Abnormal segments of right uncinate fasciculus and left anterior thalamic radiation in major and bipolar depression

Differential brain structural abnormalities between bipolar disorder (BD) and major depressive disorder (MDD) may reflect different pathological mechanisms underlying these two brain disorders. However, few studies have directly compared the brain structural properties, especially in white matter (WM) tracts, between BD and MDD. Using automated fiber-tract quantification (AFQ), we utilized diffusion tensor images (DTI) from 67 unmedicated depressed patients, including 31 BD and 36 MDD, and 45 healthy controls (HC) to create fractional anisotropy (FA) tract profiles along 20 major WM tracts. Then, we compared between-group differences in FA values at each node along the fiber tracts. To differentiate the BD and the MDD, we enrolled the diffusion measures of the tract profiles into support vector machine (SVM), a type of machine learning algorithm. The BD showed lower FA in the insular cortex portion of the right uncinate fasciculus (UF) compared to the MDD and in the prefrontal lobe portion of the right UF compared to the HC. The MDD showed lower FA in the prefrontal lobe portion of the left anterior thalamic radiation (ATR) compared to the HC. Using the SVM approach, we found the FA tract profile of the left ATR can be used to differentiate the BD and the MDD at an accuracy up to 68.33% (p=0.018). These findings suggested that the BD and the MDD may be characterized by different abnormalities in specific segments of brain WM tracts, especially in two frontal-situated tracts, the right UF and the left ATR.

Recognition of osmotolerant yeast spoilage in kiwi juices by near-infrared spectroscopy coupled with chemometrics and wavelength selection

The study developed a NIR-SVM model for accurate recognition of osmotolerant yeasts in kiwi juice for the first time.

Mycobacterium tuberculosis H37Rv infection regulates alternative splicing in Macrophages

Objective: The objective of this study was to evaluate the expression of genes encoding SR proteinsand alternative splicing of IL4 and TLR4 in Mycobacterium tuberculosis (M. tb) H37Rv-infected macrophages.

Materials and methods: THP-1 cells were induced to differentiate into macrophages with 200 nM PMA, and H37Rv strains were used for macrophage infection. After RNA extraction, qRT-PCR was performed to evaluate the expression of many SR proteins as well as the alternative splicing of IL4 and TLR4.

Results: IL4 and TLR4 play significant roles in host immunity to tuberculosis. The level of IL-4 splice variants in THP-1 cells increased after M. tb H37Rv infection. Three splice variants of TLR4 were detected in M. tb-infected THP-1 cells, when compared with uninfected controls; the expression level of these splicing variants in M. tb-infected THP-1 cell was down-regulated. Since SR proteins are RNA-binding proteins that regulate RNA splicing, the expression of SR proteins was examined, and SRSF2 and SRSF3 were significantly down-regulated. In addition, splicing factors SRp75 and SF3a were also significantly down-regulated post M. tb infection.

Conclusion: Our findings indicate that alternative splicing may be involved in host gene regulation post M. tb infection of macrophage cells.

Vitamin A maintains the airway epithelium in a murine model of asthma by suppressing glucocorticoid-induced leucine zipper

BACKGROUND

The effects of glucocorticoids (GCs) on the repair of the airway epithelium in asthma are controversial, and we previously reported that the GC dexamethasone (Dex) inhibits the repair of human airway epithelial cells and that this process is mediated by glucocorticoid-induced leucine zipper (GILZ) through MAPK-ERK signaling in vitro. Vitamin A (VA) is involved in the regulation of the MAPK-ERK pathway but has not been widely supplied during asthma treatment. It is unclear whether VA attenuates the negative regulation of GILZ on the MAPK-ERK pathway and maintains airway epithelium integrity during asthma treatment.

METHODS

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) and subsequently treated with Dex, VA or intranasal inhalation of adenovirus sh-GILZ vectors. Indexes of airway epithelium integrity, including pathological alterations, pulmonary EGFR expression and airway hyperresponsiveness (AHR), were then measured. The expression of GILZ and key components of activated MAPK-ERK signals (p-Raf-1, p-MEK, and p-Erk1/2) were also detected.

