SAT0564 BONE TEXTURE ANALYSIS WITH DEEP LEARNING IN HAND RADIOGRAPHS FOR ASSESSING THE RISK OF RHEUMATOID ARTHRITIS

Background:

Conventional x-rays are essential to identify radiographic changes of rheumatoid arthritis (RA) in structure and bone texture. Limited evidence suggests that the bone texture analysis may quantify the radiographic changes in RA;1however, current techniques such as the fractal dimension characterize fixed texture features. Deep learning offers novel methods to ‘learn’ radiographic texture features relevant to RA.

Objectives:

To develop a deep learning model to assess the radiographic bone texture in the distal metacarpal bone relevant to RA.

Methods:

We collected 3,738 conventional hand radiographs from 2,128 individuals (RA, n = 908; non-RA, n = 1220). The second, third, and fourth metacarpal bone images were segmented using a curve Graph Convolutional Network (GCN), and the distal third was used as the input to train a texture model to classify RA. The texture model was based on the Deep Texture Encoding Network (Deep-TEN) architecture (figure 1),2which put an encoding layer on top of a pre-trained 18-layered residual network (ResNet18). The vectors produced by the model represent the orderless texture features that were used to generate a texture score for RA. Five texture models are trained using 5-fold cross-validation and are ensembled during inference by averaging the model outputs to produce the final score. We then validate the model using hand radiographs of 166 RA patients and 166 non-RA patients. Overall model performance was measured by area under the curve of the receiver operator curve (AUROC). Multivariate logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of RA.

Figure 1.

Schematic representation of deep learning models to extract and encode texture features for RA classification.

Results:

We included 140 women and 26 men with RA (mean age, 55.9±1.8 years) and 166 non-RA individuals (F: M, 140:26; mean age, 55.5 ± 1.8 years). The mean texture score was 0.49 (95% CI, 0.48–0.50) in RA patients, which is significantly higher than non-RA patients (0.42, 95% CI, 0.40–0.43; p<0.01). The AUROC of the model was 0.68. In the multivariate logistic regression model, a high texture score (>0.43) is associated with an OR (95% CI) of 3.42 (2.48–4.72) for RA, adjusted by age and sex.

Conclusion:

This study indicates that the texture model can delineate radiographic changes in texture relevant to RA and, coupled with automatic joint detection and segmentation, it has the potential to aid early RA diagnosis and monitor radiographic progression.

References:

[1]Zandieh S, Haller J, Bernt R, et al. Fractal analysis of subchondral bone changes of the hand in rheumatoid arthritis. Medicine (Baltimore) 2017;96(11):e6344.

[2]Zhang H, Xue J, Dana K. Deep TEN: Texture Encoding Network. The IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 2017:708-17.

Disclosure of Interests:

None declared

OP0301 PREDICTION OF LOW BONE MINERAL DENSITY AND FRAX SCORE BY ASSESSING HIP BONE TEXTURE WITH DEEP LEARNING

Background:

Osteoporosis is a widespread health concern associated with an increased risk of fractures in individuals with low bone mineral density (BMD). Dual-energy x-ray absorptiometry (DXA) is the gold standard to measure BMD, but methods based on the assessment of plain films, such as the digital radiogrammetry,1are also available. We describe a novel approach based on the assessment of hip texture with deep learning to estimate BMD.

Objectives:

To compare the BMD estimated by assessing hip texture using a deep learning model and that measured by DXA.

Methods:

In this study, we identified 1,203 patients who underwent DXA of left hip and hip plain film within six months. The dataset was split into a training set with 1,024 patients and a testing set with 179 patients. Hip images were obtained and regions of interest (ROI) around left hips were segmented using a tool based on the curve Graph Convolutional Network. The ROIs are processed using a Deep Texture Encoding Network (Deep-TEN) model,2which comprises the first 3 blocks of Residual Network with 18 layers (ResNet-18) model followed by a dictionary encoding operator (Figure 1). The encoded features are processed using a fully connected layer to estimate BMD. Five-fold cross-validation was conducted. Pearson’s correlation coefficient was used to assess the correlation between predicted and reference BMD. We also test the performance of the model to identify osteoporosis (T-score ≤ -2.5)

Figure 1.

Schematic representation of deep learning models to extract and encode texture features for estimation of hip bone density.

Results:

We included 151 women and 18 men in the testing dataset (mean age, 66.1 ± 1.7 years). The mean predicted BMD was 0.724 g/cm2compared with the mean BMD measured by DXA of 0.725 g/cm2(p = 0.51). Pearson’s correlation coefficient between predicted and true BMD was 0.88. The performance of the model to detect osteoporosis/osteopenia was shown in Table 1. The positive predictive value was 87.46% for a T-score ≤ -1 and 83.3% for a T-score ≤ -2.5. Furthermore, the mean FRAX® 10-year major fracture risk did not differ significantly between scores based on predicted (6.86%) and measured BMD (7.67%, p=0.52). The 10-year probability of hip fracture was lower in the predicted score (1.79%) than the measured score (2.43%, p = 0.01).

Table 1.

Performance matrices of the deep texture model to detect osteoporosis/osteopenia

T-score ≤ -1T-score ≤ -2.5Sensitivity91.11%(95% CI, 83.23% to 96.08%)33.33%(95% CI, 17.29% to 52.81%)Specificity86.08%(95% CI, 76.45% to 92.84%)98.56%(95% CI, 94.90% to 99.83%)Positive predictive value88.17%(95% CI, 81.10% to 92.83%)83.33%(95% CI, 53.58% to 95.59%)Negative predictive value89.47%(95% CI, 81.35% to 94.31%)87.26%(95% CI, 84.16% to 89.83%)

Conclusion:

This study demonstrates the potential of the bone texture model to detect osteoporosis and to predict the FRAX score using plain hip radiographs.

References:

[1]Zandieh S, Haller J, Bernt R, et al. Fractal analysis of subchondral bone changes of the hand in rheumatoid arthritis. Medicine (Baltimore) 2017;96(11):e6344.

[2]Zhang H, Xue J, Dana K. Deep TEN: Texture Encoding Network. The IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 2017:708-17.

Disclosure of Interests:

None declared

OP0062 PREDICTIVE VALUE OF BONE TEXTURE FEATURES EXTRACTED BY DEEP LEARNING MODELS FOR THE DETECTION OF OSTEOARTHRITIS: DATA FROM THE OSTEOARTHRITIS INITIATIVE

Background:

Osteoarthritis is a degenerative disorder characterized by radiographic features of asymmetric loss of joint space, subchondral sclerosis, and osteophyte formation. Conventional plain films are essential to detect structural changes in osteoarthritis. Recent evidence suggests that fractal- and entropy-based bone texture parameters may improve the prediction of radiographic osteoarthritis.1In contrast to the fixed texture features, deep learning models allow the comprehensive texture feature extraction and recognition relevant to osteoarthritis.

