Evaluation of the cellular effects of silica particles used for dermal application.

The cellular effects of 5 types of spherical amorphous silica particles whose particle size were 4.2-12.8 µm for cosmetic use and two types of crystalline silica whose particle size were 2.4 and 7.1 µm particles for industrial use were examined. These silica particles were applied to HaCaT human keratinocytes for 24 hr. Crystalline silica enhanced IL-8 and IL-6 expression and caused cell membrane damage. Crystalline silica also enhanced HO-1 gene expression; however, the level of intracellular ROS did not change. Compared with crystalline silica, the cellular effects of the spherical silica employed in this study were minor. Cellular uptake of particles was observed for all of silica particle types. Cellular uptake of crystalline silica was observed 1 hr after exposure, and internalized silica particles were present in the cytoplasm. When HaCaT cells were exposed to crystalline silica for 1 hr and incubated for 23 hr in culture medium without silica particles, IL-8 expression was still detected. In addition, silica particles exerted negligible effects using a 3D skin tissue model. Thus, the following conclusions may be drawn. (1) cellular effects exerted by spherical silica are less compared to crystalline silica. (2) phagocytosis of particles is an important first step in the cellular effects of silica particles. (3) spherical silica particles might exert little, if any, effect on healthy skin attributed to no apparent cellular uptake.

Effect of Serum Perampanel Concentration on Sporadic Amyotrophic Lateral Sclerosis Progression.

BACKGROUND AND PURPOSE: To clarify the effect of perampanel (PER) on sporadic amyotrophic lateral sclerosis (sALS) progression, the relationship between the changes in Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) scores and serum PER concentrations was investigated. METHODS: 12 patients with sALS from our hospital who agreed to participate and completed the PER for sALS randomized phase 2 study were included. After completing the study, we retrospectively obtained serum PER concentration data from the patients. Based on their mean PER concentrations, we divided the patients who had been taking PER into two groups: four patients with a mean PER concentration of ≥400 ng/mL were assigned to the H group, and three with a mean PER concentration of <400 ng/mL were assigned to the L group. The control group consisted of five patients who had been taking a placebo. We obtained the ALSFRS-R scores of each patient at 36 and 48 weeks after randomization. The differences in ALSFRS-R scores at baseline (0 weeks) and each subsequent week were used in the analysis. RESULTS: At 48 weeks, there were no differences in the degree of deterioration of the bulbar, upper and lower limb, and respiratory ALSFRS-R subscores and total ALSFRS-R score. However, at 36 weeks, the bulbar subscore was significantly lower in the H group than in the control group (p=0.032). CONCLUSIONS: Because high PER concentrations may exacerbate bulbar symptoms in patients with sALS, serum PER measurements may be beneficial when patients with sALS are taking PER.

Pathological features of glial cells and motor neurons in the anterior horn of the spinal cord in sporadic ALS using ADAR2 conditional knockout mice.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by the selective degeneration of motor neurons (MNs). In the MNs of patients with ALS, adenosine deaminase acting on RNA 2 (ADAR2)-mediated RNA editing of GluA2 mRNA at the Q/R site is profoundly deficient. In genetically modified mice (ADAR2flox/flox/VAChT-Cre.Fast; AR2), the selective knockout of ADAR2 in cholinergic neurons induced progressive loss of lower MNs. MNs exhibiting an age-related increase in abnormal TDP-43 localization and reduced ADAR2 immunoreactivity are localized in the lateral areas of the anterior horns (AHs) in aged wild-type mice. However, the patterns in the AHs of AR2 mice remain unknown. In this study, we investigated whether similar degeneration is observed in AR2 mice. We compared the number of astrocytes and MNs in the lateral and medial AHs of the lumbar spinal cord of 12-month-old AR2 mice with age-matched wild-type mice. The number of MNs significantly decreased in both the lateral and medial areas in AR2 mice AHs, particularly in the former. The number of reactive astrocytes increased significantly in the lateral areas of the AHs of AR2 mice. In conclusion, stronger activation of astrocytes with reduction of MNs in the ADAR2 deficiency-related lateral area increases in AR2 mice AHs. Fast fatigable MNs are expected to be present in the lateral area of the AHs. We found that MN death is more common in the lateral area of AHs associated with FF MNs due to differences in vulnerability to MN under ADAR2 deficiency.