RESULTS

Dex failed to relieve OVA-induced asthma airway epithelium injury, as assessed through H&E staining, EGFR expression and AHR. Moreover, in the OVA-challenged mice treated with Dex, GLIZ expression was increased, whereas the ratios of p-Raf-1/Raf-1, p-MEK/MEK and p-Erk1/2/Erk1/2 were significantly decreased. Further study indicated that GILZ expression was decreased and that the ratios of p-Raf-1/Raf-1, p-MEK/MEK and p-Erk1/2/Erk1/2 were up-regulated in the GILZ-silenced OVA-challenged mice and VA-fed OVA-challenged mice, independent of Dex treatment. The airway epithelium integrity of the OVA-challenged mice was maintained by treatment with both VA and Dex.

CONCLUSIONS

Vitamin A maintained the Dex-treated asthma airway epithelium via the down-regulation of GILZ expression and the activation MAPK-ERK signaling, and these effects might contribute to improving the effects of GC therapeutics on asthma.

Plasticity in deep and superficial white matter: a DTI study in world class gymnasts

Brain white matter (WM) could be generally categorized into two types, deep and superficial WM. Studies combining these two types WM are important for a better understanding of brain plasticity induced by motor training. In this study, we applied both univariate and multivariate approaches to study gymnastic training-induced plasticity in brain WM. Specifically, we acquired diffusion tensor imaging data from 13 world class gymnasts and 14 non-athlete normal controls, reconstructed brain deep and superficial WM tracts, estimated and compared their fractional anisotropy (FA) difference between the two groups. Taking FA values as the features, we applied logistic regression and support vector machine to distinguish the gymnasts from the controls. Compared to the controls, the gymnasts showed lower FA in four regional deep WM tracts, including the occipital lobe portion of left inferior fronto-occipital fasciculus (IFOF.L), occipital and temporal lobe portion of right inferior longitudinal fasciculus (ILF.R), insular cortex portion of right uncinate fasciculus (UF.R), and parietal lobe portion of right arcuate fasciculus (AF.R). Meanwhile, we found lower FA in the superficial U-shaped tracts within the frontal lobe in the gymnasts compared to the controls. In addition, we detected that mean FA in either the AF.R or the U-shaped tracts connecting the left pars triangularis and superior frontal gyrus was negatively correlated with years of training in the gymnasts. Classification analyses indicated FA in deep WM hold higher potential to distinguish the gymnasts from the controls. Overall, our findings provide a more complete picture of training-induced plasticity in brain WM.

Apical stress distribution under vertical compaction of gutta-percha and occlusal loads in canals with varying apical sizes: a three-dimensional finite element analysis

AIM

To investigate and compare the effects of two apical canal instrumentation protocols on apical stress distribution at the root apex under vertical compaction of gutta-percha and occlusal loads using finite element analysis.

METHODOLOGY

Three finite element analysis models of a mandibular first premolar were reconstructed: an original canal model, a size 35, .04 taper apical canal enlargement model and a Lightspeed size 60 apical canal enlargement model. A 15 N compaction force was applied vertically to the gutta-percha 5 mm from the apex. A 175 N occlusal load in two directions (vertical and 45° to the longitudinal axis of the tooth) was simulated. Stresses in the apical 2 mm of the root were calculated and compared among the three models.

RESULTS

Under vertical compaction, stresses in the apical canal instrumented by Lightspeed size 60 (maximal 3.3 MPa) were higher than that of the size 35, .04 taper model (maximal 1.3 MPa). In the case of the two occlusal forces, the Lightspeed size 60 apical enlargement was associated with the greatest stress distribution in the apical region. The greatest stress and the most obvious stress difference between the models appeared at the tip of the root when occlusal and vertical compaction loads were applied.

CONCLUSIONS

Apical enlargement caused stress distribution changes in the apical region of roots. The larger apical size led to higher stress concentration at the root apex.

