Neurophysiological features of STN LFP underlying sleep fragmentation in Parkinson's disease.

BACKGROUND: Sleep fragmentation is a persistent problem throughout the course of Parkinson's disease (PD). However, the related neurophysiological patterns and the underlying mechanisms remained unclear. METHOD: We recorded subthalamic nucleus (STN) local field potentials (LFPs) using deep brain stimulation (DBS) with real-time wireless recording capacity from 13 patients with PD undergoing a one-night polysomnography recording, 1 month after DBS surgery before initial programming and when the patients were off-medication. The STN LFP features that characterised different sleep stages, correlated with arousal and sleep fragmentation index, and preceded stage transitions during N2 and REM sleep were analysed. RESULTS: Both beta and low gamma oscillations in non-rapid eye movement (NREM) sleep increased with the severity of sleep disturbance (arousal index (ArI)-betaNREM: r=0.9, p=0.0001, sleep fragmentation index (SFI)-betaNREM: r=0.6, p=0.0301; SFI-gammaNREM: r=0.6, p=0.0324). We next examined the low-to-high power ratio (LHPR), which was the power ratio of theta oscillations to beta and low gamma oscillations, and found it to be an indicator of sleep fragmentation (ArI-LHPRNREM: r=-0.8, p=0.0053; ArI-LHPRREM: r=-0.6, p=0.0373; SFI-LHPRNREM: r=-0.7, p=0.0204; SFI-LHPRREM: r=-0.6, p=0.0428). In addition, long beta bursts (>0.25 s) during NREM stage 2 were found preceding the completion of transition to stages with more cortical activities (towards Wake/N1/REM compared with towards N3 (p<0.01)) and negatively correlated with STN spindles, which were detected in STN LFPs with peak frequency distinguishable from long beta bursts (STN spindle: 11.5 Hz, STN long beta bursts: 23.8 Hz), in occupation during NREM sleep (ß=-0.24, p<0.001). CONCLUSION: Features of STN LFPs help explain neurophysiological mechanisms underlying sleep fragmentations in PD, which can inform new intervention for sleep dysfunction. TRIAL REGISTRATION NUMBER: NCT02937727.

Pharmacokinetics of ginkgolide B-lyophilized nanoparticles after intravenous injection in rats using liquid chromatography-tandem mass spectrometry.

RATIONALE: Ginkgolide B (GB) performs diverse pharmacological activities but has poor water solubility. The currently available GB injections have a short half-life and are lethal when injected rapidly. We prepared GB-lyophilized nanoparticles (GB-NPs) using a new nonsurfactant polysaccharide polymer, ZY-010, as its carrier to regulate the release of GB in vivo. Here, the pharmacokinetics (PK) of GB-NPs after intravenous injection in rats was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: The samples were separated on an Agilent Eclipse XDB-C 18 column (2.1 × 50 mm, 1.85 µm) maintained at 30°C. The MS/MS transitions of GB and glibenclamide as the internal standard (IS) were set at m/z 423.1 → 367.1 and m/z 492.1 → 367.0, respectively. The standard curve of GB content was constructed, and the specificity, sensitivity, precision, and extraction recovery of LC-MS/MS analysis were assessed. The main PK parameters were analyzed using DAS (Drug And Statistics for Windows) software, version 2.0. RESULTS: The retention time of GB and IS at elution was 2.77 and 4.75 min, respectively. An excellent linear response across the concentration range of 0.001-100 µg/ml was achieved (r = 0.9997). The relative standard deviation value of precision was less than 10%. The total extraction recovery was above 80.76 ± 2.08%. The main PK parameters for the GB-NPs were as follows: t1/2 = 69.32 h, AUC(0 → ∞) = 188 312.97 ± 143 312.41 µg/L h, CL = 0.03 ± 0.02 L/h/kg, and V = 0.09 ± 0.05 L/kg. The t1/2 of the GB-NPs was significantly longer than that of GB solution, and AUC(0 → ∞) of GB-NPs was about 1.4 times that of GB solution. The PK data demonstrated that the blood concentration of GB in rats conformed to a three-compartment model in both GB solution and GB-NPs. CONCLUSION: A rapid and accurate LC-MS/MS method was established for the determination of GB-NPs in rats. GB-NPs exhibited a sustained-release behavior in vivo compared with GB solution.