Objectives:

To assess the predictive value of deep learning-extracted bone texture features in the detection of radiographic osteoarthritis.

Methods:

We used data from the Osteoarthritis Initiative, which is a longitudinal study with 4,796 patients followed up and assessed for osteoarthritis. We used a training set of 25,978 images from 3,086 patients to develop the textual model. We use the BoneFinder software2to do the segmentation of distal femur and proximal tibia. We used the Deep Texture Encoding Network (Deep-TEN)3to encode the bone texture features into a vector, which is fed to a 5-way linear classifier for Kellgren and Lawrence grading for osteoarthritis classification. We also developed a Residual Network with 18 layers (ResNet18) for comparison since it deals with contours as well. Spearman’s correlation coefficient was used to assess the correlation between predicted and reference KL grades. We also test the performance of the model to identify osteoarthritis (KL grade≥2).

Results:

We obtained 6,490 knee radiographs from 446 female and 326 male patients who were not in the training sets to validate the performance of the models. The distribution of the KL grades in the training and testing sets were shown in Table 1. The Spearman’s correlation coefficient was 0.60 for the Deep-TEN and 0.67 for the ResNet18 model. Table 2 shows the performance of the models to detect osteoarthritis. The positive predictive value for Deep-TEN and ResNet18 model classification for OA was 81.37% and 87.46%, respectively.

Table 1

Distribution of KL grades in the training and testing sets.

KL grades01234TotalTraining set1089341.9%458218.7%611423.5%332012.8%7993.1%25,978Testing set247238.1%135320.8%169626.1%77511.9%1943.0%6,490Table 2

Performance matrices of the Deep-Ten and ResNet18 models to detect osteoarthritis

Deep-TENResNet18Sensitivity62.29%(95% CI, 60.42%–64.13%)59.14%(95% CI, 57.24%–61.01%)Specificity90.07%(95% CI, 89.07%–91.00%)94.09%(95% CI, 93.30%–94.82%)Positive predictive value81.37%(95% CI, 79.81%–82.84%)87.46%(95% CI, 85.96%–88.82%)Negative predictive value77.42%(95% CI, 77.64%–79.65%)76.77%(95% CI, 75.93%–77.59%)

Conclusion:

This study demonstrates that the bone texture model performs reasonably well to detect radiographic osteoarthritis with a similar performance to the bone contour model.

References:

[1]Bertalan Z, Ljuhar R, Norman B, et al. Combining fractal- and entropy-based bone texture analysis for the prediction of osteoarthritis: data from the multicenter osteoarthritis study (MOST). Osteoarthritis Cartilage 2018;26:S49.

[2]Lindner C, Wang CW, Huang CT, et al. Fully Automatic System for Accurate Localisation and Analysis of Cephalometric Landmarks in Lateral Cephalograms. Sci Rep 2016;6:33581.

[3]Zhang H, Xue J, Dana K. Deep TEN: Texture Encoding Network. The IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 2017:708-17.

Disclosure of Interests:

None declared

Optical monitoring of glutamate release at multiple synapses in situ detects changes following LTP induction

Information processing and memory formation in the brain relies on release of the main excitatory neurotransmitter glutamate from presynaptic axonal specialisations. The classical Hebbian paradigm of synaptic memory, long-term potentiation (LTP) of transmission, has been widely associated with an increase in the postsynaptic receptor current. Whether and to what degree LTP induction also enhances presynaptic glutamate release has been the subject of debate. Here, we took advantage of the recently developed genetically encoded optical sensors of glutamate (iGluSnFR) to monitor its release at CA3-CA1 synapses in acute hippocampal slices, before and after the induction of LTP. We attempted to trace release events at multiple synapses simultaneously, by using two-photon excitation imaging in fast frame-scanning mode. We thus detected a significant increase in the average iGluSnFR signal during potentiation, which lasted for up to 90 min. This increase may reflect an increased amount of released glutamate or, alternatively, reduced glutamate binding to high-affinity glutamate transporters that compete with iGluSnFR.

Local Resting Ca2+ Controls the Scale of Astroglial Ca2+ Signals

Astroglia regulate neurovascular coupling while engaging in signal exchange with neurons. The underlying cellular machinery is thought to rely on astrocytic Ca2+ signals, but what controls their amplitude and waveform is poorly understood. Here, we employ time-resolved two-photon excitation fluorescence imaging in acute hippocampal slices and in cortex in vivo to find that resting [Ca2+] predicts the scale (amplitude) and the maximum (peak) of astroglial Ca2+ elevations. We bidirectionally manipulate resting [Ca2+] by uncaging intracellular Ca2+ or Ca2+ buffers and use ratiometric imaging of a genetically encoded Ca2+ indicator to establish that alterations in resting [Ca2+] change co-directionally the peak level and anti-directionally the amplitude of local Ca2+ transients. This relationship holds for spontaneous and for induced (for instance by locomotion) Ca2+ signals. Our findings uncover a basic generic rule of Ca2+ signal formation in astrocytes, thus also associating the resting Ca2+ level with the physiological "excitability" state of astroglia.

[The 476th case: skin rash, edema, thrombocytopenia and anemia]

The 21-year-old male patient was admitted to the Department of Rheumatology and Immunology at Peking Union Medical College Hospital with chief complaints of "skin rash for 1 year and edema for 2 months". He was diagnosed with systemic lupus erythematosus (SLE) with renal, cardiac and hematological involvement. Remission was not achieved after glucocorticoid pulse treatment. The patient experienced oliguria, malignant hypertension, accompanied by thrombocytopenia and low serum complements, and elevated lactate dehydrogenase and serum creatinine. Schistocytes were seen in the peripheral blood smear. Thrombotic microangiopathy (TMA) secondary to SLE was diagnosed. Though plasma exchange was partially effective, TMA could not be controlled yet. The activity of serum von Willebrand factor -cleaving protease (ADAMTS 13) was 100%, and ADAMTS 13 inhibitor was negative. Finally, remission of the disease was achieved after second glucocorticoid pulse therapy and rituximab treatment. At the 3-month follow-up, the patient's condition was stable with mild anemia and normal platelet count. Patients with TMA secondary to SLE are heterogenous, while normal ADAMT 13 activity indicates poor prognosis. Early and aggressive treatment is important for disease control, and plasma exchange is helpful as a supportive care.

