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A colonic pseudo-obstruction is a disorder that causes abdominal distension and abdominal pain similar to a mechanical obstruction, but there are no structural lesions that can obstruct the gastrointestinal tract. This condition can be acute or chronic. An acute colonic pseudo-obstruction, also called Ogilvie's syndrome, is believed to be a condition induced by other causes that are different from a chronic colonic pseudo-obstruction. The pathogenesis involves abnormalities in the autonomic nervous system induced by systemic diseases or medications, and it often improves when the primary causes are treated. On the other hand, a chronic colonic pseudo-obstruction can occur repeatedly without a particular cause. The authors encountered neuroleptic malignant syndrome that caused acute colonic pseudo-obstruction. This paper reports a case with a review of the relevant literature. This is the first case reported in Korea. This case shows that physicians should consider neuroleptic malignant syndrome as a cause of an acute colonic pseudo- obstruction.

Cecal intubation is essential during colonoscopy, and observation of the terminal ileum is performed in most clinical practices. However, data on terminal ileal (TI) ulcers observed incidentally during colonoscopy are rare. We aimed to identify the characteristics and clinical course of TI ulcers observed incidentally during colonoscopy. Between January 2008 and December 2018, medical records from multi-centers reporting asymptomatic subjects who underwent biopsy on TI ulcers during colonoscopy were retrospectively reviewed. The characteristics of endoscopic findings and clinical course of TI ulcers were analyzed, and the factors affecting the clinical course of TI ulcers were evaluated. The median follow-up durations from first to second colonoscopy and from second to third colonoscopy were 20 months (interquartile range, 12–36) and 24 months (interquartile range, 12–34), respectively. A total of 134 subjects were included in the analysis. The histopathologic findings of TI ulcers were mostly chronic or active ileitis/inflammation (92.7%). On the second colonoscopy, 59 (44.0%) patients had no ulcers, 38 (28.4%) showed a decrease in size or number, and 37 (27.6%) patients showed no change in ulcers. Among 62 subjects who underwent a third colonoscopy, 14 (10.4%) had decreased size or number, 10 (7.5%) had no ulcer change, and two (1.5%) had increased ulcer size or number. In multivariate logistic regression analysis, a star shape was the only factor affecting continuation without improvement of incidental TI ulcers. Most TI ulcers observed incidentally showed no unusual findings on biopsy and improved on follow-up colonoscopy without treatment.

Colonoscopy is a safe and extremely popular diagnostic and therapeutic procedure. The most common complications are bleeding and perforation. Hemoperitoneum is a rare complication after a colonoscopy and is usually associated with splenic injury or solid organ pathology. This is potentially serious and can be life threatening. With the increasing number of colonoscopies performed, there has also been an increasing trend in reports of rare complications, such as pneumothorax, pneumomediastinum, appendicitis, small bowel perforation, septicemia, mesenteric tear, retroperitoneal abscess, and hemoperitoneum. This paper reports a unique case of hemoperitoneum after a recent colonoscopy without a splenic rupture or intra-abdominal abnormality, or external trauma. Most hemoperitoneum occurs within 48 hours after the inciting colonoscopy. In the present case, however, hemoperitoneum appeared 10 days after the colonoscopy. This case emphasizes that physicians should consider hemoperitoneum in a differential diagnosis of abdominal pain in patients after colonoscopy.

Adenoma detection rate (ADR) is an important quality indicator of colonoscopy. High-definition (HD) colonoscopy has been reported to increase ADR compared to standard-definition (SD) colonoscopy. Although there are few reports comparing the latest generation and the previous generation of HD colonoscopy equipment, there are reports that the latest generation colonoscopy equipment improves ADR. However, there are no reports on the impact of the latest generation HD colonoscopy on the ADR of trainee endoscopists. The aim of this study was to investigate whether the latest generation HD colonoscopy increases the ADR of trainee endoscopists compared with the previous generation HD colonoscopy. We conducted a retrospective review of medical records of patients aged 40–79 years old, who underwent screening or surveillance colonoscopy performed by nine gastroenterology fellows at Dong-A University Hospital from March 2019 to February 2020. We calculated the overall ratios of the ADR: the ADRs of the group using the older generation HD colonoscopy equipment and the group using the latest HD colonoscopy equipment. Polyp detection rate (PDR), sessile serrated polyp detection rate (SSPDR), and advanced neoplasia detection rate (ANDR) were calculated for each group. Factors related to adenoma detection were identified using logistic regression analysis. Altogether, 2189 patients were included in the study (the older HD colonoscopy group comprising 1183 and the latest HD colonoscopy group comprising 1006). We found that PDR (45.98 vs. 51.69%, p = 0.008) and ADR (35.67 vs. 40.85%, p = 0.013) were significantly higher in the latest generation HD colonoscopy group. The generational differences were not statistically significant for SSPDR (1.94 vs. 2.78%, p = 0.195) or ANDR (4.65 vs. 4.97%, p = 0.726). In the multivariate regression analysis, age, male sex, the latest generation HD colonoscopy, and long withdrawal time were the most significant factors affecting adenoma detection. The latest generation HD colonoscopy improved PDR and ADR by trainee endoscopists. These findings suggest that latest generation, higher-resolution colonoscopy equipment can improve the quality of colonoscopy for less experienced endoscopists.

