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1.
Phys Rev Lett ; 123(6): 061103, 2019 Aug 09.
Article in English | MEDLINE | ID: mdl-31491171

ABSTRACT

During a winter thunderstorm on 24 November 2017, a strong burst of gamma rays with energies up to ∼10 MeV was detected coincident with a lightning discharge, by scintillation detectors installed at the Kashiwazaki-Kariwa Nuclear Power Station at sea level in Japan. The burst had a subsecond duration, which is suggestive of photoneutron production. The leading part of the burst was resolved into four intense gamma-ray bunches, each coincident with a low-frequency radio pulse. These bunches were separated by 0.7-1.5 ms, with a duration of ≪1 ms each. Thus, the present burst may be considered as a "downward" terrestrial gamma-ray flash (TGF), which is analogous to upgoing TGFs observed from space. Although the scintillation detectors were heavily saturated by these bunches, the total dose associated with them was successfully measured by ionization chambers, employed by nine monitoring posts surrounding the power plant. From this information and Monte Carlo simulations, the present downward TGF is suggested to have taken place at an altitude of 2500±500 m, involving 8_{-4}^{+8}×10^{18} avalanche electrons with energies above 1 MeV. This number is comparable to those in upgoing TGFs.

2.
J Periodontal Res ; 53(5): 870-882, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29900548

ABSTRACT

OBJECTIVE AND BACKGROUND: Human periodontal ligament mesenchymal stem cells (hPDLMSCs) are reported to be responsible for homeostasis and regeneration of periodontal tissue. Although hPDLMSCs are commonly cultured in monolayers, monolayer cultures have been reported as inferior to 3-dimensional cultures such as spheroids, which are spherical clusters of cells formed by self-assembly. The aim of this study was to examine the osteogenic phenotype of spheroids of hPDLMSCs, compared with monolayer cultures of hPDLMSC, in vitro and in vivo. MATERIAL AND METHODS: Spheroids were formed using microwell chips that were tagged with polyethylene glycol. Mesenchymal stem cell (MSC) markers in hPDLMSC spheroids were examined by flow cytometer. Real-time polymerase chain reaction analysis was examined to measure the expressions of stemness markers and osteogenesis-related genes in monolayer and spheroid-cultured hPDLMSCs. Immunofluorescence analysis was performed to confirm protein expressions of stemness markers in PDLMSC spheroids. Nodule formation assay, alkaline phosphatase (ALP) activity assay and transplantation assay in a mouse calvarial defect model were performed to confirm the osteogenic potential of hPDLMSC spheroids. To elucidate the mechanism of spheroid culture enhanced osteogenesis in hPDLMSCs with osteoinductive medium (OIM), a small interfering RNA (siRNA) assay targeted with secreted frizzled-related protein 3 (SFRP3) was examined. The levels of SFRP3 expression in monolayer and spheroid-cultured hPDLMSCs with OIM were measured by real-time polymerase chain reaction and western blotting analysis. ALP gene expression and ALP activity were examined in SFRP3-deficient hPDLMSC spheroids. RESULTS: The hPDLMSC spheroids expressed MSC markers, which were similar to hPDLMSCs grown in monolayer cultures. Intriguingly, the protein and mRNA expressions of transcription factors that regulate "stemness" were significantly increased in hPDLMSC spheroids, compared with hPDLMSCs in monolayer cultures. Nodule formation by hPDLMSCs was significantly increased in spheroid cultures grown with OIM, compared with monolayer-cultured hPDLMSCs. ALP activity and expression of osteogenesis-related genes were also significantly enhanced in hPDLMSC spheroids, compared with monolayer cultures. Treatment with hPDLMSC spheroids significantly enhanced new bone formation in a murine calvarial defect model, compared with hPDLMSCs in monolayer culture. Finally, to elucidate mechanisms by which spheroid culture enhances ALP activation in hPDLMSCs grown with OIM, an siRNA assay was used to manipulate expression of SFRP3, a Wnt signaling antagonist. Knockdown of SFRP3 suppressed ALP gene expression in hPDLMSCs grown in OIM; further, it suppressed ALP activity in spheroid culture. These data suggest that the enhancement of osteogenic potential in hPDLMSC spheroids is regulated through SFRP3-mediated ALP activation. CONCLUSION: Spheroid cultures of hPDLMSCs may be a novel and useful tool in regenerative medicine.