Imaging tripartite synapses using super-resolution microscopy

Astroglia are vital facilitators of brain development, homeostasis, and metabolic support. In addition, they are also essential to the formation and regulation of synaptic circuits. Due to the extraordinary complex, nanoscopic morphology of astrocytes, the underlying cellular mechanisms have been poorly understood. In particular, fine astrocytic processes that can be found in the vicinity of synapses have been difficult to study using traditional imaging techniques. Here, we describe a 3D three-colour super-resolution microscopy approach to unravel the nanostructure of tripartite synapses. The method is based on the SMLM technique direct stochastic optical reconstruction microscopy (dSTORM) which uses conventional fluorophore-labelled antibodies. This approach enables reconstructing the nanoscale localisation of individual astrocytic glutamate transporter (GLT-1) molecules surrounding presynaptic (bassoon) and postsynaptic (Homer1) protein localisations in fixed mouse brain sections. However, the technique is readily adaptable to other types of targets and tissues.

[Construction of 3β-HSD gene silencing cell line and its effects on apoptosis induced by DEHP]

Objective: To construct 3β-HSD gene shRNA lentivirus interference vecto, then transfect into human MCF-7 cells, and construct cell line with 3β-HSD gene silencing, finally to study the effects of 3β-HSD on apoptosis induced by di- (2-ethylhexyl) phthalate (DEHP) . Methods: According to the mRNA sequence of 3β-HSD gene provided by GenBank, three interference sequences were designed and connected to PLVX-shRNA2-puro after annealing. The recombinant lentivirus vector was transfected into 293FT cells, the virus supernatants were collected and infected with MCF-7 cells. After puromycin screening, MCF-7 cells with 3β-HSD gene silencing were constructed. The cells with 3β-HSD gene silencing were identified by real-time quantitative PCR and western blot. Then the 3β-HSD gene silencing cells and MCF-7 cells were treated at various doses of DEHP for 24 hours to detect the gene expression and protein expression of apoptosis genes including Bax, Caspase-3 and Caspase-8. Results: The interference sequence of 3β-HSD gene inserted into lentivirus vector PLVX-shRNA2-puro is consistent with the designed sequence. 3β-HSD gene expression level in MCF-7 cells with 3β-HSD gene silencing was 77% lower than than that of control MCF-7 cells. 3β-HSD protein level in MCF-7 cells with 3β-HSD gene silencing was 74% lower than that of control MCF-7 cells. After DEHP treatment in MCF-7 cells with 3β-HSD gene silencing and control MCF-7 cells, qRT-PCR results showed that Bax gene expression levels increased by 28%-54%, Caspase-3 gene increased by 13%-49%, Caspase-8 gene increased by 21%-70% in MCF-7 cells when compared with the control group. Additionally, in the 3β-HSD gene silencing cells, Bax gene expression level decreased by 11%-28%, Caspase-3 gene expression decreased by 12%-23%, Caspase-8 gene expression decreased by 11%-34%, compared with the same treatment group of MCF-7 cells. Western blot results showed that Bax protein expression level increased by 28%-61%, Caspase-3 protein expression level increased by 40%-48%, Caspase-8 protein increased by 31%-84% in MCF-7 cells when compared with the control group. In 3β-HSD gene silencing cells, Bax protein expression level increased by 11%-27%, Caspase-3 protein increased by 21%-40%, Caspase-8 protein increased by 12%-25%, compared with the same treatment group of MCF-7 cells. Conclusion: The stable 3β-HSD gene silencing cell line are successfully constructed in this study. DEHP can induce increased expression of apoptotic gene and protein. Silencing of 3β-HSD gene can inhibit the activation of apoptotic gene by DEHP in a certain degree.

Multiplex imaging relates quantal glutamate release to presynaptic Ca2+ homeostasis at multiple synapses in situ

Information processing by brain circuits depends on Ca2+-dependent, stochastic release of the excitatory neurotransmitter glutamate. Whilst optical glutamate sensors have enabled detection of synaptic discharges, understanding presynaptic machinery requires simultaneous readout of glutamate release and nanomolar presynaptic Ca2+ in situ. Here, we find that the fluorescence lifetime of the red-shifted Ca2+ indicator Cal-590 is Ca2+-sensitive in the nanomolar range, and employ it in combination with green glutamate sensors to relate quantal neurotransmission to presynaptic Ca2+ kinetics. Multiplexed imaging of individual and multiple synapses in identified axonal circuits reveals that glutamate release efficacy, but not its short-term plasticity, varies with time-dependent fluctuations in presynaptic resting Ca2+ or spike-evoked Ca2+ entry. Within individual presynaptic boutons, we find no nanoscopic co-localisation of evoked presynaptic Ca2+ entry with the prevalent glutamate release site, suggesting loose coupling between the two. The approach enables a better understanding of release machinery at central synapses.

Multiplexed calcium imaging of single-synapse activity and astroglial responses in the intact brain

All-optical registration of neuronal and astrocytic activities within the intact mammalian brain has improved significantly with recent advances in optical sensors and biophotonics. However, relating single-synapse release events and local astroglial responses to sensory stimuli in an intact animal has not hitherto been feasible. Here, we present a multiplexed multiphoton excitation imaging approach for assessing the relationship between presynaptic Ca2+ entry at thalamocortical axonal boutons and perisynaptic astrocytic Ca2+ elevations, induced by whisker stimulation in the barrel cortex of C57BL/6 mice. We find that, unexpectedly, Ca2+ elevations in the perisynaptic astrocytic regions consistently precede local presynaptic Ca2+ signals during spontaneous brain activity associated with anaesthesia. The methods described here can be adapted to a variety of optical sensors and are compatible with experimental designs that might necessitate repeated sampling of single synapses over a longitudinal behavioural paradigm.

Increased risk of group B Streptococcus causing meningitis in infants with mannose-binding lectin deficiency

OBJECTIVES

To evaluate the association of mannose-binding lectin (MBL) deficiency with susceptibility and clinical features of group B Streptococcus (GBS) causing meningitis in Chinese infants.

METHODS

During 2014-2017, 33 infants with laboratory-confirmed GBS meningitis were included. Six polymorphisms (H/L, Y/X, P/Q, A/D, A/B and A/C) of MBL were sought for in these patients and in 330 healthy controls by PCR-based sequencing. Serum MBL concentration was determined.

RESULTS

Significantly higher frequency of MBL variant genotype A/B was found in patients than controls (15/33, 45%, vs. 79/330, 24%, p=0.011). Patients with variant genotype A/B had significantly lower serum MBL than those with wild-type genotype A/A (median, 482.87 vs. 1455.13 ng/mL, p=0.002). Moreover, patients with genotype A/B had significantly higher level of C-reactive protein (median, 146 vs. 41 mg/L, p=0.007), neutrophil (median, 58.1% vs. 45.7%, p=0.033) and neutrophil-to-lymphocyte ratio in blood (median, 2.32 vs. 1.03, p=0.018) compared to those with genotype A/A. No significant differences were observed in clinical features of patients with different genotypes.

CONCLUSIONS

Our result suggested that infants with MBL deficiency are at higher risk of meningitis caused by GBS. Further studies in different populations with larger number of subjects are needed.

