ペルオキシソーム増殖因子活性化受容体アルファノックアウトマウスの絶食時における睡眠変化

Peroxisome proliferator-activated receptor alpha (PPARα) is a transcription factor that belongs to the nuclear receptor family and plays an important role in regulating gene expression associated with lipid metabolism. PPARα promotes hepatic fatty acid oxidation and ketogenesis in response to fasting. Because energy metabolism is known to affect sleep regulation, manipulations that change PPARα are likely to affect sleep and other physiological phenotypes. In this study, we examined the role of PPARα in sleep/wake regulation using PPARα knockout (KO) mice. Sleep, body temperature (BT), locomotor activity, arterial pressure (AP) and heart rate (HR) were recorded in KO mice and wild-type (WT) controls under ad libitum-fed conditions and 24-hour food deprivation (FD). KO and WT mice were identical in basal sleep amount, BT, mean AP and HR, although KO mice showed enhanced sleepiness (enhanced EEG slow-wave activity). In response to FD, KO mice showed a large drop in wakefulness and locomotor activity at the end of the dark phase, whereas WT mice did not. Similarly, AP and HR, which were suppressed by FD, decreased more in KO than in WT mice. Compared to WT mice, KO mice showed a reduced concentration of plasma ketone bodies and decreased mRNA expression of the ketogenic enzyme gene Hmgcs2 in the liver and brain under FD conditions. These results suggest that PPARα and/or lipid metabolism is involved in the maintenance of wakefulness and locomotor activity during fasting in mice

Inter-assay variability of next-generation sequencing-based gene panels

BACKGROUND: Tumor heterogeneity has been known to cause inter-assay discordance among next-generation sequencing (NGS) results. However, whether preclinical factors such as sample type, sample quality and analytical features of gene panel can affect the concordance between two different assays remains largely unexplored. METHODS: Replicate sets of DNA samples extracted from formalin-fixed paraffin-embedded tissues (FFPE) (n = 20) and fresh frozen (FF) tissues (n = 10) were herein analyzed using a tumor-only (TO) and paired tumor-normal (TN) gene panel in laboratories certified by the Clinical Laboratory Improvement Amendment. Reported variants from the TO and TN panels were then compared. Furthermore, additional FFPE samples were sequentially sliced from the same FFPE block and submitted to another TN panel assay. RESULTS: Substantial discordance (71.8%) was observed between the results of the two panels despite using identical DNA samples, with the discordance rate being significantly higher for FFPE samples (p < 0.05). Among the 99 variants reported only in the TO panel, 32.3% were consistent with germline variants, which were excluded in the TN panel, while 30.3% had an allele frequency of less than 5%, some of which were highly likely to be artificial calls. The comparison of two independent TN panel assay results from the same FFPE block also showed substantial discordance rate (55.3%). CONCLUSIONS: In the context of clinical settings, our comparative analysis revealed that inter-NGS assay discordance commonly occurred due to sample types and the different analytical features of each panel

Genetic screening for malignant hyperthermia and comparison of clinical symptoms in Japan

Malignant hyperthermia (MH) is an anaesthetic complication that causes an abnormal hypermetabolic state. RYR1 encoding ryanodine receptors of the sarcoplasmic reticulum and CACNA1S encoding α subunits of dihydropyridine receptors are known to be associated with MH pathogenicity. We performed genetic screening using next-generation sequencing to evaluate the prevalence of genes associated with MH pathogenicity and clinical symptoms. This was a retrospective cohort study wherein next-generation sequencing data of 77 families diagnosed with MH predisposition by calcium-induced calcium release (CICR) tests from 1995 to 2019 was used to search for RYR1 and CACNA1S variants. Furthermore, the clinical symptoms and predisposition tests in participants with RYR1 and CACNA1S variants were compared. In the 77 families, 44.2%, 7.8%, and 48.1% individuals had RYR1, CACNA1S, and neither RYR1 nor CACNA1S variants, respectively. Clinically significant differences were found in the maximum body temperature, maximum elevated body temperature for 15 min, creatinine kinase level, and CICR rate between the RYR1 and CACNA1S groups. The prevalence of pathogenic CACNA1S variants appears to be prominent in Japan. The severity of clinical symptoms and the CICR rate were greater in individuals with RYR1 variants than in those with CACNA1S variants, likely due to more direct regulation of calcium levels by ryanodine receptors than by dihydropyridine receptors. Genetic analysis of MH in future studies may help identify other genes associated with MH, which will further clarify the relationship between genotypes and MH symptoms and contribute to safer anaesthesia practice.This study was supported by a Grant-in-Aid for Young Scientists (grant number: 17K16733 to Y.N. and 20K17783 to R.K.) from the Japan Society for the Promotion of Science and by the Takeda Science Foundation (H.K.)

Real-time In Situ Electron Spin Resonance Measurements on Fungal Spores of Penicillium digitatum during Exposure of Oxygen Plasmas

We report the kinetic analysis of free radicals on fungal spores of Penicillium digitatum interacted with atomic oxygen generated plasma electric discharge using real time in situ electron spin resonance (ESR) measurements. We have obtained information that the ESR signal from the spores was observed and preliminarily assignable to semiquinone radical with a g-value of around 2.004 and a line width of approximately 5G. The decay of the signal is possibly linked to the inactivation of the fungal spore. The real-time in situ ESR has proven to be a useful method to elucidate plasma-induced surface reactions on biological specimens.Comment: 11 pages, 5 figure

Monoclonal gammopathy of renal significance (MGRS)-related AL amyloidosis complicated by amyloid myopathy: a case report

BACKGROUND: Lately, monoclonal gammopathy of renal significance (MGRS) has been defined as a group of renal disorders that are strongly associated with monoclonal protein, including amyloid immunoglobulin light chain (AL) amyloidosis. Amyloid myopathy is rare (1.5% of all patients with amyloidosis) and the prognosis is poor. Furthermore, only approximately 20% of patients with amyloid myopathy are reported to have renal involvement, indicating a lack of data in the literature. CASE PRESENTATION: Here, we report a rare case of MGRS-related AL amyloidosis complicated by amyloid myopathy that presented with muscle weakness in the upper and lower limbs, neck and fingers, and nephrotic syndrome. Blood, urine, and bone marrow examination revealed monoclonal gammopathy of undetermined significance (MGUS) (Bence Jones protein-lambda). Muscle biopsy of the vastus lateralis muscle demonstrated amyloid proteins in the sarcolemma and in the blood vessel walls on Congo red staining, suggesting amyloid myopathy, and tiny inclusions in fibers on modified Gomori trichrome stain. Although we thought they were reminiscent of nemaline bodies, we could not confirm the nature of this structure. Renal biopsy demonstrated amyloid proteins in the mesangial region, part of the capillary walls, and the blood vessel walls on direct fast scarlet staining. As these amyloid proteins were positive for p-component staining and negative for amyloid A staining, β2-microglobulin, and pre-albumin, and as lambda light chains were positive in the mesangial region, we diagnosed the patient with MGRS-related AL amyloidosis. Although he was treated with melphalan and dexamethasone, his symptoms did not improve. CONCLUSIONS: AL amyloidosis involving the kidneys and muscles has a poor prognosis, and a delayed diagnosis of amyloid myopathy is common because of its rarity and frequent misdiagnosis, which increases organ function deterioration. Therefore, early detection, therapeutic intervention, and careful follow-up are crucial