Subject(s)
Cell Culture Techniques/methods , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/physiology , Osteogenesis/physiology , Periodontal Ligament/cytology , Spheroids, Cellular , Alkaline Phosphatase/genetics , Alkaline Phosphatase/metabolism , Animals , Cells, Cultured , Culture Media , Gene Expression , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Mice , Osteogenesis/genetics , Periodontal Ligament/metabolism , Signal Transduction/physiology
3.
Spinal Cord ; 53(7): 526-33, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25665544

ABSTRACT

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To determine the effect of injury duration on plantar-flexor elastic properties in individuals with chronic spinal cord injury (SCI) and spasticity. SETTING: National Rehabilitation Center for Persons with Disabilities, Japan. METHODS: A total of 16 chronic SCI patients (age, 33±9.3 years; injury localization, C6-T12; injury duration, 11-371 months) participated. Spasticity of the ankle plantar-flexors was assessed using the Modified Ashworth Scale (MAS). The calf circumference and muscle thickness of the medial gastrocnemius (MG), lateral gastrocnemius and soleus were assessed using tape measure and ultrasonography. In addition, the ankle was rotated from 10° plantar-flexion to 20° dorsiflexion at 5 deg s(-1) with a dynamometer, and the ankle angle and torque were recorded. After normalizing the data (the initial points of angle and torque were set to zero), we calculated the peak torque and energy. Furthermore, angle-torque data (before and after normalization) were fitted with a second- and fourth-order polynomial, and exponential (Sten-Knudsen) models, and stiffness indices (SISOP, SIFOP, SISK) and AngleSLACK (the angle at which plantar-flexor passive torque equals zero) were calculated. The stretch reflex gain and offset were determined from 0-10° dorsiflexion at 50, 90, 120 and 150 deg s(-1). After logarithmic transformation, Pearson's correlation coefficients were calculated. RESULTS: MAS, calf circumference, MG thickness, peak torque and SIFOP significantly decreased with injury duration (r log-log=-0.63, -0.69, -0.63, -0.53 and -0.55, respectively, P<0.05). The peak torque and SIFOP maintained significant relationships even after excluding impacts from muscle morphology. CONCLUSION: Plantar-flexor elasticity in chronic SCI patients decreased with increased injury duration.


Subject(s)
Lower Extremity/physiopathology , Muscle Spasticity/physiopathology , Muscle, Skeletal/physiopathology , Spinal Cord Injuries/physiopathology , Adult , Ankle/pathology , Ankle/physiopathology , Cross-Sectional Studies , Female , Humans , Lower Extremity/pathology , Male , Middle Aged , Muscle Spasticity/etiology , Muscle Spasticity/pathology , Muscle, Skeletal/pathology , Spinal Cord Injuries/complications , Spinal Cord Injuries/pathology , Time Factors , Torque , Young Adult
4.
Br J Cancer ; 111(2): 365-74, 2014 Jul 15.
Article in English | MEDLINE | ID: mdl-24921913

ABSTRACT

BACKGROUND: CD133 and CD44 are putative cancer stem cell (CSC) markers in colorectal cancer (CRC). However, their clinical significance is currently unclear. Here, we evaluated primary CRC cell isolates to determine the significance of several CSC markers, including CD133 and CD44, as predictors of tumourigenesis and prognosis. METHODS: CD133- and CD44-positive cells from fresh clinical samples of 77 CRCs were selected by flow cytometric sorting and evaluated for tumourigenicity following subcutaneous transplantation into NOD/SCID mice. Cancer stem cell marker expression was examined in both xenografts and a complementary DNA library compiled from 167 CRC patient samples. RESULTS: CD44(+), CD133(+) and CD133(+)CD44(+) sub-populations were significantly more tumourigenic than the total cell population. The clinical samples expressed several transcript variants of CD44. Variant 2 was specifically overexpressed in both primary tumours and xenografts in comparison with the normal mucosa. A prognostic assay using qRT-PCR showed that the CD44v2(high) group (n=84, 5-year survival rate (5-OS): 0.74) had a significantly worse prognosis (P=0.041) than the CD44v2(low) group (n=83, 5-OS: 0.88). CONCLUSIONS: CD44 is an important CSC marker in CRC patients. Furthermore, CRC patients with high expression of CD44v2 have a poorer prognosis than patients with other CD44 variants.


