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author:("Ito, junii")
1.  Presynaptic protein Synaptotagmin1 regulates the neuronal polarity and axon differentiation in cultured hippocampal neurons 
BMC Neuroscience  2015;16:92.
Hippocampal neurons in the brain polarize to form multiple dendrites and one long axon. The formation of central synapses remains poorly understood. Although several of the intracellular proteins involved in the clustering of central neurotransmitter receptors and ion channels have been identified, the signals involved in pre- and postsynaptic differentiation remain elusive. Synaptotagmin1 is an abundant and important presynaptic vesicle protein that binds Ca2+ (J Biol Chem 277:7629–7632, 2002) in regulation of synaptic vesicle exocytosis at the synapse. Synapse consists of the formation of synaptic connections and requires precise coordination of Synaptotagmin1. It was reported Synaptotagmin1 plays an important roles in the formation of axonal filopodia and branches in chicken forebrain neurons (Dev Neurobiol 73:27–44, 2013). To determine if Synaptotagmin1 could have a role in formation of axon in hippocampal neurons, we investigated the effects of Synaptotagmin1 overexpression and knockdown using the shRNA on the growth and branching of the axons of primary hippocampal neurons. We showed that overexpression of Synaptotagmin1 leads to abnormal multiple axon formation in cultured rat hippocampal neurons.
We first examined the effects of Synaptotagmin1 on the numbers of axon and dendrites. We found that the overexpression of Synaptotagmin1 led to the formation of multiple axons and induced an increase in the number of endogenous postsynaptic protein Homer1c clusters in cultured hippocampal neurons. Endogenous initial segment of axon was detected with anti-sodium channel (anti-NaCh) antibody and with anti-Tau1 (J Neurosci 24: 4605–4613, 2004). The endogenous initial segment of axon was stained with anti-NaCh antibodies and with anti-Tau1 antibodies. Then the numbers of prominence dyed positive were counted as axon. We attempted to specifically knockdown the endogenous Synaptotagmin1 with small hairpin RNAs (shRNAs). To further dissect the functions of endogenous Synaptotagmin1 in neuronal polarity, we used the shRNA of Synaptotagmin1 that specifically blocks the existence of endogenous Synaptotagmin1. When the shRNA of Synaptotagmin1 was introduced to the cells, the number of axons and dendrites did not change.
These results indicate that the accumulation of Synaptotagmin1 may play an important role in axon/dendrite differentiation.
PMCID: PMC4678605  PMID: 26667128
Synaptotagmin1; Axon; Dendrite; Tau1; NaCh; shRNA
2.  A Randomized, Double-Blind Pilot Trial of Hydrolyzed Rice Bran versus Placebo for Radioprotective Effect on Acute Gastroenteritis Secondary to Chemoradiotherapy in Patients with Cervical Cancer 
We aimed to evaluate the radioprotective effect of hydrolyzed rice bran (HRB) on acute gastroenteritis due to chemoradiotherapy for treatment of cervical cancer. This placebo-controlled, double-blind study was conducted as an exploratory investigation of the colitis-inhibiting effects of HRB in alleviating acute-phase gastrointestinal side effects of chemoradiotherapy. The study involved 20 patients (10 in the HRB group, 10 in the control group). The patients in the control group underwent the same chemoradiotherapy regimen as those in the HRB group, but they received a placebo instead of HRB. The diarrheal side effect assessment score was lower in the HRB than control group, and a trend toward a reduction in diarrhea symptoms was observed with the oral intake of HRB. Additionally, no significant difference was observed in the administration of intestinal regulators and antidiarrheal agents, but again the assessment score was lower in the HRB than control group, and diarrhea symptoms were alleviated with the oral intake of HRB. A trend toward no need for strong antidiarrheal agents was seen. Although this study was an exploratory clinical trial, the results suggest that HRB may relieve diarrhea, an acute-phase gastrointestinal side effect of chemoradiotherapy.
PMCID: PMC4674603  PMID: 26693248
3.  A phase I/II trial of intraoperative breast radiotherapy in an Asian population: 5-year results of local control and cosmetic outcome 
To date, there are no reports of intraoperative radiotherapy (IORT) use with long-term follow up as a method of accelerated partial breast irradiation (APBI) in Asian countries. We initiated a prospective phase I/II clinical trial of IORT in Japan in 2007, and herein, we report the 5-year follow-up results.