Multiple primary malignancies are defined as the presence of more than one malignant neoplasm with a distinct histology occurring at different sites in the same individual. They are classified as synchronous or metachronous according to the diagnostic time interval of different malignancies. Diagnosis of multiple primary malignancies should avoid misclassification from multifocal/multicentric tumors or recurrent/metastatic lesions. In multiple primary malignancies, with increase in the number of primary tumors, the frequency rapidly decreases. Here, we report an exceptionally rare case of a woman who was diagnosed with metachronous sporadic sextuple primary malignancies including bilateral breast cancers (gastric cancer, ovarian Sertoli-Leydig cell tumor, left breast cancer, thyroid cancer, right breast cancer, and rectal neuroendocrine tumor). The sextuple primary malignancies in this case involved 5 different organs: the stomach, ovary, thyroid, rectum, and bilateral breasts. Further studies are needed to elucidate the current epidemiologic status of patients with multiple primary malignancies.

Standard clinical care in neonatal and pediatric intensive-care units (NICUs and PICUs, respectively) involves continuous monitoring of vital signs with hard-wired devices that adhere to the skin and, in certain instances, can involve catheter-based pressure sensors inserted into the arteries. These systems entail risks of causing iatrogenic skin injuries, complicating clinical care and impeding skin-to-skin contact between parent and child. Here we present a wireless, non-invasive technology that not only offers measurement equivalency to existing clinical standards for heart rate, respiration rate, temperature and blood oxygenation, but also provides a range of important additional features, as supported by data from pilot clinical studies in both the NICU and PICU. These new modalities include tracking movements and body orientation, quantifying the physiological benefits of skin-to-skin care, capturing acoustic signatures of cardiac activity, recording vocal biomarkers associated with tonality and temporal characteristics of crying and monitoring a reliable surrogate for systolic blood pressure. These platforms have the potential to substantially enhance the quality of neonatal and pediatric critical care. Soft electronic patches worn on the skin of infants or children in intensive-care units have a wide range of capabilities in aiding critical care, including monitoring of hemodynamic parameters, cardiac activity, movement and crying.

Intussusception is a rare disease in adults. A demonstrable etiology is found in approximately 85% of all cases, and approximately 40% of them are caused by malignant tumors. A 65-year-old patient visited the outpatient department with mild abdominal pain without other symptoms. The initial laboratory test and simple X-ray showed normal findings. CT revealed intussusception in the ileocecal area. The initial colonoscopic biopsy revealed atypical cells. Follow up colonoscopy showed spontaneous reduction of the intussusception. Diffuse large B-cell lymphoma was suspected in the second colonoscopic biopsy. An elective operation was performed. This case reports a case of a spontaneous reduction of adult intussusception with a brief review of literature.