Subject(s)
Colorectal Neoplasms/metabolism , Hyaluronan Receptors/metabolism , AC133 Antigen , Adult , Aged , Aged, 80 and over , Animals , Antigens, CD/genetics , Antigens, CD/metabolism , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Gene Expression , Glycoproteins/genetics , Glycoproteins/metabolism , Humans , Hyaluronan Receptors/genetics , Male , Mice , Mice, Inbred NOD , Mice, SCID , Middle Aged , Neoplastic Stem Cells/pathology , Peptides/genetics , Peptides/metabolism , Prognosis , Up-Regulation , Xenograft Model Antitumor Assays
5.
Phys Rev Lett ; 112(17): 171102, 2014 May 02.
Article in English | MEDLINE | ID: mdl-24836230

ABSTRACT

Magnetars are a special type of neutron stars, considered to have extreme dipole magnetic fields reaching ∼ 10(11) T. The magnetar 4 U 0142+61, one of the prototypes of this class, was studied in broadband x rays (0.5-70 keV) with the Suzaku observatory. In hard x rays (15-40 keV), its 8.69 sec pulsations suffered slow phase modulations by ± 0.7 sec, with a period of ∼ 15 h. When this effect is interpreted as free precession of the neutron star, the object is inferred to deviate from spherical symmetry by ∼ 1.6 × 10(-4) in its moments of inertia. This deformation, when ascribed to magnetic pressure, suggests a strong toroidal magnetic field, ∼ 10(12) T, residing inside the object. This provides one of the first observational approaches towards toroidal magnetic fields of magnetars.

6.
Phys Rev Lett ; 111(1): 015001, 2013 Jul 05.
Article in English | MEDLINE | ID: mdl-23863005

ABSTRACT

We report the first observation of 3-30 MeV prolonged gamma-ray emission that was abruptly terminated by lightning. The gamma-ray detection was made during winter thunderstorms on December 30, 2010, by the Gamma-Ray Observation of Winter Thunderclouds experiment carried out in a coastal area along the Sea of Japan. The gamma-ray flux lasted for less than 3 min, continuously hardening closer to the lightning occurrence. The hardening at energies of 3-10 MeV energies was most prominent. The gamma-ray flux abruptly ceased less than 800 ms before the lightning flash that occurred over 5 km away from the experimental site. In addition, we observed a clear difference in the duration of the 3-10 MeV gamma rays and those >10 MeV, suggesting that the area of >10 MeV gamma-ray emission is considerably smaller than that of the lower-energy gamma rays. This work may give a manifestation that a local region emitting prolonged gamma rays connects with a distant region to initiate lightning.

7.
Acta Radiol ; 54(8): 934-8, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23612428

ABSTRACT

BACKGROUND: Although the morbidity of bowel ischemic events after glue embolization has been suggested, a causal relationship between glue and ischemia has not been clearly established. PURPOSE: To evaluate the efficiency and safety of transcatheter arterial embolization with n-butyl cyanoacrylate (NBCA-TAE) for upper gastrointestinal hemorrhage (GIH). MATERIAL AND METHODS: Between October 2006 and October 2012, 21 patients with upper GIH underwent NBCA-TAE, and endoscopic data were obtained within 30 days of follow-up. Shock index prior to and immediately after NBCA-TAE were compared to determine changes in hemodynamics. Days to Forrest type III, as assessed by follow-up endoscopy, was used as an indicator of the healing process. Other clinical outcomes included days for starting ingestion and for hospital discharge. RESULTS: Sixteen gastric and five duodenal ulcers, classified into Forrest type I, were treated. Immediate hemostasis was achieved in all the patients, and no re-bleeding occurred within the follow-up period. Shock index significantly (P < 0.001) improved from before (0.99 ± 0.076) to immediately after NBCA-TAE (0.67 ± 0.038). Sequential mucosal healing processes were observed in all the patients, and the number of days to Forrest type III was 9.6 ± 7.1. The number of days for starting ingestion and hospital discharge was 9.0 ± 4.5 and 15 ± 7.7 days, respectively. CONCLUSION: NBCA-TAE is an effective and safe method for the control of nonvariceal upper GIH, in terms of contribution to hemodynamics and healing process of the gastroduodenal mucosa.


