Cortical thinning in epilepsy patients with postictal generalized electroencephalography suppression

BACKGROUND AND PURPOSE

The aim was to investigate the brain microstructural abnormalities in epilepsy patients with postictal generalized electroencephalographic suppression (PGES) using a cortical surface-based analysis.

METHODS

According to the video-electroencephalography records of epilepsy patients with generalized convulsive seizures, 30 patients with PGES (PGES+) and 21 patients without PGES (PGES-) were recruited. High-resolution T1-weighted images were acquired from each patient and 30 matched healthy control subjects. Cortical thickness was compared amongst the three groups using FreeSurfer software.

RESULTS

Patients with PGES showed reduced cortical thickness in the right paracentral lobule, inferior parietal lobule, supramarginal gyrus and middle temporal lobe compared with patients without PGES. In relation to healthy control subjects, the PGES+ group presented reduced cortical thickness in the right superior parietal lobule and supramarginal gyrus, whilst the PGES- group presented reduced cortical thickness in the left precuneus, precentral gyrus, lateral occipital gyrus, parahippocampal gyrus, superior parietal lobule and right caudal middle frontal gyrus.

CONCLUSIONS

Patients with PGES exhibited characteristic brain microstructural abnormalities, corroborating the PGES mechanisms at the brain level. The right-sided predominance of the detected PGES-related cortical thinning was the same as that of sudden unexpected death in epilepsy (SUDEP) cases and patients at high risk for SUDEP, implying that PGES and SUDEP may share a common abnormal brain substrate that is involved in the pathophysiology of these conditions.

[Relationship between coronary tortuosity and coronary microvascular disease]

Objective: To explore the relationship between coronary tortuosity and coronary microvascular disease (CMVD). Methods: Patients with typical angina symptoms and without serious coronary artery stenosis by coronary angiography were enrolled from June 2014 to December 2016, and CMVD was diagnosed by single photon emission tomography (SPECT). According to the SPECT results, patients were divided to the CMVD group and non-CMVD group. The baseline clinical characteristics, results of coronary angiography were compared between the two groups. The logistic analysis was used to analyze the relationship between coronary tortuosity and CMVD. Result: A total of 117 cases were enrolled, with 69 cases in the CMVD group and 48 cases in the non-CMVD group. No differences were found in gender distribution, age, hypertension, lipid abnormality, hyperuricemia and uses of statins between the two groups (all P>0.05). Incidence of diabetes (78.26%(54/69) vs. 35.42% (17/48) , P<0.05), hs-CRP ((4.29±2.15)mmol/L vs. (2.63±1.20)mmol/L, P<0.001), LDL-C ((2.98±0.96)mmol/L vs. (2.52±0.83)mmol/L, P=0.008) and homocysteine ((13.7±5.61)mmol/L vs. (11.5±4.38)mmol/L, P=0.025) levels were higher in the CMVD group than in the non-CMVD group. The data derived from echocardiographic examination were similar between the two groups. The Corrected TIMI frame counts were higher in the CMVD group than in non-CMVD group (LAD: 31.56±4.92 vs. 27.31±3.75, LCX: 29.47±4.18 vs. 26.62±3.19, RCA: 29.09±5.05 vs. 26.24±3.28, all P<0.001). The incidences of coronary atherosclerosis (76.81% (53/69) vs. 27.08% (13/48) , P<0.001) and coronary tortuosity ( (60.87% (42/69) vs. 33.33% (16/48) , P=0.035) were also higher in the CMVD group than in non-CMVD group. Logistic analysis found that coronary tortuosity (OR=6.111, 95%CI 2.707-13.794, P<0.001), diabetes (OR=6.565, 95%CI 2.883-14.948, P<0.001) and coronary atherosclerosis (OR=8.918, 95%CI 3.822-20.808, P<0.001) were independent risk factors of CMVD. Conclusion: Coronary tortuosity, diabetes and coronary atherosclerosis are related to CMVD in this patient cohort.

Disrupted intrinsic and remote functional connectivity in heterotopia-related epilepsy

OBJECTIVES

Several neuroimaging studies have examined neural interactions in patients with periventricular nodular heterotopia (PNH). However, features of the underlying functional network remain poorly understood. In this study, we examined alterations in the local (regional) and remote (interregional) cerebral networks in this disorder.

METHODS

Twenty-eight subjects all having suffered from PNH with epilepsy, as well as 28 age- and sex- matched healthy controls, were enrolled in this study. Amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity (FC) were calculated to detect regional neural function and functional network integration, respectively.