Diffusional kurtosis imaging in assessing renal function and pathology of IgA nephropathy: a preliminary clinical study

AIM

To evaluate renal fibrosis in immunoglobulin A nephropathy (IgAN) using diffusion kurtosis imaging (DKI).

MATERIALS AND METHODS

Twenty patients with biopsy-proven IgAN were enrolled. DKI was performed on a clinical 3 T magnetic resonance imaging (MRI) system, and region-of-interest measurements were conducted to determine mean kurtosis (K), mean diffusivity (D), and apparent diffusion coefficient (ADC) of the kidney cortex. Renal biopsy specimens were scored based on the severity of renal fibrosis. The associations between the DKI data and clinicopathological parameters were investigated.

RESULTS

Both the K and ADC were not only well correlated with the estimated glomerular filtration rate, but also significantly associated with the pathological scores of fibrosis, including the glomerular sclerosis index (K: r=0.759, p<0.001; ADC: r=-0.636, p=0.003) and the percentage of tubular atrophy and interstitial fibrosis (K: r=0.767, p<0.001; ADC: r=-0.702, p=0.001). Further receiver operating characteristic analysis showed that K demonstrated better diagnostic performance in discriminating severe glomerulosclerosis (area under curve [AUC] 0.970, sensitivity 81.8%, specificity 100%), and ADC displayed better capabilities in identifying severe tubular atrophy/interstitial fibrosis (AUC 0.976, sensitivity 100%, specificity 92.9%).

CONCLUSION

This DKI method can be used to detect renal fibrosis in IgAN in a non-invasive manner and may provide additional information for characterisation and surveillance.

Monitoring intracellular nanomolar calcium using fluorescence lifetime imaging

Nanomolar-range fluctuations of intracellular [Ca2+] are critical for brain cell function but remain difficult to measure. We have advanced a microscopy technique to monitor intracellular [Ca2+] in individual cells in acute brain slices (also applicable in vivo) using fluorescence lifetime imaging (FLIM) of the Ca2+-sensitive fluorescent indicator Oregon Green BAPTA1 (OGB-1). The OGB-1 fluorescence lifetime is sensitive to [Ca2+] within the 10-500 nM range but not to other factors such as viscosity, temperature, or pH. This protocol describes the requirements, setup, and calibration of the FLIM system required for OGB-1 imaging. We provide a step-by-step procedure for whole-cell OGB-1 loading and two-photon FLIM. We also describe how to analyze the obtained FLIM data using total photon count and gated-intensity record, a ratiometric photon-counting approach that provides a highly improved signal-to-noise ratio and greater sensitivity of absolute [Ca2+] readout. We demonstrate our technique in nerve cells in situ, and it is adaptable to other cell types and fluorescent indicators. This protocol requires a basic understanding of FLIM and experience in single-cell electrophysiology and cell imaging. Setting up the FLIM system takes ∼2 d, and OGB-1 loading, imaging, and data analysis take 2 d.

Monitoring Ca2+ elevations in individual astrocytes upon local release of amyloid beta in acute brain slices

The pathogenesis of Alzheimer's disease (AD) is thought to involve acute neurotoxic effects exerted by oligomeric forms of amyloid-β 1-42 (Aβ). Application of Aβ oligomers in physiological concentrations have been shown to transiently elevate internal Ca2+ in cultured astroglia. While the cellular machinery involved has been extensively explored, to what degree this important signalling cascade occurs in organised brain tissue has remained unclear. Here we adapted two-photon excitation microscopy and calibrated time-resolved imaging (FLIM), coupled with patch-clamp electrophysiology, to monitor Ca2+ concentration ([Ca2+]) inside individual astrocytes and principal neurons in acute brain slices. Inside the slice tissue local micro-ejection of Aβ in sub-micromolar concentrations triggered prominent [Ca2+] elevations in an adjacent astrocyte translated as an approximately two-fold increase (averaged over ∼5min) in basal [Ca2+]. This elevation did not spread to neighbouring cells and appeared comparable in amplitude with commonly documented spontaneous [Ca2+] rises in astroglia. Principal nerve cells (pyramidal neurons) also showed Ca2+ sensitivity, albeit to a lesser degree. These observations shed light on the extent and dynamics of the acute physiological effects of Aβ on brain cells in situ, in the context of AD.

UV-curable ladder-like diphenylsiloxane-bridged methacryl-phenyl-siloxane for high power LED encapsulation

A UV curable ladder-like diphenylsiloxane-bridged methacryl-phenyl-siloxane (L-MPS) was synthesized from phenyltrichlorosilane, diphenylsilanediol and methacryloxypropyldimethylmethoxysilane via dehydrochlorination precoupling, supramolecular architecture-directed hydrolysis-condensation and end-capping reactions. The L-MPS has a condensation degree of ∼100%, and can be complete crosslinked by UV curing. XRD, TEM and molecular simulation suggest that the ladder-like molecules are close packed with a periodic distance of ca. 1.2 nm. The L-MPS shows transmittance of 98% and a refractive index of ca. 1.61 at 450 nm. The cured L-MPS with a T_d5% value of 465.5 °C showed excellent anti-yellowing and anti-sulfidation properties. The cured L-MPS film and the encapsulated LED samples were compared with those of Dow Corning OE-6630 and OE-7662. It is believed that the dense nano-ladder unit also contributes to the thermal, gas barrier and even optical properties. L-MPS shows promising potential as a high power LED encapsulant and optical coating for use in harsh environments. This work provides an approach to integrate this novel ladder structure with advanced properties.

UV-curable ladder-like polysiloxane was constructed to integrate high RI (1.61/450 nm) with high thermal stability etc. for high power LED encapsulation.

Reversed aqueductal cerebrospinal fluid net flow in idiopathic normal pressure hydrocephalus

OBJECTIVES

The changes of CSF flow dynamics in idiopathic normal pressure hydrocephalus (iNPH) are not fully elucidated. Most previous studies took the whole cardiac cycle as a unit. In this work, it is divided into systole and diastole phase and compared between iNPH patients and normal elderly and paid special attention to the change of netflow direction.

MATERIALS AND METHODS

Twenty iNPH patients according to international guideline and twenty healthy volunteers were included in this study and examined by MRI. Three categories of CSF flow parameters were measured: peak velocity (V_peak ), stroke volume (SV), and minute flow volume (MinV) covering the whole cycle; peak velocity (V_peak-s , V_peak-d ) and flow volume (Vol_s , Vol_d ) of the systole and diastole, respectively; net flow. Evans index (EI) was also measured and compared statistically between the two groups.

RESULTS

EI, V_peak , SV, MinV, Vol_s , Vol_d , and V_peak-d significantly increased in iNPH group (P<0.05). V_peak-s of the two groups were not significantly different (P>0.05). The net flow of 16 iNPH patients (16/20) was in the caudo-cranial direction, while 15 volunteers (15/20) were in the opposite direction, which showed statistically significant differences (P=.001).

