Direct observation of cytoskeleton-dependent trafficking of miRNA visualized by the introduction of pre-miRNA

MicroRNA (miRNA) plays physiologically and pathologically important roles in post-transcriptional regulation. Although miRNA has been suggested to dynamically interact with cellular organelles, the dynamicity of intracellular miRNA behavior has remained unclear. Here, by introducing fluorescently labeled pre-miRNA into living cells, we improved the miRNA visualization method using exogenous miRNA precursors. Through the combination of our miRNA visualization method and single-molecule sensitive fluorescence microscopy, we quantitatively analyzed the process of miRNA maturation. Furthermore, single-particle tracking of fluorescent miRNA in cells revealed the directed movements of miRNA on cytoskeletal components (i.e., microtubules and actin filaments). Our results also suggest that cytoskeleton-dependent miRNA trafficking is associated with the interaction of miRNAs with the nucleus and the endoplasmic reticulum/Golgi apparatus. Our method should facilitate the elucidation of the mechanism and physiological significance of the subcellular localization and organelle interaction of miRNA.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Antiferromagnetic topological insulator with selectively gapped Dirac cones

Antiferromagnetic (AF) topological materials offer a fertile ground to explore a variety of quantum phenomena such as axion magnetoelectric dynamics and chiral Majorana fermions. To realize such intriguing states, it is essential to establish a direct link between electronic states and topology in the AF phase, whereas this has been challenging because of the lack of a suitable materials platform. Here we report the experimental realization of the AF topological-insulator phase in NdBi. By using micro-focused angle-resolved photoemission spectroscopy, we discovered contrasting surface electronic states for two types of AF domains; the surface having the out-of-plane component in the AF-ordering vector displays Dirac-cone states with a gigantic energy gap, whereas the surface parallel to the AF-ordering vector hosts gapless Dirac states despite the time-reversal-symmetry breaking. The present results establish an essential role of combined symmetry to protect massless Dirac fermions under the presence of AF order and widen opportunities to realize exotic phenomena utilizing AF topological materials.

The Cell Tracking Challenge: 10 years of objective benchmarking

The Cell Tracking Challenge is an ongoing benchmarking initiative that has become a reference in cell segmentation and tracking algorithm development. Here, we present a significant number of improvements introduced in the challenge since our 2017 report. These include the creation of a new segmentation-only benchmark, the enrichment of the dataset repository with new datasets that increase its diversity and complexity, and the creation of a silver standard reference corpus based on the most competitive results, which will be of particular interest for data-hungry deep learning-based strategies. Furthermore, we present the up-to-date cell segmentation and tracking leaderboards, an in-depth analysis of the relationship between the performance of the state-of-the-art methods and the properties of the datasets and annotations, and two novel, insightful studies about the generalizability and the reusability of top-performing methods. These studies provide critical practical conclusions for both developers and users of traditional and machine learning-based cell segmentation and tracking algorithms.

Tracking cell lineages in 3D by incremental deep learning

Deep learning is emerging as a powerful approach for bioimage analysis. Its use in cell tracking is limited by the scarcity of annotated data for the training of deep-learning models. Moreover, annotation, training, prediction, and proofreading currently lack a unified user interface. We present ELEPHANT, an interactive platform for 3D cell tracking that addresses these challenges by taking an incremental approach to deep learning. ELEPHANT provides an interface that seamlessly integrates cell track annotation, deep learning, prediction, and proofreading. This enables users to implement cycles of incremental learning starting from a few annotated nuclei. Successive prediction-validation cycles enrich the training data, leading to rapid improvements in tracking performance. We test the software's performance against state-of-the-art methods and track lineages spanning the entire course of leg regeneration in a crustacean over 1 week (504 timepoints). ELEPHANT yields accurate, fully-validated cell lineages with a modest investment in time and effort.

