Dynamic changes in endoplasmic reticulum morphology and its contact with the plasma membrane in motor neurons in response to nerve injury

The endoplasmic reticulum (ER) extends throughout a cell and plays a critical role in maintaining cellular homeostasis. Changes in ER shape could provide a clue to explore the mechanisms that underlie the fate determination of neurons after axon injury because the ER drastically changes its morphology under neuronal stress to maintain cellular homeostasis and recover from damage. Because of their tiny structures and richness in the soma, the detailed morphology of the ER and its dynamics have not been well analysed. In this study, the focused ion beam/scanning electron microscopy (FIB/SEM) analysis was performed to explore the ultra-structures of the ER in the somata of motor neuron with axon regenerative injury models. In normal motor neurons, ER in the somata is abundantly localised near the perinucleus and represents lamella-like structures. After injury, analysis of the ER volume and ER branching points indicated a collapse of the normal distribution and a transformation from lamella-like structures to mesh-like structures. Furthermore, accompanied by ER accumulation near the plasma membrane (PM), the contact between the ER and PM (ER-PM contacts) significantly increased after injury. The accumulation of extended-synaptotagmin 1 (E-Syt1), a tethering protein of the ER and PM that regulates Ca2+-dependent lipid transfer, was also identified by immunohistochemistry and quantitative Real-time PCR after injury. These morphological alterations of ER and the increase in ER-PM contacts may be crucial events that occur in motor neurons as a resilient response for the survival after axonal injury.

Biplane fluoroscopy-guided percutaneous spinal cord stimulation

OBJECTIVE

Fluoroscopy is useful for spinal cord stimulation (SCS) lead placement. We employed biplane fluoroscopy for SCS lead placement. In this study, we sought to confirm the validity of using biplane fluoroscopy for SCS lead placement and to establish whether biplane fluoroscopy safely reduces the duration of surgery.

METHODS

Clinical data were retrospectively collected from the medical records of patients who underwent SCS lead placement under local anesthesia from 2015 to 2022. The duration of the surgical phase and the total radiation exposure time per case were recorded.

RESULTS

Forty-six patients underwent percutaneous SCS lead implantation. Recording was completed in 41 cases: one lead was placed in 13 cases and two leads were placed in 28 cases. Monoplane and biplane fluoroscopy was used in 15 and 26 patients, respectively. Although the type of fluoroscopy did not significantly affect the mean duration of the surgical phase in patients in which one lead was placed, biplane fluoroscopy was associated with a significant reduction in the mean duration of the surgical phase in patients that underwent placement of two leads (P=0.002). No significant differences in the total radiation exposure time were observed between patients in the monoplane and biplane fluoroscopy groups that were implanted with one (P=0.21) or two leads (P=0.62).

CONCLUSIONS

The use of biplane fluoroscopy reduced the duration of surgery necessary for the placement of two SCS leads. Biplane fluoroscopy represents a practical and safe adjustment to the current practice of SCS lead implantation.

Seeking Repeating Anthropogenic Seismic Sources: Implications for Seismic Velocity Monitoring at Fault Zones

Seismic velocities in rocks are highly sensitive to changes in permanent deformation and fluid content. The temporal variation of seismic velocity during the preparation phase of earthquakes has been well documented in laboratories but rarely observed in nature. It has been recently found that some anthropogenic, high-frequency (>1 Hz) seismic sources are powerful enough to generate body waves that travel down to a few kilometers and can be used to monitor fault zones at seismogenic depth. Anthropogenic seismic sources typically have fixed spatial distribution and provide new perspectives for velocity monitoring. In this work, we propose a systematic workflow to seek such powerful seismic sources in a rapid and straightforward manner. We tackle the problem from a statistical point of view, considering that persistent, powerful seismic sources yield highly coherent correlation functions (CFs) between pairs of seismic sensors. The algorithm is tested in California and Japan. Multiple sites close to fault zones show high-frequency CFs stable for an extended period of time. These findings have great potential for monitoring fault zones, including the San Jacinto Fault and the Ridgecrest area in Southern California, Napa in Northern California, and faults in central Japan. However, extra steps, such as beamforming or polarization analysis, are required to determine the dominant seismic sources and study the source characteristics, which are crucial to interpreting the velocity monitoring results. Train tremors identified by the present approach have been successfully used for seismic velocity monitoring of the San Jacinto Fault in previous studies.