Prolyl Isomerase Pin1 Expression in the Spinal Motor Neurons of Patients With Sporadic Amyotrophic Lateral Sclerosis.

BACKGROUND AND PURPOSE: Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease. Selective deficiency of edited adenosine deaminase acting on RNA 2 (ADAR2), a key molecule in the acquisition of Ca2+ resistance in motor neurons, has been reported in sporadic ALS (sALS) spinal motor neurons. Since ADAR2 activity is positively regulated by prolyl isomerase Protein never in mitosis gene A interacting-1 (Pin1), a known phosphorylation-dependent peptidyl-prolyl cis/trans isomerase, we investigated Pin1 expression in spinal motor neurons in sALS. METHODS: Specimens of the spinal cord were obtained from the lumbar region in eight sALS patients and age-matched five controls after postmortem examinations. The specimens were double stained with anti-Pin1 and anti-TAR DNA-binding protein of 43 kDa (TDP-43) antibodies, and examined under a fluorescence microscope. RESULTS: This study analyzed 254 and 422 spinal motor neurons from 8 sALS patients and 5 control subjects, respectively. The frequency of motor neurons with high cytoplasmic Pin1 expression from the spinal cord did not differ significantly between sALS specimens without cytoplasmic TDP-43 inclusions and control specimens. However, in sALS specimens, neurons for which the Pin1 immunoluminescence intensity in the cytoplasm was at least twice that in the background were more common in specimens with cytoplasmic TDP-43 inclusions (p<0.05 in χ² test). CONCLUSIONS: In sALS, neurons with higher expression levels of Pin1 levels had more TDP-43 inclusions. Despite the feedback mechanism between Pin1 and ADAR2 being unclear, since Pin1 positively regulates ADAR2, our results suggest that higher Pin1 expression levels in motor neurons with TDP-43 pathology from sALS patients represent a compensatory mechanism.

Randomized phase 2 study of perampanel for sporadic amyotrophic lateral sclerosis.

OBJECTIVE: To evaluate the efficacy and safety of perampanel in patients with sporadic amyotrophic lateral sclerosis (SALS). METHODS: This randomized, double-blind, placebo-controlled, multicenter, phase 2 clinical study was conducted at 12 sites. Patients with probable or definite ALS as defined by revised El Escorial criteria were enrolled. Sixty-six patients were randomly assigned (1:1:1) to receive placebo, 4 mg perampanel, or 8 mg perampanel daily for 48 weeks. Adverse events (AEs) were recorded throughout the trial period. The primary efficacy outcome was the change in Amyotrophic Lateral Sclerosis Rating Scale-Revised (ALSFRS-R) score after 48 weeks of treatment. RESULTS: One patient withdrew before starting the treatment. Of 65 patients included, 18 of 22 patients randomized to placebo (82%), 14 of 22 patients randomized to 4 mg perampanel (64%), and 7 of 21 patients randomized to 8 mg perampanel (33%) completed the trial. There was a significant difference in the change of ALSFRS-R scores [- 8.4 (95% CI - 13.9 to - 2.9); p = 0.015] between the placebo and the perampanel 8 mg group, primarily due to worsening of the bulbar subscore in the perampanel 8 mg group. Serious AEs were more frequent in the perampanel 8 mg group than in the placebo group (p = 0.0483). CONCLUSIONS: Perampanel was associated with a significant decline in ALSFRS-R score and was linked to worsening of the bulbar subscore in the 8 mg group.

Characteristics of sagittal spinopelvic alignment in patients with Parkinson's disease.