Cigarette smoking and mitochondrial dysfunction in peripheral artery disease.

BACKGROUND: This study evaluated the association of smoking with mitochondrial function in gastrocnemius muscle of people with peripheral artery disease (PAD). METHODS: Participants were enrolled from Chicago, Illinois and consented to gastrocnemius biopsy. Mitochondrial oxidative capacity was measured in muscle with respirometry. Abundance of voltage-dependent anion channel (VDAC) (mitochondrial membrane abundance), peroxisome proliferator-activated receptor-γ coactivator (PGC-1α) (mitochondrial biogenesis), and electron transport chain complexes I-V were measured with Western blot. RESULTS: Fourteen of 31 people with PAD (age 72.1 years, ABI 0.64) smoked cigarettes currently. Overall, there were no significant differences in mitochondrial oxidative capacity between PAD participants who currently smoked and those not currently smoking (complex I+II-mediated oxidative phosphorylation: 86.6 vs 78.3 pmolO2/s/mg, respectively [p = 0.39]). Among participants with PAD, those who currently smoked had a higher abundance of PGC-1α (p < 0.01), VDAC (p = 0.022), complex I (p = 0.021), and complex III (p = 0.021) proteins compared to those not currently smoking. People with PAD who currently smoked had lower oxidative capacity per VDAC unit (complex I+II-mediated oxidative phosphorylation [137.4 vs 231.8 arbitrary units, p = 0.030]) compared to people with PAD not currently smoking. Among people without PAD, there were no significant differences in any mitochondrial measures between currently smoking (n = 5) and those not currently smoking (n = 63). CONCLUSIONS: Among people with PAD, cigarette smoking may stimulate mitochondrial biogenesis to compensate for reduced oxidative capacity per unit of mitochondrial membrane, resulting in no difference in overall mitochondrial oxidative capacity according to current smoking status among people with PAD. However, these results were cross-sectional and a longitudinal study is needed.

Epidemiological characteristics, spatial clusters and monthly incidence prediction of hand, foot and mouth disease from 2017 to 2022 in Shanxi Province, China.

Hand, foot and mouth disease (HFMD) is a common infection in the world, and its epidemics result in heavy disease burdens. Over the past decade, HFMD has been widespread among children in China, with Shanxi Province being a severely affected northern province. Located in the temperate monsoon climate, Shanxi has a GDP of over 2.5 trillion yuan. It is important to have a comprehensive understanding of the basic features of HFMD in those areas that have similar meteorological and economic backgrounds to northern China. We aimed to investigate epidemiological characteristics, identify spatial clusters and predict monthly incidence of HFMD. All reported HFMD cases were obtained from the Shanxi Center for Disease Control and Prevention. Overall HFMD incidence showed a significant downward trend from 2017 to 2020, increasing again in 2021. Children aged < 5 years were primarily affected, with a high incidence of HFMD in male patients (relative risk: 1.316). The distribution showed a seasonal trend, with major peaks in June and July and secondary peaks in October and November with the exception of 2020. Other enteroviruses were the predominant causative agents of HFMD in most years. Areas with large numbers of HFMD cases were primarily in central Shanxi, and spatial clusters in 2017 and 2018 showed a positive global spatial correlation. Local spatial autocorrelation analysis showed that hot spots and secondary hot spots were concentrated in Jinzhong and Yangquan in 2018. Based on monthly incidence from September 2021 to August 2022, the mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean square error (RMSE) of the long short-term memory (LSTM) and seasonal autoregressive integrated moving average (SARIMA) models were 386.58 vs. 838.25, 2.25 vs. 3.08, and 461.96 vs. 963.13, respectively, indicating that the predictive accuracy of LSTM was better than that of SARIMA. The LSTM model may be useful in predicting monthly incidences of HFMD, which may provide early warnings of HFMD epidemics.

Temperature Thresholds of Pyrogenic Dissolved Organic Matter in Heating Experiments Simulating Forest Fires.