Significance Monitoring vital signs for laboring women and their fetuses is foundational to the delivery of obstetrical care; however, monitoring platforms for pregnancy have undergone little innovation over the last several decades with many low-income settings lacking basic access. We report a new time-synchronized, flexible, and wireless sensor system applicable across the entire continuum of antepartum and postpartum care that provides continuous, comprehensive, and noninvasive monitoring (heart rate, respiratory rate, and pulse oxygenation) compatible with a wide range of mobile devices. This system offers advanced features such as continuous blood pressure, uterine electrohysterography, and automated body position classification. We further demonstrate the performance of this new system among pregnant individuals (n = 576) in both high-resource settings and low-resource care settings., Vital signs monitoring is a fundamental component of ensuring the health and safety of women and newborns during pregnancy, labor, and childbirth. This monitoring is often the first step in early detection of pregnancy abnormalities, providing an opportunity for prompt, effective intervention to prevent maternal and neonatal morbidity and mortality. Contemporary pregnancy monitoring systems require numerous devices wired to large base units; at least five separate devices with distinct user interfaces are commonly used to detect uterine contractility, maternal blood oxygenation, temperature, heart rate, blood pressure, and fetal heart rate. Current monitoring technologies are expensive and complex with implementation challenges in low-resource settings where maternal morbidity and mortality is the greatest. We present an integrated monitoring platform leveraging advanced flexible electronics, wireless connectivity, and compatibility with a wide range of low-cost mobile devices. Three flexible, soft, and low-profile sensors offer comprehensive vital signs monitoring for both women and fetuses with time-synchronized operation, including advanced parameters such as continuous cuffless blood pressure, electrohysterography-derived uterine monitoring, and automated body position classification. Successful field trials of pregnant women between 25 and 41 wk of gestation in both high-resource settings (n = 91) and low-resource settings (n = 485) demonstrate the system’s performance, usability, and safety.

Sparganosis is a parasitic infestation caused by sparganum, a plerocercoid tapeworm larva of the genus Spirometra. Since the first case of human sparganosis reported in 1908, sparganosis has been a global disease, and is common in China, Japan, and Southeast Asian countries. Consumption of raw snakes, frogs, fish, or drinking contaminated beverages are sources of human infections. Human sparganosis usually manifests in subcutaneous fat in areas such as the abdomen, genitourinary tract, and limbs. Breast sparganosis cases are rare, representing less than 2% of total cases of human infections. Complete surgical extraction of the sparganum is the treatment of choice. Because of the rarity of the disease, clinical suspicion is vital to reach the diagnosis of breast sparganosis. Here we report 2 rare cases of breast sparganosis presenting with a painless breast lump, both treated with surgical excision and sparganum extraction.

Significance Continuous measurements of health status can be used to guide the care of patients and to manage the spread of infectious diseases. Conventional monitoring systems cannot be deployed outside of hospital settings, and existing wearables cannot capture key respiratory biomarkers. This paper describes an automated wireless device and a data analysis approach that overcome these limitations, tailored for COVID-19 patients, frontline health care workers, and others at high risk. Vital signs and respiratory activity such as cough can reveal early signs of infection and quantitate responses to therapeutics. Long-term trials on COVID-19 patients in clinical and home settings demonstrate the translational value of this technology., Capabilities in continuous monitoring of key physiological parameters of disease have never been more important than in the context of the global COVID-19 pandemic. Soft, skin-mounted electronics that incorporate high-bandwidth, miniaturized motion sensors enable digital, wireless measurements of mechanoacoustic (MA) signatures of both core vital signs (heart rate, respiratory rate, and temperature) and underexplored biomarkers (coughing count) with high fidelity and immunity to ambient noises. This paper summarizes an effort that integrates such MA sensors with a cloud data infrastructure and a set of analytics approaches based on digital filtering and convolutional neural networks for monitoring of COVID-19 infections in sick and healthy individuals in the hospital and the home. Unique features are in quantitative measurements of coughing and other vocal events, as indicators of both disease and infectiousness. Systematic imaging studies demonstrate correlations between the time and intensity of coughing, speaking, and laughing and the total droplet production, as an approximate indicator of the probability for disease spread. The sensors, deployed on COVID-19 patients along with healthy controls in both inpatient and home settings, record coughing frequency and intensity continuously, along with a collection of other biometrics. The results indicate a decaying trend of coughing frequency and intensity through the course of disease recovery, but with wide variations across patient populations. The methodology creates opportunities to study patterns in biometrics across individuals and among different demographic groups.

We report the development of a skin-conformable wireless sensor capable of assessing scratching for the quantification of itch., Itch is a common clinical symptom and major driver of disease-related morbidity across a wide range of medical conditions. A substantial unmet need is for objective, accurate measurements of itch. In this article, we present a noninvasive technology to objectively quantify scratching behavior via a soft, flexible, and wireless sensor that captures the acousto-mechanic signatures of scratching from the dorsum of the hand. A machine learning algorithm validated on data collected from healthy subjects (n = 10) indicates excellent performance relative to smartwatch-based approaches. Clinical validation in a cohort of predominately pediatric patients (n = 11) with moderate to severe atopic dermatitis included 46 sleep-nights totaling 378.4 hours. The data indicate an accuracy of 99.0% (84.3% sensitivity, 99.3% specificity) against visual observation. This work suggests broad capabilities relevant to applications ranging from assessing the efficacy of drugs for conditions that cause itch to monitoring disease severity and treatment response.

