Search for Boosted Dark Matter in COSINE-100.

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7 kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

DFTB+, a software package for efficient approximate density functional theory based atomistic simulations.

DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods. Based on the DFTB framework, it additionally offers approximated versions of various DFT extensions including hybrid functionals, time dependent formalism for treating excited systems, electron transport using non-equilibrium Green's functions, and many more. DFTB+ can be used as a user-friendly standalone application in addition to being embedded into other software packages as a library or acting as a calculation-server accessed by socket communication. We give an overview of the recently developed capabilities of the DFTB+ code, demonstrating with a few use case examples, discuss the strengths and weaknesses of the various features, and also discuss on-going developments and possible future perspectives.

Comparative outcomes of robot-assisted minimally invasive versus open esophagectomy in patients with esophageal squamous cell carcinoma: a propensity score-weighted analysis.

Robots are increasingly used in minimally invasive surgery. We evaluated the clinical benefits of robot-assisted minimally invasive esophagectomy (RAMIE) in comparison with the conventional open esophageal surgery. From 2012 to 2016, 371 patients with esophageal squamous cell carcinoma underwent an Ivor Lewis or McKeown procedure at our institution. Of these, 130 patients underwent laparoscopic gastric conduit formation followed by RAMIE, whereas 241 patients underwent conventional esophageal surgery, including laparotomy and open esophagectomy (OE). We compared the short- and long-term clinical outcomes of these patients using the propensity score-based inverse probability of treatment weighting technique (IPTW). Among the early outcomes, the OE group showed a higher incidence of pneumonia (P = 0.035) and a higher requirement for vasopressors (P = 0.001). Regarding the long-term outcomes, all-cause mortality was significantly higher (P = 0.001) and disease-free survival was lower (P = 0.006) in the OE group. Wound-related problems also occurred more frequently in the OE group (P = 0.020) during the long-term follow-up. There was no statistical intergroup difference in the recurrence rates (P = 0.191). The Cox proportional-hazard analysis demonstrated that wound problems (HR 0.16, 95% CI 0.02-0.57; P = 0.017), pneumonia (HR 0.23, 95% CI 0.06-0.68; P = 0.019), and use of vasopressors (HR 0.14, 95% CI 0.08-0.25; P = 0.001) were independent predictors of mortality. RAMIE could be a better surgical option for selected patients with esophageal squamous cell carcinoma.

Diagnostic Performance of Multidetector Computerized Tomography in the Detection of Abdominal Complications Early and Late After Liver Transplantation: A 10-Year Experience.

BACKGROUND: Multidetector computerized tomography (MDCT) is considered to be a fast noninvasive diagnostic technique for the evaluation of postoperative complications in patients with liver transplantation (LT). However, its role has not been fully established in the diagnosis for detecting complications after liver transplantation. The aim of this work was to evaluate the diagnostic performance of MDCT for detecting abdominal complications in the early and late periods after LT. METHODS: We retrospectively enrolled 75 patients who had undergone LT from March 2006 to January 2010, followed by MDCT from March 2006 to November 2017. Patients were divided into 2 groups according to the timing after LT: within the first 3 months (early period) or ≥3 months after LT (late period). We evaluated vascular, biliary, and other complications on MDCT. Angiography, endoscopic retrograde cholangiography, and percutaneous transhepatic cholangiography were used as reference standards. RESULTS: We initially found 77 complications in 45 patients (60.0%) with the use of MDCT. After comparison with the reference standards, 83 complications were diagnosed in 49 patients (65.3%). Forty-seven complications (34 vascular, 10 biliary, 3 other complications) were diagnosed in 33 patients (44.0%) during the early period, and 36 complications (6 vascular, 20 biliary, 10 other complications) were detected in 27 patients (36.0%) in the late period. The sensitivity, specificity, and diagnostic accuracy of MDCT for diagnosing overall complications were, respectively, 93.6%, 90.2%, and 92.0% in the early period (for vascular complications: 97.1%, 92.6%, and 94.3%,; for biliary complications: 80.0%, 100%, and 97.7%) and 77.8%, 98.1%, and 89.8% in the late period (for vascular complications: 83.3%, 100%, and 98.9%; for biliary complications: 65.0%, 98.6%, and 90.9%). CONCLUSIONS: Although MDCT in the late period should be interpreted with caution in patients with suspected biliary complication, MDCT is a reliable diagnostic technique for the identification of early and late abdominal complications after LT.