Heating temperature (HT) during forest fires is a critical factor in regulating the quantity and quality of pyrogenic dissolved organic matter (DOM). However, the temperature thresholds at which maximum amounts of DOM are produced (TTmax) and at which the DOC gain turns into net DOC loss (TT0) remain unidentified on a component-specific basis. Here, based on solid-state 13C nuclear magnetic resonance, absorbance and fluorescence spectroscopies, and Fourier transform ion cyclotron resonance mass spectrometry, we analyzed variations in DOM composition in detritus and soil with HT (150-500 °C) and identified temperature thresholds for components on structural, fluorophoric, and molecular formula levels. TTmax was similar for detritus and soil and ranged between 225 and 250 °C for bulk dissolved organic carbon (DOC) and most DOM components. TT0 was consistently lower in detritus than in soil. Moreover, temperature thresholds differed across the DOM components. As the HT increased, net loss was observed initially in molecular formulas tentatively associated with carbohydrates and aliphatics, then proteins, peptides, and polyphenolics, and ultimately condensed aromatics. Notably, at temperatures lower than TT0, particularly at TTmax, burning increased the DOC quantity and thus might increase labile substrates to fuel soil microbial community. These composition-specific variations of DOM with temperature imply nonlinear and multiple temperature-dependent wildfire impacts on soil organic matter properties.

Astaxanthin promotes mitochondrial biogenesis and antioxidant capacity in chronic high-intensity interval training.

PURPOSE: Reactive oxygen and nitrogen species are required for exercise-induced molecular adaptations; however, excessive exercise may cause cellular oxidative distress. We postulate that astaxanthin (ASX) can neutralize oxidative distress and stimulate mitochondrial biogenesis in high-intensity exercise-trained mice. METHODS: Six-week-old mice (n = 8/group) were treated with ASX (10 mg/kg BW) or placebo. Training groups participated in 30 min/day high-intensity interval training (HIIT) for 6 weeks. Gastrocnemius muscle was collected and assayed following the exercise training period. RESULTS: Compared to the HIIT control mice, the ASX-treated HIIT mice reduced malonaldehyde levels and upregulated the expression of Nrf2 and FOXO3a. Meanwhile, the genes NQO1 and GCLC, modulated by Nrf2, and SOD2, regulated by FOXO3a, and GPx4, were transcriptionally upregulated in the ASX-treated HIIT group. Meanwhile, the expression of energy sensors, AMPK, SIRT1, and SIRT3, increased in the ASX-treated HIIT group compared to the HIIT control group. Additionally, PGC-1α, regulated by AMPK and SIRT1, was upregulated in the ASX-treated HIIT group. Further, the increased PGC-1α stimulated the transcript of NRF1 and Tfam and mitochondrial proteins IDH2 and ATP50. Finally, the ASX-treated HIIT mice had upregulations in the transcript level of mitochondrial fusion factors, including Mfn1, Mfn2, and OPA1. However, the protein level of AMPK, SIRT1, and FOXO3a, and the transcript level of Nrf2, NQO1, PGC-1α, NRF1, Mfn1, Mfn2, and OPA1 decreased in the HIIT control group compared to the sedentary control group. CONCLUSION: Supplementation with ASX can reduce oxidative stress and promote antioxidant capacity and mitochondrial biogenesis during strenuous HIIT exercise in mice.

Model-based analysis of the incidence trends and transmission dynamics of COVID-19 associated with the Omicron variant in representative cities in China.

