A Network Inversion Technique for Estimating Equivalent Dipole Description of Visual Evoked Potential

For the activation study of the brain, dipole localization from the scalp potential is one of the most promising techniques to realize a reasonable temporal resolution which cannot be realized in functional MR and PET. The goal of our study is to estimate inversely the electrical brain activity in the form of several dipoles from the scalp potential, using a network inversion technique. As a basic approach, we have inversely estimated several dipoles from the potential distribution on a spherical surface, in the homogeneous sphere model.

In the training phase, by expanding the neural network input dimensions being redundant, the network can easily learn the forward mapping. In the inversion phase, the space of the expanded-network-input-vector can be narrowed by introducing a penalty term. Additionally, a consensus term was used to force several dipoles to have a similar orientation. We estimate that this is applicable to the localization of several dipoles that reflect the actual brain activity, especially in the visual evoked potentials.

Combined rTMS and virtual reality brain-computer interface training for motor recovery after stroke

OBJECTIVE

Combining repetitive transcranial magnetic stimulation (rTMS) with brain-computer interface (BCI) training can address motor impairment after stroke by down-regulating exaggerated inhibition from the contralesional hemisphere and encouraging ipsilesional activation. The objective was to evaluate the efficacy of combined rTMS  +  BCI, compared to sham rTMS  +  BCI, on motor recovery after stroke in subjects with lasting motor paresis.

APPROACH

Three stroke subjects approximately one year post-stroke participated in three weeks of combined rTMS (real or sham) and BCI, followed by three weeks of BCI alone. Behavioral and electrophysiological differences were evaluated at baseline, after three weeks, and after six weeks of treatment.

MAIN RESULTS

Motor improvements were observed in both real rTMS  +  BCI and sham groups, but only the former showed significant alterations in inter-hemispheric inhibition in the desired direction and increased relative ipsilesional cortical activation from fMRI. In addition, significant improvements in BCI performance over time and adequate control of the virtual reality BCI paradigm were observed only in the former group.

SIGNIFICANCE

When combined, the results highlight the feasibility and efficacy of combined rTMS  +  BCI for motor recovery, demonstrated by increased ipsilesional motor activity and improvements in behavioral function for the real rTMS  +  BCI condition in particular. Our findings also demonstrate the utility of BCI training alone, as shown by behavioral improvements for the sham rTMS  +  BCI condition. This study is the first to evaluate combined rTMS and BCI training for motor rehabilitation and provides a foundation for continued work to evaluate the potential of both rTMS and virtual reality BCI training for motor recovery after stroke.

Cortical Dipole Imaging of Movement-related Potentials by Means of Parametric Inverse Filters Incorporating with Signal and Noise Covariance

Objective : The objective of this study is to explore suitable spatial filters for inverse estimation of cortical equivalent dipole layer imaging from the scalp electroencephalogram. We utilize cortical dipole source imaging to locate the possible generators of scalpmeasured movement-related potentials (MRPs) in human.

Methods : The effects of incorporating signal and noise covariance into inverse procedures were examined by computer simulations and experimental study. The parametric projection filter (PPF) and parametric Weiner filter (PWF) were applied to an inhomogeneous threesphere head model under various noise conditions.

Results : The present simulation results suggest that the PWF incorporating signal information provides better cortical dipole layer imaging results than the PPF and Tikhonov regularization under the condition of moderate and high correlation between signal and noise distributions. On the other hand, the PPF has better performance than other inverse filters under the condition of low correlation between signal and noise distributions. The proposed methods were applied to self-paced MRPs in order to identify the anatomic substrate locations of neural generators. The dipole layer distributions estimated by means of PPF are well-localized as compared with blurred scalp potential maps and dipole layer distribution estimated by Tikhonov regularization. The proposed methods demonstrated that the contralateral premotor cortex was preponderantly activated in relation to movement performance.

Conclusions : In cortical dipole source imaging, the PWF has better performance especiallywhen the correlation between the signal and noise is high. The proposed inverse method was applicable to human experiments of MRPs if the signal and noise covariances were obtained.