Deep Brain Stimulation in Parkinsons Disease in Nepal

Background Parkinsons disease is a central nervous system degenerative disorder affecting motor system and characterized by progressive tremor, rigidity, gait abnormalities. Surgical treatment of Parkinsons disease is based on the changes in the basal gangliothalamocortical circuits which is altered in Parkinsons disease. Currently pallidotomy and Deep Brain Stimulation are available modes of surgical treatment of Parkinsons disease. Objective To know efficacy of deep brain stimulation in Parkinsons Disease in Nepal. Method All patients of idiopathic Parkinsons disease who underwent Deep Brain Stimulation in Annapurna Neurological Institute and Allied sciences since 2014 were included. The standard functional coordinates for Subthalamic nucleus and Globus pallidus internus was used. We used Zamarano-Dujovny (ZD) Fisher Frame with its software. Patients' Unified Parkinsons disease rating score, Modified Hoehn and Yahr Staging and Schwab and England Activities of daily living Scale were evaluated preoperativelyv as well as postoperatively. Result Ten patients underwent Deep Brain Stimulation. The male is to female ratio was 2:1. The mean age was 55.4±8.9 years and duration of illness was 5.5±2 years. There was a significant improvement in the scores for the main motor manifestations of the disease between the preoperative off-dopa and postoperative off-dopa/on-stim conditions. There was a significant improvement in Schwab and England Activities of daily living scale scores in the off-dopa condition between the preoperative score and the postoperative M6 score. Conclusion Our result of Deep Brain Stimulation is quite promising. However, it is very expensive and requires frequent follow-up for neuromodulation.

A Combined test using both cell sediment and supernatant cell-free DNA in pleural effusion shows increased sensitivity in detecting activating EGFR mutation in lung cancer patients

INTRODUCTION

The aim of this study was to examine whether a combined test using both cell sediment and supernatant cytology cell-free DNA (ccfDNA) is more useful in detecting EGFR mutation than using cell sediment DNA or supernatant ccfDNA alone in pleural effusion of lung cancer patients.

METHODS

A total of 74 lung adenocarcinoma patients with paired samples between primary tumour and corresponding metastatic tumour with both cell sediment and supernatant ccfDNA of pleural effusion cytology were enrolled in this study. Cell sediment and supernatant ccfDNA were analysed separately for EGFR mutations by polymerase chain reaction.

RESULTS

Out of 45 patients with mutant EGFR in primary tumours, EGFR mutations were detected in 23 cell sediments of corresponding metastases (sensitivity; 51.1%) and 20 supernatant ccfDNA corresponding metastases (sensitivity; 44.4%). By contrast, the combined test detected EGFR mutations in 27 corresponding metastases (sensitivity; 60.0%), and had a higher sensitivity than the cell sediment or the supernatant ccfDNA alone (P < .05). Out of 45 patients with mutant EGFR, 24, three and 18 were cytologically diagnosed as positive, atypical or negative, respectively. The detection rate in the combined test was highest (95.8%) in the positive group, and mutant EGFR was also detected in four of 18 samples (22.2%) in the negative group.

CONCLUSIONS

A combined test using both cell sediment DNA and supernatant ccfDNA samples increases the concordance rate of EGFR mutations between primary tumour and corresponding metastases. Our findings indicate that supernatant ccfDNA is useful even in cases where the cytological diagnosis is negative.

Fluorinated polymer surfactants bearing an alternating peptide skeleton prepared by three-component polycondensation

A new species of fluorinated polymer surfactant was developed by three component polycondensation analogous to Ugi four-component condensation. The surfactant exhibited unique surface properties, which made cellulose-based materials hydrophobic and decreased the surface tension of CHCl₃. It turned out that the polymer forms micelles in CHCl₃.

A new species of fluorinated polymer surfactant was developed by three component polycondensation analogous to Ugi four-component condensation.