BACKGROUND: In 2022, Omicron outbreaks occurred at multiple sites in China. It is of great importance to track the incidence trends and transmission dynamics of coronavirus disease 2019 (COVID-19) to guide further interventions. METHODS: Given the population size, economic level and transport level similarities, two groups of outbreaks (Shanghai vs. Chengdu and Sanya vs. Beihai) were selected for analysis. We developed the SEAIQRD, ARIMA, and LSTM models to seek optimal modeling techniques for waves associated with the Omicron variant regarding data predictive performance and mechanism transmission dynamics, respectively. In addition, we quantitatively modeled the impacts of different combinations of more stringent interventions on the course of the epidemic through scenario analyses. RESULTS: The best-performing LSTM model showed better prediction accuracy than the best-performing SEAIQRD and ARIMA models in most cases studied. The SEAIQRD model had an absolute advantage in exploring the transmission dynamics of the outbreaks. Regardless of the time to inflection point or the time to Rt curve below 1.0, Shanghai was later than Chengdu (day 46 vs. day 12/day 54 vs. day 14), and Sanya was later than Beihai (day 16 vs. day 12/day 20 vs. day 16). Regardless of the number of peak cases or the cumulative number of infections, Shanghai was higher than Chengdu (34,350 vs. 188/623,870 vs. 2,181), and Sanya was higher than Beihai (1,105 vs. 203/16,289 vs. 3,184). Scenario analyses suggested that upgrading control level in advance, while increasing the index decline rate and quarantine rate, were of great significance for shortening the time to peak and Rt below 1.0, as well as reducing the number of peak cases and final affected population. CONCLUSIONS: The LSTM model has great potential for predicting the prevalence of Omicron outbreaks, whereas the SEAIQRD model is highly effective in revealing their internal transmission mechanisms. We recommended the use of joint interventions to contain the spread of the virus.

Identifying gaps in disease knowledge among patients with peripheral artery disease.

OBJECTIVE: An individual's understanding of disease risk factors and outcomes is important for the ability to make healthy lifestyle choices and decisions about disease treatment. Peripheral artery disease (PAD) is a condition with increasing global prevalence and high risk of adverse patient outcomes. This study seeks to understand the adequacy of disease understanding in patients with PAD. METHODS: This was an observational study of patients with PAD recruited from vascular surgery outpatient clinic and PAD clinical studies at a single academic medical center over an 8-month period. A 44-item paper survey assessed demographic and socioeconomic information, knowledge of personal medical history, PAD risk factors, consequences of PAD, and health education preferences. Patients with documented presence of PAD were offered the survey. Patients unable to complete the survey or provide informed consent were not considered eligible. Disease "awareness" was defined as correct acknowledgement of the presence or absence of a disease, including PAD, in the personal medical history. "PAD knowledge score" was the percentage of correct responses to questions on general PAD risk factors and consequences. Of 126 eligible patients, 109 participated. Bivariate analysis was used to study factors associated with awareness of PAD diagnosis. Factors associated with the PAD knowledge score were studied using the Pearson correlation coefficient, two-sample t test, or one-way analysis of variance. P value < .05 was considered statistically significant. RESULTS: The mean participant age was 69.4 ± 11.0 years, and 39.4% (n = 43) were female. Most participants (78.9%; n = 86) had critical limb-threatening ischemia. Only 65.4% (n = 70) of participants were aware of a diagnosis of PAD, which was less than their awareness of related comorbidities. Factors positively associated with PAD diagnosis awareness were female sex (81.4% vs 54.7%; P = .004) and history of percutaneous leg revascularization (78.6% vs 47.9%; P = .001). Among 17 patients who had undergone major leg amputation, 35% (n = 6) were unaware of a diagnosis of PAD. PAD knowledge scores correlated positively with an awareness of PAD diagnosis (59.1% vs 48.7%; P = .02) and negatively with a history of hypertension (53.4% vs 68.1%; P = .001). Most participants (86.5%; n = 90) expressed a desire to be further educated on PAD. The most popular education topics were dietary recommendations, causes, and treatment for PAD. CONCLUSIONS: Patients with PAD have deficits in their awareness of this diagnosis and general knowledge about PAD. Future research priorities should further define these deficits and their causes in order to inform new strategies that foster information-seeking behavior and effective educational programs for PAD.

Role of Ten eleven translocation-2 (Tet2) in modulating neuronal morphology and cognition in a mouse model of Alzheimer's disease.

