Structural Categorization of Adenine, Guanine, and Xanthine Derivatives Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry with 5-Nitrosalicylic Acid and 1,5-Diaminonaphtalene.

In this study, we analyzed purine derivatives using multimatrix variation matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) with α-cyano-4-hydroxycinnamic acid (CHCA), 1,5-diaminonaphtalene (DAN), 5-formylsalicylic acid (FSA), and 5-nitrosalicylic acid (NSA) as matrices. Further, we focused on the abstraction/attachment of hydrogen from/to analytes and detected [M - H], [M + 2H] and/or [M + 3H] in MALDI MS spectra of compounds containing nitrogen and/or carbonyl oxygen. Although [M - H] generation of purine compounds in MALDI MS with conventional matrices was challenging, NSA-MALDI MS effectively yielded the [M - H]species of purine derivatives compared with CHCA, FSA, and DAN, and the [M - H]/[M + H] ratios reflected their structures, such as the substituting groups and positions.

Deletion of Pax1 scoliosis-associated regulatory elements leads to a female-biased tail abnormality.

Adolescent idiopathic scoliosis (AIS), a sideways curvature of the spine, is sexually dimorphic, with increased incidence in females. A genome-wide association study identified a female-specific AIS susceptibility locus near the PAX1 gene. Here, we use mouse enhancer assays, three mouse enhancer knockouts, and subsequent phenotypic analyses to characterize this region.

High-throughput PRIME-editing screens identify functional DNA variants in the human genome.

Despite tremendous progress in detecting DNA variants associated with human disease, interpreting their functional impact in a high-throughput and single-base resolution manner remains challenging. Here, we develop a pooled prime-editing screen method, PRIME, that can be applied to characterize thousands of coding and non-coding variants in a single experiment with high reproducibility. To showcase its applications, we first identified essential nucleotides for a 716 bp MYC enhancer via PRIME-mediated single-base resolution analysis.

High throughput PRIME editing screens identify functional DNA variants in the human genome.

Despite tremendous progress in detecting DNA variants associated with human disease, interpreting their functional impact in a high-throughput and base-pair resolution manner remains challenging. Here, we develop a novel pooled prime editing screen method, PRIME, which can be applied to characterize thousands of coding and non-coding variants in a single experiment with high reproducibility. To showcase its applications, we first identified essential nucleotides for a 716 bp enhancer via PRIME-mediated saturation mutagenesis.

Deletion of scoliosis-associated regulatory elements leads to a female-biased tail abnormality.

Adolescent idiopathic scoliosis (AIS), a sideways curvature of the spine, is sexually dimorphic, with increased incidence in females. A GWAS identified a female-specific AIS susceptibility locus near the gene. Here, we used mouse enhancer assays, three mouse enhancer knockouts and subsequent phenotypic analyses to characterize this region.

Disulfide bond formation in microtubule-associated tau protein promotes tau accumulation and toxicity in vivo.

Accumulation of microtubule-associated tau protein is thought to cause neuron loss in a group of neurodegenerative diseases called tauopathies. In diseased brains, tau molecules adopt pathological structures that propagate into insoluble forms with disease-specific patterns. Several types of posttranslational modifications in tau are known to modulate its aggregation propensity in vitro, but their influence on tau accumulation and toxicity at the whole-organism level has not been fully elucidated.

Quantitative fractionation of tissue microtubules with distinct biochemical properties reflecting their stability and lability.

Microtubules form a major cytoskeleton and exhibit dynamic instability through the repetitive polymerization/depolymerization of tubulin dimers. Although microtubule stability should be precisely controlled to maintain various cellular functions, it has been difficult to assess its status in vivo. Here, we propose a tubulin fractionation method reflecting the stability of microtubules in mouse tissues.

The heteromeric PC-1/PC-2 polycystin complex is activated by the PC-1 N-terminus.

Mutations in the polycystin proteins, PC-1 and PC-2, result in autosomal dominant polycystic kidney disease (ADPKD) and ultimately renal failure. PC-1 and PC-2 enrich on primary cilia, where they are thought to form a heteromeric ion channel complex. However, a functional understanding of the putative PC-1/PC-2 polycystin complex is lacking due to technical hurdles in reliably measuring its activity.

Inhibition of microtubule assembly competent tubulin synthesis leads to accumulation of phosphorylated tau in neuronal cell bodies.