RESULTS

Compared with healthy controls, patients with PNH-related epilepsy showed decreased ALFF in the ventromedial prefrontal cortex (vmPFC) and precuneus areas. ALFF values in both areas were negative correlated with epilepsy duration (P < .05, Bonferroni-corrected). Furthermore, patients with PNH-related epilepsy had increased remote interregional FC mainly in bilateral prefrontal and parietal cortices, supramarginal gyrus, dorsal cingulate gyrus, and right insula; lower FC was found in posterior brain regions including bilateral parahippocampal gyrus and inferior temporal gyrus.

CONCLUSIONS

Focal spontaneous hypofunction, as assessed by ALFF, correlates with epilepsy duration in patients with PNH-related epilepsy. Abnormalities existed both within the default-mode network and then across the whole brain, demonstrating that intrinsic brain dysfunction may be related to specific network interactions. Our findings provide novel understanding of the connectivity-based pathophysiological mechanisms of PNH.

Construction of a ptfA chitosan nanoparticle DNA vaccine against Pasteurella multocida and the immune response in chickens

The aim of this study was to evaluate the effect of chitosanon the immune response induced by a DNA vaccine based on the ptfA gene of avian Pasteurella multocida. Naked DNA vaccine was packed with chitosanmolecules, resulting in a chitosannanoparticle DNA vaccine. The encapsulation efficiency, shape, size and resistance to DNA degradation were determined. The vaccine was administered to chickens and serum antibody, interferon-γ (IFN-γ), interleukin-2 (IL-2) and interleukin-4 (IL-4) concentrations were determined and lymphocyte proliferation assays were performed. After challenge with virulent avian P. multocida, protective efficacy was evaluated. The encapsulation efficiency of the chitosan nanoparticle DNA vaccine was 95.3%. The particle size was approximately 200nm and close to spherical in shape and it could effectively resist degradation by DNases. Following vaccination, serum antibodies, stimulation index (SI) value and concentrations of IFN-γ and IL-2 in chickens vaccinated with the chitosan nanoparticle DNA vaccine were significantly higher than those that were vaccinated with the naked DNA vaccine (P-values are 0.026, 0.045, 0.039 and 0.024, respectively). However, the concentrations of IL-4 in the two DNA vaccines group were no significant difference (P=0.157). The protective efficacy rate provided by naked DNA vaccine, chitosan nanoparticle DNA vaccine and the attenuated live vaccine were 56%, 68% and 88%, respectively. The results indicated that chitosan was able to enhance the immune response to a naked DNA vaccine based on the ptfA gene of P. multocida.

InP-based pseudomorphic InAs/InGaAs triangular quantum well lasers with bismuth surfactant

An InP-based 2.1 μm InAs/In_0.53Ga_0.47As triangular quantum well laser grown with Bi surfactant has shown improved performance in comparison to the device with the same structure but grown without Bi surfactant. Under continuous-wave driving operation, the output light power is increased from 32.6 to 37.5 mW at the same injecting current of 850 mA at 200 K. The external differential and internal quantum efficiencies for the laser with Bi surfactant are 18.4% and 41%, respectively, which are correspondingly higher than 13.1% and 31% for the reference device. Furthermore, a decreased internal loss from 20.9 to 17.6  cm^-1 for the Bi surfactant laser is also observed. These results suggest that Bi surfactant is promising for further enhancing performances of strained quantum well laser diodes.

Perilesional and contralateral white matter evolution and integrity in patients with periventricular nodular heterotopia and epilepsy: a longitudinal diffusion tensor imaging study

BACKGROUND AND PURPOSE

This study aimed to assess the evolution of perinodular and contralateral white matter abnormalities in patients with periventricular nodular heterotopia (PNH) and epilepsy.

METHODS

Diffusion tensor imaging (DTI) (64 directions) and 3 T structural magnetic resonance imaging were performed in 29 PNH patients (mean age 27.3 years), and 16 patients underwent a second scan (average time between the two scans 1.1 years). Fractional anisotropy and mean diffusivity were measured within the perilesional and contralateral white matter.

RESULTS

Longitudinal analysis showed that white matter located 10 mm from the focal nodule displayed characteristics intermediate to tissue 5 mm away, and normal-appearing white matter (NAWM) also established evolution profiles of perinodular white matter in different cortical lobes. Compared to 29 age- and sex-matched healthy controls, significant decreased fractional anisotropy and elevated mean diffusivity values were observed in regions 5 and 10 mm from nodules (P < 0.01), whilst DTI metrics of the remaining NAWM did not differ significantly from controls. Additionally, normal DTI metrics were shown in the contralateral region in patients with unilateral PNH.