Abnormal expression of Ten eleven translocation-2 (Tet2) contributes to the pathogenesis of Alzheimer's disease (AD). However, to date, the role of Tet2 in modulating neuronal morphology upon amyloid-ß (Aß)-induced neurotoxicity has not been shown in a mouse model of AD. Here, we have developed a model of injured mouse hippocampal neurons induced by Aß42 oligomers in vitro. We also investigated the role of Tet2 in injured neurons using recombinant plasmids-induced Tet2 inhibition or over-expression. We found that the reduced expression of Tet2 exacerbated neuronal damage, whereas the increased expression of Tet2 was sufficient to protect neurons against Aß42 toxicity. Our results indicate that the brains of aged APPswe/PSEN1 double-transgenic (2 × Tg-AD) mice exhibit an increase in Aß plaque accumulation and a decrease in Tet2 expression. As a result, we have also explored the underlying mechanisms of Tet2 in cognition and amyloid load in 2 × Tg-AD mice via adeno-associated virus-mediated Tet2 knockdown or over-expression. Recombinant adeno-associated virus was microinjected into bilateral dentate gyrus regions of the hippocampus of the mice. Knocking down Tet2 in young 2 × Tg-AD mice resulted in the same extent of cognitive dysfunction as aged 2 × Tg-AD mice. Importantly, in middle-aged 2 × Tg-AD mice, knocking down Tet2 accelerated the accumulation of Aß plaques, whereas over-expressing Tet2 alleviated amyloid burden and memory loss. Furthermore, our hippocampal RNA-seq data, from young 2 × Tg-AD mice, were enriched with aberrantly expressed lncRNAs and miRNAs that are modulated by Tet2. Tet2-modulated lncRNAs (Malat1, Meg3, Sox2ot, Gm15477, Snhg1) and miRNAs (miR-764, miR-211, and miR-34a) may play a role in neuron formation. Overall, these results indicate that Tet2 may be a potential therapeutic target for repairing neuronal damage and cognitive impairment in AD.

Subthalamic Nucleus Deep Brain Stimulation Modulates 2 Distinct Neurocircuits.

OBJECTIVE: Current understanding of the neuromodulatory effects of deep brain stimulation (DBS) on large-scale brain networks remains elusive, largely due to the lack of techniques that can reveal DBS-induced activity at the whole-brain level. Using a novel 3T magnetic resonance imaging (MRI)-compatible stimulator, we investigated whole-brain effects of subthalamic nucleus (STN) stimulation in patients with Parkinson disease. METHODS: Fourteen patients received STN-DBS treatment and participated in a block-design functional MRI (fMRI) experiment, wherein stimulations were delivered during "ON" blocks interleaved with "OFF" blocks. fMRI responses to low-frequency (60Hz) and high-frequency(130Hz) STN-DBS were measured 1, 3, 6, and 12 months postsurgery. To ensure reliability, multiple runs (48 minutes) of fMRI data were acquired at each postsurgical visit. Presurgical resting-state fMRI (30 minutes) data were also acquired. RESULTS: Two neurocircuits showed highly replicable, but distinct responses to STN-DBS. A circuit involving the globus pallidus internus (GPi), thalamus, and deep cerebellar nuclei was significantly activated, whereas another circuit involving the primary motor cortex (M1), putamen, and cerebellum showed DBS-induced deactivation. These 2 circuits were dissociable in terms of their DBS-induced responses and resting-state functional connectivity. The GPi circuit was frequency-dependent, selectively responding to high-frequency stimulation, whereas the M1 circuit was responsive in a time-dependent manner, showing enhanced deactivation over time. Finally, activation of the GPi circuit was associated with overall motor improvement, whereas M1 circuit deactivation was related to reduced bradykinesia. INTERPRETATION: Concurrent DBS-fMRI using 3T revealed 2 distinct circuits that responded differentially to STN-DBS and were related to divergent symptoms, a finding that may provide novel insights into the neural mechanisms underlying DBS. ANN NEUROL 2020;88:1178-1193.

Global, regional, and national burden of ovarian cancer and the attributable risk factors in all 194 countries and territories during 2007-2017: A systematic analysis of the Global Burden of Disease Study 2017.