Morphological and Morphometrical Analyses of Fracture-Healing Sites of an Atypical Femoral Fracture in Patients with and without Long-Term Bisphosphonate Treatment for Osteoporosis: A Report of Two Cases

Bisphosphonates have been the first drug of choice for osteoporosis in the recent years because of their known ability to suppress osteoclast activity. The adverse effect of long-term bisphosphonate administration in the fracture-healing process is controversial. The aim of our study was to observe not only morphology but also morphometry of the fracture site of atypical femoral fracture with and without long-term bisphosphonate administration, in a case study of two difficult-to-obtain human samples. The patients with insufficient healing of atypical femoral fracture were treated with valgus wedge osteotomy. Histomorphometrical analysis was performed in bone samples of fracture sites harvested during osteotomy. The thickness of the femoral cortex was measured in the fracture site and the adjacent, non-fracture site. A comparative analysis of the content of hypertrophic osteoclasts in fracture sites, shape and size of osteons, mass, and ratio of the woven bone to the total bone mass was performed, comparing bisphosphonate-treated and untreated samples. In bisphosphonate-treated samples, we observed femoral cortex thickening at the fracture site; the appearance of hypertrophic osteoclasts; decreased bone resorption surface, decreased osteoclast numbers on the bone resorption surface, and increased ratio of multinuclear osteoclasts; osteons were misshapen and thin; and the mass and ratio of the woven bone to the total bone mass were higher. This study demonstrated that long-term bisphosphonate administration can alter the morphological features of the fracture site compared to its physiological state.

Conversion of a conventional superconductor into a topological superconductor by topological proximity effect

Realization of topological superconductors (TSCs) hosting Majorana fermions is a central challenge in condensed-matter physics. One approach is to use the superconducting proximity effect (SPE) in heterostructures, where a topological insulator contacted with a superconductor hosts an effective p-wave pairing by the penetration of Cooper pairs across the interface. However, this approach suffers a difficulty in accessing the topological interface buried deep beneath the surface. Here, we propose an alternative approach to realize topological superconductivity without SPE. In a Pb(111) thin film grown on TlBiSe₂, we discover that the Dirac-cone state of substrate TlBiSe₂ migrates to the top surface of Pb film and obtains an energy gap below the superconducting transition temperature of Pb. This suggests that a Bardeen-Cooper-Schrieffer superconductor is converted into a TSC by the topological proximity effect. Our discovery opens a route to manipulate topological superconducting properties of materials.

Realizing topological superconductivity is essential for applicable fault-tolerant quantum computation. Here, Trang et al. report migration of Dirac-cone from TlBiSe₂ substrate to top surface of superconducting Pb film due to topological proximity effect, suggesting realization of topological superconductivity.

Association of preoperative inflammation-based prognostic score with survival in patients undergoing salvage esophagectomy

Salvage esophagectomy (SALV) is potentially beneficial for patients with residual or relapsed esophageal carcinoma after definitive chemoradiotherapy (dCRT), although preoperatively identifying good candidates for SALV remains difficult. We investigated the prognostic impacts of inflammatory and nutritional status in patients undergoing SALV after dCRT. Forty-seven SALV patients were retrospectively reviewed, of whom 46 (98%) had squamous cell carcinoma and 1 (2%) adenocarcinoma. Possible prognostic factors included patients' demographic data, physical status, blood chemistry profiles, and clinical/pathological tumor features. The Glasgow prognostic score (GPS) was derived from preoperative C-reactive protein (CRP) and albumin values. Thirty (64%), 11 (23%), and 6 (13%) patients were classified into the GPS 0, 1, and 2, respectively, groups. None of the possible prognostic factors showed significant correlations with GPS. Patients with GPS 0 had better outcomes than those with GPS 1 or GPS 2 (Median survivals: 37.8, 15.9, and 5.1 months, respectively, P < 0.001). In the multivariable Cox proportional hazards model, GPS 1 (HR 5.62, 95% CI 1.94-16.4, P = 0.002), GPS 2 (HR 9.10, 95% CI 2.60-31.8, P < 0.001), R1/2 resection (HR 16.3, 95% CI 3.62-86.7, P < 0.001) and incomplete response to dCRT (HR 3.53, 95% CI 1.12-12.5, P = 0.03) were all independent risk factors for a poor outcome. Preoperative GPS is potentially useful for predicting outcomes in esophageal cancer patients undergoing SALV.