CONCLUSIONS

Periventricular nodular heterotopia is associated with microstructural abnormalities within the perilesional white matter and the extent decreases with increasing distance from the nodule. In the homologous contralateral region, white matter diffusion metrics were unchanged in unilateral PNH. These findings have clinical implications with respect to the medical and surgical interventions of PNH-related epilepsy.

Association of Mutations in Toll-like Receptor 2 Signaling Genes With Fulminant Form of Hepatitis B-Related Acute Liver Failure

BACKGROUND

The fulminant form of hepatitis B-related acute liver failure (FHB-ALF) is a rare but highly fatal outcome of acute hepatitis B virus (HBV) infection. Its related host factors have not been studied to our knowledge.

METHODS

To identify functionally relevant biological pathway(8) in FHB-ALF pathogenesis, pathway enrichment analysis was conducted on a data set of rare case-specific variants derived from exomic sequencing of 10 unrelated cases. Key variants in identified pathways were validated using 312 controls with HBV disease. Mechanistic studies of a recurrent Toll-like receptor (TLR) 2 gene (TLR2) variant were performed in vitro and in vivo.

RESULTS

The TLR signaling pathway was highly enriched, with associated variants found in 9 of the 10 cases. Notably, a rare heterozygous single-nucleotide variation causing F679I mutation in TLR2 was identified in 2 unrelated cases. In vitro analysis demonstrated F679I to cause loss of function. In both heterozygous and homozygous TLR2 knockout mice, injection of HBV replicon plasmid resulted in more prominent alanine aminotransferase elevations and hepatic necroinflammation than in wild-type mice. Mechanistic analyses demonstrated reduced regulatory T-cell percentages in postexposure TLR2 knockout mice.

CONCLUSIONS

TLR2 signaling is very likely impaired in patients with FHB-ALF. The recurrence of rare case-specific TLR2 variant strongly suggests mechanistic contribution to fulminancy in HBV infection.

The relation of the serum aldosterone level and central serous chorioretinopathy - a pilot study

OBJECTIVE

The aim of this study was to investigate the serum aldosterone level and abnormal levels of mineral corticoid in patients with the central serous chorioretinopathy (CSC).

PATIENTS AND METHODS

All recruited patients with CSC received fundus fluorescein angiography (FFA), enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) and serum aldosterone assay. The patients were classified into spontaneously resolved group and unresolved group according to a 3-months follow-up of Optical Coherence Tomography (OCT) examination. Patients from unresolved group were recruited to receive treatment with 40 mg spironolactone orally for 2 months. After the treatment, the EDI-OCT and best corrected visual acuity (BCVA) were performed again to assess the treatment efficacy.

RESULTS

The study included 61 patients (72 eyes) with 34 patients in the unresolved group and 27 patients in the resolved group. The aldosterone level was significantly associated with the subfoveal choroidal thickness (SFCT) of revolved CSC eyes (r=0.342, p<0.05) as well as the SFCT of unresolved CSC eyes (r=0.348, p<0.05). And the aldosterone level in the unresolved CSC group was greater than that in the spontaneously resolved group (161.8 ± 50.1 ng/dl vs. 122.5 ± 50.5 ng/dl, p<0.05). The central macular thickness and SFCT were decreased significantly (p<0.05) after the treatment with 40 mg/d spironolactone for two months.

CONCLUSIONS

The unresolved CSC patients were characterized by high level of aldosterone and thickened SFCT. Spironolactone treatment was associated with the improvement of chronic CSC. Besides, the side effect of spironolactone treatment was rare.