INTRODUCTION: The aim of this study was to characterize the associations between sagittal spinopelvic alignment and motor symptoms in patients with Parkinson's disease (PD). METHODS: The study included patients with idiopathic PD (aged <80 years and with abnormal posture). All patients underwent whole-spine lateral and coronal radiography. Sagittal spinopelvic alignment was evaluated using nine parameters. Motor symptoms were evaluated using the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III score-with bradykinesia and axial motor sub-scores. Multivariate analysis was used to analyze associations between motor symptoms and sagittal spinopelvic alignment in PD patients according to sex. RESULTS: The study subjects were 79 PD patients (39 men, 40 women; median age, 70 years). Clear sex-related differences were noted. In male patients, the MDS-UPDRS part III score correlated significantly with cervical sagittal vertical axis (SVA), and bradykinesia and axial motor scores correlated significantly with SVA, cervical SVA, and T1 slope. In female patients, the MDS-UPDRS part III score correlated significantly with thoracic kyphosis, bradykinesia score correlated significantly with cervical SVA and thoracic kyphosis, and the axial motor score correlated significantly with SVA, cervical SVA, T1 slope, sacral slope, and pelvic tilt. CONCLUSION: Our results showed clear correlations among various motor symptoms and sagittal global alignment in PD patients and that these correlations are different in female PD patients and their male counterparts.

Novel Colloidal Dispersing Concept in Aqueous Media for Preparation by Wet-Jet Milling Dispersing Method.

Dispersing particles in a liquid phase is significant for producing various functional nano/bio applications. The wet-jet milling method has been gaining attention as an attractive dispersing method in the preparation of soft material suspensions. This is because the main driving force of dispersion by the wet-jet milling method is the shear force, which is weaker than that it is in the ultrasonication dispersing method. In the wet-jet milling method, the pressure of the narrow channel which the liquid is passes through and the number of passes are used as the control parameters for dispersing the particles. However, the values of the pressure depend on the size (diameter and length) of the narrow channel, thus, it is not a commonly used dispersing parameter in dispersing by wet-jet milling to set the dispersing condition by various wet-jet milling instruments. In addition, wet-jet milling users must optimize the dispersing conditions such as the pressure and number of passes in the narrow channel, therefore, a simple prediction/optimization method of the dispersing size by the wet-jet milling method is desired. In this study, we established a novel colloidal dispersing concept, the dispersing energy input based on a calorimetric idea, for particle suspension preparation using the wet-jet milling method. The dispersing energy input by wet-jet milling was quantitatively calculated under various conditions during the dispersing by wet-jet milling, and then, the dispersing size of the particles was easily predicted/optimized. We demonstrated the usability of the concept by preparing aqueous suspensions of calcium carbonate (CaCO3) particles with various surfactants using the wet-jet milling method. Based on the established concept, in a case study on dispersing CaCO3, we found that changes in the micelle sizes of the surfactants played a role in wet-jet milling. The novel idea of the representation of energy input makes it possible to estimate the appropriate condition of the dispersing process by wet-jet milling to control the size of particles.

Photocatalytic activity of nanoparticles: the development of the standardized measurement for physiological conditions.

Recently a new International Standard for testing nanomaterial photocatalytic activity under physiological conditions was issued by Technical Committee 229 (Nanotechnologies) of the International Organization for Standardization (ISO 20814:2019 Nanotechnologies-Testing the photocatalytic activity of nanoparticles for NADH oxidation). The document offers a robust, high throughput photocatalytic assay using a bio-compatible indicator nicotinamide amide dinucleotide (NAD) and provides a screening tool to gauge nanomaterial potency for phototoxicity. This paper describes the measurement principles behind this assay, the scope of the standard and its validation through an interlaboratory comparison study using a traceable standard reference material (SRM 1898).

Persistent Hemichorea as a Preceding Symptom of Cerebral Infarction Due to Middle Cerebral Artery Stenosis.

We herein report an 84-year-old woman with right middle cerebral artery (MCA) stenosis who presented with persistent left hemichorea preceding cerebral infarction. She visited our hospital on day 9 after the hemichorea onset. Magnetic resonance imaging (MRI) showed no acute cerebral infarction. Magnetic resonance angiography revealed right MCA stenosis. Her hemichorea persisted for 19 days and subsequently disappeared. On day 21, she developed left hemiplegia. Repeat MRI revealed a cerebral infarction in the right putamen. MCA stenosis can present with persistent hemichorea, even in the absence of cerebral infarction. Persistent hemichorea with MCA stenosis may presage cerebral infarction.

[Posterior reversible encephalopathy syndrome during intravenous immunoglobulin therapy in Guillain-Barré syndrome].