Neurofibrillary tangles, a pathological hallmark of Alzheimer's disease (AD), are somatodendritic filamentous inclusions composed of hyperphosphorylated tau. Microtubule loss is also a common feature of affected neurons in AD. However, whether and how the disruptions of microtubules and the microtubule-associated proteins occur in the pathogenesis of AD remain unclear.

Plasma Globotriaosylsphingosine Level as a Primary Screening Target for Fabry Disease in Patients With Left Ventricular Hypertrophy.

Background: Although previous studies have suggested a certain prevalence of Fabry disease (FD) in left ventricular hypertrophy (LVH) patients, the screening of FD is difficult because of its wide-ranging clinical phenotypes. We aimed to clarify the utility of combined measurement of plasma globotriaosylsphingosine (lyso-Gb3) concentration and α-galactosidase A activity (α-GAL) as a primary screening of FD in unexplained LVH patients.

Methods and results: Between 2014 and 2016, both lyso-Gb3 and α-GAL were measured in 277 consecutive patients (male 215, female 62, age 25-79 years) with left ventricular wall thickness >12 mm on echocardiogram: 5 patients (1.

Glycosylation status of nicastrin influences catalytic activity and substrate preference of γ-secretase.

γ-Secretase complex, the assembly of nicastrin (NCT), Presenilin (PS), Presenilin Enhancer-2 (PEN-2) and Anterior pharynx defective 1 (Aph-1), catalyzes the cleavage of amyloid precursor protein to generate amyloid-β protein (Aβ), the main culprit of Alzheimer's disease. NCT becomes matured through complex glycosylation and play important role in γ-secretase activity by interacting with catalytic subunit PS. However, the role of NCT glycosylation on γ-secretase activity and substrate specificity is still unknown.

Alanine substitutions in the GXXXG motif alter C99 cleavage by γ-secretase but not its dimerization.

The amyloid β (Aβ) protein is a major component of senile plaques, one of the neuropathological hallmarks of Alzheimer's disease. Amyloidogenic processing of amyloid precursor protein (APP) by β- and γ-secretases leads to production of Aβ. APP contains tandem triple repeats of the GXXXG motif in its extracellular juxtamembrane and transmembrane regions.

The A673T mutation in the amyloid precursor protein reduces the production of β-amyloid protein from its β-carboxyl terminal fragment in cells.

Introduction: The A673T mutation in the amyloid precursor protein (APP) protects against Alzheimer's disease by reducing β-amyloid protein (Aβ) production. This mutation reduced the release of the soluble APP fragment (sAPPβ), which is processed by β-secretase, suggesting a concomitant decrease in the β-carboxyl fragment of APP (C99), which is a direct substrate of γ-secretase for Aβ production. However, it remains controversial whether the level of C99 is significantly reduced in cells expressing APP that carry A673T as the cause of reduced Aβ production.

Characteristics of intra-left atrial flow dynamics and factors affecting formation of the vortex flow – analysis with phase-resolved 3-dimensional cine phase contrast magnetic resonance imaging.

Background: The intra-left atrial (LA) blood flow from pulmonary veins (PVs) to the left ventricle (LV) changes under various conditions and might affect global cardiac function. By using phase-resolved 3-dimensional cine phase contrast magnetic resonance imaging (4D-Flow), the intra-LA vortex formation was visualized and the factors affecting the intra-LA flow dynamics were examined.

Methods And Results: Thirty-two patients with or without organic heart diseases underwent 4D-Flow and transthoracic echocardiography.

Functional, morphological and electrocardiographical abnormalities in patients with apical hypertrophic cardiomyopathy and apical aneurysm: correlation with cardiac MR.

Objective: The prognosis of apical hypertrophic cardiomyopathy (APH) has been benign, but apical myocardial injury has prognostic importance. We studied functional, morphological and electrocardiographical abnormalities in patients with APH and with apical aneurysm and sought to find parameters that relate to apical myocardial injury.

Study Design: a multicentre trans-sectional study.

Distribution of late gadolinium enhancement in various types of cardiomyopathies: Significance in differential diagnosis, clinical features and prognosis.

The recent development of cardiac magnetic resonance (CMR) techniques has allowed detailed analyses of cardiac function and tissue characterization with high spatial resolution. We review characteristic CMR features in ischemic and non-ischemic cardiomyopathies (ICM and NICM), especially in terms of the location and distribution of late gadolinium enhancement (LGE). CMR in ICM shows segmental wall motion abnormalities or wall thinning in a particular coronary arterial territory, and the subendocardial or transmural LGE.

Characteristics and clinical relevance of late gadolinium enhancement in cardiac magnetic resonance in patients with systemic sclerosis.