Incidence of psoriasiform diseases secondary to tumour necrosis factor antagonists in patients with inflammatory bowel disease: a nationwide population-based cohort study.

BACKGROUND: There are increasing reports of paradoxical psoriasiform diseases secondary to anti-tumour necrosis factor (TNF) agents. AIMS: To determine the risks of paradoxical psoriasiform diseases secondary to anti-TNF agents in patients with inflammatory bowel disease (IBD). METHODS: A nationwide population study was performed using the Korea National Health Insurance Claim Data. A total of 50 502 patients with IBD were identified between 2007 and 2016. We compared 5428 patients who were treated with any anti-TNF agent for more than 6 months (anti-TNF group) and 10 856 matched controls who had never taken anti-TNF agents (control group). RESULTS: Incidence of psoriasis was significantly higher in the anti-TNF group (36.8 per 10 000 person-years) compared to the control group (14.5 per 10 000 person-years) (hazard ratio [HR] 2.357, 95% confidence interval [CI] 1.668-3.331). Palmoplantar pustulosis (HR 9.355, 95% CI 2.754-31.780) and psoriatic arthritis (HR 2.926, 95% CI 1.640-5.218) also showed higher risks in the anti-TNF group. In subgroup analyses, HRs for psoriasis by IBD subtype were 2.549 (95% CI 1.658-3.920) in Crohn's disease and 2.105 (95% CI 1.155-3.836) in ulcerative colitis. Interestingly, men and younger (10-39 years) patients have significantly higher risks of palmoplantar pustulosis (HR 19.682 [95% CI 3.867-100.169] and HR 14.318 [95% CI 2.915-70.315], respectively), whereas women and older (≥40 years) patients showed similar rates between the two groups. CONCLUSIONS: The risks of psoriasiform diseases are increased by anti-TNF agents in patients with IBD. Among psoriasiform diseases, the risk of palmoplantar pustulosis shows the biggest increase particularly in male and younger patients.

Effect of weight bearing exercise to improve bone mineral density in children with cerebral palsy: a meta-analysis.

BACKGROUND: Despite widespread clinical use of weight bearing exercises to manage low bone mineral density (BMD) in children and adolescents with cerebral palsy (CP), previous studies have reported heterogeneous results on the effect of weight bearing exercise on BMD. PURPOSE: We performed the current meta-analysis to assess the effects of weight bearing exercise on increasing BMD in children who have CP with low BMD. MATERIALS AND METHODS: We searched PubMed, Cochrane, and Embase from inception through to October 2016 for studies that aims to investigate the effect of weight bearing exercise on BMD in children with CP. Following the searching result, the 118 relevant studies were reviewed and undergone selection process. Standardized mean difference (SMD), 95% confidence intervals (CIs) and p-values were calculated for analysis. RESULTS: Three studies were ultimately included in the meta-analysis: one randomized-controlled study and two case-controlled studies. No significant difference was observed in the BMD of the lumbar spine between before treatment and after treatment (SMD,0.341; 95% CI,-0.647-1.330; p=0.449) but the BMD of the femur significantly improved after applying weight bearing exercise compared to pre-treatment values (SMD, 0.916; 95% CI, 0.382-1.114; p⟨0.001). CONCLUSIONS: Weight bearing exercise has a significant effect on improving BMD of the femur in children with CP.

Functional neuroimaging studies in functional dyspepsia patients: a systematic review.

BACKGROUND: There is increasing evidence in support of the presence of abnormal central changes (compared to healthy controls) in functional dyspepsia (FD) in addition to the peripheral changes in gastrointestinal tract. PURPOSE: This systematic review aims to provide an integrative understanding of the abnormal functional brain activity, visceral sensation, dyspeptic symptoms, and psychological changes of FD. Electronic and hand searches were conducted to identify functional neuroimaging studies involving FD patients. Sixteen studies were selected and divided into three categories: 10 resting state studies, three visceral distention studies, and three acupuncture studies. Changes were reported in several brain areas in FD patients including the frontal cortex, somatosensory cortex, insula, anterior cingulate cortex, thalamus, hippocampus, and amygdala. These brain activity changes were associated with visceral hypersensitivity, dyspeptic symptoms, poorer quality of life, anxiety, and depression. The results show that FD is associated with functional abnormalities in sensory and pain modulation, emotion, saliency, and homeostatic processing regions. The diversity of conditions, heterogeneous results, poorly standardized diagnoses of FD, and various comorbidities may be responsible for the variability in the results.