IMACEL: A cloud-based bioimage analysis platform for morphological analysis and image classification

Automated quantitative image analysis is essential for all fields of life science research. Although several software programs and algorithms have been developed for bioimage processing, an advanced knowledge of image processing techniques and high-performance computing resources are required to use them. Hence, we developed a cloud-based image analysis platform called IMACEL, which comprises morphological analysis and machine learning-based image classification. The unique click-based user interface of IMACEL’s morphological analysis platform enables researchers with limited resources to evaluate particles rapidly and quantitatively without prior knowledge of image processing. Because all the image processing and machine learning algorithms are performed on high-performance virtual machines, users can access the same analytical environment from anywhere. A validation study of the morphological analysis and image classification of IMACEL was performed. The results indicate that this platform is an accessible and potentially powerful tool for the quantitative evaluation of bioimages that will lower the barriers to life science research.

Weak localization in bilayer graphene with Li-intercalation/desorption

We performed in-situ electrical transport measurements for bilayer graphene grown on SiC(0 0 0 1) substrate, Li-intercalated bilayer graphene, and after that desorbing Li atoms by heating. Bilayer graphene after desorbing intercalated Li atoms showed a higher resistivity and different behavior in magnetoconductance compared to pristine bilayer graphene. We observed the weak localization of carriers at low temperatures in all the three samples and analyzed the experimental results with the extended Hikami-Larkin-Nagaoka equation to investigate the transport properties. The result shows that the magnetoconductance of pristine bilayer graphene is described by the AB stacking structure model and the phase breaking scattering is dominated by the electron-electron scattering. The intra-valley scattering occurs most frequently probably due to dopants in SiC substrate. However, in Li-desorbed graphene, the magnetoconductance can be described by neither AB nor AA-stacking model, suggesting the coexistence of domains with several different stacking structures.

[A Case of Granulocyte-Colony Stimulating Factor-Producing Esophageal Squamous Cell Carcinoma Treated with Chemoradiation Therapy]

The patient was a 64-year-old man who presented with a hoarse voice, pharyngalgia, and high fever.Despite receiving therapy, he presented with dysphagia, and endoscopy revealed a tumor in the thoracic esophagus.A biopsy indicated squamous cell carcinoma.Despite no evidence of infection, laboratory findings revealed leukocytosis and high serum levels of granulocyte-colony stimulating factor(G-CSF).An immunohistochemical study showed positive staining for G-CSF in the tumor cells.Chemoradiation therapy(CRT)with 5-fluorouracil and cisplatin was administered, but his response to treatment was evaluated as progressive disease.Bone, brain, and liver metastases were detected consecutively, and he died 7 months after diagnosis.There are few reports of G-CSF-producing esophageal tumors, and the prognosis is very poor.

Enhancement of electron-phonon coupling in Cs-overlayered intercalated bilayer graphene

We have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) on cesium (Cs) intercalated bilayer graphene with a Cs overlayer (Cs-C8CsC8). Low-energy electron diffraction shows a (2  ×  2) pattern consistent with intercalation of a Cs layer similar to bulk C8Cs, in addition to the signature of a nearly commensurate superstructure created by the Cs overlayer. ARPES results reveal folding of the π bands due to the periodic (2  ×  2) potential of the intercalated Cs atoms, together with a free-electron-like state at the [Formula: see text] point. Significant mass renormalization is observed in the band dispersion near the Fermi level, indicative of strong electron-phonon coupling. Based on analysis of the self-energy, we find anisotropic electron-phonon coupling with an estimated strength of [Formula: see text]  ±  0.02 in the K-[Formula: see text] direction, and [Formula: see text] in the K-M direction. This coupling is much larger than that of other doped graphenes, and comparable to superconducting bulk GICs. We attribute this large electron-phonon coupling constant to the presence of the Cs overlayer, which highly dopes [Formula: see text] bands, and creates a structure similar to stage-I graphite intercalation compounds.

Switching of Dirac-Fermion Mass at the Interface of Ultrathin Ferromagnet and Rashba Metal

We have performed spin- and angle-resolved photoemission spectroscopy on tungsten (110) interfaced with an ultrathin iron (Fe) layer to study an influence of ferromagnetism on the Dirac-cone-like surface-interface states. We found an unexpectedly large energy gap of 340 meV at the Dirac point, and have succeeded in switching the Dirac-fermion mass by controlling the direction of Fe spins (in plane or out of plane) through tuning the thickness of the Fe overlayer or adsorbing oxygen on it. Such a manipulation of Dirac-fermion mass via the magnetic proximity effect opens a promising platform for realizing new spintronic devices utilizing a combination of exchange and Rashba-spin-orbit interactions.

