A case of rectal schwannoma presenting with hematochezia]

Rectal schwannoma is a rare mesenchymal tumor originating from Schwann's cell. We experienced a 61- year-old female patient who complained of blood tinged and narrow calibered stool for several years, and found a 4 cm sized submucosal tumor with a central ulcer on the rectal wall during colonoscopy. She underwent transanal excision. Microscopically, the tumor was composed of fasciculating bundles of spindle cells with benign nuclear atypia and peripheral lymphoid cell cuffing. Tumor cells showed a diffuse strong immunoreactivity to S-100 protein, but not stain for CD 34, desmin and smooth muscle actin. This is the first case report of rectal schwannoma in Korea.     

Association of Lung Function Genes with Chronic Obstructive Pulmonary Disease

Background

Spirometric measurements of pulmonary function are important in diagnosing and determining the severity of chronic obstructive pulmonary disease (COPD). We performed this study to determine whether candidate genes identified in genome-wide association studies of spirometric measurements were associated with COPD and if they interacted with smoking intensity.

Methods

The current analysis included 1,000 COPD subjects and 1,000 controls recruited from 24 hospital-based pulmonary clinics. Thirteen SNPs, chosen based on genome-wide association studies of spirometric measurements in the Korean population cohorts, were genotyped. Genetic association tests were performed, adjusting for age, sex, and smoking intensity, using models including a SNP-by-smoking interaction term.

Results

PID1 and FAM13A were significantly associated with COPD susceptibility. There were also significant interactions between SNPs in ACN9 and FAM13A and smoking pack-years, and an association of ACN9 with COPD in the lowest smoking tertile. The risk allele of FAM13A was associated with increased expression of FAM13A in the lung.

Conclusions

We have validated associations of FAM13A and PID1 with COPD. ACN9 showed significant interaction with smoking and is a potential candidate gene for COPD. Significant associations of genetic variants of FAM13A with gene expression levels suggest that the associated loci may act as genetic regulatory elements for FAM13A gene expression.     

Evaluation of the Sigmoid Notch Involvement in the Intra-Articular Distal Radius Fractures: The Efficacy of Computed Tomography Compared with Plain X-ray

Background

The purpose of this study is to evaluate the efficacy of computed tomography (CT) scans compared with plain radiographs on detecting the involvement of the sigmoid notch.

Methods

This study involved 121 cases diagnosed as the intra-articular distal radius fracture and performed post-reduction CT scans. We determined the presence of the sigmoid notch involvement with both plain radiographs and CT scans and compared findings of plain radiographs with CT scans about the incidence and the pattern of injuries. And the differences of results between arbeitsgemeinschaft für osteosyntheses (AO) type C2 and C3 were compared.

Results

The incidences of sigmoid notch involvement detected in plain radiographs were 81 cases (66.9%), whereas CT scans were 99 cases (81.9%). The sensitivity of plain radiographs compared with CT scans was 74.7%, the specificity was 68.2%, the positive predictive value was 91.4%, the negative predictive value was 37.5%, the false negative value was 25.3%, and the false positive value was 31.8%. In comparison between AO type C2 and C3, the incidence of sigmoid notch involvement was not a significant difference, but the displacement of fracture fragment showed a significant difference.

Conclusions

The intra-articular distal radius fracture usually accompanies the sigmoid notch involvement. Considering that the evaluation of sigmoid notch involvement by plain radiography often results in misinterpretation or underestimation, performing CT scan in intra-articular distal radius fracture is thought to be beneficial.     

Artificial intelligence in oral and maxillofacial radiology: what is currently possible?