Common pattern of gray-matter abnormalities in drug-naive and medicated first-episode schizophrenia: a multimodal meta-analysis

Studies of schizophrenia at drug-naive state and on antipsychotic medication have reported a number of regions of gray-matter (GM) abnormalities but the reports have been inconsistent. The aim of this study was to conduct multimodal meta-analysis to compare the cross-sectional voxel-based morphometry studies of brain GM in antipsychotic-naive first-episode schizophrenia (AN-FES) and those with antipsychotic treatment within 1 year (AT-FES) to determine the similarities and differences in these groups. We conducted two separate meta-analyses containing 24 studies with a sample size of 801 patients and 957 healthy controls. A multimodal meta-analysis method was used to compare the findings between AN-FES and AT-FES. Meta-regression analyses were done to determine the influence of different variables including age, duration of illness, and positive and negative symptom scores. Finally, jack-knife analyses were done to test the robustness of the results. AN-FES and AT-FES showed common patterns of GM abnormalities in frontal (gyrus rectus), superior temporal, left hippocampal and insular cortex. GM in the left supramarginal gyrus and left middle temporal gyrus were found to be increased in AN-FES but decreased in AT-FES, whereas left median cingulate/paracingulate gyri and right hippocampus GM was decreased in AN-FES but increased in AT-FES. Findings suggest that both AN-FES and AT-FES share frontal, temporal and insular regions as common anatomical regions to be affected indicating these to be the primary regions of GM abnormalities in both groups.

Cortical Thickness of Native Tibetans in the Qinghai-Tibetan Plateau

BACKGROUND AND PURPOSE

High-altitude environmental factors and genetic variants together could have exerted their effects on the human brain. The present study was designed to investigate the cerebral morphology in high-altitude native Tibetans.

MATERIALS AND METHODS

T1-weighted brain images were obtained from 77 Tibetan adolescents on the Qinghai-Tibetan Plateau (altitude, 2300-5300 m) and 80 matched Han controls living at sea level. Cortical thickness, curvature, and sulcus were analyzed by using FreeSurfer.

RESULTS

Cortical thickness was significantly decreased in the left posterior cingulate cortex, lingual gyrus, superior parietal cortex, precuneus, and rostral middle frontal cortex and the right medial orbitofrontal cortex, lateral occipital cortex, precuneus, and paracentral lobule. Curvature was significantly decreased in the left superior parietal cortex and right superior marginal gyrus; the depth of the sulcus was significantly increased in the left inferior temporal gyrus and significantly decreased in the right superior marginal gyrus, superior temporal gyrus, and insular cortex. Moreover, cortical thickness was negatively correlated with altitude in the left superior and middle temporal gyri, rostral middle frontal cortex, insular cortex, posterior cingulate cortex, precuneus, lingual gyrus, and the right superior temporal gyrus. Curvature was positively correlated with altitude in the left rostral middle frontal cortex, insular cortex, and middle temporal gyrus. The depth of the sulcus was negatively correlated with altitude in the left lingual gyrus and right medial orbitofrontal cortex.

CONCLUSIONS

Differences in cortical morphometry in native Tibetans may reflect adaptations related to high altitude.

High-field magnetic resonance imaging of structural alterations in first-episode, drug-naive patients with major depressive disorder

Previous structural imaging studies have found evidence of brain morphometric changes in patients with major depressive disorder (MDD), but these studies rarely excluded compounding effects of certain important factors, such as medications and long duration of illnesses. Furthermore, the neurobiological mechanism of the macroscopic findings of structural alterations in MDD patients remains unclear. In this study, we utilized magnetization transfer imaging, a quantitative measure of the macromolecular structural integrity of brain tissue, to identify biophysical alterations, which are represented by a magnetization transfer ratio (MTR), in MDD patients. To ascertain whether MTR changes occur independent of volume loss, we also conduct voxel-based morphometry (VBM) analysis. The participants included 27 first-episode, drug-naive MDD patients and 28 healthy controls matched for age and gender. Whole-brain voxel-based analysis was used to compare MTR and gray matter volume across groups and to analyse correlations between MTR and age, symptom severity, and illness duration. The patients exhibited significantly lower MTR in the left superior parietal lobule and left middle occipital gyrus compared with healthy controls, which may be related to the attentional and cognitive dysfunction in MDD patients. The VBM analysis revealed significantly increased gray matter volume in right postcentral gyrus in MDD patients. These findings in first-episode, drug-naive MDD patients may reflect microstructural gray matter changes in the parietal and occipital cortices close to illness onset that existed before volume loss, and thus potentially provide important new insight into the early neurobiology of depression.