Subject(s)
Blood Pressure , Embolization, Therapeutic/methods , Enbucrilate/therapeutic use , Heart Rate , Peptic Ulcer Hemorrhage/therapy , Peptic Ulcer/complications , Adult , Aged , Aged, 80 and over , Contrast Media/administration & dosage , Female , Follow-Up Studies , Humans , Iodized Oil/administration & dosage , Length of Stay/statistics & numerical data , Male , Middle Aged , Peptic Ulcer Hemorrhage/etiology , Treatment Outcome , Wound Healing
8.
Int J Sports Med ; 33(4): 310-3, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22383130

ABSTRACT

The purpose of the present study was to ascertain whether increase in step frequency at a given velocity during running reduces the lower extremity loading variables, which is associated with tibial stress fracture in runner. We hypothesized that the lower extremity loading variables at a given speed would be minimized at around +15% f step. 10 male subjects were asked to run at 2.5 m/s on a treadmill-mounted force platform. 5 step frequencies were controlled using a metronome: the preferred, below preferred (-15 and -30%) and above preferred (+15 and +30%). From the vertical ground reaction force, we measured following lower extremity loading variables; vertical impact peak (VIP), vertical instantaneous loading rate (VILR) and vertical average loading rate (VALR). We found that there were significant differences in lower extremity loading variables among 5 step frequency conditions. Furthermore, quadratic regression analyses revealed that the minimum loading variable frequencies were 17.25, 17.55, and 18.07% of preferred step frequency for VIP, VILR and VIAR, respectively. Thus, adopting a step frequency greater than one's preferred may be practical in reducing the risk of developing a tibial stress fracture by decreasing lower extremity loading variables.


Subject(s)
Fractures, Stress/prevention & control , Gait , Lower Extremity/physiology , Running/injuries , Tibial Fractures/prevention & control , Adult , Biomechanical Phenomena , Humans , Male , Regression Analysis , Running/physiology , Weight-Bearing
9.
J Periodontal Res ; 46(6): 673-81, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21644999

ABSTRACT

BACKGROUND AND OBJECTIVE: The gram-negative anaerobe Porphyromonas gingivalis has been implicated as an important pathogen in the development of adult periodontitis, and its colonization of subgingival sites is critical in the pathogenic process. We previously identified a 35 kDa surface protein (hemin binding protein 35; HBP35) from P. gingivalis that exhibited coaggregation activity, while additional analysis suggested that this protein possessed an ability to bind heme molecules. For development of passive immunotherapy for periodontal diseases, human-type monoclonal antibodies have been prepared using HBP35 as an antigen in TransChromo mice. In the present study, we focused on a single antibody, TCmAb-h13, which is known to inhibit heme binding to recombinant HBP35. The aim of our investigation was to clarify the redox-related function of HBP35 and consider the benefits of human-type monoclonal antibodies. MATERIAL AND METHODS: To examine the antigen recognition capability of TCmAbs with immunoblotting and Biacore techniques, we used the native form as well as several Cys-to-Ser variants of recombinant HBP35. RESULTS: We found that the redox state of recombinant HBP35 was dependent on two Cys residues, (48) C and (51) C, in the thioredoxin active center (WCGxCx). Furthermore, TCmAb-h13 recognized the reduced forms of recombinant HBP35, indicating its inhibitory effect on P. gingivalis growth. CONCLUSION: Hemin binding protein 35 appears to be an important molecule involved in recognition of the redox state of environmental conditions. In addition, TCmAb-h13 had an inhibitory effect on heme binding to recombinant HBP35, thereby interfering with P. gingivalis growth.