Inter-observer reproducibility of endometrial cytology by the Osaki Study Group method: utilising the Becton Dickinson SurePath™ liquid-based cytology

OBJECTIVE

The purpose of the present study was to evaluate the reproducibility of the cytological diagnosis of endometrial lesions by the Osaki Study Group (OSG) method of new cytological diagnostic criteria using BD SurePath^™ (SP)-liquid-based cytology (LBC).

METHODS

This cytological classification using the OSG method consists of six categories: (i) normal endometrium (NE), (ii) endometrial glandular and stromal breakdown (EGBD), (iii) atypical endometrial cells, cannot exclude atypical endometrial hyperplasia or more (ATEC-A), (iv) adenocarcinoma including atypical endometrial hyperplasia or malignant tumour (Malignancy), (v) endometrial hyperplasia without atypia (EH) and (vi) atypical endometrial cells of undetermined significance (ATEC-US). For this study, a total 244 endometrial samplings were classified by two academic cytopathologists as follows: 147 NE cases , 36 EGBD cases , 47 Malignant cases, eight ATEC-A cases, two EH cases and four ATEC-US cases. To confirm the reproducibility of the diagnosis and to study the inter- and intra-observer agreement further, a second review round followed at 3-month intervals, which included three additional cytopathologists.

RESULTS

The inter-observer agreement of NE classes improved progressively from 'good to fair' to 'excellent', with values increasing from 0.70 to 0.81. Both EGBD and Malignancy classes improved progressively from 'good to fair' to 'excellent', with values increasing from 0.62-0.63 to 0.84-0.95, respectively. The overall intra-observer agreement between the first and the second rounds was 'good to fair' to 'excellent', with values changing from 0.79 to 0.85. All kappa improvements were significant (P < 0.0001).

CONCLUSION

In this study, it seemed that the use of the OSG method as the new diagnostic criteria for SP-LBC preparation, may be a valid method to improve the precision (reproducibility) of endometrial cytology.

GluA4 subunit of AMPA receptors mediates the early synaptic response to altered network activity in the developing hippocampus

Development of the neuronal circuitry involves both Hebbian and homeostatic plasticity mechanisms that orchestrate activity-dependent refinement of the synaptic connectivity. AMPA receptor subunit GluA4 is expressed in hippocampal pyramidal neurons during early postnatal period and is critical for neonatal long-term potentiation; however, its role in homeostatic plasticity is unknown. Here we show that GluA4-dependent plasticity mechanisms allow immature synapses to promptly respond to alterations in network activity. In the neonatal CA3, the threshold for homeostatic plasticity is low, and a 15-h activity blockage with tetrodotoxin triggers homeostatic upregulation of glutamatergic transmission. On the other hand, attenuation of the correlated high-frequency bursting in the CA3-CA1 circuitry leads to weakening of AMPA transmission in CA1, thus reflecting a critical role for Hebbian synapse induction in the developing CA3-CA1. Both of these developmentally restricted forms of plasticity were absent in GluA4(-/-) mice. These data suggest that GluA4 enables efficient homeostatic upscaling and responsiveness to temporal activity patterns during the critical period of activity-dependent refinement of the circuitry.

High-power, widely tunable, room-temperature picosecond optical parametric oscillator based on cylindrical 5%MgO:PPLN

We report a high-power picosecond optical parametric oscillator (OPO) based on cylindrical MgO:PPLN synchronously pumped by an Yb-fiber laser. The singly resonant OPO is tunable in the near-infrared signal across 1413-1900 nm and mid-infrared idler over 2418-4307 nm by angle tuning of the crystal at room temperature. With non-optimized output coupling of ∼10%, the OPO simultaneously delivers 2.4 W of signal at 1664 nm and 1.7 W of idler at 2950 nm at an overall extraction efficiency of ∼45% with high beam-pointing stability <30  μrad and <14  μrad for the signal and idler, respectively. The generated signal and idler exhibit passive power stability better than 1% rms and 0.8% rms over 15 h, respectively, in high beam quality with TEM(00) profile. The extracted signal pulses from the OPO have duration of 15.2 ps with a spectral bandwidth of 0.7 nm, corresponding to a time-bandwidth product of ΔυΔτ∼1.2.