Environment-stimulated nanocarriers enabling multi-active sites for high drug encapsulation as an “on demand” drug release system

Limited active sites in polyesters hinder fabrication of multifunctional biodegradable nanocarriers for successful clinical applications.

[Early detection of the cardiotoxicity induced by chemotherapy drug through two-dimensional speckle tracking echocardiography combined with high-sensitive cardiac troponin T]

Objective: To investigate the clinical value of two-dimensional speckle tracking echocardiography(2D-STE) combined with high-sensitive cardiac troponin T (hs-cTnT) in early detection of the cardiotoxicity induced by chemotherapy drug. Methods: Seventy-five non-Hodgkin's lymphoma patients who received the CHOP regimen were recruited in this study. Conventional echocardiography and 2D-STE were performed on these patients before chemotherapy, the second day after the third course of chemotherapy (during chemotherapy) and the second day after the last course of chemotherapy (after chemotherapy). The parameters included left ventricular ejection fraction (LVEF), global longitudinal strain (LS), global circumferential strain (CS) and global radial strain (RS). The serum hs-cTNT levels were tested simultaneously. Results: Three cycles of CHOP were completed in 30 patients and 6-8 cycles of CHOP were completed in 45 patients. The LVEF of 75 patients before, during and after chemotherapy was (63.8±2.6)%, (63.8±2.8)% and (64.0±3.3)%, respectively, without significant difference (P=0.91). However, the LS of 75 patients before, during and after chemotherapy was (-18.5±1.7)%, (-16.5±1.9)% and (-16.0±1.6)%, respectively. The CS was (-20.9±2.9)%, (-19.3±3.5)% and (-19.2±3.2)%, respectively. The RS was (39.2±6.4)%, (35.3±5.2)% and (35.0±6.2)%, respectively. The hs-cTnT was (0.001 0±0.002 0)ng/ml, (0.006 3±0.008 9)ng/ml and (0.007 3±0.003 8)ng/ml, respectively. The LS, CS and RS were significantly decreased while hs-cTnT was significantly increased during chemotherapy when compared to those before chemotherapy (all of P<0.01). Alternatively, the LS, CS, RS and hs-cTnT after chemotherapy were marginally different from those during chemotherapy (all of P>0.05). Moreover, T(LS-SD), T(CS-SD) and T(RS-SD) showed no significant difference before, during and after chemotherapy (all of P>0.05). The reduction of LS was positively associated with the enhancement of hs-cTnT after chemotherapy (r=0.60, P<0.01). Conclusion: 2D-STE combined with hs-cTnT can effectively and precisely detect the occult cardiotoxicity induced by anthracycline.

[Reversed halo sign: chest CT findings in 5 patients and cause analysis]

Objective: To describe diseases that may present with the reversed halo sign (RHS) on high-resolution CT, and therefore to improve the recognition of this thoracic radiological feature. Methods: We retrospectively reviewed the HRCT scans and medical records of 5 patients who presented with RHS on chest CT from Peking University Third Hospital. With "reversed halo sign, fairy ring, atoll sign" as the Chinese and English keywords, 420 cases from the literatures were also reviewed through PubMed, Wanfang and CNKI databases until August 2015. Results: The 5 patients were all males, aging 19-55 years. The diagnosis of the diseases included cryptogenic organizing pneumonia (patient 1), pulmonary tuberculosis (patient 2), pulmonary infarction (patient 3), pulmonary edema (patient 4) and mycoplasma pneumonia (patient 5). Literature review showed that RHS was observed in 206 cases of infectious pulmonary diseases and 219 cases of noninfectious pulmonary diseases. Invasive fungal infection (including 59 cases of mucormycosis and 27 aspergillosis) and pulmonary tuberculosis (79 cases) predominated in infectious pulmonary diseases. However, in non-infectious pulmonary diseases, RHS was most frequently observed in organizing pneumonia (66%), sarcoidosis, lung cancer, pulmonary infarction, pulmonary edema and other interstitial lung diseases. There were some differences in the morphologic findings of RHS among invasive fungal infection, pulmonary tuberculosis and organizing pneumonia. In addition, our patient with mycoplasma pneumonia was the first case reported to present with RHS on HRCT. Conclusions: Although a wide spectrum of pulmonary diseases may present with RHS on chest CT, this sign is still a characteristic thoracic radiological feature, which is more commonly found in organizing pneumonia, pulmonary tuberculosis and invasive fungal infection, and is helpful in differential diagnosis.