Smartphone-compatible, wireless, battery-free hydration sensors can monitor skin diseases in any environment., Present-day dermatological diagnostic tools are expensive, time-consuming, require substantial operational expertise, and typically probe only the superficial layers of skin (~15 μm). We introduce a soft, battery-free, noninvasive, reusable skin hydration sensor (SHS) adherable to most of the body surface. The platform measures volumetric water content (up to ~1 mm in depth) and wirelessly transmits data to any near-field communication–compatible smartphone. The SHS is readily manufacturable, comprises unique powering and encapsulation strategies, and achieves high measurement precision (±5% volumetric water content) and resolution (±0.015°C skin surface temperature). Validation on n = 16 healthy/normal human participants reveals an average skin water content of ~63% across multiple body locations. Pilot studies on patients with atopic dermatitis (AD), psoriasis, urticaria, xerosis cutis, and rosacea highlight the diagnostic capability of the SHS (PAD = 0.0034) and its ability to study impact of topical treatments on skin diseases.

Small, wireless dosimeters with light-adaptive, ultralow power consumption continuously monitor personalized light exposure., Exposure to electromagnetic radiation (EMR) from the sun and from artificial lighting systems represents a modifiable risk factor for a broad range of health conditions including skin cancer, skin aging, sleep and mood disorders, and retinal damage. Technologies for personalized EMR dosimetry could guide lifestyles toward behaviors that ensure healthy levels of exposure. Here, we report a millimeter-scale, ultralow-power digital dosimeter platform that provides continuous EMR dosimetry in an autonomous mode at one or multiple wavelengths simultaneously, with time-managed wireless, long-range communication to standard consumer devices. A single, small button cell battery supports a multiyear life span, enabled by the combined use of a light-powered, accumulation mode of detection and a light-adaptive, ultralow-power circuit design. Field studies demonstrate single- and multimodal dosimetry platforms of this type, with a focus on monitoring short-wavelength blue light from indoor lighting and display systems and ultraviolet/visible/infrared radiation from the sun.

To control such a hemorrhage, a displaced pelvic ring must be rapidly reduced and stabilized with a pelvic binder, an external fixator, or a pelvic clamp. Among them, pelvic clamps can be life-saving but pin malposition may cause vascular complications. We present a case of superior gluteal artery pseudoaneurysm caused by AO pelvic C-clamp pin malposition.

Purpose To evaluate the clinicopathological and imaging features of mammography, ultrasonography, and magnetic resonance imaging (MRI) for breast cancer in Korean women under 40 years of age according to molecular subtypes. Materials and Methods We included 183 breast cancers in 176 consecutive women under 40 years old who had been diagnosed with breast cancer between January 2012 and November 2014. The patients' clinical and pathologic records were available as electronic medical records. A retrospective review of the pre-operative imaging studies was performed with 177 mammographies, 183 ultrasonographies, and 178 MRIs. Results Eighty-six percent (158/183) of lesions were symptomatic, with masses (147/183) as the most common presentation. Eighty percent (22/25) of the asymptomatic lesions were diagnosed via screening ultrasonography. The luminal A subtype was the most common (n = 79, 43%), human epidermal growth factor receptor 2-enriched subtype showed indistinct margins on mammography (p = 0.006), the triple negative subtype depicted a posterior enhancement on ultrasonography (p < 0.001) and rim enhancement on MRI (p < 0.001). Conclusion Breast cancers in Korean women under 40 years of age are commonly presented with a palpable mass, and luminal A is the most common molecular subtype. In our study, the imaging and pathologic characteristics of breast cancer in younger women were similar to those previously reported for older patients.