Evaluation of immunogenicity and protective efficacy of recombinant ptfA of avian Pasteurella multocida

Avian Pasteurella multocida is the causative agent of fowl cholera, a disease much affecting the poultry industry. In order to study the efficacy of the recombinant subunit vaccine constructed with ptfA gene of avian P. multocida, the ptfA gene fragment amplified by PCR from avian P. multocida was cloned into the prokaryotic expression vector pET32a and the recombinant plasmid pET32a-ptfA was obtained. The pET32a-ptfA was expressed in Escherichiacoli BL21(DE3) and the target protein rPtfA was purified. The purified protein was then mixed with Freund's adjuvant and the recombinant subunit vaccine was obtained. Three groups of chickens labeled as rPtfA, attenuated live vaccine and PBS were vaccinated with the recombinant subunit vaccine, attenuated live vaccine and PBS, respectively. Serum antibodies, peripheral blood lymphocyte proliferation (PBLP) and interferon-γ (IFN-γ) level secreted by peripheral blood lymphocyte were tested. The immunized chickens were finally challenged with virulent avian P. multocida and the protection rate was counted. Indirect ELISA showed the levels of antibodies in rPtfA and attenuated vaccine groups were most significantly higher than the other groups (P<0.01), and the former was slightly lower than the latter. Peripheral blood lymphocyte proliferation experiments and IFN-γ experiments indicated that SI value and the levels of IFN-γ induced by ConA in the two vaccine groups were significantly higher than those of the PBS groups (P<0.01), and that the attenuated vaccine group was higher than the rPtfA group. The protection rates of rPtfA and attenuated live vaccines were 45% and 75%, respectively. The results indicated that the PtfA recombinant subunit vaccine was capable of improving the immunity level and inducing a protective effect for the vaccinated chickens, but it was barely satisfactory.

Recurrent activating mutations of CD28 in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) comprise a heterogeneous group of mature T-cell neoplasms with a poor prognosis. Recently, mutations in TET2 and other epigenetic modifiers as well as RHOA have been identified in these diseases, particularly in angioimmunoblastic T-cell lymphoma (AITL). CD28 is the major co-stimulatory receptor in T cells which, upon binding ligand, induces sustained T-cell proliferation and cytokine production when combined with T-cell receptor stimulation. We have identified recurrent mutations in CD28 in PTCLs. Two residues-D124 and T195-were recurrently mutated in 11.3% of cases of AITL and in one case of PTCL, not otherwise specified (PTCL-NOS). Surface plasmon resonance analysis of mutations at these residues with predicted differential partner interactions showed increased affinity for ligand CD86 (residue D124) and increased affinity for intracellular adaptor proteins GRB2 and GADS/GRAP2 (residue T195). Molecular modeling studies on each of these mutations suggested how these mutants result in increased affinities. We found increased transcription of the CD28-responsive genes CD226 and TNFA in cells expressing the T195P mutant in response to CD3 and CD86 co-stimulation and increased downstream activation of NF-κB by both D124V and T195P mutants, suggesting a potential therapeutic target in CD28-mutated PTCLs.

Effect of adding gemtuzumab ozogamicin to induction chemotherapy for newly diagnosed acute myeloid leukemia: a meta-analysis of prospective randomized phase III trials

BACKGROUND

Gemtuzumab ozogamicin (GO) is a targeted antineoplastic agent comprised of a recombinant anti-CD33 humanized antibody linked to calicheamicin. Previous trials have showed conflicting results concerning the efficacy and toxicity of adding GO to induction chemotherapy for newly diagnosed acute myeloid leukemia (AML). A systematic review and meta-analysis was conducted to resolve this controversial issue.

PATIENTS AND METHODS

Summary data from five randomized phase III trials compared adding GO to induction chemotherapy with induction chemotherapy alone for newly diagnosed AML were meta-analyzed. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) and relapse-free survival (RFS), and pooled odds ratios (ORs) and 95% CIs for complete remission (CR) rate, incidences of resistance disease, relapse and toxicity were calculated.

RESULTS

Data of 3596 patients (1798 GO and 1798 controls) from five randomized phase III trials were analyzed. Compared with induction chemotherapy alone, adding GO significantly prolonged OS (HR 0.93, 95% CI 0.86-1.00, P=0.05) and RFS (HR 0.87, 95% CI 0.79-0.95, P=0.003), decreased the incidences of resistant disease (OR 0.71, 95% CI 0.55-0.93, P=0.01) and relapse (OR 0.75, 95% CI 0.63-0.90, P=0.002), but had no effect on CR rate (OR 1.15, 95% CI 0.91-1.46, P=0.24). Sensitivity analysis yielded similar results. Subgroup analysis identified that cytogenetics might be an influencing factor for the effect of adding GO. In addition, the risks of grade 3-4 nausea/vomiting, diarrhea and liver aspartate transaminase (AST) elevation were increased in GO arm.