Cardiac involvement in systemic sclerosis (SSc) is considerably frequent in autopsy, but the early identification is clinically difficult. Recent advantages in cardiac magnetic resonance (CMR) enabled to detect myocardial fibrotic scar as late gadolinium enhancement (LGE). We aimed to examine the prevalence and distribution of LGE in patients with SSc, and associate them with clinical features, electrocardiographic abnormalities and cardiac function.

Roles of mitochondrial fragmentation and reactive oxygen species in mitochondrial dysfunction and myocardial insulin resistance.

Purpose: Evidence suggests an association between aberrant mitochondrial dynamics and cardiac diseases. Because myocardial metabolic deficiency caused by insulin resistance plays a crucial role in heart disease, we investigated the role of dynamin-related protein-1 (DRP1; a mitochondrial fission protein) in the pathogenesis of myocardial insulin resistance.

Methods And Results: DRP1-expressing H9c2 myocytes, which had fragmented mitochondria with mitochondrial membrane potential (ΔΨm) depolarization, exhibited attenuated insulin signaling and 2-deoxy-d-glucose (2-DG) uptake, indicating insulin resistance.

Substrate ectodomain is critical for substrate preference and inhibition of γ-secretase.

Understanding the substrate recognition mechanism of γ-secretase is a key step for establishing substrate-specific inhibition of amyloid β-protein (Aβ) production. However, it is widely believed that γ-secretase is a promiscuous protease and that its substrate-specific inhibition is elusive. Here we show that γ-secretase distinguishes the ectodomain length of substrates and preferentially captures and cleaves substrates containing a short ectodomain.

Mitochondrial dysfunction caused by saturated fatty acid loading induces myocardial insulin-resistance in differentiated H9c2 myocytes: a novel ex vivo myocardial insulin-resistance model.

Heart failure (HF) is often accompanied with metabolic disorders and insufficient energy production. Some previous studies have suggested an elevated serum free fatty acid (FA) due to chronic adrenergic stimulation induces myocardial insulin-resistance, which further impairs myocardial energy production. Because little is known about the pathogenesis of FA-induced cardiac insulin-resistance, we established an ex vivo cardiac insulin-resistant model and investigated the relationship between insulin-resistance and mitochondrial dysfunction.

Angioedema of the periorbital region that developed during treatment with etanercept in a case of refractory adult-onset Still's disease.

A 78-year-old Japanese man with adult-onset Still's disease that was refractory to conventional treatment, such as prednisolone (PSL) concomitant with methotrexate (MTX). Etanercept (50 mg/week) was added to PSL (12.5 mg/day) and MTX (12 mg/week).

Ultrasound analysis of the relationship between right internal jugular vein and common carotid artery in the left head-rotation and head-flexion position.

Common carotid artery (CCA) injury is a serious complication of internal jugular vein (IJV) cannulation. To minimize unintentional CCA puncture, the anatomic relationship between the IJV and the CCA and the size of IJV were compared under different head positions. Ultrasound analyses of the IJV and the CCA were performed in 103 consecutive patients.

Appearance of nuclear-sorted caspase-12 fragments in cerebral cortical and hippocampal neurons in rats damaged by autologous blood clot embolic brain infarctions.

Following endoplasmic reticulum (ER) stress, cerebral infarctions have been reported to involve an apoptotic process, including the activation of the caspase cascade. To confirm whether fragmented caspase-12, which is activated by cleavage and is detectable during ER stress, is also involved in embolic cerebral infarctions in rats, we adopted an autologous blood clot model for the analysis of cerebral infarctions. We performed experiments in rats with brain infarctions, which are closely related to embolic cerebral infarctions.

Intravenous glutathione prevents renal oxidative stress after coronary angiography more effectively than oral N-acetylcysteine.

This study proposes the intravenous administration of glutathione (GSH) as a novel strategy to prevent contrast medium-induced renal oxidative stress. Renal oxidative stress is a critical cause of contrast-induced nephropathy (CIN). Recent reports have described that N-acetylcysteine (NAC) may prevent CIN by scavenging reactive oxygen species in the kidney.

Glucose-responsive insulinoma in a patient with postprandial hypoglycemia in the morning.

We report the case of an obese 79-year-old woman who experienced postprandial hypoglycemia in the morning. The serum immunoreactive insulin (IRI) and C-peptide levels responded in parallel with her serum glucose level during a 75-g oral glucose tolerance test. A prolonged fast test lowered her serum glucose level to 30 mg/dL, but serum IRI was not fully suppressed.