Preparation and evaluation of cefquinome-loaded gelatin microspheres and the pharmacokinetics in pigs

Cefquinome (CEF) is widely used for veterinary clinical applications because of its broad spectrum and high efficiency. However, frequent administrations are required due to its short elimination half-life. In this study, cefquinome sulfate gelatin microspheres (CEF-GMS) were prepared as a sustained-release formulation using emulsion chemical cross-linking technique. Physical properties, stability, sustained-release property in vitro, and pharmacokinetics in pigs were assessed. The morphology of CEF-GMS showed a good sphericity with porous structure on the surface, and the mean diameter was 8.80 ± 0.78 μm, with 90.60 ± 3.98% of the total in the range of 5-20 μm. There were no significant changes of all estimated indexes in the stability tests. In vitro drug release study showed that the release of CEF from CEF-GMS was much slower than that from crude CEF in a release medium. Pharmacokinetic characteristics were evaluated following intramuscular administration of CEF-GMS or Cefquinome sulfate injection (CEF-Inj) in pigs at a dosage of 4 mg CEF/kg body weight. The plasma drug concentration-time data of CEF-GMS and CEF-Inj were both best fitted by two-compartment models with first-order absorption, and the elimination half-life of CEF-GMS was almost 10 times that of CEF-Inj. Overall, CEF-GMS might be used as a sustained-release formulation of CEF for veterinary clinical applications.

The anatomy of Wassel type IV-D thumb duplication

We describe Wassel type IV-D thumb duplication anatomy after surgery on 11 affected children (12 hands, seven boys (eight hands) and four girls). We studied the structure and course of the flexor pollicis longus tendon and its action at the joint. Four patients had secondary deformity associated with an absent A2 pulley and a tendon that clung to the radial side of a small thumb. In patients with primary deformity, the flexor tendon sheath became membranous in the A2 area and attached to neighbouring sites on the opposite side of the proximal phalanx. In the proximal A2 area, the tendon divided - one division attached on the ulnar side of the distal phalanx base; the other, the base of the radial side. There was slight ulnar angulation of the distal phalanx on the radial portion of the duplication and slight ulnar angulation on the radial portion.

LEVEL OF EVIDENCE

V.

Diagnostic value of combined diffusion-weighted imaging with dynamic contrast enhancement MRI in differentiating malignant from benign bone lesions

AIM

To determine the diagnostic value of combined diffusion-weighted imaging (DWI) with dynamic contrast enhancement magnetic resonance imaging (DCE-MRI) in differentiating malignant from benign bone lesions.

MATERIALS AND METHODS

DWI and DCE-MRI were performed in 36 patients (14 were benign and 22 were malignant). The mean apparent diffusion coefficient (ADC) values and signal enhanced extent (SEE), slope value, and time-signal intensity curve (TIC) type were recorded by two observers. Between-group comparison was made using the independent sample t-test and receiver-operating characteristic (ROC) analysis.

RESULTS

There was a significant difference between the mean ADC value of the benign ([1.75±0.50]×10^-3 mm²/s) and malignant ([1.11±0.47]×10^-3 mm²/s) groups (p=0.001). The threshold ADC value of ≤1.10×10^-3 mm²/s resulted in a sensitivity of 77.3%, a specificity of 92.9%, and an accuracy of 85.1%. A type III curve was found in 23 cases (21 malignant and two benign), a type II curve was seen in six cases (one malignant and five benign), and a type I curve in seven cases (all were benign). The SEE and slope values in the benign and malignant groups were 227.96±172.08, 325.60±125.86 (p=0.058); 0.97±0.67%/s, 3.19±3.20%/s (p=0.016), respectively. ROC analysis showed a sensitivity of 95.5%, a specificity of 85.7%, and an accuracy of 90.6% for malignancy, based on a slope cut-off value of >1.46%/s. Combining ADC and slope values resulted in a sensitivity of 100%, a specificity of 85.7%, and an accuracy of 92.9%.