Mutant allele frequency predicts the efficacy of EGFR-TKIs in lung adenocarcinoma harboring the L858R mutation

BACKGROUND

Whether the mutant allele frequency (MAF) may also have predictive implications for tyrosine kinase inhibitor (TKI) therapy in patients with advanced epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma (AELAd) remains unknown.

PATIENTS AND METHODS

Based on a biobanking system in conjunction with our institution, we assessed EGFR mutation status using pyrosequencing (Py) and by outsourcing laboratory tests, such as the Cycleave (Cy) and the Scorpion ARMS (A).

RESULTS

Out of 705 patients enrolled in the Shizuoka Lung Cancer Mutation Study between July 2011 and March 2013, 102 AELAd patients were identified as carrying the L858R mutation (L858Rm) using Py to analyze histological specimens. Of these 102 patients, the EGFR mutation status was assessed using both Py and Cy in 48 patients: the median MAF of L858R (MAFLR) was 18.5% (range: 8%-82%), and 45 patients (94%) were identified as having an L858Rm using both Py and Cy. Three patients (6%) with discrepant L858Rm findings were only identified using Py. The plotting of a receiver operating characteristic curve to identify the discordance in L858Rm findings showed that the area under the curve for MAFLR was 0.967 (95% confidence interval: 0.91-1) and that an MAFLR of 9% resulted in high sensitivity (100%) and specificity (99%). Also, 29 patients with AELAd, excluding those with postoperative recurrences, had their L858R status assessed using Cy or A. The median age, 69 years (range: 47-84 years); male/female, 14 (48%)/15 (52%); smokers/never-smokers 13 (45%)/16 (55%); ECOG PS 0-1/2-3, 26 (90%)/3 (10%); stage IIIB/IV, 4 (14%)/25 (86%); median MAFLR, 18% (range: 8%-63%). Patients with an MAFLR of ≤9% had a significantly shorter progression-free survival (PFS) period after TKI therapy than those with an MAFLR of >9% (mPFS: 92 versus 284 days, P = 0.0027).

CONCLUSION

The MAF may be a potential predictive factor of TKI treatment efficacy in patients with AELAd carrying the L858Rm.

Efficient second to ninth harmonic generation using megawatt peak power microchip laser

We report the design and use of a megawatt peak power Nd:YAG/Cr4+:YAG microchip laser for efficient second to ninth harmonic generation. We show that the sub-nanosecond pulse width region, between 100 ps and 1 ns, is ideally suited for efficient wavelength conversion. Using this feature, we report 85% second harmonic generation efficiency using lithium triborate (LBO), 60% fourth harmonic generation efficiency usingß-barium borate, and 44% IR to UV third harmonic generation efficiency using Type I and Type II LBO. Finally, we report the first demonstration of 118 nm VUV generation in xenon gas using a microchip laser.

Excitation Energy-Transfer Dynamics of Brown Algal Photosynthetic Antennas

Fucoxanthin-chlorophyll-a/c protein (FCP) complexes from brown algae Cladosiphon okamuranus TOKIDA (Okinawa Mozuku in Japanese) contain the only species of carbonyl carotenoid, fucoxanthin, which exhibits spectral characteristics attributed to an intramolecular charge-transfer (ICT) property that arises in polar environments due to the presence of the carbonyl group in its polyene backbone. Here, we investigated the role of the ICT property of fucoxanthin in ultrafast energy transfer to chlorophyll-a/c in brown algal photosynthesis using femtosecond pump-probe spectroscopic measurements. The observed excited-state dynamics show that the ICT character of fucoxanthin in FCP extends its absorption band to longer wavelengths and enhances its electronic interaction with chlorophyll-a molecules, leading to efficient energy transfer from fucoxanthin to chlorophyll-a.