Materials and methods
The following inclusion criteria were used for enrollment in the trial: (1) tumor size < 2.5 cm, (2) desire for breast-conserving surgery, (3) age >50 years, and (4) negative margins after resection. In February 2009, the eligibility criteria were changed to include only patients with sentinel lymph node-negative disease. In phase I, the radiotherapy dose was escalated from 19 Gy/fr to 21 Gy/fr, incremented by 1 Gy per step, with 3 patients in each step. Doses were escalated after all patients in the preceding cohort had completed treatment and exhibited only grade 1 or 2 toxicities at a given dose level. The recommended phase II dose was set at 21 Gy at 90 % isodose. The primary endpoint was early toxicity. Secondary endpoints were long-term efficacy and late toxicity. In addition, Hypertrophic scarring was evaluated retrospectively as a cosmetic outcome by a radiation oncologist.
Between December 2007 and March 2010, 32 women with breast cancer were enrolled in the trial. The median age was 65 years (51–80 years), and the median follow-up time was 6 years. No recurrence or metastasis was observed in any patient. Grade 2 fibrosis was detected in 3 patients as an acute adverse event and in 2 patients as a late adverse event. Ten patients developed a hypertrophic scar 1 year after the IORT; the number of patients decreased to 7 in the 3 years of follow-up.
The first group of female Asian patients tolerated the treatment with IORT in this Phase I/II study and remained recurrence-free for more than 5 years after treatment. However, 24 % of the patients developed hypertrophic scarring, an event that is being further examined in our ongoing multi-center Phase II trial of IORT for early breast cancer.
PMCID: PMC4513388  PMID: 26205241
Breast cancer; APBI; IORT; Asia; Cosmesis; Recurrences
4.  Eye movement-related brain activity during perceptual and cognitive processing 
PMCID: PMC4006019  PMID: 24795577
eye movements; saccade; smooth pursuit; eye tracking; free viewing; EEG; local field potentials; fMRI
5.  Preliminary analysis of risk factors for late rectal toxicity after helical tomotherapy for prostate cancer 
Journal of Radiation Research  2013;54(5):919-924.
The purpose of this study is to examine risk factors for late rectal toxicity for localized prostate cancer patients treated with helical tomotherapy (HT). The patient cohort of this retrospective study was composed of 241 patients treated with HT and followed up regularly. Toxicity levels were scored according to the Radiation Therapy Oncology Group grading scale. The clinical and dosimetric potential factors increasing the risk of late rectal toxicity, such as age, diabetes, anticoagulants, prior abdominal surgery, prescribed dose, maximum dose of the rectum, and the percentage of the rectum covered by 70 Gy (V70), 60 Gy (V60), 40 Gy (V40) and 20 Gy (V20) were compared between ≤ Grade 1 and ≥ Grade 2 toxicity groups using the Student's t-test. Multivariable logistic regression analysis of the factors that appeared to be associated with the risk of late rectal toxicity (as determined by the Student's t-test) was performed. The median follow-up time was 35 months. Late Grade 2–3 rectal toxicity was observed in 18 patients (7.4%). Age, the maximum dose of the rectum, V70 and V60 of the ≥ Grade 2 toxicity group were significantly higher than in those of the ≤ Grade 1 toxicity group (P = 0.00093, 0.048, 0.0030 and 0.0021, respectively). No factor was significant in the multivariable analysis. The result of this study indicates that the risk of late rectal toxicity correlates with the rectal volume exposed to high doses of HT for localized prostate cancer. Further follow-up and data accumulation may establish dose–volume modeling to predict rectal complications after HT.