CONCLUSIONS

INPH patients present hyperdynamic flow with increased velocity and volume both in systole and diastole phase. Degree of rising in diastole phase exceeds that of systole phase. The resulting reversal of netflow direction may play a key role in the occurrence of ventriculomegaly in iNPH patients.

A cytochrome P450 gene plays a role in the recognition of sex pheromones in the tobacco cutworm, Spodoptera litura

Cytochrome P450 (P450 or CYP) genes are involved in fundamental physiological functions, and might be also associated with the olfactory recognition of sex pheromones in beetles and moths. A P450 gene, Spodoptera litura CYP4L4 (SlituCYP4L4), was cloned for the first time from the antennae of S. litura. SlituCYP4L4 was almost exclusively expressed in the adult stage and predominantly expressed in the adult antennae. In situ hybridization showed that SlituCYP4L4 localized mainly at the base of the long sensilla trichoidea, which responds to sex pheromone components. Pretreatment with an S. litura sex pheromone significantly reduced the expression levels of SlituCYP4L4, consistent with other genes involved in sex pheromone recognition. The expression level of SlituCYP4L4 was different in moths collected with different ratios of sex pheromone lures and collected in different geographical locations. After gene knockdown of SlituCYP4L4 in the antennae, the electroantennogram (EAG) responses of male and female moths to (9Z,11E)-tetradecadienyl acetate or (9Z,12E)-tetradecadienyl acetate were significantly decreased. In contrast, EAG responses to plant volatiles and sex pheromones of other moth species were not significantly influenced in these moths. SlituCYP4L4 was also expressed in the gustatory tissues and sensilla, which suggests that SlituCYP4L4 may have other functions in the chemosensory system. Our results have shown for the first time the function of a CYP gene with appendage-specific expression in insect sex pheromone recognition, especially in adult moths.

Atrophy of retinal inner layers is associated with poor vision after endophthalmitis: a spectral domain optical coherence tomography study

PurposeTo investigate the retinal structural changes in endophthalmitis and their association with visual outcome.Patients and methodsForty-five eyes of 45 patients diagnosed with endophthalmitis were included. Spectral domain optical coherence tomography (SD-OCT) was performed after inflammation was controlled. The relationship between SD-OCT features and best-corrected visual acuity (BCVA) at the last follow-up was analyzed.ResultsThe structural changes included inner segment ellipsoid (ISe) disruption (49%), atrophy of retinal inner layers (24%), epimacular membrane (24%), and macular edema (24%). BCVA was worse in patients with ISe disruption (P=0.005) and retinal inner layers' atrophy (P=0.004) compared with those without. There was no significant difference of BCVA between the patients with and without epimacular membrane, or intraretinal cysts. Multivariate regression showed that atrophy of retinal inner layers (b=0.41±0.17, P=0.022) was the only independent factor associated with BCVA.ConclusionAtrophy of retinal inner layers is associated with visual impairment in endophthalmitis, despite successful management.

Enhanced stability of filament-type resistive switching by interface engineering

The uncontrollable rupture of the filament accompanied with joule heating deteriorates the resistive switching devices performance, especially on endurance and uniformity. To suppress the undesirable filaments rupture, this work presents an interface engineering methodology by inducing a thin layer of NiOx into a sandwiched Al/TaOx/ITO resistive switching device. The NiOx/TaOx interface barrier can confine the formation and rupture of filaments throughout the entire bulk structure under critical bias setups. The physical mechanism behind is the space-charge-limited conduction dominates in the SET process, while the Schottky emission dominates under the reverse bias.

ARACHNE: A neural-neuroglial network builder with remotely controlled parallel computing

Creating and running realistic models of neural networks has hitherto been a task for computing professionals rather than experimental neuroscientists. This is mainly because such networks usually engage substantial computational resources, the handling of which requires specific programing skills. Here we put forward a newly developed simulation environment ARACHNE: it enables an investigator to build and explore cellular networks of arbitrary biophysical and architectural complexity using the logic of NEURON and a simple interface on a local computer or a mobile device. The interface can control, through the internet, an optimized computational kernel installed on a remote computer cluster. ARACHNE can combine neuronal (wired) and astroglial (extracellular volume-transmission driven) network types and adopt realistic cell models from the NEURON library. The program and documentation (current version) are available at GitHub repository https://github.com/LeonidSavtchenko/Arachne under the MIT License (MIT).

Monitoring single-synapse glutamate release and presynaptic calcium concentration in organised brain tissue

Brain function relies in large part on Ca²⁺-dependent release of the excitatory neurotransmitter glutamate from neuronal axons. Establishing the causal relationship between presynaptic Ca²⁺ dynamics and probabilistic glutamate release is therefore a fundamental quest across neurosciences. Its progress, however, has hitherto depended primarily on the exploration of either cultured nerve cells or giant central synapses accessible to direct experimental probing in situ. Here we show that combining patch-clamp with time-resolved imaging of Ca²⁺ -sensitive fluorescence lifetime of Oregon Green BAPTA-1 (Tornado-FLIM) enables readout of single spike-evoked presynaptic Ca²⁺ concentration dynamics, with nanomolar sensitivity, in individual neuronal axons in acute brain slices. In parallel, intensity Tornado imaging of a locally expressed extracellular optical glutamate sensor iGluSnFr provides direct monitoring of single-quantum, single-synapse glutamate releases in situ. These two methods pave the way for simultaneous registration of presynaptic Ca²⁺ dynamics and transmitter release in an intact brain at the level of individual synapses.

A two-dimensional van der Waals CdS/germanene heterojunction with promising electronic and optoelectronic properties: DFT + NEGF investigations

Two new 2D materials, germanene and monolayer cadmium sulfide (CdS), have been theoretically predicted and experimentally fabricated recently.

Dopamine elevates and lowers astroglial Ca2+ through distinct pathways depending on local synaptic circuitry

Whilst astrocytes in culture invariably respond to dopamine with cytosolic Ca²⁺ rises, the dopamine sensitivity of astroglia in situ and its physiological roles remain unknown. To minimize effects of experimental manipulations on astroglial physiology, here we monitored Ca²⁺ in cells connected via gap junctions to astrocytes loaded whole‐cell with cytosolic indicators in area CA1 of acute hippocampal slices. Aiming at high sensitivity of [Ca²⁺] measurements, we also employed life‐time imaging of the Ca²⁺ indicator Oregon Green BAPTA‐1. We found that dopamine triggered a dose‐dependent, bidirectional Ca²⁺ response in stratum radiatum astroglia, a jagged elevation accompanied and followed by below‐baseline decreases. The elevation depended on D1/D2 receptors and engaged intracellular Ca²⁺ storage and removal whereas the dopamine‐induced [Ca²⁺] decrease involved D2 receptors only and was sensitive to Ca²⁺ channel blockade. In contrast, the stratum lacunosum moleculare astroglia generated higher‐threshold dopamine‐induced Ca²⁺ responses which did not depend on dopamine receptors and were uncoupled from the prominent inhibitory action of dopamine on local perforant path synapses. Our findings thus suggest that a single neurotransmitter—dopamine—could either elevate or decrease astrocyte [Ca²⁺] depending on the receptors involved, that such actions are specific to the regional neural circuitry and that they may be causally uncoupled from dopamine actions on local synapses. The results also indicate that [Ca²⁺] elevations commonly detected in astroglia can represent the variety of distinct mechanisms acting on the microscopic scale. GLIA 2017;65:447–459