Subject(s)
Antibodies, Monoclonal, Humanized/immunology , Bacterial Proteins/immunology , Carrier Proteins/immunology , Hemeproteins/immunology , Immunization, Passive/methods , Porphyromonas gingivalis/growth & development , Amino Acid Substitution , Animals , Antibodies, Monoclonal, Humanized/chemistry , Carrier Proteins/chemistry , Cysteine , Heme-Binding Proteins , Hemeproteins/chemistry , Hemin/metabolism , Humans , Mice , Mice, Transgenic , Porphyromonas gingivalis/chemistry , Porphyromonas gingivalis/immunology , Protein Binding/immunology , Protein Structure, Tertiary , Serine , Thioredoxins/chemistry , Virulence Factors/immunology
10.
Clin Exp Dermatol ; 36(5): 502-5, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21463351

ABSTRACT

We report a patient with cutaneous polyarteritis nodosa, who had a 3-year history of recurrent leg and foot ulcers. Symptoms of ischaemia in the left foot, including severe pain, coldness, paraesthesia and violaceous discoloration, deteriorated abruptly, because of complete occlusion of the left anterior tibial artery. The occluded segment was revascularized by percutaneous transluminal angioplasty, resulting in a dramatic improvement in the ischaemic symptoms.


Subject(s)
Angioplasty/methods , Arterial Occlusive Diseases/therapy , Ischemia/therapy , Polyarteritis Nodosa/therapy , Skin/blood supply , Tibial Arteries/pathology , Arterial Occlusive Diseases/diagnostic imaging , Arterial Occlusive Diseases/etiology , Arterial Occlusive Diseases/pathology , Female , Humans , Ischemia/etiology , Leg Ulcer/etiology , Leg Ulcer/therapy , Middle Aged , Polyarteritis Nodosa/complications , Radiography , Tibial Arteries/diagnostic imaging
11.
Int J Sports Med ; 32(9): 653-8, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21567352

ABSTRACT

In this study, we aimed to investigate the acute effects of exercise on postural measures in arthritic patients. We obtained posturographic measurements of 8 women with lower extremity arthritis for 30 s before and after a 60-min aquatic exercise. The center of pressure (COP) was recorded while the volunteers were in an upright position with their eyes open. The time domain measures and the frequency domain measures of the COP time series in the anterior-posterior (AP) and medial-lateral (ML) directions were calculated. In addition, the frequency domain measures were calculated for the COP velocity time series. A paired T-test revealed no significant differences in any time domain measures between pre- and post-exercise; however, there were significant decreases in the 95% power frequency of the COP in the AP direction (0.834 ± 0.296 to 0.627 ± 0.230 Hz, p=0.027) for the frequency domain measures. For the velocity time series, the mean power frequency in both the AP (1.47 ± 0.528 to 1.22 ± 0.360 Hz, p=0.047) and ML (1.28 ± 0.245 to 1.13 ± 0.151 Hz, p=0.022) directions, and the 95% power frequency in the ML direction (3.41 ± 0.653 to 2.96 ± 0.468 Hz, p=0.038) decreased significantly in the post-exercise condition. This study reports that a single session of exercise has a subtle but detectable acute effect on postural balance in arthritic patients.


Subject(s)
Arthritis/therapy , Exercise Therapy/methods , Postural Balance , Aged , Arthritis/physiopathology , Female , Humans , Middle Aged , Posture
12.
Int J Clin Pharmacol Ther ; 48(2): 109-19, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20137763