BACKGROUND: We estimated the global burden of ovarian cancer (OC) in 194 countries and territories between 2007 and 2017. METHODS: Data were extracted from the Global Burden of Disease (GBD), Injuries, and Risk Factors 2017 study. RESULTS: Globally, 286 126.80 (95% UI = 278 075.38-295 311.41) incident cases, 4.67 million (4.53-4.83) disability-adjusted life-years (DALYs), and 175 981.99 (171 384.15-181 198.43) deaths were reported in 2017. The age-standardized incidence and DALY rates increased by 2.05% and 1.34% during 2007-2017, respectively, while the age-standardized mortality rate decreased by -0.14%. The age-standardized incidence, DALY, and mortality rates in 2017 were the highest in the high socio-demographic index (SDI) quintile, but the largest percentage increase during 2007-2017 was in the low-SDI quintile. Among regions, Central Europe showed the highest 2017 age-standardized incidence, DALY, and mortality rates, whereas South Asia and East Asia showed the largest percentage increases in both rates during 2007-2017. Among countries, India showed the largest percentage increase in age-standardized incidence and DALY rates, whereas Iran showed the largest percentage increase in age-standardized mortality rates. Globally, the largest percentage increase in risk-attributable DALYs was associated with metabolic risk factors (e.g., high fasting plasma glucose levels). CONCLUSION: The global age-standardized incidence, DALYs, and mortality rates of OC remain stable during 2007-2017. However, the low SDI quintile and the greatest burden in South and East Asia, India, and Iran suggested that more targeted strategies should be performed in those regions and countries.

The application of nasoseptal "rescue" flap technique in endoscopic transsphenoidal pituitary adenoma resection.

To explore the reliability and superiority of nasoseptal "rescue" flap technique in neuroendoscopic transnasal pituitary adenoma resection. Retrospective clinical analysis of 113 cases of endoscopic transsphenoid pituitary adenoma resection with the application of nasoseptal "rescue" flap technology. The reliability and the superiority of the technique were evaluated according to the duration of nasal cavity and sphenoid sinus stage, the incidence of postoperative anosmia, and cerebrospinal rhinorrhea. The duration of nasal and sphenoid sinus stage was 15-30 min, averaging 24 min. There were 27 cases of intro-operative cerebrospinal fluid leakage, including 24 cases of low-flow cerebrospinal fluid leak and 3 cases of high-flow cerebrospinal fluid leak. Twenty-three cases were converted from nasoseptal "rescue" flap to nasal septum flap. There were 17 cases of postoperative olfactory decline or disappearance, 1 case of epistaxis and 1 case of cerebrospinal rhinorrhea. The application of nasoseptal "rescue" flap technique can proceed sellar floor reconstruction when the diaphragma sellae rupture occurs during the operation. There is no obvious increase of the duration of sphenoid sinus and nasal stage and the rate of postoperative olfactory loss. This technique can be used as a conventional technique for endoscopic transsphenoid pituitary adenoma resection.

Using Self-Nanoemulsifying System to Improve Oral Bioavailability of a Pediatric Antiepileptic Agent Stiripentol: Formulation and Pharmacokinetics Studies.

This study aimed to develop a self-nanoemulsifying drug delivery system (SNEDDS) for poorly water-soluble drug stiripentol (STP) with enhanced oral bioavailability. Optimal excipients were selected by constructing pseudo-ternary phase diagrams using determined solubilities of STP, and then the proper composition of SNEDDS was investigated by employing a central composite design method. The optimized SNEDDS was composed of oil (ethyl oleate 39.61%), surfactant (Cremophor® RH 40 43.18%), co-surfactant (1,2-propanediol 17.21%), and STP of 50 mg/mL. The hydrodynamic size, zeta potential, and polydispersity index (PDI) were found to be 45.52 ± 1.99 nm, - 21.67 ± 0.24 mV, and 0.076 ± 0.011, respectively. The optimized STP-SNEDDS showed good stability in accelerated and dilution stability studies. It was also helpful to suppress STP degradation in acidic solution. Compared with STP suspension, STP-SNEDDS presented much faster dissolution rate. STP-SNEDDS successfully resulted in superior levels of Cmax and AUC0 → 6 h (4048.38 ± 704.54 µg/L and 7754.58 ± 1489.37 h µg/L, respectively) to STP suspension (1894.09 ± 1077.64 µg/L and 3556.93 ± 2470.01 h µg/L, respectively). The relative oral bioavailability of STP was 218.01%. The brain biodistribution studies showed that STP-SNEDDS presented significantly higher STP concentrations in the brain at 0.5 h and 1 h than that of STP suspension after administration. These findings indicated that a SNEDDS-based oral formulation of STP would be helpful for increasing its therapeutic potential.