CONCLUSIONS

Both DWI and DCE-MRI showed promising results for differentiating malignant from benign bone lesions. A combination of DWI and DCE-MRI was the most valuable of the three.

Cobalt-zinc nitride on nitrogen doped carbon black nanohybrids as a non-noble metal electrocatalyst for oxygen reduction reaction

Bimetallic nitrides are now being considered as one of the emerging advanced functional materials due to their characteristic features and remarkable physicochemical properties. Herein, we report a new crystalline bimetallic nitride (Co₃ZnN) that belongs to the cubic crystal phase, which was successfully synthesized through direct nitridation of metallic salts as precursors. Co₃ZnN nanoparticles were then supported on nitrogen-doped XC-72 carbon black (N-CB), and this typical Co₃ZnN/N-CB nanohybrid discovered can serve as an efficient non-noble metal electrocatalyst with a 4e^- reaction pathway for ORR, and demonstrated excellent electrocatalytic performance with high activity and stability.

[Population pharmacokinetics of vancomycin from severe in patients with lower respiratory tract infection]

Objective: To develop a population pharmacokinetic (PPK) model of vancomycin in Chinese inpatients with severe lower respiratory tract infection. Methods: We gathered serum concentrations of vancomycin from inpatients who received vancomycin during Nov 2011 to Nov 2012.Vancomycin serum concentrations was measured by high performance liquid chromatography. Vancomycin PPK analysis was performed using nonlinear mixed effects model (NONMEM) program. Results: We gathered the data of 70 inpatients with lower respiratory tract infection at respiratory ward or respiratory intensive care unit(RICU) between Nov 2011 to Nov 2012 [58 males, 12 females; 78(23-91) years old; the mean of APACHⅡ score was 16.4±4.8]. A total of 267 concentrations of vancomycin were gathered from 70 patients. A 2-compartment model fit the concentration data best. The final vancomycin PPK model was: CL(i)=1.67×e(η1), V(1i)=33.04×[1-0.199×(60/Scr)] ×e(η2), Q(i)=7.08×2.053(AI)×e(η3), V(2i)=19.29×e(η4).(CL: vancomycin clearance; V(1): distribution volume of the central compartment; Q: intercompartment clearance; V(2): distribution volume of the intercompartment). The population mean values were 1.67 L/h, 33.04 L; 7.08 L/h and 19.29 L respectively. Serum creatinine was the covariate to affect vancomycin apparent distribution volume of the central compartment. Intercompartment clearance was 2.053 times larger in patients with albumin infusion than that in patients without. Conclusions: We found that a 2-compartment model fit the concentration data best in Chinese patients with severe lower respiratory tract infection. Serum creatinine and albumin infusion were the most significant covariates to affect vancomycin PK.

High-frequency repetitive transcranial magnetic stimulation over the left DLPFC for major depression: Session-dependent efficacy: A meta-analysis

Background

Depression is a major debilitating psychiatric disorder. Current antidepressant drugs are often associated with side effects or treatment resistance. The aim of this meta-analysis was to evaluate therapeutic effects of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) in major depression (MD).

Methods

The medical data bases of PubMed, Medline, Embase and Cochrane Central Register were searched for randomized controlled trials (RCTs) reporting the therapeutic effects of high-frequency rTMS for depression, which were published in English between January 1990 and June 2016. The index terms were “depress*”, “depression” and “transcranial magnetic stimulation”. Depression outcome data of different sessions (5, 10, 15, and 20 sessions of rTMS treatment) were extracted and synthesized by calculating standardized mean difference (SMD) with 95% confidence intervals (CI) by using a random-effect model. Within each session group, the subgroup analyses based on the number of pulses (≤ 1000, 1200–1500, 1600–1800, and 2000–3000) were also conducted.