Effect of electrical stimulation-induced muscle force and streptomycin treatment on muscle and trabecular bone mass in early-stage disuse musculoskeletal atrophy

OBJECTIVES

The aim was to determine whether daily muscle electrical stimulation (ES) and streptomycin treatment would have positive or negative effects on trabecular bone mass in disuse rats.

METHODS

Seven-week-old male F344 rats were randomly divided into five groups of eight animals each: an age-matched control group (CON); a sciatic denervation group (DN); a DN + direct electrical stimulation group (DN+ES); a DN + streptomycin treatment group (DN+SM); and a DN+ES+SM group. The tibialis anterior (TA) muscles in all ES groups were stimulated with 16mA at 10Hz for 30 min/day, six days/week, for one week. Bone volume and structure were evaluated using micro-CT, and histological examinations of the tibiae were performed.

RESULTS

Direct ES significantly reduced the disuse-induced trabecular bone loss. Osteoid thickness were also significantly greater in the ES groups than in the DN group. Micro CT and histomorphological parameters were significantly lower in the DN+ES+SM group than in the DN+ES group, while there were no significant differences between the DN and DN+SM groups.

CONCLUSIONS

These results suggest that ES-induced muscle force reduced trabecular bone loss, and streptomycin treatment did not induce bone loss, but attenuated the effects of ES-induced muscle force on reducing the loss of disused bone.

High-temperature superconductivity in potassium-coated multilayer FeSe thin films

The recent discovery of possible high-temperature (T(c)) superconductivity over 65 K in a monolayer FeSe film on SrTiO3 (refs 1-6) triggered a fierce debate on how superconductivity evolves from bulk to film, because bulk FeSe crystal exhibits a T(c) of no higher than 10 K (ref. 7). However, the difficulty in controlling the carrier density and the number of FeSe layers has hindered elucidation of this problem. Here, we demonstrate that deposition of potassium onto FeSe films markedly expands the accessible doping range towards the heavily electron-doped region. Intriguingly, we have succeeded in converting non-superconducting films with various thicknesses into superconductors with T(c) as high as 48 K. We also found a marked increase in the magnitude of the superconducting gap on decreasing the FeSe film thickness, indicating that the interface plays a crucial role in realizing the high-temperature superconductivity. The results presented provide a new strategy to enhance and optimize T(c) in ultrathin films of iron-based superconductors.

First Report of Pythium Root and Stalk Rot of Forage Corn Caused by Pythium arrhenomanes in Japan

Corn (Zea mays L.) is the most important forage crop in Japan. It was cultivated on 92,000 ha in 2011 and was mainly used as whole crop silage for cattle feed. In September 2009, a root and stalk rot disease was detected on corn plants cultivated in Tochigi, located in the central region of Japan. The symptoms of the disease included wilting of whole plants after the R5 (dent) stage (2) with drooping ears. Roots turned black and their number decreased. Further, the stalks became hollow and soft and harbored white hyphae. This tissue deterioration made machine harvest difficult. We obtained seven isolates of a Pythium-like organism by single hypha isolation from surface-sterilized pieces of diseased roots and stems on water agar and deposited one of the isolates at the NIAS genebank, Japan, under the accession no. MAFF511547. The isolate was grown in the dark on V8 juice agar medium for 10 days to produce oogonia. The oogonia were globose, light brown to yellow, smooth, 23.9 to 30.5 μm in size, and had 1 to 8 antheridia. Oospores were mostly plerotic, and oogonia walls were 1.3 to 2.7 μm thick. The morphology of the isolates was similar to that of Pythium arrhenomanes Drechsler and consistent with the species description (3). We analyzed the rDNA-ITS region sequences of the isolate as described by Kageyama et al. (1). The sequence (GenBank Accession No. AB903904) showed 99.1% (783/790 bp) similarity with that of P. arrhenomanes (AY598628). On the basis of morphological and rDNA sequence similarities, we identified the isolates obtained from corn as P. arrhenomanes. The pathogenicity of the isolate was confirmed by planting corn seedlings of the commercial Pioneer Brand hybrid 36B08 immediately after germination in five replicate pots containing soil mixed with 5% boiled barley grain by weight, incubated with or without the isolate for 7 days. After 10 days of incubation in a greenhouse at 20 to 25°C, only the inoculated plants exhibited symptoms of root and stalk rot. Since the inoculated organism was readily re-isolated from the diseased stems and roots, the pathogenicity of the isolate was confirmed. For field observation, the same hybrid of forage corn was sown in the fields in Nasushiobara, Tochigi, on 16 May 2011. The hybrid was sown in a row of 2 m, with 20 seeds planted at a distance of 10 cm with two replicates. For inoculum, the isolate was cultured on 5-cm-long wooden toothpicks, previously soaked in potato dextrose broth and placed on a V8 agar plate for 7 days at 25°C in the dark until covered by hyphae. The toothpicks were pierced into wounds made on the stems of corn plants, approximately 10 cm above the ground, using a thin iron needle. The wounds were about 2 mm in diameter and 2 cm deep. Field inoculation was conducted in late July at the R1 (silking) growth stage. Disease symptoms were observed in mid-September at R5, and only those plants that were inoculated with the toothpicks harboring the hyphae exhibited the typical stem rot symptoms. To our knowledge, this is the first report of root and stalk rot caused by P. arrhenomanes in forage corn in Japan. References: (1) K. Kageyama et al. J. Phytopathol. 151:485, 2003. (2) S. W. Ritchie et al. Spec. Rep. 48. Iowa State Univ. Coop Ext. Serv., Ames, 1993. (3) A. J. Van der Plaats-Niterink. Stud. Mycol. 21:1, 1981.