A Survey of the Literature on Unintended Consequences Associated with Health Information Technology: 2014-2015

OBJECTIVE

To summarize recent research on unintended consequences associated with implementation and use of health information technology (health IT). Included in the review are original empirical investigations published in English between 2014 and 2015 that reported unintended effects introduced by adoption of digital interventions. Our analysis focuses on the trends of this steam of research, areas in which unintended consequences have continued to be reported, and common themes that emerge from the findings of these studies.

METHOD

Most of the papers reviewed were retrieved by searching three literature databases: MEDLINE, Embase, and CINAHL. Two rounds of searches were performed: the first round used more restrictive search terms specific to unintended consequences; the second round lifted the restrictions to include more generic health IT evaluation studies. Each paper was independently screened by at least two authors; differences were resolved through consensus development.

RESULTS

The literature search identified 1,538 papers that were potentially relevant; 34 were deemed meeting our inclusion criteria after screening. Studies described in these 34 papers took place in a wide variety of care areas from emergency departments to ophthalmology clinics. Some papers reflected several previously unreported unintended consequences, such as staff attrition and patients' withholding of information due to privacy and security concerns. A majority of these studies (71%) were quantitative investigations based on analysis of objectively recorded data. Several of them employed longitudinal or time series designs to distinguish between unintended consequences that had only transient impact, versus those that had persisting impact. Most of these unintended consequences resulted in adverse outcomes, even though instances of beneficial impact were also noted. While care areas covered were heterogeneous, over half of the studies were conducted at academic medical centers or teaching hospitals.

CONCLUSION

Recent studies published in the past two years represent significant advancement of unintended consequences research by seeking to include more types of health IT applications and to quantify the impact using objectively recorded data and longitudinal or time series designs. However, more mixed-methods studies are needed to develop deeper insights into the observed unintended adverse outcomes, including their root causes and remedies. We also encourage future research to go beyond the paradigm of simply describing unintended consequences, and to develop and test solutions that can prevent or minimize their impact.

Association between ERCC1 and ERCC2 gene polymorphisms and susceptibility to pancreatic cancer

We conducted a study to investigate the association between ERCC1 (rs3212986) and ERCC2 (rs13181) gene polymorphisms and the risk of pancreatic cancer in a Chinese population. A total of 217 pancreatic cancer patients and 244 control subjects were recruited from the Nuclear Industry 215 Hospital of Shaanxi Province between February 2013 and December 2014. Genomic DNA was extracted from peripheral blood samples using a TIANamp Blood DNA Kit (Tiangen, Beijing, China) according to the manufacturer's instructions. The ERCC1 rs3212986 and ERCC2 rs13181 polymorphisms were genotyped by polymerase chain reaction-restriction fragment length of polymorphism. Unconditional logistic regression analyses showed that subjects with the CC genotype of ERCC1 rs3212986 were susceptible to the development of pancreatic cancer when compared with subjects with the AA genotype (OR = 2.57, 95%CI = 1.34-5.02). The ERCC1 rs3212986 gene polymorphism was associated with increased risk of pancreatic cancer in the dominant (OR = 1.54, 95%CI = 1.05-2.28) and recessive (OR = 2.22, 95%CI = 1.20-4.19) models. However, no significant difference was found between the ERCC2 rs13181 polymorphism and the risk of pancreatic cancer in the codominant, dominant, and recessive models. We suggest that the ERCC1 rs3212986 polymorphism increases susceptibility to pancreatic cancer in the codominant, dominant, and recessive models, although further studies are needed to confirm our findings.

Color tunable electroluminescence and resistance switching from a ZnO-nanorod-TaOx-p-GaN heterojunction

Well-aligned ZnO nanorods have been prepared on p-GaN-sapphire using a vapor phase transport (VPT) technique. A thin sputtered layer of TaOx is employed as the intermediate layer and an n-ZnO-TaOx-p-GaN heterojunction device has been achieved. The current transport of the heterojunction exhibited a typical resistance switching behavior, which originated from the filament forming and breaking in the TaOx layer. Color controllable electroluminescence (EL) was observed from the biased heterojunction at room temperature. Bluish-white wide band emission is achieved from the forward biased device in both the high resistance and low resistance states, while red emission can only be observed for the reverse biased device in the low resistance state. The correlation between the EL and resistance switching has been analyzed in-depth based on the interface band diagram of the heterojunction.

Efficient integration of synaptic events by NMDA receptors in three-dimensional neuropil

Sustained activation of NMDA receptors (NMDARs) plays an important role in controlling activity of neural circuits in the brain. However, whether this activation reflects the ambient level of excitatory neurotransmitter glutamate in brain tissue or whether it depends mainly on local synaptic discharges remains poorly understood. To shed light on the underlying biophysics here we developed and explored a detailed Monte Carlo model of a realistic three-dimensional neuropil fragment containing 54 excitatory synapses. To trace individual molecules and their individual receptor interactions on this scale, we have designed and implemented a dedicated computer cluster and the appropriate software environment. Our simulations have suggested that sparse synaptic discharges are 20-30 times more efficient than nonsynaptic (stationary, leaky) supply of glutamate in controlling sustained NMDAR occupancy in the brain. This mechanism could explain how the brain circuits provide substantial background activation of NMDARs while maintaining a negligible ambient glutamate level in the extracellular space. Thus the background NMDAR occupancy, rather than the background glutamate level, is likely to reflect the ongoing activity in local excitatory networks.

Time-Resolved Imaging Reveals Heterogeneous Landscapes of Nanomolar Ca(2+) in Neurons and Astroglia

Maintaining low intracellular calcium is essential to the functioning of brain cells, yet the phenomenology and mechanisms involved remain an enigma. We have advanced a two-photon excitation time-resolved imaging technique, which exploits high sensitivity of the OGB-1 fluorescence lifetime to nanomolar Ca²⁺ concentration ([Ca²⁺]) and enables a high data acquisition rate in situ. The [Ca²⁺] readout is not affected by dye concentration, light scattering, photobleaching, micro-viscosity, temperature, or the main known concomitants of cellular activity. In quiescent tissue, standard whole-cell configuration has little effect on resting [Ca²⁺] inside neuronal dendrites or inside astroglia dye-filled via gap junctions. Mapping basal [Ca²⁺] in neurons and astrocytes with submicron resolution unveils heterogeneous concentration landscapes that depend on age and preceding activity. The rich information content represented by such landscapes in acute slices and in vivo promises to unveil the hitherto unexplored, potentially fundamental aspects of brain cell physiology.