A 63-year-old woman was diagnosed with Guillain-Barré syndrome (GBS), and intravenous immunoglobulin (IVIg) therapy was initiated. On the second day of IVIg therapy, she became less alert (JCS III-200) and had hyponatremia. Brain MRI showed vasogenic edema in bilateral occipital lobes, which disappeared afterwards. Her clinical course and MRI findings were consistent with those of posterior reversible encephalopathy syndrome (PRES). As a result of considering the timing of the onset of GBS and PRES and the degree of hyponatremia and hypertension in some documented patients, the cause of PRES onset in this case is considered to be IVIg therapy itself and IVIg therapy-induced hyponatremia.

Particle density determination using resonant mass measurement method combined with asymmetrical flow field-flow fractionation method.

A novel characterization system using a combinational analysis of the resonant mass measurement (RMM) and asymmetrical flow field-flow fractionation (AF4) methods is developed as a hybrid analytical tool for the particle density of mixtures of different-sized materials. The function of the RMM method is to determine the particle mass by observing the shift in frequency proportional to the particle mass. However, to determine the density of particles using the RMM method, information on the size or size distribution is necessary. Because the size distribution of the particles could influence the accuracy of the determination of the density of the particles, this study addresses the weak point of the RMM method using the AF4 method. First, AF4 is used to fractionate the narrow-sized distributed particles as an effective sample preparation method before the RMM assessment. Moreover, the accurate size distribution determined by the AF4 method with multi-angle light scattering analysis supports the reliable density determination by the RMM method on the transformation from the mass distribution of the particles to the density distribution. Using our developed combinational analytical method of RMM and AF4 methods for mixed particle samples (different sizes and different materials), the densities of the respective particles are evaluated. This approach clearly resolved the problems of the RMM method using a combination analysis with the AF4 method for RMM assessment on the density of particles. The investigated analysis method can have an important role in developing new applications of colloidal nano- and micro-materials in industrial and biological research.

Novel Approach for Reliable Determination of the Refractive Index of Particles in the Liquid Phase Using a Hybrid Flow Particle Tracking Method.

We developed a novel method for the reliable determination of the refractive index (RI) of particles under flow conditions: the hybrid flow particle tracking (FPT) method, i.e., simultaneous observation of Brownian motion and light scattering intensities for individual particles under flow conditions. After determination of the size of individual particles from their diffusive motion by Stokes-Einstein assumption, the RI was determined using the relationship between the size and corresponding light scattering intensity according to Rayleigh/Mie theory. However, there were two problems in the establishment of the hybrid FPT method. First, the calculated size of the individual particles from their diffusion motion has considerable error because of the randomness in the diffusion trajectory owing to the Brownian motion. Second, the observed light scattering intensities of the particles varied depending on the position of the particles in the incident beam because of the spatial light intensity profile of the incident beam. After resolving these two adverse effects, we successfully obtained reliable RIs for the different types of particles. This established method will contribute to the simultaneous determination of the size and types of particles in a flow system.

Characterization of the Volume-based or Number-based Size Distribution for Silica Nanoparticles Using a Unique Combination of Online Dynamic Light Scattering Having a Uni-tau Multi-bit Correlator and High-resolution Centrifugal Field-Flow Fractionation Separator.

This paper presents a study of the size distributions of colloidal nanoparticles using an online dynamic light scattering (DLS) unit with a uni-tau multi-bit correlator (UMC) combined with a centrifugal field-flow fractionation (CF3) separator. Conventionally, the FFF-UV-MALS system utilizing field-flow fractionation (FFF) combined with a UV detector and multi-angle light scattering instrument (MALS) could be used to obtain the particle size distribution of colloidal nanoparticles. Lately, DLS as a technique to measure the size distributions of colloid materials has become prevalent. However, the DLS instrument will practically measure only the large particles in a multi-modal particle mixture. Therefore, the CF3-DLS w/UMC system that was developed consisted of a CF3 unit connected to an online DLS instrument with UMC. The system could measure the volume- or number-based size distribution with highly quantitative and accurate histograms for multi-modal samples. The size distributions were validated with size distributions obtained by images of an atomic force microscope (AFM). Two types of colloidal silica nanoparticles with different distribution widths were used in this study.