Artificial intelligence, which has been actively applied in a broad range of industries in recent years, is an active area of interest for many researchers. Dentistry is no exception to this trend, and the applications of artificial intelligence are particularly promising in the field of oral and maxillofacial (OMF) radiology. Recent researches on artificial intelligence in OMF radiology have mainly used convolutional neural networks, which can perform image classification, detection, segmentation, registration, generation, and refinement. Artificial intelligence systems in this field have been developed for the purposes of radiographic diagnosis, image analysis, forensic dentistry, and image quality improvement. Tremendous amounts of data are needed to achieve good results, and involvement of OMF radiologist is essential for making accurate and consistent data sets, which is a time-consuming task. In order to widely use artificial intelligence in actual clinical practice in the future, there are lots of problems to be solved, such as building up a huge amount of fine-labeled open data set, understanding of the judgment criteria of artificial intelligence, and DICOM hacking threats using artificial intelligence. If solutions to these problems are presented with the development of artificial intelligence, artificial intelligence will develop further in the future and is expected to play an important role in the development of automatic diagnosis systems, the establishment of treatment plans, and the fabrication of treatment tools. OMF radiologists, as professionals who thoroughly understand the characteristics of radiographic images, will play a very important role in the development of artificial intelligence applications in this field.     

Comparison of patients with transient and sustained increments of antiphospholipid antibodies after acute ischemic stroke

Journal of Neurology - Antiphospholipid syndrome (APS) is one of the uncommon causes of ischemic stroke, and is associated with young and female patients. However, the significance of...     

The Influence of Anti-Platelet Resistance on the Development of Cerebral Ischemic Lesion after Carotid Artery Stenting

Purpose

Cerebral ischemic lesions are frequently observed after carotid artery stenting (CAS), and anti-platelet agents are used to prevent stent thrombosis and peri-procedural complications. However, despite the premedication, cerebral ischemic lesions are observed, suggesting that they may rather be related to anti-platelet resistance. We, therefore, investigated the effects of anti-platelet resistance on the development of cerebral ischemic lesions after CAS.

Materials and Methods

We retrospectively reviewed patients who received CAS and selected patients for whom brain MRI was performed within 24 hours after CAS and for whom anti-platelet resistance was checked. Anti-platelet resistance was examined by the VerifyNow system. We analyzed the correlation between anti-platelet resistance and cerebral ischemic lesions detected on follow-up MRI.

Results

Among 76 patients, 45 (59.2%) developed new ischemic lesions after CAS. Twelve (15.8%) patients showed aspirin resistance and 50 (65.8%) patients showed clopidogrel resistance. Patients with a new ischemic lesion demonstrated a significantly greater frequency of clopidogrel resistance than those who had no new ischemic lesion (82.2% versus 41.9%, p=0.001). The frequency of aspirin resistance was not significantly different between the groups of patients with and without new ischemic lesions (20.0% versus 9.7%, p=0.340). In multivariate analysis, clopidogrel resistance was a significant risk factor for post-procedural cerebral ischemia.

Conclusion

Anti-platelet resistance can be used to predict new ischemic lesions after CAS. Anti-platelet resistance should be evaluated in all patients prior to CAS to prevent ischemic complications related to CAS.     

Complete genomic sequences and comparative analysis of Mamestra brassicae nucleopolyhedrovirus isolated in Korea

Mamestra brassicae nucleopolyhedrovirus-K1 (MabrNPV-K1) was isolated from naturally infected M. brassicae (Lepidoptera: Noctuidae) larvae in Korea. The full genome sequences of MabrNPV-K1 were determined, analysed and compared to those of other baculoviruses. The MabrNPV-K1 genome consisted of 152,710 bp and had an overall G + C content of 39.9 %. Computer-assisted analysis predicted 158 open reading frames (ORFs) of 150 nucleotides or greater that showed minimal overlap. Two inhibitor of apoptosis (iap) and six baculovirus repeated ORFs were interspersed in the MabrNPV-K1 genome. The unique MabrNPV-K1 ORF133 was identified in the MabrNPV-K1 genome that was not previously reported in baculoviruses. The gene content and arrangement in MabrNPV-K1 had the highest similarity with those of Helicoverpa armigera MNPV (HearMNPV) and Mamestra configurata NPV-B (MacoNPV-B), and their shared homologous genes were 99 % collinear. The MabrNPV-K1 genome contained four homologous repeat regions (hr1, hr2, hr3 and hr4) that accounted for 3.3 % of the genome. The genomic positions of the four MabrNPV-K1 hr regions were conserved among those of HearMNPV and MacoNPV-B. The gene parity plot, percent identity of the gene homologues and a phylogenetic analysis suggested that these three viruses are closely related not only to each other but also to the same virus strains rather than different virus species.