Saturation of the biological response to orthodontic forces and its effect on the rate of tooth movement.

OBJECTIVES: Investigate the expression and activity of inflammatory markers in response to different magnitudes of orthodontic forces and correlate this response with other molecular and cellular events during orthodontic tooth movement. SETTING AND SAMPLE POPULATION: CTOR Laboratory; 245 Sprague Dawley male rats. METHODS AND MATERIALS: Control, sham, and 5 different experimental groups received different magnitudes of force on the right maxillary first molar using a coil spring. In the sham group, the spring was not activated. Control group did not receive any appliance. At days 1, 3, 7, 14, and 28, the maxillae were collected for RNA and protein analysis, immunohistochemistry, and micro-CT. RESULTS: There was a linear relation between the force and the level of cytokine expression at lower magnitudes of force. Higher magnitudes of force did not increase the expression of cytokines. Activity of CCL2, CCL5, IL-1, TNF-α, RANKL, and number of osteoclasts reached a saturation point in response to higher magnitudes of force, with unchanged rate of tooth movement. CONCLUSION: After a certain magnitude of force, there is a saturation in the biological response, and higher forces do not increase inflammatory markers, osteoclasts, nor the amount of tooth movement. Therefore, higher forces to accelerate the rate of tooth movement are not justified.

Impact of extranodal extension on prognosis in lymph node-positive gastric cancer.

BACKGROUND: The TNM classification system is used widely for tumour staging, and directs the treatment and prognosis of patients with cancer. The aim of this study was to assess the prognostic value of extranodal extension (ENE) in patients with early gastric cancer. METHODS: All patients who underwent gastrectomy with lymphadenectomy for primary gastric cancer with lymph node metastases between January 2003 and June 2006 were reviewed. Histological slides of metastatic nodes were reviewed by two gastrointestinal pathologists. The association of ENE with clinicopathological characteristics was assessed. The disease-specific survival rate was calculated by the Kaplan-Meier method, and a multivariable Cox regression model was used to identify independent prognostic factors. RESULTS: Some 1143 patients were included. ENE was associated with advanced pT and pN category, larger tumour size and lymphovascular/perineural invasion. In multivariable analysis, pT category, pN category, ENE, lymphovascular invasion and perineural invasion were found to be independent prognostic factors in node-positive gastric carcinoma. The 5-year survival rate of patients with ENE was 48·1 per cent, compared with 78·2 per cent for patients without ENE (P < 0·001). In the subgroup of patients with early gastric cancer, ENE was associated with a worse 5-year survival rate in patients with early (T1) gastric cancer: 75 per cent in patients with ENE versus 96·9 per cent in those without (P < 0·001). CONCLUSION: ENE is an independent prognostic factor in patients with early and advanced gastric cancer.

Comparison of three-dimensional isotropic and conventional MR arthrography with respect to the diagnosis of rotator cuff and labral lesions: focus on isotropic fat-suppressed proton density and VIBE sequences.

AIM: To compare the diagnostic accuracies of three-dimensional (3D) isotropic magnetic resonance arthrography (MRA) using fat-suppressed proton density (PD) or volume interpolated breath-hold examination (VIBE) sequences with that of conventional MRA for the diagnosis of rotator cuff and labral lesions. MATERIALS AND METHODS: Eighty-six patients who underwent arthroscopic surgery were included. 3D isotropic sequences were performed in the axial plane using fat-suppressed PD (group A) in 53 patients and using VIBE (group B) in 33 patients. Reformatted images were obtained corresponding to conventional images, and evaluated for the presence of labral and rotator cuff lesions using conventional and 3D isotropic sequences. The diagnostic performances of each sequence were determined using arthroscopic findings as the standard. RESULTS: Good to excellent interobserver agreements were obtained for both 3D isotropic sequences for the evaluation of rotator cuff and labral lesions. Excellent agreement was found between two-dimensional (2D) and 3D isotropic MRA, except for supraspinatus tendon (SST) tears by both readers and for subscapularis tendon (SCT) tears by reader 2 in group B. 2D MRA and 3D isotropic sequences had high diagnostic performances for rotator and labral tears, and the difference between the two imaging methods was insignificant. CONCLUSIONS: The diagnostic performances of 3D isotropic VIBE and PD sequences were similar to those of 2D MRA.