Video Abstract

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OGB-1 lifetime readout is specific to low [Ca²⁺] and enables 100 Hz acquisition rate

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Neurons and astrocytes maintain uneven landscapes of resting [Ca²⁺]

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Resting [Ca²⁺] patterns in neurons and astroglia are age and activity dependent

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Astroglia in situ split into two sub-groups with respect to their resting [Ca²⁺]

Self-organized graphene-like boron nitride containing nanoflakes on copper by low-temperature N2 + H2 plasma

A simple and efficient method for synthesizing complex graphene-inspired BNCO nanoflakes by plasma-enhanced hot filament chemical vapour deposition using B₄C as a precursor and N₂/H₂ reactive gases is reported.

Growth and photoluminescence of oriented MoSe2nanosheets produced by hot filament CVD

Oriented MoSe₂nanosheets with varying layers and structures were synthesized on silicon substrates by hot filament chemical vapour deposition in a nitrogen environment using MoO₃and Se powders as precursors.

Endovascular Coiling versus Surgical Clipping for Poor-Grade Ruptured Intracranial Aneurysms: Postoperative Complications and Clinical Outcome in a Multicenter Poor-Grade Aneurysm Study

BACKGROUND AND PURPOSE

Endovascular coiling is an alternative to surgical clipping for ruptured intracranial aneurysms. However, no large multicenter prospective study has compared coiling and clipping in patients with poor-grade ruptured aneurysms. We aimed to determine differences in postoperative complications and clinical outcome between the 2 treatments in this group of patients.

MATERIALS AND METHODS

A Multicenter Poor-Grade Aneurysm Study was a prospective, multicenter, observational registry of consecutive patients who presented with poor-grade ruptured aneurysms. Three hundred sixty-six patients were enrolled from October 2010 to March 2012. "Poor-grade aneurysm" was defined as a World Federation of Neurosurgical Societies grade of IV or V at the time of aneurysm treatment. Two hundred sixty-two patients received aneurysm treatment within 21 days and were included. Clinical outcomes were assessed at discharge and at 6 and 12 months by the modified Rankin Scale.

RESULTS

One hundred thirty-three (50.8%) patients underwent endovascular coiling. Unadjusted analysis showed that the outcome rate (mRS 0-1 or mRS 0-2) at 6 and 12 months in patients undergoing coiling was higher than that in patients undergoing clipping. In adjusted analyses, there was no statistically significant difference in outcomes at 6 and 12 months between the 2 groups. The risk of radiologic hydrocephalus was higher in patients treated with coiling than that in those treated with clipping (adjusted OR, 3.36; 95% CI, 1.13-10.01; P = .030).

CONCLUSIONS

The long-term outcome in selected patients was similar between endovascular coiling and clipping for poor-grade ruptured aneurysms. The risk of radiologic hydrocephalus was higher after endovascular treatment of poor-grade aneurysms.

miRNAs are required for the terminal differentiation of white matter astrocytes in the developing CNS

While the regulation of the neurogenesis and oligodendrogenesis by microRNAs has been intensively studied, little is known about the role of microRNAs (miRNAs) in the development of astrocytes. Here, we report that microRNAs play an essential role in the differentiation and maturation of white matter astrocytes in mouse spinal cord tissues. In glial fibrillary acidic protein (GFAP)/Dicer conditional mutants, the initial generation of astrocyte progenitor cells was normal in the spinal cord. However, there was a much reduced number of GFAP+ astrocytes with shorter processes in the white matter of mutant tissues. In contrast, the expression of gray matter protoplasmic astrocyte marker was not affected. Together, our studies indicated that miRNAs are required for the differentiation and morphological maturation of white matter fibrous astrocytes in the developing spinal cord.

Lack of clinical significance of the ImmuKnow(TM)-Cylex assay for the detection of cellular immune function in patients with renal cell carcinoma

This study aimed to explore the clinical value of the CD4(+) T cell ATP levels in patients with renal cell carcinoma through the application of the ImmuKnow(TM)-Cylex(®) assay. We recruited 104 patients with renal cancer who had undergone surgery at Fuzhou General Hospital from March 2009 to June 2012, and were subsequently treated by dendritic cell and cytokine-induced killer cell bio-therapy or interferon-α therapy. The changes in CD4(+) T cell ATP levels were detected at the perioperative period and at 10 days, 1 month, 3 months, and 1 year after the surgery using the ImmuKnow assay. In addition, the differences in ATP levels in different therapy groups were compared and the prognosis conditions were analyzed. Our results demonstrated that no significant difference in the ATP levels occurred at different time points; furthermore, there were no obviously different ATP levels between the different therapy groups, and the ATP levels were found to have no clinical significance for the assessment of renal cancer prognosis. Overall, this study suggested that CD4(+) T cell ATP levels as detected by the ImmuKnow assay have no obvious clinical value in patients with renal cancer.

Benefits of fluorine-18 fludeoxyglucose positron emission tomography in secondary cytoreductive surgery for patients with recurrent epithelial ovarian cancer

OBJECTIVE

To investigate the benefits of fluorine-18 fludeoxyglucose positron emission tomography ((18)F-FDG-PET) in patients undergoing secondary cytoreductive surgery (SCRS) for recurrent epithelial ovarian cancer.

METHODS

Patients were identified, and their clinical information was extracted by review of the gynaecologic oncology database of Peking Union Medical College Hospital. (18)F-FDG-PET scan and analysis were performed by nuclear medicine experts at our hospital.

RESULTS

The PET group and the control group of patients evaluated by conventional imaging methods differed significantly with respect to the proportion of patients who underwent complete SCRS and the number of residual lesions (p = 0.002 and 0.006, respectively). A Cox model showed that longer progression-free survival (PFS) correlated significantly with (18)F-FDG-PET evaluation [relative risk (RR) = 0.432; p = 0.001], sensitivity to platinum-based chemotherapies (RR = 0.604; p = 0.034) and resection completeness (RR = 0.679; p = 0.039). Longer overall survival (OS) correlated significantly with sensitivity to platinum-based chemotherapy (RR = 0.317; p = 0.000) and the CA-125 level after two cycles of chemotherapy (RR = 2.663; p = 0.003). Surgical safety and complications did not significantly differ between the two groups of patients.

CONCLUSION

(18)F-FDG-PET is useful for evaluating patients with recurrent epithelial ovarian carcinoma. Patients who undergo PET-guided SCRS have a greater chance of complete tumour resection and a longer PFS.