CONCLUSIONS

Adding GO to induction chemotherapy for newly diagnosed AML can significantly prolong OS and RFS, decrease incidences of resistant disease and relapse, but may increase risks of grade 3-4 nausea/vomiting, diarrhea and liver AST elevation.

Resting-state brain function in schizophrenia and psychotic bipolar probands and their first-degree relatives

BACKGROUND

Schizophrenia (SCZ) and psychotic bipolar disorder (PBD) share considerable overlap in clinical features, genetic risk factors and co-occurrence among relatives. The common and unique functional cerebral deficits in these disorders, and in unaffected relatives, remain to be identified.

METHOD

A total of 59 healthy controls, 37 SCZ and 57 PBD probands and their unaffected first-degree relatives (38 and 28, respectively) were studied using resting-state functional magnetic resonance imaging (rfMRI). Regional cerebral function was evaluated by measuring the amplitude of low-frequency fluctuations (ALFF). Areas with ALFF alterations were used as seeds in whole-brain functional connectivity analysis. We then tested whether abnormalities identified in probands were present in unaffected relatives.

RESULTS

SCZ and PBD probands both demonstrated regional hypoactivity in the orbital frontal cortex and cingulate gyrus, as well as abnormal connectivity within striatal-thalamo-cortical networks. SCZ probands showed greater and more widely distributed ALFF alterations including the thalamus and bilateral parahippocampal gyri. Increased parahippocampal ALFF was related to positive symptoms and cognitive deficit. PBD patients showed uniquely increased functional connectivity between the thalamus and bilateral insula. Only PBD relatives showed abnormal connectivity within striatal-thalamo-cortical networks seen in both proband groups.

CONCLUSIONS

The present findings reveal a common pattern of deficits in frontostriatal circuitry across SCZ and PBD, and unique regional and functional connectivity abnormalities that distinguish them. The abnormal network connectivity in PBD relatives that was present in both proband groups may reflect genetic susceptibility associated with risk for psychosis, but within-family associations of this measure were not high.

Relationship between the angle of vertebral screws and spinal lateral angulation after fixation of thoracolumbar fractures via an anterior approach

This study investigated possible contributors to lateral spinal angulation after surgical fixation of thoracolumbar fractures via an anterior approach. We retrospectively examined lateral angulation in 172 cases of thoracolumbar fractures treated in this manner. The coronal Cobb angle and angles of the screws relative to the endplates were determined from radiographs. The patients completed the Short Form 36, Oswestry Disability Index, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, and Visual Analogue Scale at the final follow-up visit. The mean coronal Cobb angle was 0.75° ± 3.91° (-14.25° to 14.55°) preoperatively, 3.17° ± 4.07° (-8.18° to 14.01°) immediately postoperatively, and 3.46° ± 4.21° (-1.05° to 17.27°) at the final follow-up visit. The superior posterior and inferior anterior screws were more parallel to their respective endplates when the approach was made ≥2 vs ≤1 vertebral levels above the fracture (P < 0.001). Lateral angulation was more likely when the approach was made ≤1 vs ≥2 levels above the fracture (P < 0.001). The coronal Cobb angle differed significantly (P < 0.01) between patients with lumbar and thoracic fractures. The immediate postoperative coronal Cobb angle correlated tightly with the sum of the screw angles (superior plus inferior posterior and/or inferior plus superior anterior). Lateral angulation may occur after surgical fixation of thoracic and lumbar fractures via an anterior approach. Non-parallelism between the vertebral screws and their corresponding endplates may predict postoperative lateral spinal angulation. Postoperative lateral angulation does not correlate with low back pain, quality of life, or preoperative lateral angulation.

Extensive brain structural network abnormality in first-episode treatment-naive patients with schizophrenia: morphometrical and covariation study

BACKGROUND

Alterations in gray matter (GM) are commonly observed in schizophrenia. Accumulating studies suggest that the brain changes associated with schizophrenia are distributed rather than focal, involving interconnected networks of areas as opposed to single regions. In the current study we aimed to explore GM volume (GMV) changes in a relatively large sample of treatment-naive first-episode schizophrenia (FES) patients using optimized voxel-based morphometry (VBM) and covariation analysis.

METHOD

High-resolution T1-weighted images were obtained using 3.0-T magnetic resonance imaging (MRI) from 86 first-episode drug-naive patients with schizophrenia and 86 age- and gender-matched healthy volunteers. Symptom severity was evaluated using the Positive and Negative Syndrome Scale (PANSS). GMV was assessed using optimized VBM and in 16 regions of interest (ROIs), selected on the basis of a previous meta-analysis. The relationships between GMVs in the ROIs were examined using an analysis of covariance (ANCOVA).