Polynucleotide phosphorylase (PNPase) is required for Salmonella enterica serovar Typhimurium colonization in swine.

The pnp gene encodes polynucleotide phosphorylase, an exoribonuclease involved in RNA processing and degradation. A mutation in the pnp gene was previously identified by our group in a signature-tagged mutagenesis screen designed to search for Salmonella enterica serovar Typhimurium genes required for survival in an ex vivo swine stomach content assay. In the current study, attenuation and colonization potential of a S. Typhimurium pnp mutant in the porcine host was evaluated. Following intranasal inoculation with 10(9) cfu of either the wild-type S. Typhimurium χ4232 strain or an isogenic derivative lacking the pnp gene (n = 5/group), a significant increase (p < 0.05) in rectal temperature (fever) was observed in the pigs inoculated with wild-type S. Typhimurium compared to the pigs inoculated with the pnp mutant. Fecal shedding of the pnp mutant was significantly reduced during the 7-day study compared to the wild-type strain (p < 0.001). Tissue colonization was also significantly reduced in the pigs inoculated with the pnp mutant compared to the parental strain, including the tonsils, ileocecal lymph nodes, Peyer's Patch region of the ileum, cecum and contents of the cecum (p < 0.05). The data indicate that the pnp gene is required for S. Typhimurium virulence and gastrointestinal colonization of the natural swine host.

Suitability of endoscopic submucosal dissection for treatment of submucosal gastric cancers.

BACKGROUND: Endoscopic submucosal dissection (ESD) is not considered appropriate for all submucosal cancers owing to the risk of lymph node metastasis and difficulty estimating the deep margin status. This study aimed to determine predictive factors for lymph node metastases in submucosal cancer and to explore in which patients ESD might be feasible. METHODS: Details of patients who had curative gastrectomy for submucosal gastric cancer at Asan Medical Centre from 2007 to 2011 were reviewed retrospectively to determine the relationship between lymph node metastasis and clinicopathological characteristics, including age, sex, tumour location, size, gross appearance, depth of invasion, histological type/differentiation, presence of lymphovascular/perineural invasion, and immunohistochemical staining results for p53, human epidermal growth factor receptor (HER) 1 and HER2. RESULTS: A total of 1773 patients were analysed. The presence of lymphovascular invasion was related most strongly to lymph node metastasis. Multivariable analysis revealed that depth of invasion, tumour size, differentiation, gross appearance and perineural invasion were also related. Metastatic lymph nodes were found in four of 105 patients who met the classical criteria for ESD; all showed a moderately differentiated histological appearance. No lymph node metastases were observed in well differentiated SM1 tumours of any size (infiltration into upper third of submucosa), or in well differentiated SM2 (infiltration into middle third of submucosa) tumours of 2 cm or less without lymphovascular invasion. CONCLUSION: Patients with well differentiated SM1 cancer of any size and those with well differentiated SM2 cancer of 2 cm or less without lymphovascular invasion may be suitable candidates for ESD.

Analyses of short-term follow-up MRI and PET-CT for evaluation of residual tumour after inadequate primary resection of malignant soft-tissue tumours.

