Antibody-recognizing residues 188-211 of TMEM106B exhibit immunohistochemical reactivity with the TMEM106B C-terminal fragment.

Accumulation of TMEM106B fibrils composed of cleaved C-terminal fragments (CTF) of transmembrane protein 106B (TMEM106B) has recently been observed in the brains of elderly subjects and individuals with neurodegenerative diseases. To date, one antibody recognizing the residues 239-250 has been found to display immunoreactivity to the TMEM106B CTF, thereby defining TMEM106B C-terminal immunoreactive (TMEM-ir) material. Immunohistochemical characterization of the CTF using antibodies targeting different immunogens could further shed light on the attributes of TMEM-ir material and the biological relevance of TMEM106B fibril accumulation in vivo. Therefore, we generated and validated five polyclonal antibodies against distinct CTF immunogens, namely the residues 140-163, 164-187, 188-211, 239-250, and 253-274. The antibody recognizing the residues 239-250 (antibody no. 5: 239-250) was employed to identify cases positive for TMEM-ir material. Among the remaining four antibodies, antibody no. 3: 188-211 exhibited significant immunoreactivity in TMEM-ir material-positive cases. Comparative analyzes indicated that antibody no. 3: 188-211 and antibody no. 5: 239-250 likely recognized the same TMEM-ir material. The TMEM-ir material detected by antibody no. 3: 188-211 was observed across multiple brain cell types without co-localization with other pathogenic proteins. In conclusion, our findings suggest that the antibody recognizing the residues 188-211 displays immunohistochemical reactivity to TMEM-ir material. Therefore, in addition to the established antibody recognizing the residues 239-250, the antibody recognizing the residues 188-211 can potentially be used in immunohistochemical studies to further elucidate the significance of CTF accumulation in the brain.

Case report: Mitochondrial trifunctional protein deficiency caused by HADHB gene mutation (c.1175C>T) characterized by higher brain dysfunction followed by neuropathy, presented gadolinium enhancement on brain imaging in an adult patient.

Mitochondrial trifunctional protein (MTP) deficiency is an autosomal recessive disorder caused by impaired metabolism of long-chain fatty acids (LCFAs). Childhood and late-onset MTP deficiency is characterized by myopathy/rhabdomyolysis and peripheral neuropathy; however, the features are unclear. A 44-year-old woman was clinically diagnosed with Charcot-Marie-Tooth disease at 3 years of age due to gait disturbance. Her activity and voluntary speech gradually decreased in her 40s. Cognitive function was evaluated and brain imaging tests were performed. The Mini-Mental State Examination and frontal assessment battery scores were 25/30 and 10/18, respectively, suggesting higher brain dysfunction. Peripheral nerve conduction studies revealed axonal impairments. Brain computed tomography showed significant calcification. Magnetic resonance imaging revealed an increased gadolinium contrast-enhanced signal in the white matter, suggesting demyelination of the central nervous system (CNS) due to LCFAs. The diagnosis of MTP deficiency was confirmed through genetic examination. Administration of L-carnitine and a medium-chain fatty triglyceride diet was initiated, and the progression of higher brain dysfunction was retarded within 1 year. This patient's presentation was suggestive of CNS demyelination. The presence of brain calcification, higher brain dysfunction, or gadolinium enhancement in the white matter in patients with peripheral neuropathy may be suggestive of MTP deficiency.

Swallowing sound evaluation using an electronic stethoscope and artificial intelligence analysis for patients with amyotrophic lateral sclerosis.

Background and purpose: Non-invasive, simple, and repetitive swallowing evaluation is required to prevent aspiration pneumonia in neurological care. We investigated the usefulness of swallowing sound evaluation in patients with amyotrophic lateral sclerosis (ALS) using our new electronic stethoscope artificial intelligence (AI) analysis tool. Methods: We studied patients with ALS who provided written informed consent. We used an electronic stethoscope, placed a Bluetooth-enabled electronic stethoscope on the upper end of the sternum, performed a 3-mL water swallow three times, and remotely identified the intermittent sound components of the water flow caused at that time by AI, with the maximum value as the swallowing sound index. We examined the correlation between the swallowing sound index and patient background, including swallowing-related parameters. Results: We evaluated 24 patients with ALS (age 64.0 ± 11.8 years, 13 women, median duration of illness 17.5 months). The median ALS Functional Rating Scale-Revised (ALSFRS-R) score was 41 (minimum 18, maximum 47). In all cases, the mean swallowing sound index was 0.209 ± 0.088. A multivariate analysis showed that a decrease in the swallowing sound index was significantly associated with a low ALSFRS-R score, an ALSFRS-R bulbar symptom score, % vital capacity, tongue pressure, a Mann Assessment of Swallowing Ability (MASA) score, and a MASA pharyngeal phase-related score. Conclusion: Swallowing sound evaluation using an electronic stethoscope AI analysis showed a correlation with existing indicators in swallowing evaluation in ALS and suggested its usefulness as a new method. This is expected to be a useful examination method in home and remote medical care.

A 36-year-old Man with Repeated Short-term Transient Hyperammonemia and Impaired Consciousness with a Confirmed Carbamoyl Phosphate Synthase 1 Gene Monoallelic Mutation.

A 36-year-old man experienced severely impaired consciousness twice after drinking because of hyperammonemia. No abnormal blood tests were found other than ammonia levels. However, magnetic resonance imaging (MRI) showed atrophy of the brain parenchyma. One the second occasion, the patient suffered severe impairment of consciousness, and because of seizures and glossoptosis, mechanical ventilation was started. Urea cycle disorders (UCDs) were assumed to be involved. Genetic testing revealed a monoallelic mutation of the carbamoyl phosphate synthase 1 (CPS1) gene. When transient hyperammonemia of unknown cause occurs repeatedly in adults, an active investigation for UCDs should be conducted.

Initial deterioration and intravenous methylprednisolone therapy in patients with myasthenia gravis.

INTRODUCTION: In myasthenia gravis (MG) patients on intravenous methylprednisolone (IVMP) therapy, initial deterioration should be carefully monitored because it may cause myasthenic crisis. The aim of this study was to investigate the onset, duration and related factors of initial deterioration from the first IVMP in MG patients. METHODS: A total dose of IVMP in the first cycle of 750 mg or less, over 750 to 1500 mg, and over 1500 to 3000 mg was used in the analysis. Initial deterioration was evaluated in qualitative and quantitative evaluation and was defined as an increase of 2 or more points on the The Myasthenia Gravis Activities of Daily Living (MG-ADL) scale after the start of IVMP therapy in the quantitative evaluation. RESULTS: We enrolled 51 mainly mild MG patients. The mode of onset of initial deterioration from the first IVMP treatment was day 4 in the qualitative and quantitative evaluation. In addition, the mode of duration was 3 days. In multiple logistic regression analysis, factors related to initial deterioration were MGFA classification with overall disease duration up to just before IVMP and thymectomy before IVMP in both the qualitative and the quantitative evaluation (p < .001). One to four cycles of IVMP improved the MG-ADL score at hospital discharge from that at the start of IVMP (p < .001). CONCLUSION: Disease severity and thymectomy before IVMP are related to initial deterioration in MG patients. IVMP can be repeated after initial deterioration weekly in most patients.