ABSTRACT

OBJECTIVE: Brugada syndrome (BrS) is a rare sodium channelopathy typically seen in middle-aged, Southeast Asian males conferring high risks of cardiac sudden death. Loss-of-function mutations in SCN5A encoding the alpha-subunit of cardiac sodium channels may account partially for its etiology. We aimed to study whether mutations in the beta-subunits of sodium channel (SCN1B and SCN2B) would also be associated with abnormal cardiac excitation in BrS. METHODS: 85 Japanese patients suspected to have BrS undertook a diagnostic challenge test with a sodium channel blocker, pilsicainide. Genetic screenings were performed for SCN5A, SCN1B and SCN2B by PCR-SSCP and direct sequence of amplicons in the patients and 50 healthy controls. RESULTS: 30 patients exhibited BrS-like ECG pattern (i.e., a coved-type ST-segment elevation) either at baseline or after the drug challenge. Genetic screenings revealed a sequence variation (p.R190Q) and 3 polymorphisms (p.H558R, p.R1193Q, IVS24+53T > C) in SCN5A, a sequence variation (g.-26G > T) and 2 polymorphisms (IVS1+53G > T and IVS3 +2996(TTA)8-15) in SCN1B and 2 polymorphisms (IVS2+27A > G, IVS2+76G > A) in SCN2B. A logistic analysis revealed that male, middle age (40 - 59 years of age) and IVS3+2996(TTA)8 of SCN1B were significantly (p < 0.05) associated with the development of BrS-like ECG pattern with odds ratios (95% confidence intervals) of 5.9 (1.8 - 19.6), 2.9 (1.4 - 6.1) and 2.3 (1.1 - 4.9), respectively. While the IVS3+2996(TTA)8 allele has not been reported in Caucasians previously, its allelic frequency in the patients exhibiting the BrS-like ECG pattern (0.250) was comparable to that in the healthy controls (0.260). CONCLUSION: The IVS3+ 2996(TTA)8 allele commonly seen in Japanese would not be pathogenic itself but may render male, middle-aged Japanese more susceptible to BrS.


Subject(s)
Brugada Syndrome/genetics , Genetic Predisposition to Disease , Sodium Channels/genetics , Adult , Age Factors , Aged , Asian People , Electrocardiography , Female , Humans , Japan , Lidocaine/analogs & derivatives , Logistic Models , Male , Microsatellite Repeats , Middle Aged , Muscle Proteins/genetics , Mutation , NAV1.5 Voltage-Gated Sodium Channel , Nerve Tissue Proteins/genetics , Polymorphism, Genetic , Risk Factors , Sex Factors , Sodium Channel Blockers , Voltage-Gated Sodium Channel beta-1 Subunit , Voltage-Gated Sodium Channel beta-2 Subunit
13.
Spinal Cord ; 48(12): 886-93, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20404833

ABSTRACT

OBJECTIVES: (1) To evaluate the learning potential and performance improvements during standing balance training with visual feedback (VBT) in individuals with incomplete spinal cord injury (SCI) and (2) to determine whether standing static and dynamic stability during training-irrelevant tasks can be improved after the VBT. SETTING: National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan. METHODS: Six participants with chronic motor and sensory incomplete SCI who were able to stand for at least 5 min without any form of assistive device performed the VBT, 3 days per week, for a total of 12 sessions. During the training, participants stood on a force platform and were instructed to shift their center of pressure in the indicated directions as represented by a cursor on a monitor. The performance and the rate of learning were monitored throughout the training period. Before and after the program, static and dynamic stability was assessed. RESULTS: All participants showed substantial improvements in the scores, which varied between 236±94 and 130±14% of the initial values for different exercises. The balance performance during training-irrelevant tasks was significantly improved: for example, the area inside the stability zone after the training reached 221±86% of the pre-training values. CONCLUSION: Postural control can be enhanced in individuals with incomplete SCI using VBT. All participants showed substantial improvements during standing in both game performance and training-irrelevant tasks after the VBT.


Subject(s)
Exercise Therapy/methods , Feedback, Sensory , Postural Balance/physiology , Spinal Cord Injuries/rehabilitation , Adult , Female , Humans , Male , Middle Aged
14.
Ultramicroscopy ; 217: 113077, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32795865

ABSTRACT

The nanometer-scale spatial distributions of local thickness or composition of noncrystalline materials are generally measured by spectroscopy with scanning transmission electron microscopy (STEM). Since spectroscopy requires a high electron dose and causes irradiation damage, alternative non-spectroscopic methods are required to measure the local thickness or composition of electron-sensitive noncrystalline materials. Here, we focus on the radial distribution function (RDF) of the electron diffraction of non-crystalline materials. We confirm that the RDF of the electron diffraction obtained by simulation contains information on the thickness and composition. Next, we demonstrate the determination of both thickness and composition from experimentally obtained RDFs. Although some constraints are required, we determine the local thickness and composition of a BaO-SiO2 glass sample by comparing the RDFs of diffraction measured by a high-speed pixelated detector with those of the simulated diffractions. Collaterally, this determination method can improve the quality of STEM images.