Results

Thirty RCTs with a total of 1754 subjects including 1136 in the rTMS group and 618 in the sham group were included in this meta-analysis. rTMS had a significant overall therapeutic effect on depression severity scores (SMD = −0.73, P < 0.00001). The five, 10, 15, 20 sessions of rTMS treatments yielded the significant mean effect sizes of −0.43, −0.60, −1.13, and −2.74, respectively. In the four groups (5, 10, 15, 20 sessions), the maximal mean effect size was all obtained in the subgroup of 1200–1500 pulses per day (−0.97, −1.14, −1.91, −5.47; P < 0.05).

Conclusions

The increasing of HF-rTMS sessions is associated with the increased efficacy of HF-rTMS in reducing depressed patients’ symptom severity. A total number of pulses of 1200–1500 per day appear to deliver the best antidepressant effects of HF-rTMS.

Treatment with hydrogen sulfide attenuates sublesional skeletal deterioration following motor complete spinal cord injury in rats

Treatment with hydrogen sulfide mitigates spinal cord injury-induced sublesional bone loss, possibly through abating oxidative stress, suppressing MMP activity, and activating Wnt/β-catenin signaling.

INTRODUCTION

Spinal cord injury (SCI)-induced sublesional bone loss represents the most severe osteoporosis and is resistant to available treatments to data. The present study was undertaken to explore the therapeutic potential of hydrogen sulfide (H₂S) against osteoporosis in a rodent model of motor complete SCI.

METHODS

SCI was generated by surgical transaction of the cord at the T3-T4 levels in rats. Treatment with NaHS was initiated through intraperitoneal injection of 0.1 ml/kg/day of 0.28 mol/l NaHS from 12 h following the surgery and over 14 subsequent days.

RESULTS

H₂S levels in plasma of SCI rats were lower, which was restored by treatment with exogenous H₂S. Treatment of SCI rats with exogenous H₂S had no significant effect on body mass but increased bone mineral density in femurs and tibiae, increased BV/TV, Tb.Th, and Tb.N and reduced Tb.Sp in proximal tibiae, and increased mineral apposition rate (MAR), bone formation rate (BFR), and osteoblast surface and reduced eroded surface and osteoclast surface in proximal tibiae. More importantly, H₂S treatment led to a significant enhancement in ultimate load, stiffness, and energy to max force of femoral diaphysis. Treatment of SCI rats with exogenous H₂S reduced malondialdehyde (MDA) levels in serum and femurs, decreased hydroxyproline levels, suppressed activities of matrix metallopeptidase 9 (MMP9), and upregulated Wnt3a, Wnt6, Wnt10, and ctnnb1 expression in femurs.

CONCLUSION

Treatment with H₂S mitigates SCI-induced sublesional bone loss, possibly through abating oxidative stress, suppressing MMP activity, and activating Wnt/β-catenin signaling.

[Airway oxidative stress and inflammation markers in chronic obstructive pulmonary diseases(COPD) patients are linked with exposure to traffic-related air pollution: a panel study]

OBJECTIVE

To investigate the effects of short-term exposure to traffic-related air pollution on airway oxidative stress and inflammation in chronic obstructive pulmonary diseases (COPD) patients.

METHODS

A panel of forty-five diagnosed COPD patients were recruited and followed with repeated measurements of biomarkers reflecting airway oxidative stress and inflammation in exhaled breath condensate (EBC), including nitrate and nitrite, 8-isoprostane, interleukin-8 and acidity of EBC (pH), between 5(th) September in 2014 and 26(th) May in 2015. The associations between air pollution and biomarkers were analyzed with mixed-effects models, controlling for confounding covariates.