RESULTS

The VBM analysis revealed that first-episode patients showed reduced GMV in the hippocampus bilaterally. The ROI analysis identified reductions in GMV in the left inferior frontal gyrus, bilateral hippocampus and right thalamus. The ANCOVA revealed different patterns of regional GMV correlations in patients and controls, including of inter- and intra-insula, inter-amygdala and insula-postcentral gyrus connections.

CONCLUSIONS

Schizophrenia involves regional reductions in GMV and changes in GMV covariance in the insula, amygdala and postcentral gyrus. These findings were evident at the onset of the disorder, before treatment, and therefore cannot be attributable to the effects of chronic illness progression or medication.

Altered structural covariance of the striatum in functional dyspepsia patients

BACKGROUND

Functional dyspepsia (FD) is thought to be involved in dysregulation within the brain-gut axis. Recently, altered striatum activation has been reported in patients with FD. However, the gray matter (GM) volumes in the striatum and structural covariance patterns of this area are rarely explored. The purpose of this study was to examine the GM volumes and structural covariance patterns of the striatum between FD patients and healthy controls (HCs).

METHODS

T1-weighted magnetic resonance images were obtained from 44 FD patients and 39 HCs. Voxel-based morphometry (VBM) analysis was adopted to examine the GM volumes in the two groups. The caudate- or putamen-related regions identified from VBM analysis were then used as seeds to map the whole brain voxel-wise structural covariance patterns. Finally, a correlation analysis was used to investigate the effects of FD symptoms on the striatum.

KEY RESULTS

The results showed increased GM volumes in the bilateral putamen and right caudate. Compared with the structural covariance patterns of the HCs, the FD-related differences were mainly located in the amygdala, hippocampus/parahippocampus (HIPP/paraHIPP), thalamus, lingual gyrus, and cerebellum. And significant positive correlations were found between the volumes in the striatum and the FD duration in the patients.

CONCLUSIONS & INFERENCES

These findings provided preliminary evidence for GM changes in the striatum and different structural covariance patterns in patients with FD. The current results might expand our understanding of the pathophysiology of FD.

Abnormalities in whole-brain functional connectivity observed in treatment-naive post-traumatic stress disorder patients following an earthquake

BACKGROUND

Convergent studies have highlighted the dysfunction of the amygdala, prefrontal cortex and hippocampus in post-traumatic stress disorder (PTSD). However, only a few studies have investigated the functional connectivity between brain regions in PTSD patients during the resting state, which may improve our understanding of the neuropathophysiology of PTSD. The aim of this study was to investigate patterns of whole-brain functional connectivity in treatment-naive PTSD patients without co-morbid conditions who experienced the 8.0-magnitude earthquake in the Sichuan province of China.

METHOD

A total of 72 PTSD patients and 86 trauma-exposed non-PTSD controls participated in the resting-state functional magnetic resonance imaging study. All these subjects were recruited from the disaster zone of the 2008 Sichuan earthquake. Functional connectivities between 90 paired brain regions in PTSD patients were compared with those in trauma-exposed non-PTSD controls. Furthermore, Pearson correlation analysis was performed between significantly abnormal connectivities in PTSD patients and their clinician-administered PTSD scale (CAPS) scores.

RESULTS

Compared with non-PTSD controls, PTSD patients showed weaker positive connectivities between the middle prefrontal cortex (mPFC) and the amygdala, hippocampus, parahippocampal gyrus and rectus, as well as between the inferior orbitofrontal cortex and the hippocampus. In addition, PTSD patients showed stronger negative connectivity between the posterior cingulate cortex (PCC) and the insula. The CAPS scores in PTSD patients correlated negatively with the connectivity between the amygdala and the mPFC.

CONCLUSIONS

PTSD patients showed abnormalities in whole-brain functional connectivity, primarily affecting the connectivities between the mPFC and limbic system, and connectivity between the PCC and insula.