Skin-mounted soft electronics that incorporate high-bandwidth triaxial accelerometers can capture broad classes of physiologically relevant information, including mechano-acoustic signatures of underlying body processes (such as those measured by a stethoscope) and precision kinematics of core-body motions. Here, we describe a wireless device designed to be conformally placed on the suprasternal notch for the continuous measurement of mechano-acoustic signals, from subtle vibrations of the skin at accelerations of around 10−3 m s−2 to large motions of the entire body at about 10 m s−2, and at frequencies up to around 800 Hz. Because the measurements are a complex superposition of signals that arise from locomotion, body orientation, swallowing, respiration, cardiac activity, vocal-fold vibrations and other sources, we exploited frequency-domain analysis and machine learning to obtain—from human subjects during natural daily activities and exercise—real-time recordings of heart rate, respiration rate, energy intensity and other essential vital signs, as well as talking time and cadence, swallow counts and patterns, and other unconventional biomarkers. We also used the device in sleep laboratories and validated the measurements using polysomnography. A wireless device designed to be conformally placed on the suprasternal notch can continuously provide real-time information of essential vital signs as well as talking time, swallow counts and sleep patterns.

We aimed to investigate the potential of preoperative mammographic breast density (MBD) as a prognostic factor in breast cancer. Data of 969 patients with primary breast cancer were analyzed. We defined low MBD as fatty or fibroglandular breast, and high MBD as heterogeneously dense or extremely dense breast, respectively. The high MBD group demonstrated a superior overall survival rate compared to the low MBD group (p 50 years (p 2 (p 50 years and the HRc(+)/HER2(−) subtype. Favorable clinicopathologic features, active treatments, and other factors could contribute to this causality.

Hydrocephalus is a common and costly neurological condition caused by the overproduction and/or impaired resorption of cerebrospinal fluid (CSF). The current standard of care, ventricular catheters (shunts), is prone to failure, which can result in nonspecific symptoms such as headaches, dizziness, and nausea. Current diagnostic tools for shunt failure such as computed tomography (CT), magnetic resonance imaging (MRI), radionuclide shunt patency studies (RSPSs), and ice pack–mediated thermodilution have disadvantages including high cost, poor accuracy, inconvenience, and safety concerns. Here, we developed and tested a noninvasive, skin-mounted, wearable measurement platform that incorporates arrays of thermal sensors and actuators for precise, continuous, or intermittent measurements of flow through subdermal shunts, without the drawbacks of other methods. Systematic theoretical and experimental benchtop studies demonstrate high performance across a range of practical operating conditions. Advanced electronics designs serve as the basis of a wireless embodiment for continuous monitoring based on rechargeable batteries and data transmission using Bluetooth protocols. Clinical studies involving five patients validate the sensor’s ability to detect the presence of CSF flow ( P = 0.012) and further distinguish between baseline flow, diminished flow, and distal shunt failure. Last, we demonstrate processing algorithms to translate measured data into quantitative flow rate. The sensor designs, fabrication schemes, wireless architectures, and patient trials reported here represent an advance in hydrocephalus diagnostics with ability to visualize flow in a simple, user-friendly mode, accessible to the physician and patient alike.

The aims of this study were to determine the malignancy rate of probably benign lesions that show an interval change on follow-up ultrasound and to evaluate the differences seen on imaging between benign and malignant lesions initially categorized as probably benign but with interval change on follow-up breast ultrasound. We retrospectively reviewed 11,323 lesions from ultrasound-guided core-biopsies performed between June 2004 and December 2014 and identified 289 lesions (266 patients) with an interval change from probably benign (Breast Imaging Reporting and Data System [BI-RADS] category 3) in the previous 2 years. Malignancy rates were compared according to the ultrasound findings and the characteristics of the interval changes, including changes in morphology and/or diameter. The malignancy rate for probably benign lesions that showed an interval change on follow-up ultrasound was 6.9% (20/289). The malignancy rate was higher for clustered cysts (33.3%) and irregular or noncircumscribed masses (12.7%) than for circumscribed oval masses (5%) or complicated cysts (5%) seen on initial ultrasound (P = 0.043). Fifty-five percent of the malignancies were found to be ductal carcinoma in situ and there was 1 case of lymph node metastasis among the patients with invasive disease in whom biopsy was delayed by 6 to 15 months. The extent of invasiveness was greater in missed cases. There was a significant difference in the maximal diameter change between the 20 malignant lesions and the 269 benign lesions (4.0 mm vs 2.7 mm, P = 0.002). The cutoff value for maximal diameter change per initial diameter was 39.0% for predicting malignancy (sensitivity 95%, specificity 53.5%). The malignancy rate for morphologically changed lesions was significantly higher than for morphologically stable lesions (13.6% vs 4.9%; P = 0.024) Our 6.9% of probably benign lesions that showed an interval change finally turned out to be malignancy was mostly DCIS. The sonographic features, interval changes in sonographic features, and lesion size might help in the recategorization of these lesions.