A spontaneously blinking fluorophore based on intramolecular spirocyclization for live-cell super-resolution imaging

Single-molecule localization microscopy is used to construct super-resolution images, but generally requires prior intense laser irradiation and in some cases additives, such as thiols, to induce on-off switching of fluorophores. These requirements limit the potential applications of this methodology. Here, we report a first-in-class spontaneously blinking fluorophore based on an intramolecular spirocyclization reaction. Optimization of the intramolecular nucleophile and rhodamine-based fluorophore (electrophile) provide a suitable lifetime for the fluorescent open form, and equilibrium between the open form and the non-fluorescent closed form. We show that this spontaneously blinking fluorophore is suitable for single-molecule localization microscopy imaging deep inside cells and for tracking the motion of structures in living cells. We further demonstrate the advantages of this fluorophore over existing methodologies by applying it to nuclear pore structures located far above the coverslip with a spinning-disk confocal microscope and for repetitive time-lapse super-resolution imaging of microtubules in live cells for up to 1 h.

Electrical stimulation of denervated rat skeletal muscle retards trabecular bone loss in early stages of disuse musculoskeletal atrophy

OBJECTIVES

We aimed to determine the intensity of muscle stimulation required to prevent structural failure as well as bone and skeletal muscle loss after denervation-induced disuse.

METHODS

Seven-week-old rats (weight, 198-225 g) were randomly assigned to age-matched groups comprising control (CON), sciatic nerve denervation (DN) or direct electrical stimulation (ES) one day later [after denervation] with 4, 8 and 16 mA at 10 Hz for 30 min/day, six days/week, for one or three weeks. Bone architecture and mean osteoid thickness in histologically stained tibial sections and tension in tibialis anterior muscles were assessed at one and three weeks after denervation.

RESULTS

Direct ES with 16 mA generated 23-30% maximal contraction force. Denervation significantly decreased trabecular bone volume fraction, thickness and number, connectivity density and increased trabecular separation in the DN group at weeks one and three. Osteoid thickness was significantly greater in the ES16 group at week one than in the DN and other ES groups. Trabecular bone volume significantly correlated with muscle weight.

CONCLUSIONS

Relatively low-level muscle contraction induced by low-frequency, high-intensity electrical muscle stimulation delayed trabecular bone loss during the early stages (one week after DN) of musculoskeletal atrophy due to disuse.

