Correlation-based and feature-driven mutation signature analyses to identify genetic features associated with DNA mutagenic processes in cancer genomes

Mutation signatures represent unique sequence footprints of somatic mutations resulting from specific DNA mutagenic and repair processes. However, their causal associations and the potential utility for genome research remain largely unknown. In this study, we performed PanCancer-scale correlative analyses to identify the genomic features associated with tumor mutation burdens (TMB) and individual mutation signatures. We observed that TMB was correlated with tumor purity, ploidy, and the level of aneuploidy, as well as with the expression of cell proliferation-related genes representing genomic covariates in evaluating TMB. Correlative analyses of mutation signature levels with genes belonging to specific DNA damage-repair processes revealed that deficiencies of NHEJ1 and ALKBH3 may contribute to mutations in the settings of APOBEC cytidine deaminase activation and DNA mismatch repair deficiency, respectively. We further employed a strategy to identify feature-driven, de novo mutation signatures and demonstrated that mutation signatures can be reconstructed using known causal features. Using the strategy, we further identified tumor hypoxia-related mutation signatures similar to the APOBEC-related mutation signatures, suggesting that APOBEC activity mediates hypoxia-related mutational consequences in cancer genomes. Our study advances the mechanistic insights into the TMB and signature-based DNA mutagenic and repair processes in cancer genomes. We also propose that feature-driven mutation signature analysis can further extend the categories of cancer-relevant mutation signatures and their causal relationships.

Anatomical Findings of Hemiplegia Cruciata in Multiple Sclerosis / 대한임상신경생리학회지

Hemiplegia cruciata (HC) manifests as paralysis of the ipsilateral arm and contralateral leg. Herein, we report a 64-year-old man with weakness of the right leg and of the left arm after multiple sclerosis (MS). His brain and spine magnetic resonance imaging show a lower medulla lesion, which is extended to posterior part of C1 spine through cervicomedullary junction. HC usually results from stroke or trauma, but it is rare as presenting symptom of MS.

Risus Sardonicus in Multiple System Atrophy

No abstract available.

Limb-Girdle Type Myasthenia Gravis

No abstract available.

Creutzfeldt-Jakob Disease Mimicking a Stroke as Initial Manifestation

No abstract available.

Herpes Meningoencephalitis Complicated by Cerebral Hematomas During Acyclovir Therapy / 대한뇌졸중학회지

Petechial cortical hemorrhages are common in Herpes simplex virus (HSV) encephalitis, however, cerebral hematoma is extremely rare. We report a case of a 47-year-old immunocompetent woman diagnosed with herpes encephalitis but complicated by cerebral hematoma despite of early diagnosis and treatment.

Killer Cell Immunoglobulin-like Receptor (KIR) Analysis in Adult Korean Patients with Acute Myeloid Leukemia

BACKGROUND: The prevalent natural killer (NK) cells induce alloreaction against leukemic cells during post-transplant. NK cell alloreactivity depends on the compatibility of killer cell immunoglobulin-like receptors (KIR) epitopes for graft-versus-host disease. Genotypic expressions of inhibitory or activating KIR in patients with acute myelogenous leukemia (AML) and their HLA-matched sibling donors, as a model for Korean KIR haplotype diversity and NK alloreactivity, were investigated. METHODS: Ninety-two patients in complete remission and their 76 HLA-matched sibling donors were enrolled in this study. All the patients were scheduled to receive allogeneic hematopoietic stem cell transplantations (HSCT). KIR PCR-SSP typing was performed for 19 different kinds of KIR genes and pseudogenes. The PCR data representing the KIR genotypes from both the patients and donors were compared. RESULTS: We found 43 Korean KIR haplotypes. Thirty-three variable haplotypes for the AML patients, in addition to 25 haplotypes for the normal HSCT donors, were demonstrated. Of note, the expressions of specific genes such as 2DL2 (P=0.026), 2DS2 (P=0.042), and 2DS4 (P=0.037) revealed remarkable differences between the patients and the normal donors. Korean HLA-identical sibling pairs showed 38% KIR matches in terms of the gene content and allelic polymorphism. Although the KIR gene content was the same between the patients and the donors, 40% of those matched pairs of patients and donors showed allelic polymorphism, specifically in the context of 2DL5 and 2DS4 genes. CONCLUSION: These results indicate that the expressions of donor inhibitory and activating repertoire of KIR genotypes, even in the HLA-matched sibling setting, are unique parameters to be considered when we perform allogeneic sibling HSCT.

Involvement of NAD (P) H Oxidase in a Potential Link between Diabetes and Vascular Smooth Muscle Cell Proliferation

The cellular mechanisms that contribute to the acceleration of atherosclerosis in diabetes are poorly understood. Therefore, the potential mechanisms involved in the diabetes-dependent increase in vascular smooth muscle cell (VSMC) proliferation was investigated. Using primary culture of VSMC from streptozotocin-induced diabetic rat aorta, cell proliferation assay showed two-fold increase in cell number accompanied with enhanced superoxide generation compared to normal VSMC, 2 days after plating. Both the increased superoxide production and cell proliferation in diabetic VSMC were significantly attenuated by not only tiron (1 mM), a superoxide scavenger, but also by diphenyleneiodonium (DPI; 10micrometer), an NAD (P) H oxidase inhibitor. NAD (P) H oxidase activity in diabetic VSMC was significantly higher than that in control cell, accompanied with increased mRNA expression of p22phox, a membrane subunit of oxidase. Furthermore, inhibition of p22phox expression by transfection of antisense p22phox oligonucleotides into diabetic VSMC resulted in a decrease in superoxide production, which was accompanied by a significant inhibition of cell proliferation. Based on these results, it is suggested that diabetes-associated increase in NAD (P) H oxidase activity via enhanced expression of p22phox contributes to augmented VSMC proliferation in diabetic rats.