InPBi single crystals grown by molecular beam epitaxy

InPBi was predicted to be the most robust infrared optoelectronic material but also the most difficult to synthesize within In-VBi (V = P, As and Sb) 25 years ago. We report the first successful growth of InPBi single crystals with Bi concentration far beyond the doping level by gas source molecular beam epitaxy. The InPBi thin films reveal excellent surface, structural and optical qualities making it a promising new III-V compound family member for heterostructures. The Bi concentration is found to be 2.4 ± 0.4% with 94 ± 5% Bi atoms at substitutional sites. Optical absorption indicates a band gap of 1.23 eV at room temperature while photoluminescence shows unexpectedly strong and broad light emission at 1.4-2.7 μm which can't be explained by the existing theory.

Altered intrinsic regional activity and corresponding brain pathways reflect the symptom severity of functional dyspepsia

BACKGROUND

Increasing evidence shows central abnormalities in functional dyspepsia (FD) patients, but whether the symptom severity is directly reflected in altered brain patterns remains unclear. The purpose of this study was to explore how FD affected the resting functional brain patterns for different degrees of symptom severity.

METHODS

Functional magnetic resonance imaging was carried out in 40 FD patients and 20 healthy controls. The resting-state brain changes in regional homogeneity (ReHo) and seed correlation analysis were investigated in patients relative to controls. To what degree the brain changes reflected the severity of the disease was assessed by a pattern classification technique.

KEY RESULTS

Altered ReHo values (p < 0.05, FDR corrected) were discovered in multiple brain areas in FD patients, and only the anterior cingulate cortex (ACC) and thalamus exhibited significant correlation with the severity of dyspepsia symptoms. Compared with controls, the neural signal changes of the thalamus were not found in the less severe FD patient group but in the relatively more severe group, while the ACC showed aberrations in both groups. Seed-based correlation analysis revealed ACC- and thalamus-related functional connectivity differences between FD patients and controls at a voxel-wise level, and the altered thalamic circuits provided the best performance in distinguishing FD patients with different levels of symptom severity.

CONCLUSIONS & INFERENCES

Our results indicated that the functional abnormalities of the ACC and thalamus may occur at different clinical courses in FD. This may help us better understand the progression of FD.

A novel semiconductor compatible path for nano-graphene synthesis using CBr4 precursor and Ga catalyst

We propose a novel semiconductor compatible path for nano-graphene synthesis using precursors containing C-Br bonding and liquid catalyst. The unique combination of CBr4 as precursor and Ga as catalyst leads to efficient C precipitation at a synthesis temperature of 200 °C or lower. The non-wetting nature of liquid Ga on tested substrates limits nano-scale graphene to form on Ga droplets and substrate surfaces at low synthesis temperatures of T ≤ 450 °C and at droplet/substrate interfaces by C diffusion via droplet edges when T ≥ 400 °C. Good quality interface nano-graphene is demonstrated and the quality can be further improved by optimization of synthesis conditions and proper selection of substrate type and orientation. The proposed method provides a scalable and transfer-free route to synthesize graphene/semiconductor heterostructures, graphene quantum dots as well as patterned graphene nano-structures at a medium temperature range of 400-700 °C suitable for most important elementary and compound semiconductors.

Using structural neuroanatomy to identify trauma survivors with and without post-traumatic stress disorder at the individual level

BACKGROUND

At present there are no objective, biological markers that can be used to reliably identify individuals with post-traumatic stress disorder (PTSD). This study assessed the diagnostic potential of structural magnetic resonance imaging (sMRI) for identifying trauma-exposed individuals with and without PTSD.

METHOD

sMRI scans were acquired from 50 survivors of the Sichuan earthquake of 2008 who had developed PTSD, 50 survivors who had not developed PTSD and 40 healthy controls who had not been exposed to the earthquake. Support vector machine (SVM), a multivariate pattern recognition technique, was used to develop an algorithm that distinguished between the three groups at an individual level. The accuracy of the algorithm and its statistical significance were estimated using leave-one-out cross-validation and permutation testing.

RESULTS

When survivors with PTSD were compared against healthy controls, both grey and white matter allowed discrimination with an accuracy of 91% (p < 0.001). When survivors without PTSD were compared against healthy controls, the two groups could be discriminated with accuracies of 76% (p < 0.001) and 85% (p < 0.001) based on grey and white matter, respectively. Finally, when survivors with and without PTSD were compared directly, grey matter allowed discrimination with an accuracy of 67% (p < 0.001); in contrast the two groups could not be distinguished based on white matter.

CONCLUSIONS

These results reveal patterns of neuroanatomical alterations that could be used to inform the identification of trauma survivors with and without PTSD at the individual level, and provide preliminary support to the development of SVM as a clinically useful diagnostic aid.