Determination of number-based size distribution of silica particles using centrifugal field-flow fractionation.

Determination of the number-based size distribution of silica particles using the centrifugal field-flow fractionation (CF3) method was investigated. Since the accurate determination of the number-based size distribution of materials is essential in the fields of nanotechnology and biotechnology, the establishment of a robust evaluation method is attractive. We explored optimization of the fractionation conditions for CF3 using silica particles. Using pure water media as the eluent, a band broadening effect was clearly found, and this effect became stronger with higher initial centrifugal field strengths. After addition of 0.05 wt% aqueous FL-70 as a dispersant in the eluent, size fractionation could be performed effectively at higher centrifugal field strengths, providing excellent size separation results. After optimization of the CF3 separation condition, we determined the number-based size distribution of silica particles using three methods: FE-SEM only, CF3 with multi-angle light scattering (CF3-MALS), and a combined CF3 with FE-SEM method (CF3-FE-SEM). To meaningfully compare the CF3-MALS results with the other two methods, we transformed the light scattering intensity to particle numbers using Mie theory. The determined number-based mean sizes of silica particles by the three methods agreed well; however, the evaluated standard deviation of the number-based size distribution of silica particles by the CF3-MALS method was slightly different. This was attributed to the unreliable sizing by MALS of smaller sized particles or low particle concentrations. The combined CF3-FE-SEM method provided near equal accuracy as the costly FE-SEM only and allowed for a significantly faster methodology because CF3 separation reduced the number of silica particles required for an accurate sizing down to just 50 particles per fraction.

Impaired Nucleoporins Are Present in Sporadic Amyotrophic Lateral Sclerosis Motor Neurons that Exhibit Mislocalization of the 43-kDa TAR DNA-Binding Protein.

BACKGROUND AND PURPOSE: Disruption of nucleoporins has been reported in the motor neurons of patients with sporadic amyotrophic lateral sclerosis (sALS). However, the precise changes in the morphology of nucleoporins associated with the pathology of the 43-kDa TAR DNA-binding protein (TDP-43) in the disease process remain unknown. We investigated the expression of nucleoporins that constitute the nuclear pore complex (NPC) in spinal motor neurons that exhibit sALS in relation to TDP-43 pathology, which is a reliable neuropathological hallmark of sALS. METHODS: Paraffin-embedded sections of the lumbar spinal cord were obtained for immunofluorescence analysis from seven control subjects and six sALS patients. Anti-TDP-43 antibody, anti-nucleoporin p62 (NUP62) antibody, and anti-karyopherin beta 1 (KPNB1) antibody were applied as primary antibodies, and then visualized using appropriate secondary antibodies. The sections were then examined under a fluorescence microscope. RESULTS: NUP62 and KPNB1 immunoreactivity appeared as a smooth round rim bordering the nuclear margin in normal spinal motor neurons that exhibited nuclear TDP-43 immunoreactivity. sALS spinal motor neurons with apparent TDP-43 mislocalization demonstrated irregular, disrupted nuclear staining for NUP62 or KPNB1. Some atrophic sALS spinal motor neurons with TDP-43 mislocalization presented no NUP62 immunoreactivity. CONCLUSIONS: Our findings suggest a close relationship between NPC alterations and TDP-43 pathology in the degenerative process of the motor neurons of sALS patients.

Characteristics of apathy in treatment-naïve patients with Parkinson's disease.

INTRODUCTION: Although apathy is a common psychiatric symptom of Parkinson's disease (PD), there are many unknown aspects of its pathology. This study aimed to investigate the characteristics of apathy in treatment-naïve patients with early-stage PD. METHODS: Fifty treatment-naïve patients with early-stage PD were divided into 1 of 2 groups-apathetic or non-apathetic-based on Starkstein Apathy Scale (AS) scores. Cognitive function, depressive symptoms, olfactory function, and motor severity were compared between the two groups using validated assessment scales. Multiple linear regression was performed to assess the association between AS scores and clinical parameters. RESULTS: Apathy (AS score ≥16) was observed in 13 (26%) patients. Assessment scale scores (Beck Depression Inventory-Second Edition [p < .004]; modified Hoehn & Yahr stage [p = .039]; Unified Parkinson's Disease Rating Scale part III [p < .001]) were significantly higher in apathetic patients than in non-apathetic patients. Significant association between these scale scores and AS score was also evident (all p ≤ .001). There were no significant differences in the test scores derived from several other validated scales. CONCLUSION: Apathy was observed in 26% of treatment-naïve patients with early-stage PD. Significant association between apathy and motor severity was found, suggesting that dysfunction of the dopaminergic pathway is involved in the pathology of apathy.