A case study of the electrical properties of astrocytes by multimode AFM.

Astrocytes play an important role in the physiological functions of the central nervous system. In this study, contact potential differences (CPD) and capacitance gradients of the cell bodies and glial filaments of astrocytes were measured. Charge propagation properties in the astrocyte gap junctions were also studied using multimode Atomic Force Microscopy (AFM) at nanometre resolution. The CPD of the cell bodies and glial filaments were 324.2 ± 138.4 and 119.1 ± 31.7 mV, respectively. The measured capacitance gradients were 1.51 ± 0.31 and 1.98 ± 0.32 zF nm-1 , respectively. The gap junctions in the astrocytes showed no charge propagation and were not electrically sensitive. This furthers our understanding of astrocytes and other types of neuroglia. LAY DESCRIPTION: Neuroglia cells play important structural and functional roles in central nervous system (CNS). Neuroglia cells exceed the number of neurons by 10∼50 and can be divided into macroglia and microglia. Astrocytes are macroglia and are the largest and most abundant cells in the CNS. Astrocytes lack axons and dendrites and do not propagate action potentials. They have few cytoplasmic organelles, but possess abundant glial filaments, the main components of the cytoskeleton. Glial filaments are composed of the glial fibrillary acidic protein (GFAP). Astrocytes produce intercellular calcium waves in their gap junctions mediated through receptor activator (such as glutamate) to permit signal transduction._ENREF_5 In addition to their role in the support and nutrition of neurons, astrocytes are involved in various types of CNS activity including: (1) cytokine secretion for neuronal survival, growth and differentiation; (2) protection from brain injury; (3) modulation of the blood brain barrier; and (4) neuronal immunity. Bidirectional crosstalk between the astrocytes and neurons exists. Astrocytes can be activated by neurotransmitters released and can themselves release gliotransmitters to act upon neurons. Astrocytes are closely related to various disease states, including epilepsy and Alzheimer's disease. In this study, the electrical properties of astrocytes, including the contact potential difference (CPD) and capacitance gradients of the cell bodies and glial filaments, and charge propagation in the gap junctions were investigated at the nanometer level using quantitative Kelvin Probe Force Microscopy (KPFM) and Electrostatic Force Microscopy (EFM). The CPD of the cell bodies and glial filaments of the astrocytes were 324.2 mV and 119.1 mV, respectively. Capacitance gradients of the cell bodies and glial filaments of the astrocytes were 1.51 zF/nm and 1.98 zF/nm, respectively. Gap junctions in the astrocytes do not perform charge propagation functions and the astrocytes are not electrically sensitive. One should note that these results from KPFM and EFM were measured on dried cell and the situation might be different when studying in operando environment, still these findings aid our understanding of the electrical properties and functions of astrocytes, and further our knowledge of the electrical properties of the CNS.

A Standard Operation Procedure of Clean and Fast Craniotomy Technique for Retrosigmoid Approach.

Clean and fast craniotomy and closure (CAC) for retrosigmoid approach with safe and satisfactory exposure remains our primary goal. A standard operation procedure (SOP) of retrosigmoid approach was developed and reviewed. Between January 2015 and January 2017, 97 patients suffering various lesions underwent surgeries using this technique in the Department of Neurosurgery, Qilu Hospital of Shandong University. The records concerning time of craniotomies, blood losses, and complications were reviewed. By applying this SOP, a craniotomy generally took 15 to 35 minutes, with an average of around 25 minutes. Six cases had a blood loss of more than 30 mL during craniotomy. One patient had cerebrospinal fluid rhinorrhea and another case had subcutaneous effusion. There was no record of venous sinus injury or wound infection. To sum up, the SOP of retrosigmoid approach is simple, reliable and bloodless. In addition to avoiding complications such as venous sinus injury effectively, the SOP also benefits training of residents and early recovery after surgery (ERAS).