Enhancing performances of a passively Q-switched Nd:YAGCr(4+):YAG microlaser with a volume Bragg grating output coupler

A diode end-pumped Nd:YAG microlaser passively Q-switched by Cr(4+):YAG with performances controlled by a volume Bragg grating (VBG) output coupler has been developed. Compared with operation at room temperature, the Q-switched laser pulse energy was increased, by a factor of 2 or more, by elevating the Nd:YAG temperature and locking the wavelength of emission with the VBG. Furthermore, the emission wavelength was tuned over 0.7 nm bandwidth by changing the VBG temperature while maintaining laser pulses of millijoule-level energy and short (less than 4 ns) duration.

[Intrathecal baclofen therapy for spastic paraparesis due to aortic dissecting aneurysm; recent progress in treatment strategy]

A 48-year-old man suffered from acute dissection of thoracic aortic aneurysm which eventually led to replacement of the ascending aorta with a tube graft. During this clinical course, circulatory failure in intercostal artery resulted in spinal cord infarction followed by moto-sensory disturbance below Th7 dermatomic area. Seven months later, spasticity with pain in both lower extremities became conspicuous that was uncontrollable by any oral medication. Eventually the patient underwent the implantation of continuous infusion pump for intrathecal baclofen therapy (ITB). The clinical condition was remarkably improved and now has been well controlled. ITB, authorized by Japanese Ministry of Health Labour and Welfare in 2006, has notable therapeutic effects on spasticity derived from any sort of central nervous disorder. More promotive enlightenment if ITB is indispensable for enhancement of its medical benefit in Japan.

Diaphragm pacing with a spinal cord stimulator: current state and future directions

Diaphragm pacing with electrical stimulation of the phrenic nerve is an established treatment for central hypoventilation syndrome. The device, however, is not readily available. We tested the same spinal cord stimulator we use for pain control in phrenic nerve stimulation. We implanted a spinal cord stimulator (Itrel 3 or X-trel, Medtronic, MN) in 6 patients with chronic hypoventilation because of brainstem or high cervical cord dysfunction. The stimulation electrode was placed along the right phrenic nerve in the neck, and the device was implanted in the anterior chest. We used the cyclic mode, and set the parameters at I second ramp up, 2 seconds on, 3 seconds off. The pulse width and the frequency were set at 150 microseconds and 21 Hz, respectively. The amplitude of the output was adjusted to obtain sufficient tidal volume and to maintain PaCO2 at around 40 mm Hg. During a follow-up period up to four years, stable and sufficient ventilation was observed in all patients without any complications. Although further long follow-up is necessary, diaphragm pacing with the spinal cord stimulator is feasible and effective for the treatment of the central hypoventilation syndrome.

Increased serum high mobility group box-1 level in Churg-Strauss syndrome

Churg-Strauss syndrome (CSS) is a rare form of systemic vasculitis occurring in patients with asthma and hypereosinophilia; however, its mechanisms involved in the severe tissue inflammation with vasculitis are poorly understood. High mobility group box 1 (HMGB1) protein, originally identified as a DNA binding protein, also has potent pro-inflammatory and proangiogenic properties. In this study, we hypothesized that HMGB1 might be associated with CSS, and examined serum HMGB1 levels and compared those of asthma patients and healthy volunteers. We also investigated HMGB1 expression in the lesion, and eosinophil HMGB1 amount in CSS patients. We found that the serum HMGB1 levels in CSS patients were significantly higher than those of asthma patients and healthy volunteers. Eosinophils in the CSS lesion expressed HMGB1 and HMGB1 level in eosinophils from CSS patients was significantly higher than that of asthma patients, while there was no significant difference in HMGB1 levels in peripheral mononuclear cells. The serum HMGB1 level in CSS patients decreased after the steroid therapy, and showed significant positive correlations with several molecules, including soluble interleukin-2 receptor, soluble thrombomodulin, and eosinophil cationic protein in sera. We propose that HMGB1 might contribute to the pathogenesis of CSS.