RESULTS

The concentration of PM2.5, black carbon, NO2 and number concentration of particles with diameter less than 100 nm (PNC100), and particles in size ranges between 100 nm to 200 nm (PNC100-200) during the first follow-up were (156.5±117.7), (10.7±0.7), (165.9±66.0)μg/m(3) and 397 521±96 712, 79 421±44 090 per cubic meter, respectively; the concentration were (67.9±29.6), (3.4±1.3), (126.1±10.9) μg/m(3) and (295 682±39 430), (24 693±12 369) per cubic meter, respectively during the second follow-up. The differences were of significance, with t value being 3.10, 4.42, 2.61, 4.02, 5.12, respectively and P value being 0.005,<0.001, 0.016, <0.001 and <0.001, respectively. In our COPD-patient panel, per interquartile range (IQR) increase in PNC100-200, we observed an increase of 65% (95% CI: 8%-152%) in nitrate and nitrite in EBC reflecting airway oxidative stress. For an IQR increase in PM2.5, black carbon and PNC100-200, respective increases of 0.17 ng/ml (95% CI: 0.02-0.33), 0.12 ng/ml (95% CI: 0.01-0.24) and 0.13 ng/ml (95% CI:0.02-0.24) in interleukin-8 in EBC reflecting airway inflammation were also observed. An IQR increase in ozone was also associated with a 0.24 (95%CI: 0.05-0.42) decrease in pH of EBC reflecting increased airway inflammation. No significant association observed between air pollution and 8-isoprostane in EBC in COPD patients.

CONCLUSION

Our results suggested that short-term exposure to traffic-related air pollution was responsible for exacerbation of airway oxidative stress and inflammation in COPD patients.

Radioiodinated Capsids Facilitate In Vivo Non-Invasive Tracking of Adeno-Associated Gene Transfer Vectors

Viral vector mediated gene therapy has become commonplace in clinical trials for a wide range of inherited disorders. Successful gene transfer depends on a number of factors, of which tissue tropism is among the most important. To date, definitive mapping of the spatial and temporal distribution of viral vectors in vivo has generally required postmortem examination of tissue. Here we present two methods for radiolabeling adeno-associated virus (AAV), one of the most commonly used viral vectors for gene therapy trials, and demonstrate their potential usefulness in the development of surrogate markers for vector delivery during the first week after administration. Specifically, we labeled adeno-associated virus serotype 10 expressing the coding sequences for the CLN2 gene implicated in late infantile neuronal ceroid lipofuscinosis with iodine-124. Using direct (Iodogen) and indirect (modified Bolton-Hunter) methods, we observed the vector in the murine brain for up to one week using positron emission tomography. Capsid radioiodination of viral vectors enables non-invasive, whole body, in vivo evaluation of spatial and temporal vector distribution that should inform methods for efficacious gene therapy over a broad range of applications.

Dynamic intracellular tracking nanoparticles via pH-evoked “off–on” fluorescence

Strong fluorescence induced by spiropyran isomerized into merocyanine in low pH was utilized as a probe for efficient dynamic intracellular tracking.

Causes of secondary deformity after surgery to correct Wassel type IV-D thumb duplication

This study was undertaken to document the causes of secondary deformities after surgery for correction of Wassel type IV-D thumb duplication. We carefully dissected and observed the flexor pollicis longus, and bone and joint anatomy in eight patients with secondary deformities after surgical correction. We transferred the flexor pollicis longus and thenar muscle attachments, reconstructed the A2 pulley, released and tightened the joint capsule, and performed osteotomies to correct skeletal malalignment. Kirschner wire fixation was used for 4-5 weeks, followed by brace fixation for 3 months. Patients were followed up for 13-34 months (mean 20 months). According to the Tada scores, the outcomes were good in six patients, and fair and poor in one patient each. The main causes of the secondary deformities were failure to reconstruct the A2 pulley, to transfer the flexor pollicis longus and thenar muscles, and incomplete resection of the radial metacarpal head. Brace fixation after Kirschner wire removal is crucial in preventing secondary deformities.

LEVEL OF EVIDENCE

IV.