AIM: To differentiate remnant tumour from postoperative changes on short-term follow-up magnetic resonance imaging (MRI) or combined positron-emission tomography (PET) and computed tomography (CT) after inadequate primary resection of malignant soft-tissue tumours. MATERIALS AND METHODS: From January 2007 through September 2010, 35 patients (18 women and 17 men; mean age 48 years; age range 18-78 years) who underwent MRI and PET-CT within 64 days after surgery for malignant soft-tissue tumours were included. MRI images were assessed for the following findings: the presence of delineated enhancing portions; fascial thickening; and fluid or haematomas with measurable wall thickening. The PET-CT data were analysed using the standardized uptake value (SUV) and the uptake pattern. RESULTS: The correlation of tumour grade and the presence of remnant tumour was significant (p = 0.026). After re-excision, remnant tumour was demonstrated in 15 patients and no tumour cells were discovered in 20 patients. The finding of focally delineated enhancing portions on MRI images and the SUVmax on PET-CT analysis were significantly correlated with the remnant tumour (each p = 0.001 and p = 0.036). CONCLUSIONS: To evaluate the presence of remnant tumour after inadequate excision of malignant soft-tissue tumours, an MRI finding of a focally enhancing area and an SUVmax of >2 on PET-CT might be helpful factors. The coexistence of these two findings would be even more helpful for the detection of residual tumours.

The clinical characteristics of gastroesophageal reflux disease in patients with laryngeal symptoms who are referred to gastroenterology.

The prevalence of gastroesophageal reflux disease (GERD) has increased recently in Asia-Pacific countries. However, little is known about its prevalence and clinical characteristics in GERD patients with atypical symptoms in Asia. The aim of this study was to investigate the clinical characteristics of GERD in patients who had laryngeal symptoms in Korea. Data were gathered retrospectively from patients who presented with atypical symptoms, such as throat discomfort, globus pharyngeus, hoarseness, and chronic cough. They underwent a 24-hour ambulatory intraesophageal pH monitoring and filled in a validated reflux questionnaire. Overall, 128 patients (36 men and 92 women) with laryngeal symptoms were included. Of these 128, 43 patients (34%) had erosive esophagitis or pathological reflux from 24-hour ambulatory pH monitoring, and 24 (19%) had a positive Bernstein test or positive symptom index from 24-hour pH monitoring. Sixty-one patients (48%) had no evidence of reflux esophagitis on upper endoscopy and pathological acid reflux on 24-hour pH monitoring. Fifty-six patients (44%) had weekly heartburn or regurgitation. Typical symptoms and dyspepsia were significantly more common in patients with GERD who had laryngeal symptoms than non-GERD. Fifty-two percent of patients had laryngeal symptoms that were associated with GERD. The presence of typical reflux symptoms and dyspepsia are risk factors for GERD in patients who present with laryngeal symptoms.

Prognostic factors and recurrence pattern in node-negative advanced gastric cancer.

AIMS: Despite better overall survival in node-negative advanced gastric cancer (AGC), a significant proportion of patients develop recurrence and they may benefit from adjuvant therapy. The aim of this study was to evaluate the prognostic factors and recurrence pattern of node-negative AGC. METHODS: A total of 424 patients who underwent curative gastrectomy with extended lymphadenectomy for node-negative AGC between 2003 and 2005 were retrospectively reviewed. Patients with tumor involvement of adjacent organs (T4b), gastric cancer recurrence, tumor in the remnant stomach, less than 15 harvested lymph nodes, and those who received neoadjuvant chemotherapy were excluded. RESULTS: Invasion to deeper layers, undifferentiated histology, signet ring cell type compared with tubular adenocarcinoma, and tumor size larger than 6.3 cm correlated with poorer prognosis in univariate analysis. In multivariate one, however, only differentiation and depth of invasion, especially the presence of serosa involvement were significant. The 5-year survival rates of the four groups classified by differentiation and depth of invasion [T2/3 (differentiated type), T2/3 (undifferentiated type), T4a (differentiated type), and T4a (undifferentiated type)] were 98%, 92%, 80%, and 72%, respectively (P < 0.01). In terms of recurrence pattern, Lauren's type and depth of invasion were significant. Recurrence with peritoneal seeding was associated with the diffuse type and invasion into the subserosa or serosa, while hematogenous metastasis was related to the intestinal type and invasion to the proper muscle or subserosa layer. CONCLUSIONS: Differentiation and serosa involvement should be considered to stratify patients with node-negative AGC for adjuvant treatment.

CT and MRI of fibrous dysplasia of the spine.