Susceptibility for homeostatic plasticity is down-regulated in parallel with maturation of the rat hippocampal synaptic circuitry

Homeostatic regulation, i.e. the ability of neurons and neuronal networks to adjust their output in response to chronic alterations in electrical activity is a prerequisite for the pronounced functional plasticity in the developing brain. Cellular mechanisms of homeostatic plasticity have mainly been studied in cultured preparations. To understand the developmental time frame and properties of homeostatic plasticity under more physiological conditions, we have here compared the effects of activity deprivation on synaptic transmission in acutely isolated and cultured hippocampal slices at different stages of development. We find that transmission at both glutamatergic and GABAergic synapses is strongly and rapidly (15 h) regulated in the opposite directions in response to inactivity during narrow, separated time windows early in development. Following this critical period of synaptic development, induction of the homeostatic response requires longer periods (40 h) of inactivity. At glutamatergic synapses, activity blockade led to an increase in the amplitude and frequency of mEPSCs, and the threshold for induction of this response was increased during development. In contrast, homeostatic regulation at GABAergic synapses was expressed in a qualitatively distinct manner at different developmental stages. Immature neurons responded rapidly to inactivity by regulating mIPSC frequency, while longer activity blockade led to a decrease in the mIPSC amplitude independent of the neuronal maturation. The susceptibility of immature networks to homeostatic regulation may serve as a safety mechanism against rapid runaway destability during the time of intense remodelling of the synaptic circuitry.

Intrathecal baclofen in the treatment of post-stroke central pain, dystonia, and persistent vegetative state

Intrathecal baclofen (ITB) administration is a fully established treatment for severe spasticity. However, it is not widely known that baclofen, an agonist of the GABA-B receptor, has additional beneficial effects in other conditions such as chronic pain, coma, dystonia, tetanus, and hyypothalamic storm. Sporadic cases of dramatic recovery from persistent vegetative state after intrathecal administration of baclofen have been reported. There have been also reports on the use of baclofen for control of dystonia due to cerebral palsy, neuropathic central pain syndrome or reflex sympathetic dystrophy. On the other hand, epidural spinal cord stimulation (SCS) has been used in the management not only of pain but also of spasticity, dystonia, and in order to improve deteriorated consciousness, but the effects so far have been modest and variable. Similarities between ITB and SCS are interesting as both involve the spinal GABAergic system. Based on a 15-year personal experience of intrathecal baclofen, I would stress the importance of this treatment not only for spasticity but also for other difficult neurological disorders.

52 mJ narrow-bandwidth degenerated optical parametric system with a large-aperture periodically poled MgO:LiNbO3 device

We have demonstrated efficient, high-energy, narrow-spectral-bandwidth 2.128 microm pulse generation by use of periodically poled MgO:LiNbO3 devices with a 36 mm length and a 5 mm x 5 mm large aperture. A free-running degenerated optical parametric oscillator (OPO) pumped with a Q-switched 1.064 microm Nd:YAG laser exhibits a high slope efficiency of 75% and an optical-to-optical conversion efficiency of 70% with a broad spectral bandwidth (>100 nm). In a configuration with a spectrally narrowed master oscillator followed by a power amplifier, we have achieved an output pulse energy of 52 mJ with a spectral bandwidth of less than 2 nm at the degeneracy point. The total optical-to-optical conversion efficiency of the system reached 50%.

Proper SUMO-1 conjugation is essential to DJ-1 to exert its full activities

DJ-1 is a multifunctional protein that plays roles in transcriptional regulation and antioxidative stress, and loss of its function is thought to result in the onset of Parkinson's disease (PD). Here, we report that DJ-1 was sumoylated on a lysine residue at amino-acid number 130 (K130) by PIASxalpha or PIASy. The K130 mutation abrogated all of the functions of DJ-1, including ras-dependent transformation, cell growth promotion and anti-UV-induced apoptosis activities. Sumoylation of DJ-1 was increased after UV irradiation concomitant with a pI shift to an acidic point of DJ-1. Furthermore, L166P, a mutant DJ-1 found in PD patients, and K130RX, an artificial mutant containing four mutations in DJ-1, were improperly sumoylated, and they became insoluble, partly localized in the mitochondria and degraded by the proteasome system. Both L166P-expressing cells and DJ-1-knockdown cells were found to be highly susceptible to UV-induced cell apoptosis.