused on the representation of effective stress in power-law models. Through arithmetic manipulations from Navier-Stokes equation, we showed that effective stress can be represented in terms of energy dissipation, which can be readily obtained from CFD simulations. Three cases were tested, including a capillary tube, the FDA benchmark cases of nozzle model and blood pump. The results showed that the representation of effective stress in terms of energy dissipation greatly improved the prediction of hemolysis for a wide range of flow conditions. The improvement increases as Reynolds number increases; the overprediction of hemolysis was reduced by up to two orders of magnitude.

Dominant effect of relative tropical Atlantic warming on major hurricane occurrence.

Here we explore factors potentially linked to the enhanced major hurricane activity in the Atlantic Ocean during 2017. Using a suite of high-resolution model experiments, we show that the increase in 2017 major hurricanes was not primarily caused by La Niña conditions in the Pacific Ocean but rather triggered mainly by pronounced warm sea surface conditions in the tropical North Atlantic. Further, we superimpose a similar pattern of North Atlantic surface warming on data for long-term increasing sea surface temperature (a product of increases in greenhouse gas concentrations and decreases in aerosols) to show that this warming trend will likely lead to even higher numbers of major hurricanes in the future. The key factor controlling Atlantic major hurricane activity appears to be the degree to which the tropical Atlantic warms relative to the rest of the global ocean.

Two-color volumetric laser-induced fluorescence for 3D OH and temperature fields in turbulent reacting flows.

Single-shot, two-color, volumetric laser-induced fluorescence was demonstrated for three-dimensional (3D), tomographic imaging of the structural properties of the OH radical and temperature field in a turbulent hydrogen-air flame. Two narrowband laser sources were tuned to the Q1(5) and Q1(14) transitions of the (1,0) band in the A2Σ←X2Π system and illuminated a volumetric region of the flame. Images from eight unique perspectives collected simultaneously from each of the two transitions were used to reconstruct overlapping OH fields with different Boltzmann fractions and map the 3D temperature distribution with nanosecond precision. Key strategies for minimizing sources of error, such as detector sensitivity and spatial overlap of the two fields, are discussed.

The application of individual virtual nostalgic game design to the evaluation of cognitive function.

The aim of this study was to develop a task set based on personalized material for nostalgic experience, which could detect cognitive ability via a virtual experience system combined with Kinect somatosensory interactive operation applications without the user wearing any accessory input device. Fifty-nine subjects participated in the experiment. The receiver operating characteristic curve of the game system was statistically analyzed for determining the best cutoff-point in the cognitive function assessment. Correlation analysis and regression analysis were used to explore the correlations between the results and the clinical cognitive assessment scales. According to the MoCA scores, the results showed that the accuracy of the system was 86.4% in evaluating mild cognitive impairment. The system seems feasible and was strongly correlated with clinical cognitive assessment scales. We anticipate that daily use of our system could keep track of changes of cognitive function of the elderly in home life.

The risk of lower gastrointestinal bleeding in low-dose aspirin users.

BACKGROUND: Aspirin increases the risk of gastrointestinal bleeding. AIM: To investigate the risk of lower gastrointestinal bleeding (LGIB) in aspirin users. METHODS: Low-dose (75-325 mg daily) aspirin users and controls matched by age, gender and enrollment time in a 1:5 ratio were selected from 1 million randomly sampled subjects in the National Health Insurance Research Database of Taiwan. Cox proportional hazard regression models were developed to evaluate the predictors of LGIB with adjustments for age, gender, comorbidities including coronary artery disease, ischaemic stroke, diabetes, hypertension, chronic kidney disease, liver cirrhosis, chronic obstructive pulmonary disease, dyslipidemia, uncomplicated peptic ulcer disease, history of peptic ulcer bleeding, and concomitant use of clopidogrel, ticlopidine, warfarin, nonsteroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase-2 inhibitors, steroids, proton pump inhibitors (PPIs), histamine-2 receptor antagonists (H2RAs), nitrates, alendronate, selective serotonin reuptake inhibitors (SSRIs) and calcium channel blockers. RESULTS: A total of 53 805 aspirin users and 269 025 controls were included. Aspirin group had a higher incidence of LGIB within 1 year than control group (0.20% vs 0.06%, P<.0001). Aspirin (hazard ratio [HR]: 2.75, 95% confidence interval [CI]: 2.06-3.65), NSAIDs (HR: 8.61, 95% CI: 3.28-22.58), steroids (HR: 10.50, 95% CI: 1.98-55.57), SSRIs (HR: 11.71, 95% CI: 1.40-97.94), PPIs (HR: 8.47, 95% CI: 2.26-31.71), and H2RAs (HR: 10.83, 95% CI: 2.98-39.33) were significantly associated with LGIB. CONCLUSIONS: The risk of LGIB was higher in low-dose aspirin users than in aspirin nonusers in this nationwide cohort. Low-dose aspirin, NSAIDs, steroids, SSRIs, PPIs and H2RAs were independent risk factors for LGIB.