Screening of As-accumulating plants using a foliar application and a native accumulation of As

The discovery of novel accumulating plants is useful for efficient phytoremediation due to the demands of various conditions of impacted sites such as land use, soil properties, concentration of pollutants, and climate. In the present study, we investigated foliar application or a field with highly bioavailable arsenic (As) to screen As-accumulating plants. Plants grown in the downstream of a hot springs area were analyzed for native As accumulation and As foliar application, and the rhizosphere soils were collected. The water-soluble As in the rhizosphere soils had a high average, 144 microg/kg, whereas total As was similar to normal soil in Japan. Among 34 herbaceous plants and 17 woody plants, Chelidonium majus var. asiaticum accumulated a relatively high As level, 8.07 mg/kg DW (93.6% of As added), that was not revealed by native accumulation. In a further pot experiment, C. majus accumulated a moderately high As level (314 mg/kg DW) in the roots but not in the shoot (30.1 mg/kg DW), and exhibited a low transfer factor (TF = 0.096). Thus, a foliar application would be a simple and high-throughput method to screen plants that accumulate and tolerate As. C. majus would be useful as a tool for phytostabilization of As.

The unique correlation between anti-mutagenicity of human saliva and change in body weight

The purpose of this study was to investigate the effect of weight reduction on the anti-mutagenicity of human saliva. Subjects were 16 male college judo players. The anti-mutagenicity of the saliva was measured using the umu test. There was an inhibiting effect of the saliva on the mutagenicity of AF-2. However, a modifying effect of the saliva on Trp-P-1 was not observed. On the day before a competition and 7 days after the competition, the inhibiting capacity of the saliva for the mutagenicity of AF-2 decreased and increased in two non-weight reduction and two weight reduction groups, respectively.However, on the day before the competition, the changed body weights (r=-0.77, p<0.01) and BMI (r=-0.77, p<0.01) were significantly correlated with that of the inhibiting capacity of the saliva for the mutagenicity of AF-2. In addition, the BMI at 20 days before the competition was not significantly but markedly correlated with it (r=0.50, p=0.057). At 7 days after the competition, however, these correlations were not found.These findings suggest a unique correlation between the anti-mutagenicity of human saliva and body weight or BMI.

Changes in physical characteristics, hematological parameters and nutrients and food intake during weight reduction in judoists

We studied changes in physical characteristics: body composition; muscle and physical strength; hematological parameters; and nutrients and food intake in 22 male college judoists who were losing weight purposefully. Nutritional parameters in blood, such as triglycerides, decreased immediately before matches and rebounded after matches. Free fatty acid increased before matches and returned to previous levels 10 days after matches. IgM and complements decreased before matches and did not return to previous levels even 10 days after matches. These changes were noted in the marked weight reduction group (weight lost / body weight before weight reduction, weight reduction rate≥6%). In contrast, creatine kinase increased before matches in the slight and moderate weight reduction groups (weight reduction rate< 3%, 3≤and<6%, respectively). The marked weight reduction group showed no changes in creatine kinase, however, indicating inadequate exercise due to excessive weight reduction. Muscle strength (grip) and nutrients and food intake decreased significantly before matches. These changes were noted in the marked weight reduction group. These findings suggested that a weight reduction rate of 6% or more adversely affected the performance and health of the judoist.

Diurnal variation in neutrophil function

Neutrophil functions, including chemotaxis, reactive oxygen species (ROS)-producing capacity of neutrophils, and serum opsonic activity were investigated in 9 young healthy male volunteers. Venous blood of these volunteers was obtained under standardized conditions at 4-h intervals over a 24-h span. Neutrophil chemotaxis was evaluated by a modified Boyden technique, ROS-producing capacity of neutrophils and serum opsonic activity were measured by a simultaneous multiple measurement system based on luminol-dependent chemiluminescence and indicated by peak height and peak time. ROS-producing capacity of neutrophils and serum opsonic activity were activated in the daytime, and decreased from night to morning. There were negative correlations between the peak time of the luminol-dependent chemiluminescent response, neutrophil number (p<0.01) and segmented neutrophil number (p>0.01). On the other hand, no significant correlations were noted between serum opsonic activity and IgG, IgA, IgM, C3 or C4. In contrast, the peaks of neutrophil chemotaxis were at the wake-up time (6:00a.m.) and in the evening (6:00p.m.). This study indicates that diurnal variation of neutrophil function exists.