Effects of Angular Dependency of Particulate Light Scattering Intensity on Determination of Samples with Bimodal Size Distributions Using Dynamic Light Scattering Methods.

The angular dependency of light scattering intensity from differently sized particles strongly influences the apparent particle size distribution, as determined by dynamic light scattering (DLS) methods. Manufactured nanomaterials have size distributions more or less; therefore, the effect of detecting the angular dependency of the apparent size distribution by DLS is crucial. Commercial DLS instruments typically have two different types of detector angular position. The first is a detector angled at 90°, and the other is a backscattering angle detector. We therefore investigated the coverage and angular dependency when determining the relative concentrations of nanoparticles in polystyrene latex samples with a bimodal size distribution, using DLS methods both experimentally and theoretically. We used five differently sized polystyrene latex particles (one was a 70-nm nanoparticle and the others were various submicron-sized particles) in a variety of mixtures (the ratio of the difference of particle sizes ranged from approximately 2 to 7) to investigate the coverage and angular dependency of the recognition of the relative concentration ratio. In the case of size difference of approximately a factor of 2 or 3 between the two mixed particles (one was fixed at 70 nm), for DLS measurements at light scattering detector angles ranging from 60° to 150°, the homodyne photon correlation functions were approximately straight lines for mixtures of two differently sized polystyrene latex particles. The straight homodyne photon correlation functions were caused by the relatively strong light scattering from larger submicron particles masking the weaker light scattering from the smaller nanoparticles. As a result, DLS analysis could not recognize the relative concentration of nanoparticles in the mixture. In contrast to these samples, for mixtures of two differently sized polystyrene latex particles (one was 70 nm in size) with a size difference of a factor of 5, the homodyne correlation functions displayed an obvious curve for angles larger than 120°. This curve reflected an appropriate relative concentration ratio for the two differently sized polystyrene latex particles. Furthermore, for a mixture of two differently sized particles (one was again 70 nm) with size differences of a factor of 7, the homodyne correlation functions showed a clearly curved shape for detector angles larger than 90°, and yielded appropriate relative concentration ratios for the two different sizes of polystyrene latex particles. These observations were supported by theoretical investigation using Mie theory and asymmetric flow field-flow fractionation measurements with a multi-angle light scattering detector. Our investigation is crucial for achieving some degree of concordance on the determination of the size distribution of particles using DLS methods in industrial and academic fields.

Determination of an accurate size distribution of nanoparticles using particle tracking analysis corrected for the adverse effect of random Brownian motion.

The particle tracking analysis (PTA) method has been widely used to determine the size of nanoparticles from their Brownian motion, using the Stokes-Einstein assumption. However, the size distribution obtained by PTA is broader than the true distribution because of the uncertainties in determining the diffusion coefficients, and a correction of such a broadening effect is essential to obtain reliable results. In order to transform the apparent broadened size distribution from the PTA method to the true size distribution, we begin by approximating the true size distribution as a gamma distribution determined by a shape parameter and a scale parameter, and then we perform a hybrid analysis based on the maximum likelihood estimation and Bayesian parameter inference that accounts for the uncertainties in determining the diffusion coefficients. To examine the accuracy of our analysis, we compared the size distributions of polystyrene-latex spherical nanoparticles obtained by this transformation process, dynamic light scattering, and asymmetric flow field-flow fractionation with multi-angle light scattering (AF4-MALS). The transformed size distribution resulting from applying our Brownian motion correction to apparent PTA data agrees well with that obtained from AF4-MALS, indicating the success of the correction in obtaining the true nanoparticle size distribution.