Purpose We investigated B-cell lymphoma 2 (BCL2) regulation across DNA, RNA, protein, and methylation status according to molecular subtype of breast cancer using The Cancer Genome Atlas (TCGA) database. Materials and Methods We analyzed clinical and biological data on 1,096 breast cancers from the TCGA database. Biological data included reverse phase protein array (RPPA), mRNA sequencing (mRNA-seq), mRNA microarray, methylation, copy number alteration linear, copy number alteration nonlinear, and mutation data. Results The luminal A and luminal B subtypes showed upregulated expression of RPPA and mRNAseq and hypomethylation compared to the human epidermal growth factor receptor 2 (HER2) and triple-negative subtypes (all p < 0.001). No mutations were found in any subjects. High mRNA-seq and high RPPA were strongly associated with positive estrogen receptor, positive progesterone receptor (all p < 0.001), and negative HER2 (p < 0.001 and p=0.002, respectively). Correlation analysis revealed a strong positive correlation between protein and mRNA levels and a strong negative correlation between methylation and protein and mRNA levels (all p < 0.001). The high BCL2 group showed superior overall survival compared to the low BCL2 group (p=0.006). Conclusion The regulation of BCL2 was mainly associated with methylation across the molecular subtypes of breast cancer, and luminal A and luminal B subtypes showed upregulated expression of BCL2 protein, mRNA, and hypomethylation. Although copy number alteration may have played a minor role, mutation status was not related to BCL2 regulation. Upregulation of BCL2 was associated with superior prognosis than downregulation of BCL2.

Aortoesophageal fistula (AEF) is an extremely rare but lethal cause of massive gastrointestinal hemorrhage. Characteristic symptoms are mid-thoracic pain, sentinel minor hemorrhage, and massive hemorrhage after a symptom-free interval. Prompt diagnosis and immediate treatments are necessary to reduce mortality. However, AEF is difficult to diagnose because it is uncommon and often leads to death with massive bleeding before proper evaluation. We report a case of endoscopic diagnosis of AEF that did not present with hematemesis; it was treated with thoracic endovascular aortic repair (TEVAR) and surgery. A 71-year-old female presented to the emergency department with epigastric discomfort. Endoscopy demonstrated a submucosal tumor-like protrusion and pulsating mass with blood clots. Contrast-enhanced chest CT confirmed AEF due to descending thoracic aortic aneurysm. The patient immediately underwent TEVAR to prevent massive bleeding and subsequently underwent surgery. Endoscopists should consider AEF if they see a submucosal tumor-like mass with a central ulcerative lesion or a pulsating protrusion covered with blood clots in mid-esophagus during an endoscopy.

To evaluate the value of the computer-aided diagnosis (CAD) program applied to diagnostic breast ultrasonography (US) based on operator experience.US images of 100 breast masses from 91 women over 2 months (from May to June 2015) were collected and retrospectively analyzed. Three less experi

The aim of this study was to investigate the follow-up results and characteristics of oval circumscribed lesions with fast initial enhancement on preoperative magnetic resonance imaging (MRI) in patients with newly diagnosed breast cancer. Preoperative data from consecutive patients newly diagnosed with breast cancer between 2010 and 2013 were retrospectively reviewed. Only MRI reports containing, “oval shape, circumscribed margin, and fast initial enhancement,” were extracted and analyzed. Follow-up results and clinical and pathological findings were evaluated. A total of 430 oval circumscribed lesions with fast initial enhancement were included. Forty-eight lesions were pathologically confirmed at initial workup and 382 were followed up. Among the 48 lesions, 14 were found to have additional malignancy and 34 were benign. Among the 382 followed-up lesions, only 1 was subsequently confirmed to be malignant. There were no evident changes in any of the remaining lesions during follow-up. The overall rate of malignancy was 3.5% (15/430). When lesions exhibited delayed washout enhancing kinetics (P

One of the challenges of building natural language processing (NLP) applications for education is finding a large domain-specific corpus for the subject of interest (e.g., history or science). To address this challenge, we propose a tool, Dexter, that extracts a subject-specific corpus from a heterogeneous corpus, such as Wikipedia, by relying on a small seed corpus and distributed document representations. We empirically show the impact of the generated corpus on language modeling, estimating word embeddings, and consequently, distractor generation, resulting in better performances than while using a general domain corpus, a heuristically constructed domain-specific corpus, and a corpus generated by a popular system: BootCaT.