PMCID: PMC3766297  PMID: 23525159
prostate cancer; helical tomotherapy; late toxicity; intensity-modulated radiation therapy; image-guided radiation therapy
6.  Cross-frequency interaction of the eye-movement related LFP signals in V1 of freely viewing monkeys 
Recent studies have emphasized the functional role of neuronal activity underlying oscillatory local field potential (LFP) signals during visual processing in natural conditions. While functionally relevant components in multiple frequency bands have been reported, little is known about whether and how these components interact with each other across the dominant frequency bands. We examined this phenomenon in LFP signals obtained from the primary visual cortex of monkeys performing voluntary saccadic eye movements (EMs) on still images of natural-scenes. We identified saccade-related changes in respect to power and phase in four dominant frequency bands: delta-theta (2–4 Hz), alpha-beta (10–13 Hz), low-gamma (20–40 Hz), and high-gamma (>100 Hz). The phase of the delta-theta band component is found to be entrained to the rhythm of the repetitive saccades, while an increment in the power of the alpha-beta and low-gamma bands were locked to the onset of saccades. The degree of the power modulation in these frequency bands is positively correlated with the degree of the phase-locking of the delta-theta oscillations to EMs. These results suggest the presence of cross-frequency interactions in the form of phase-amplitude coupling (PAC) between slow (delta-theta) and faster (alpha-beta and low gamma) oscillations. As shown previously, spikes evoked by visual fixations during free viewing are phase-locked to the fast oscillations. Thus, signals of different types and at different temporal scales are nested to each other during natural viewing. Such cross-frequency interaction may provide a general mechanism to coordinate sensory processing on a fast time scale and motor behavior on a slower time scale during active sensing.
PMCID: PMC3572441  PMID: 23420631
local field potential; oscillation; saccade; natural vision; cross-frequency coupling
8.  Saccade-Related Modulations of Neuronal Excitability Support Synchrony of Visually Elicited Spikes 
Cerebral Cortex (New York, NY)  2011;21(11):2482-2497.
During natural vision, primates perform frequent saccadic eye movements, allowing only a narrow time window for processing the visual information at each location. Individual neurons may contribute only with a few spikes to the visual processing during each fixation, suggesting precise spike timing as a relevant mechanism for information processing. We recently found in V1 of monkeys freely viewing natural images, that fixation-related spike synchronization occurs at the early phase of the rate response after fixation-onset, suggesting a specific role of the first response spikes in V1. Here, we show that there are strong local field potential (LFP) modulations locked to the onset of saccades, which continue into the successive fixation periods. Visually induced spikes, in particular the first spikes after the onset of a fixation, are locked to a specific epoch of the LFP modulation. We suggest that the modulation of neural excitability, which is reflected by the saccade-related LFP changes, serves as a corollary signal enabling precise timing of spikes in V1 and thereby providing a mechanism for spike synchronization.
PMCID: PMC3183421  PMID: 21459839
free viewing; local field potential; phase locking; primary visual cortex; spike synchrony
9.  Display of both N- and C-terminal target fusion proteins on the Aspergillus oryzae cell surface using a chitin-binding module 
A novel cell surface display system in Aspergillus oryzae was established by using a chitin-binding module (CBM) from Saccharomyces cerevisiae as an anchor protein. CBM was fused to the N or C terminus of green fluorescent protein (GFP) and the fusion proteins (GFP-CBM and CBM-GFP) were expressed using A. oryzae as a host. Western blotting and fluorescence microscopy analysis showed that both GFP-CBM and CBM-GFP were successfully expressed on the cell surface. In addition, cell surface display of triacylglycerol lipase from A. oryzae (tglA), while retaining its activity, was also successfully demonstrated using CBM as an anchor protein. The activity of tglA was significantly higher when tglA was fused to the C terminus than N terminus of CBM. Together, these results show that CBM used as a first anchor protein enables the fusion of both the N and/or C terminus of a target protein.
PMCID: PMC2903697  PMID: 20499230
Cell surface display; Aspergillus oryzae; Chitin-binding module; Triacylglycerol lipase
10.  Regulation of the Display Ratio of Enzymes on the Saccharomyces cerevisiae Cell Surface by the Immunoglobulin G and Cellulosomal Enzyme Binding Domains▿  
Applied and Environmental Microbiology  2009;75(12):4149-4154.
We constructed a novel cell surface display system to control the ratio of target proteins on the Saccharomyces cerevisiae cell surface, using two pairs of protein-protein interactions. One protein pair is the Z domain of protein A derived from Staphylococcus aureus and the Fc domain of human immunoglobulin G. The other is the cohesin (Coh) and dockerin (Dock) from the cellulosome of Clostridium cellulovorans. In this proposed displaying system, the scaffolding proteins (fusion proteins of Z and Coh) were displayed on the cell surface by fusing with the 3′ half of α-agglutinin, and the target proteins fused with Fc or Dock were secreted. As a target protein, a recombinant Trichoderma reesei endoglucanase II (EGII) was secreted into the medium and immediately displayed on the yeast cell surface via the Z and Fc domains. Display of EGII on the cell surface was confirmed by hydrolysis of β-glucan as a substrate, and EGII activity was detected in the cell pellet fraction. Finally, two enzymes, EGII and Aspergillus aculeatus β-glucosidase 1, were codisplayed on the cell surface via Z-Fc and Dock-Coh interactions, respectively. As a result, the yeast displaying two enzymes hydrolyzed β-glucan to glucose very well. These results strongly indicated that the proposed strategy, the simultaneous display of two enzymes on the yeast cell surface, was accomplished by quantitatively controlling the display system using affinity binding.
