Acute Leriche Syndrome Mimicking Spinal Cord Infarction: A Case Report.

Introduction: Acute Leriche syndrome is a rare but potentially life-threatening condition. Pain, pallor, and coldness of the lower extremities serve as clues for suspecting Leriche syndrome. However, the absence of these findings may pose a diagnostic challenge. Case Presentation: An 83-year-old man presented at our emergency department with a complaint of sudden-onset paraparesis. Initially, spinal cord infarction was suspected due to clinical course and neurological findings, but thoracolumbar MRI showed normal findings. On admission, symptoms associated with aortoiliac occlusion were not present, except for muscle atrophy in the thigh. CT angiography revealed aortoiliac occlusion, leading to a diagnosis of Leriche syndrome. Conclusion: Leriche syndrome should be considered as a potential differential diagnosis in patients with acute paraparesis. Muscle atrophy of the lower limbs disproportionate to the clinical course may be the clue for suspecting acute Leriche syndrome with symptoms related to atherosclerotic occlusion which are inconspicuous.

Nasogastric Tube Syndrome: The Size and Type of the Nasogastric Tube May Contribute to the Development of Nasogastric Tube Syndrome.

Nasogastric tube syndrome (NGTS) is a rare but life-threatening complication associated with nasogastric tube (NGT) placement. The effect of the NGT size and type on the development of NGTS has not yet been fully elucidated. We herein report the case of a 77-year-old man with cerebral infarction who was complicated with NGTS. The immediate removal of the NGT improved the symptoms of NGTS. Although the NGT was passed through the same route during reinsertion, the use of a softer and smaller-sized NGT did not cause any NGTS recurrence. To prevent the development of NGTS, using a NGT that is appropriate for the patient's condition is important.

Myasthenia gravis with inflammatory myopathy without elevation of creatine kinase.

Cases of myasthenia gravis with inflammatory myopathy usually show elevated creatine kinase (CK) levels. There are few case reports of myasthenia gravis with inflammatory myopathy without elevated CK levels, and clinical features and useful diagnostic methods for these patients are little known. We describe the case of a 79-year-old man with myasthenia gravis that was complicated with inflammatory myopathy without elevated CK levels and successfully treated with immunological treatment. Initially, he was diagnosed with ocular myasthenia gravis and treated with pyridostigmine, but dysphagia and weakness in the neck and bilateral upper limb without fatigability gradually developed. Needle electromyography revealed myopathic changes, and the results of muscle biopsy were consistent with inflammatory myopathy. Blood tests showed normal CK levels throughout the clinical course and elevated myoglobin levels alone. The possibility of developing inflammatory myopathy in patients with myasthenia gravis cannot be excluded, even if CK levels are normal.

Neuromyelitis optica spectrum disorder with severe orthostatic hypotension due to hypothalamic lesions.

BACKGROUND: Rare cases of neuromyelitis optica spectrum disorder (NMOSD) occur with only hypothalamic lesions as the initial lesion, and such cases can present with hypersomnia, endocrinopathy, and autonomic failure. However, orthostatic hypotension (OH) caused by hypothalamic lesions due to NMOSD has not been reported. CASE REPORT: We report the case of a patient with NMOSD who presented with severe OH due to hypothalamic lesions. CONCLUSION: We suggest that clinicians should be aware that NMOSD with hypothalamic lesions can present with OH.

Unexpected Mutations by CRISPR-Cas9 CTG Repeat Excision in Myotonic Dystrophy and Use of CRISPR Interference as an Alternative Approach.

Myotonic dystrophy type 1 is the most common type of adult-onset muscular dystrophy. This is an autosomal dominant disorder and caused by the expansion of the CTG repeat in the 3' untranslated region of the dystrophia myotonica protein kinase (DMPK) gene. Messenger RNAs containing these expanded repeats form aggregates as nuclear RNA foci. Then, RNA binding proteins, including muscleblind-like 1, are sequestered to the RNA foci, leading to systemic abnormal RNA splicing. In this study, we used CRISPR-Cas9 genome editing to excise this CTG repeat. Dual cleavage at the 5' and 3' regions of the repeat using a conventional Cas9 nuclease and a double nicking with Cas9 nickase successfully excised the CTG repeat. Subsequently, the formation of the RNA foci was markedly reduced in patient-derived fibroblasts. However, contrary to expectations, a considerable amount of off-target digestions and on-target genomic rearrangements were observed using high-throughput genome-wide translocation sequencing. Finally, the suppression of DMPK transcripts using CRISPR interference significantly decreased the intensity of RNA foci. Our results indicate that close attention should be paid to the unintended mutations when double-strand breaks are generated by CRISPR-Cas9 for therapeutic purposes. Alternative approaches independent of double-strand breaks, including CRISPR interference, may be considered.

Production of human monoclonal and polyclonal antibodies in TransChromo animals.

We have developed TransChromo (TC) technology, which enables the introduction of megabase-sized segments of DNA into cells. We have used this approach to derive mice that carry megabases of human DNA by the use of a human chromosome fragment (HCF) as a vector. TC technology has been applied to the construction of the TC Mouse,trade mark which incorporates entire human immunoglobulin (hIg) loci. TC Mouse expresses a fully diverse repertoire of hIgs, including all the subclasses of IgGs (IgG1-G4). Immunization of the TC Mouse with various human antigens produced antibody responses comprised of human antibodies. Furthermore, it was possible to obtain hybridoma clones expressing fully human antibodies specific for the target human antigen. However, because of the instability of the Igkappa locus-bearing HCF2, the efficiency of hybridoma production was less than one-tenth of that observed in normal mice. An instant solution to this problem was to cross-breed the Kirin TC Mouse carrying the HCF14, which was stable in mouse cells, with the Medarex YAC-transgenic mouse carrying about 50% of the hIgVkappa gene segments as a region that is stably integrated into the mouse genome. The resulting mouse, dubbed the KM Mouse, performed as well as normal mice with regard to immune responsiveness and efficiency of hybridoma production. Another application of TC technology is the production of polyclonal antibodies in large animals such as chickens and cows. To test the efficacy of human polyclonal antibodies derived from TC animals, feasibility studies were performed using antisera and purified gamma-globulin from TC mice immunized with Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), or Japanese encephalitis virus (JEV). The TC mouse-derived antisera and gamma-globulin showed a much higher titer and efficacy in terms of the neutralizing activity of the pathogens in vitro and in vivo than either human serum or gamma-globulin prepared from human blood.