ADVANCES IN KNOWLEDGE

SCRS guided by PET results in fewer residual lesions. PET-guided SCRS is safe and can prolong PFS and OS in patients with recurrent ovarian cancer.

Mutation of the rice ASL2 gene encoding plastid ribosomal protein L21 causes chloroplast developmental defects and seedling death

The plastid ribosome proteins (PRPs) play important roles in plastid protein biosynthesis, chloroplast differentiation and early chloroplast development. However, the specialised functions of individual protein components of the chloroplast ribosome in rice (Oryza sativa) remain unresolved. In this paper, we identified a novel rice PRP mutant named asl2 (Albino seedling lethality 2) exhibiting an albino, seedling death phenotype. In asl2 mutants, the alteration of leaf colour was associated with chlorophyll (Chl) content and abnormal chloroplast development. Through map-based cloning and complementation, the mutated ASL2 gene was isolated and found to encode the chloroplast 50S ribosome protein L21 (RPL21c), a component of the chloroplast ribosome large subunit, which was localised in chloroplasts. ASL2 was expressed at a higher level in the plumule and leaves, implying its tissue-specific expression. Additionally, the expression of ASL2 was regulated by light. The transcript levels of the majority of genes for Chl biosynthesis, photosynthesis and chloroplast development were strongly affected in asl2 mutants. Collectively, the absence of functional ASL2 caused chloroplast developmental defects and seedling death. This report establishes the important role of RPL21c in chloroplast development in rice.

Understanding the opposite electrical responses of an individual ZnO nanowire under different bending deformations

Opposite electrical responses have been observed in the same individual ZnO nanowire during bending via changes in the contact modes.

[A case report of cerebral resuscitation by surface cooling in a patient with cardiac arrest]

Therapeutic hypothermia is an important treatment for cerebral resuscitation in patients after cardiac arrest. But it is rarely used for comatose survivor post-cardiac arrest in China. The patient was the first case who was in coma post cardiac arrest caused by acute myocardial infarction and given hypothermia therapy in our hospital. After coronary reperfusion and therapeutic hypothermia, the patient's sneurologic function was recovered to normal. The paper discussed the indications, contraindications, cooling methods and complications of therapeutic hypothermia.

Band filling effect on polaron localization in La1-x(Ca(y)Sr1-y)xMnO3 manganites

We report on a ìSR and 55 Mn NMR investigation of the magnetic order parameter as a function of temperature in the optimally doped La(5/8)(CaySr(1.y))(3/8)MnO3 and in the underdoped La1.xSrxMnO3 and La1.xCaxMnO3 metallic manganite families. The study is aimed at unravelling the effect of lattice distortions, implicitly controlled by the Ca-Sr isoelectronic substitution, from that of hole doping x on the Curie temperature TC and the order of the magnetic transition. At optimal doping, the transitions are second order at all y values, including the y = 1 (La(5/8)Ca(3/8)MnO3) end member. By contrast, they are first order in the underdoped samples, which show a finite (truncated) order parameter at the Curie point, including La(0.75)Sr(0.25)MnO3 whose TC is much higher than that of La(5/8)Ca(3/8)MnO3. The order parameter curves, on the other hand, exhibit a very minor dependence on x, if truncation is excepted. This suggests that the effective exchange interaction between Mn ions is essentially governed by local distortions, in agreement with the original double-exchange model, while truncation is primarily, if not entirely, an effect of under- or over-doping. A phase diagram, separating in the x.y plane polaron-driven first order transitions from regular second order transitions governed by critical fluctuations, is proposed for the La(1.x)(CaySr(1.y))xMnO3 system.

Optogenetic and potassium channel gene therapy in a rodent model of focal neocortical epilepsy

Neocortical epilepsy is frequently drug-resistant. Surgery to remove the epileptogenic zone is only feasible in a minority of cases, leaving many patients without an effective treatment. We report the potential efficacy of gene therapy in focal neocortical epilepsy using a rodent model in which epilepsy is induced by tetanus toxin injection in the motor cortex. By applying several complementary methods that use continuous wireless electroencephalographic monitoring to quantify epileptic activity, we observed increases in high frequency activity and in the occurrence of epileptiform events. Pyramidal neurons in the epileptic focus showed enhanced intrinsic excitability consistent with seizure generation. Optogenetic inhibition of a subset of principal neurons transduced with halorhodopsin targeted to the epileptic focus by lentiviral delivery was sufficient to attenuate electroencephalographic seizures. Local lentiviral overexpression of the potassium channel Kv1.1 reduced the intrinsic excitability of transduced pyramidal neurons. Coinjection of this Kv1.1 lentivirus with tetanus toxin fully prevented the occurrence of electroencephalographic seizures. Finally, administration of the Kv1.1 lentivirus to an established epileptic focus progressively suppressed epileptic activity over several weeks without detectable behavioral side effects. Thus, gene therapy in a rodent model can be used to suppress seizures acutely, prevent their occurrence after an epileptogenic stimulus, and successfully treat established focal epilepsy.

A transanal procedure using an endoscopic linear stapler for obstructed defecation syndrome: the first Chinese experience

BACKGROUND

Transanal surgery using an endoscopic linear stapler is a recognized, but not widely performed technique for the treatment of obstructed defecation syndrome (ODS). A study of consecutive patients was conducted to evaluate the safety and effectiveness of the technique for the treatment of ODS in Chinese patients.

METHODS

From November 2008 to December 2010, 43 female patients with ODS caused by rectocele and/or rectal intussusception underwent transanal surgery using an endoscopic linear stapler in three Chinese hospitals. Clinical and functional data including the Wexner constipation score and outcome classification were analyzed retrospectively.

RESULTS

The average duration of surgery was 23 ± 4 min (range 15-30 min). Blood loss was 10 ± 2 ml (range 5-15 ml). The average postoperative hospital stay was 5 days (range 4-6 days). The pathologic findings showed that the specimen contained rectal muscle in all patients. Postoperative complications included 4 patients with transient fecal urgency, 3 patients with anorectal pain, and one patient with mild bleeding from the stapled suture line. Three patients reported minor fecal incontinence (Wexner score less than 3). During a median follow-up of 12 months (range, 3-26 months), the mean constipation score improved from preoperative 13.56 to postoperative 5.07 at 1 year (P < 0.05). The outcome at 1 year was excellent in 18 of 43 patients, good in 13, fairly good in 7, and poor in 5. Postoperative defecography was performed in 28 patients. Rectocele disappeared in 15 patients. Rectocele depth was reduced from 34 ± 4 mm preoperatively to 17 ± 3 mm postoperatively (P < 0.05).

CONCLUSION

The transanal procedure using an endoscopic linear stapler is an easy, safe, and effective option for selected patients with ODS. Long-term prospective, randomized, controlled studies are needed to confirm the advantages of this procedure in comparison with the traditional transanal and stapled transanal rectal resection (STARR) techniques.