PMCID: PMC2698344  PMID: 19411409
11.  Inadvertent C2–C3 Union After C1–C2 Posterior Fusion in Adults 
European Spine Journal  2005;15(3):270-277.
Introduction: Some authors pointed out that there were more than a few patients with inadvertent C2–C3 union after C1–C2 posterior fusion, although few detailed studies of C2–C3 union have been reported. The purpose of this study was to clarify whether C2–C3 union accelerated adjacent C3–C4 disc degeneration after C1–C2 posterior fusion and to investigate the related factors for C2–C3 union. Methods: Sixteen patients with rheumatoid arthritis (RA group) (4 males, 12 females, mean age 60 years, mean follow-up period 4 years and 3 months) and fifteen patients without RA (non-RA group) (11 males, 4 females, mean 52 years, mean follow-up period 3 years and 10 months) who underwent C1–C2 posterior fusion were radiologically assessed. The C2–C3 union was defined as trabecular bone formation at C2–C3 interlamina in lateral radiograph. C3–C4 disc height was measured to evaluate the disc degeneration. Results: C2–C3 union rate was 56% and 60% in RA group and non-RA group, respectively. In RA group, postoperative C3–C4 disc height was lower (Student’s t-test, P = 0.029) and the decrease rate of C3–C4 disc height was higher (Student’s t-test, P = 0.015) in patients with C2–C3 union than in patients without C2–C3 union. In non-RA group, the age at operation was older (Student’s t-test, P = 0.0007), and the C1–C2 fusion angle (Student’s t-test, P = 0.012) was smaller in patients with C2–C3 union than in patients without C2–C3 union. Conclusions: C2–C3 union after C1–C2 posterior fusion occurred in more than half of both groups. Inadvertent C2–C3 union should be considered a radiological complication and a potential risk factor due to acceleration of C3–C4 disc degeneration in RA.
PMCID: PMC3489302  PMID: 15940474
Atlanto-axial subluxation; Disc degeneration; Posterior fusion; Rheumatoid arthritis; Union
12.  Synergistic Saccharification, and Direct Fermentation to Ethanol, of Amorphous Cellulose by Use of an Engineered Yeast Strain Codisplaying Three Types of Cellulolytic Enzyme 
A whole-cell biocatalyst with the ability to induce synergistic and sequential cellulose-degradation reaction was constructed through codisplay of three types of cellulolytic enzyme on the cell surface of the yeast Saccharomyces cerevisiae. When a cell surface display system based on α-agglutinin was used, Trichoderma reesei endoglucanase II and cellobiohydrolase II and Aspergillus aculeatus β-glucosidase 1 were simultaneously codisplayed as individual fusion proteins with the C-terminal-half region of α-agglutinin. Codisplay of the three enzymes on the cell surface was confirmed by observation of immunofluorescence-labeled cells with a fluorescence microscope. A yeast strain codisplaying endoglucanase II and cellobiohydrolase II showed significantly higher hydrolytic activity with amorphous cellulose (phosphoric acid-swollen cellulose) than one displaying only endoglucanase II, and its main product was cellobiose; codisplay of β-glucosidase 1, endoglucanase II, and cellobiohydrolase II enabled the yeast strain to directly produce ethanol from the amorphous cellulose (which a yeast strain codisplaying β-glucosidase 1 and endoglucanase II could not), with a yield of approximately 3 g per liter from 10 g per liter within 40 h. The yield (in grams of ethanol produced per gram of carbohydrate consumed) was 0.45 g/g, which corresponds to 88.5% of the theoretical yield. This indicates that simultaneous and synergistic saccharification and fermentation of amorphous cellulose to ethanol can be efficiently accomplished using a yeast strain codisplaying the three cellulolytic enzymes.
PMCID: PMC348929  PMID: 14766607

Results 1-12 (12)