RRM2 promotes the progression of human glioblastoma.

Glioblastoma pathogenesis is related to multiple processes that affected by dozens of regulatory factors, but the potential underlying factors regulating glioblastoma progression remains unclear. The goal of this research was to determine how the ribonucleotide reductase M2 subunit (RRM2) influenced proliferation, invasion, migration, and apoptosis of human glioblastoma cells. The level of proliferation of human glioblastoma cells was measured through CCK8, colony formation assay and immunofluorescence stains. Flow cytometry (FCM), wound healing, and transwell assays were conducted to detect cell apoptosis, migration, and invasion. Apoptotic level of cells and invasion-related expression of protein were measured by Western blot. Xenograft tumor model was established to confirm effect of RRM2 on the proliferation of human glioblastoma cells in vivo. Silencing RRM2 inhibited proliferation, invasion, and migration of glioblastoma cells whereas enhanced apoptosis rate. Overexpressing RRM2 promoted proliferation, migration and invasion but suppressed apoptosis. In vivo, Overexpressing RRM2 accelerated the tumor growth in glioblastoma cells. The present study illustrated that RRM2 was overexpressed in human glioblastoma cells. RRM2 promoted proliferation, migration, and invasion but inhibited apoptosis of human glioblastoma cells.

Taxifolin prevents ß-amyloid-induced impairments of synaptic formation and deficits of memory via the inhibition of cytosolic phospholipase A2/prostaglandin E2 content.

Taxifolin is a potent flavonoid with anti-inflammatory activity. Taxifolin has been reported to decrease the accumulation of ß-amyloid (Aß), and reduce Aß-induced neurotoxicity. However, the detail molecular mechanism of taxifolin against Aß-induced neurotoxicity is largely unknown. In this study, we revealed the protective effects and the underlying mechanisms of taxifolin on the impairments of cognitive function and synapse formation induced by soluble Aß oligomers. Our results showed that taxifolin prevented neuronal cell death in a concentration-dependent manner. The recognition memory in novel object recognition tasks and the spatial memory in Morris water maze tests are significantly lower in the Alzheimer's disease (AD) model mice induced by hippocampal injection of Aß42. Taxifolin treatment prevented the recognitive and spatial memory deficits of the AD mice. 10 mg/kg taxifolin treatment also significantly prevented the decreased expression levels of PSD 95 induced by Aß42. Live cell imaging study showed that 2 h pre-treatment of taxifolin prevented the decrease in the number of filopodium and spine induced by Aß42 oligomers. Aß42 oligomers significantly increased the production of cytosolic phospholipase A2 (cPLA2), a crucial enzyme of pro-inflammatory mediator, and prostaglandin E2 (PGE2), a neuroinflammatory molecule. Taxifolin significantly reduced the content of cPLA2 and PGE2 induced by Aß42 both in the primary hippocampal neurons and hippocampal tissues. These results indicated that taxifolin might prevent Aß42 oligomer-induced synapse and cognitive impairments through decreasing cPLA2 and PGE2. Our study provided novel insights into the cellular mechanisms for the protective effects of taxifolin on AD.

A Standard Operating Procedure of Clean and Fast Craniotomy Without Application of Raney Clips.

Clean and fast craniotomy and closure (CAC) is a fundamental part of modern microneurosurgery, and is an essential technique that young neurosurgeons shall master. The hemostatic instruments of CAC have evolved from forceps to raney clips. Thanks to the wide application of bipolar coagulation, local infiltration anesthesia combined with cauterization is become an effective method of hemostasis. The authors worked out a standard operating procedure (SOP) of CAC assisted by fishhooks without the application of raney clips. According to the authors' experience, the average time spent on CAC decreased from more than 1 hour to <40 minutes. Owning to little bleeding, the operative field is clean throughout the procedure. Patients also experience less pain and enjoy an earlier discharge. With few complications, the authors believe that this cost-effective SOP may become a cornerstone of early recovery after surgery.