OBJECTIVES: The purpose of this study was to present the CT and MRI findings of patients with fibrous dysplasia (FD) of the spine. METHODS: Among the patients with pathologically proven skeletal FD, 12 (8 males and 4 females; mean age, 43 years) who were evaluated with either spine CT or MRI were included. The number and location of the involved vertebral segments, the presence of lytic lesions, ground-glass opacity (GGO), an expansile nature, cortical disruption, a sclerotic rim, a decrease in body height and contour deformity were examined on CT scans (n=12), while signal intensity, enhancement patterns and the presence of a dark signal rim on the lesion were examined using MRI (n=9). RESULTS: Nine patients had polyostotic FD, including one with an isolated spinal localisation, while three had monostotic FD. An expansile nature (n=3) and osteolytic lesions with GGO (n=3) were seen. On CT images, GGO was noted in all patients. An expansile nature (n=11) and presence of lytic lesions (n=11) were noted. A decrease in body height (n=9) and sclerotic rim formation (n=9) were indicated. Contour deformities were visible in six patients. The MRI findings were non-specific. Dark signal rims were visible on MRI in seven patients. CONCLUSION: Typical imaging findings of extraspinal FD were noted on spine CT scans. These characteristic CT imaging findings of spinal FD may be helpful in differentiating FD from other common spine diseases.

In vivo biocompatibility and degradation behavior of Mg alloy coated by calcium phosphate in a rabbit model.

This study is conducted to investigate the biocompatibility and biodegradation behavior of calcium phosphate-coated Mg alloy in vivo. Calcium phosphate (Ca-P) was coated on the Mg alloy (AZ31) by a chemical process. Samples of Ca-P coated rods, the naked alloy rods, and degradable polymer as controls were implanted into the thighbone of rabbits to investigate the bone response at the early stage. The reduction in implant volume was determined by micro-computed tomography and three-dimensional reconstruction of the remaining Mg alloy segmented from the bone matrix. It was observed that the biodegradation rate of naked Mg implant is faster than that of the coated ones. The bone-implant interface was characterized in sections by scanning electron microscopy with energy-dispersive spectroscopy. Biodegradation or reaction layer was formed on the surface of Mg alloy implants and direct contact with the surrounding bone. The layer was mainly composed of Ca, P, O, and Mg. After 8 weeks of post-operation, paraffin sections were generated for histomorphologic analysis; 100% implants were fixed and no inflammation was observed. Histological analysis showed that new bone tissue is formed around the Mg implants, and no fibrous capsule was found. Blood examination showed that the biodegradation of the Mg implant caused little change to blood composition. Ca-P coating on Mg alloy substrate might be an effective method to reduce the biodegradation rate of Mg alloy in vivo and improve the surface bioactivity of Mg alloy implants.

Comparison of bolus transit patterns identified by esophageal impedance to barium esophagram in patients with dysphagia.

Bolus transit through the esophagus has not been validated by videoesophagram in patients with dysphagia and changes in impedance with abnormal barium transit have not been described in those patients. The aim of this study was to compare esophageal impedance findings with barium esophagram measurements in patients with dysphagia. The consecutive patients with dysphagia underwent conventional multichannel esophageal impedance manometry, after which a barium videoesophagram was performed simultaneously with multichannel esophageal impedance manometry using a mean of three swallows of barium. Esophageal emptying patterns shown in the esophagogram were classified by the degree of intraesophageal stasis and presence of intraesophageal reflux. Bolus transit patterns in impedance were classified as complete and incomplete transit. Sixteen patients (M : F = 8 : 8, mean age, 47 years) were enrolled. Their manometric diagnosis were normal (n= 6), ineffective esophageal motility (n= 1), diffuse esophageal spasm (DES; n= 2), and achalasia (n= 7). Sixty-three swallows were analyzed. According to impedance analysis, 21/22 swallows with normal barium emptying showed complete transit (96%) and 31/32 swallows with severe stasis showed incomplete transit (97%). Nine swallows with mild stasis showed either complete or incomplete transit patterns in impedance. Swallows with mild barium stasis and complete transit in impedance were observed in patients who had received treatment (two patients with achalasia with history of esophageal balloonplasty and a patient with DES after nifedipine administration). Impedance reflected severe stasis with retrograde barium movement and described typical bolus transit patterns in patients with achalasia and DES. In conclusion, impedance-barium esophagram concordance is high for swallows with normal esophageal emptying and for severe barium stasis in patients with dysphagia.