15.
Science ; 180(4082): 188-90, 1973 Apr 13.
Article in English | MEDLINE | ID: mdl-17811659

ABSTRACT

Ammonoid cephalopods serve significantly as a basis for correlation of strata near the boundary between the Paleozoic and Mesozoic Erathems. This is a report of the diagnostically Late Permian (uppermost Paleozoic) ammonoid Cyclolobus walkeri (Diener, 1903) from the Zewan Formation 20 meters below the Permian-Triassic contact at the classic section in Guryul Ravine, Srinagar region, Kashmir.

16.
Neuron ; 15(3): 697-709, 1995 Sep.
Article in English | MEDLINE | ID: mdl-7546748

ABSTRACT

We generated a polyclonal antibody, 12P3, specifically recognizing rat AMPA-type glutamate receptor (GluR) subunits phosphorylated at Ser-696 of GluR2 or at the homologous sites in GluR1, GluR3, and GluR4. Using 12P3, we demonstrate that a brief exposure of a rat cerebellar slice to AMPA leads to transient phosphorylation of the GluR subunits in Purkinje cell dendrites. Persistent phosphorylation over 30 min was obtained when exposure to AMPA was preceded by a 15 min perfusion of the slice with 8-bromo-cGMP, dibutyryl-cGMP, or calyculin A but not phorbol 12,13-diacetate. These results indicate that Ser-696 of GluR2, or the corresponding sites in other AMPA receptor subunits, is a specific site at which phosphorylation takes place when AMPA-type GluRs are activated by agonists, especially under the influence of certain second messenger activities.


Subject(s)
Phosphoserine/metabolism , Purkinje Cells/metabolism , Receptors, AMPA/metabolism , Amino Acid Sequence , Animals , Binding Sites , Cyclic GMP/analogs & derivatives , Cyclic GMP/pharmacology , Dendrites/metabolism , Drug Tolerance , Long-Term Potentiation , Male , Marine Toxins , Molecular Sequence Data , Oxazoles/pharmacology , Phosphoprotein Phosphatases/antagonists & inhibitors , Phosphorylation , Rats , Rats, Wistar , Synapses/physiology , alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/pharmacology
17.
Gait Posture ; 27(1): 97-102, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17408954

ABSTRACT

To elucidate the effect on movement-related potentials (MRPs) of anticipatory postural adjustments (APAs) accompanied by voluntary focal movement, we examined the MRPs of shoulder flexion movement under standing and sitting postural conditions in 12 normal subjects. MRPs were evaluated based on three components: readiness potential (RP), motor potential (MP), and movement-monitoring potential. APAs were observed in the activities of postural muscles including the biceps femoris and erector spinae muscles only under standing conditions. The amplitudes of the three MRP components were larger under standing conditions than under sitting conditions for all recorded electrode positions, and the RP and MP amplitudes at the vertex position, which lies over the supplementary motor area (SMA), showed a prominent increase under standing conditions with the highest statistical significance. These results suggest that a recruited neural process of the cortical area including the SMA may be necessary to generate voluntary movement accompanied by APA.


Subject(s)
Postural Balance/physiology , Posture/physiology , Upper Extremity/physiology , Adult , Arm/physiology , Electroencephalography , Electromyography , Evoked Potentials, Motor/physiology , Female , Humans , Male , Motor Cortex/physiology , Movement/physiology , Muscle, Skeletal/physiology , Recruitment, Neurophysiological/physiology , Rectus Abdominis/physiology , Shoulder/physiology , Somatosensory Cortex/physiology , Time Factors
18.
Transplant Proc ; 40(2): 614-6, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18374144