First Report of Guinea Grass Smut Caused by Conidiosporomyces ayresii in Japan

Guinea grass (Panicum maximum Jacq.) is an important C-4 perennial plant that grows in southern Japan. In March 2010, a smut disease was found in grass that is cultivated in the Ishigaki Islands, Okinawa, in southernmost Japan. Spikelets of susceptible cultivars were swollen and filled with gray spore masses and seed production was substantially reduced. Two single-spore isolates of a smut fungus were obtained from infected spikelets and deposited at the NIAS Genebank, Japan as MAFF511519 and 511520. The 28S rDNA sequences of the isolates were analyzed as described by Boekhout et al. (1). The 28S rDNA sequence (GenBank Accession No. AB647346) of isolate MAFF511519 matched that of Conidiosporomyces ayresii (GenBank Accession No. AY819017) isolated from P. maximum with 99.8% similarity. Spores were pale brown to brown, globose to subglobose, verrucose, and 14 to 16 × 15 to 18 μm in diameter with relatively thick walls of 2 to 3 μm. With scanning electron microscopy, warts appeared dense and short with pointed tips. Spores germinated under wet conditions and produced masses of basidiospores. Basidiospores were aseptate, long, cylindrical, straight to slightly curved, 20 to 37 × 2 to 3 μm, and often germinated into Y-shaped conidia. This description matches previous descriptions (3) of C. ayresii (Berk.) Vánky (Tilletia ayresii Berk.) of the smut pathogen of guinea grass (2). The smut fungus was identified as C. ayresii on the basis of morphology and molecular phylogenetic analysis. To produce inoculum, the isolates were grown on potato dextrose agar at 25°C in the dark for 7 days. Two plants of cv. Ryukyu 5-gou with half-flowering heads were grown in a greenhouse for approximately 1 month and then inoculated by atomizing them with conidial suspensions of each isolate (10⁶ conidia/ml). A plant sprayed with sterilized distilled water served as the control. Inoculated heads were covered with plastic bags for 48 h at 25°C. After 30 days, all inoculated plants were symptomatic with swollen spikelets releasing gray spores. Controls remained asymptomatic. The smut fungus was reisolated from released gray spores, confirming Koch's postulates. To our knowledge, this is the first report of smut caused by C. ayresii on guinea grass in Japan. References: (1) T. Boekhout et al. Stud. Mycol. 38:175, 1995. (2) J. M. Lenné and P. Trutmann. Diseases of Tropical Pasture Plants. CAB International, Wallingford, UK, 1994. (3) K. Vánky and R. Bauer. Mycotaxon 43:427, 1992.

Severe erosive lesions in the digestive tract of patients with Henoch-Schönlein Purpura (HSP) and its impact on prognosis - presentation of two cases and statistical review of adult-onset Japanese HSP

INTRODUCTION

Although many pediatric patients with Henoch-Schönlein Purpura (HSP) recover spontaneously, disease activity in adult patients often cannot be controlled by treatment.

PURPOSE

To assess the specific signs not formerly considered to be those of uncontrollable adult HSP patients.

PATIENTS AND METHODS

Clinical records of 2 adult patients who died during HSP were reviewed and previous reports on HSP were consulted.

RESULTS

Both patients had lesions in the digestive tract diagnosed as hemorrhagic erosion in the small intestine and colon. They were elderly and showed renal dysfunction. They died from severe infection after potent immunosuppressive treatment. A univariate analysis showed that age of over 60 years, severe renal symptoms (nephrotic syndrome and/or end-stage renal failure), Birmingham Vasculitis Activity Score (BVAS) of more than 18 points, massive immunosuppression and melena had significantly higher prevalence among patients who died. Multivariate statistical analysis with theoretical quantification analysis II revealed that age of over 60 and severe renal symptoms (nephrotic syndrome and/or end-stage renal failure) contributed to poor prognosis. The presence of melena did not contribute to poor prognosis despite results of the univariate analysis and our clinical impressions.

DISCUSSION

In multivariate statistical analysis, melena was selected as a sign of severe erosive lesions in the digestive tract because some of the patients were not examined by fiberscopy. Melena is caused by various lesions in the digestive tract and each of them has different effects on prognosis.

CONCLUSION

Elderly HSP patients with severe renal impairment should be carefully treated. Examination of the digestive tract by fiberscopy is recommended when melena is observed in these patients.