ABSTRACT

BACKGROUND: We have previously developed a hybrid artificial liver (HAL) using polyurethane foam (PUF)/hepatocyte spheroid culture. The PUF-HAL has been successfully scaled up to a clinical level. However, one of the most difficult problems for clinical application of HALs is obtaining a cell source. We now focused our attention on embryonic stem (ES) cells as a potential source for HAL. In this study, we investigated the differentiation of mouse ES (mES) cells into functional hepatocytes in the PUF-HAL module. METHODS: The PUF-HAL module included a cylindrical PUF block having many capillaries for medium flow. mES cells were immobilized in the module. To induce hepatic differentiation, growth factors were added to the culture medium. We evaluated cell density, gene expression analysis, and liver-specific functions. RESULTS: mES cells spontaneously formed spherical multicellular aggregates (spheroids) in the pores of PUF. mES cells proliferated by 20 days, achieving a high cell density (about 1 x 10(8) cells/cm3 PUF). Differentiating ES cells expressed endodermal-specific genes such as alpha-fetoprotein, albumin, and tryptophan 2, 3-deoxygenase. The activity of ammonia removal of mES cells per unit volume of the module was detectable by 15 days and increased with culture time. Maximal expression levels were comparable to those of primary (porcine and human) hepatocytes. SUMMARY: mES cells immobilized in the PUF module expressed liver-specific functions at high level, because of high cell density in culture and hepatic differentiation. These results indicated that PUF module-immobilized mES cells may be useful as a biocomponent of HALs.


Subject(s)
Bioreactors , Cell Culture Techniques/methods , Embryonic Stem Cells/cytology , Liver, Artificial , Liver/cytology , Animals , Cell Aggregation , Hepatocytes/cytology , Mice , Polyurethanes
19.
Transplant Proc ; 40(2): 611-3, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18374143

ABSTRACT

OBJECTIVE: The use of embryonic stem cells (ES cells) has recently received much attention as a novel cell source for various hybrid artificial organs. To use ES cells, it is necessary to be able to produce functional mature cells from ES cells in large quantities. We applied HF/organoid culture, where cultured cells formed cylindrical multicellular aggregates (organoids) in the lumen of hollow fibers, to mouse and cynomolgus monkey ES cells for hepatic differentiation. MATERIALS AND METHODS: ES cells were injected into hollow fibers. The hollow fibers were centrifuged to induce organoid formation and cultured in medium including factors for hepatic differentiation. To determine the characteristics of cells in the bundle, we evaluated gene expression and liver-specific functions. RESULTS: ES cells immobilized inside hollow fibers proliferated and formed cylindrical organoids. In mouse ES cell cultures, the expression of mRNAs of hepatocyte-specific genes increased with culture time. Ammonia removal activity detected at 15 days increased with culture time. Albumin secretion activity detected at 12 days increased by 21 days. In cynomolgus monkey ES cell cultures, ES cells showed spontaneous ammonia removal functions. The maximum levels of these functions per unit volume of the hollow fibers were roughly comparable to those of primary hepatocyte-organoids. CONCLUSIONS: ES cells differentiated into hepatocyte-like cells using the organoid culture technique. The results indicated that the combination of ES cells and an organoid culture technique was useful to obtain mature hepatocytes.


Subject(s)
Cell Differentiation/physiology , Embryonic Stem Cells/cytology , Liver/cytology , Animals , Culture Media , Liver Diseases/therapy , Mice , Organ Culture Techniques/methods , Stem Cell Transplantation
20.
Int J Artif Organs ; 31(1): 55-61, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18286455

ABSTRACT

We studied the recovery of rats with fulminant hepatic failure (FHF) by treating them with our original hybrid artificial liver support system (HALSS). We developed an original artificial liver module having a liver lobule-like structure (LLS). This module consists of many hollow fibers regularly arranged in close proximity and hepatocyte aggregates (organoids) induced into the extra capillary space of the module by centrifugal force. The LLS module can express some liver specific functions at high levels and maintain them for several months in vitro. In this study, we evaluated the efficacy of our LLS-HALSS by using rats with FHF induced by a method that combined partial hepatectomy with hepatic ischemia. In the animal experiments, blood ammonia levels rapidly increased in the control group (sham-HALSS group). These rats died during or immediately after application of the sham-HALLS. On the other hand, in the LLS module application group (LLS-control group), the increase in blood ammonia was completely suppressed and all rats recovered. Blood constituents at 4 weeks after application were at normal levels, and the weight of the liver was the same as that of a normal rat. These results indicate that HALSS may be useful for treating liver failure patients until liver transplantation can be performed or until regeneration of the native liver occurs.


Subject(s)
Liver Failure, Acute/rehabilitation , Liver Regeneration/physiology , Liver, Artificial , Organoids/physiology , Animals , Disease Models, Animal , Equipment Design , Hepatocytes/physiology , Male , Rats , Tissue Scaffolds
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