Optimal Factors of Diffusion Tensor Imaging Predicting Corticospinal Tract Injury in Patients with Brain Tumors

Objective

To identify the optimal factors in diffusion tensor imaging for predicting corticospinal tract (CST) injury caused by brain tumors.

Materials and Methods

This prospective study included 33 patients with motor weakness and 64 patients with normal motor function. The movement of the CST, minimum distance between the CST and the tumor, and relative fractional anisotropy (rFA) of the CST on diffusion tensor imaging, were compared between patients with motor weakness and normal function. Logistic regression analysis was used to obtain the optimal factor predicting motor weakness.

Results

In patients with motor weakness, the displacement (8.44 ± 6.64 mm) of the CST (p = 0.009), minimum distance (3.98 ± 7.49 mm) between the CST and tumor (p < 0.001), and rFA (0.83 ± 0.11) of the CST (p < 0.001) were significantly different from those of the normal group (4.64 ± 6.65 mm, 14.87 ± 12.04 mm, and 0.98 ± 0.05, respectively) (p = 0.009, p < 0.001, and p < 0.001). The frequencies of patients with the CST passing through the tumor (6%, p = 0.002), CST close to the tumor (23%, p < 0.001), CST close to a malignant tumor (high grade glioma, metastasis, or lymphoma) (19%, p < 0.001), and CST passing through infiltrating edema (19%, p < 0.001) in the motor weakness group, were significantly different from those of the patients with normal motor function (0, 8, 1, and 10%, respectively). Logistic regression analysis showed that decreased rFA and CST close to a malignant tumor were effective variables related to motor weakness.

Conclusion

Decreased fractional anisotropy, combined with closeness of a malignant tumor to the CST, is the optimal factor in predicting CST injury caused by a brain tumor.

Dynamic Default Mode Network across Different Brain States

The default mode network (DMN) is a complex dynamic network that is critical for understanding cognitive function. However, whether dynamic topological reconfiguration of the DMN occurs across different brain states, and whether this potential reorganization is associated with prior learning or experience is unclear. To better understand the temporally changing topology of the DMN, we investigated both nodal and global dynamic DMN-topology metrics across different brain states. We found that DMN topology changes over time and those different patterns are associated with different brain states. Further, the nodal and global topological organization can be rebuilt by different brain states. These results indicate that the post-task, resting-state topology of the brain network is dynamically altered as a function of immediately prior cognitive experience, and that these modulated networks are assembled in the subsequent state. Together, these findings suggest that the changing topology of the DMN may play an important role in characterizing brain states.

Metabolic changes in normal appearing white matter in multiple sclerosis patients using multivoxel magnetic resonance spectroscopy imaging

Demyelination and axonal degeneration caused by multiple sclerosis (MS) exist in the white matter and not only in the lesion area. Magnetic resonance spectroscopy (MRS) could provide a unique insight into metabolic changes in the normal appearing white matter (NAWM). To evaluate the subtle axonal degeneration and delineate the spatial distribution of metabolite abnormalities in the NAWM in patients with MS. A total of 17 clinically definite relapsing-remitting MS (RRMS) patients and 21 healthy controls were enrolled in this study. 2D 1H magnetic resonance spectroscopic imaging (MRSI) performed at 3 Tesla was used to measure metabolite concentrations in the frontal-parietal-occipital NAWM. Ratios of N-acetyl-aspartate (NAA) and choline (Cho) to creatine (Cr) and Cho to NAA were calculated in each voxel. MS patients showed decreased NAA/Cr and increased Cho/NAA ratios in the NAWM compared to healthy controls. In the parietal NAWM, the extent of NAA/Cr decrease was significantly higher than that in the frontal and parietal-occipital NAWM. Decreased NAA in the NAWM would provide useful metabolic information for evaluation of disease progression in MS. The high extent of NAA decrease in the parietal NAWM helps improve the accuracy of the prediction.

Grafting density dominant glass transition of dry polystyrene brushes

The effects of the grafting densities (σ_p), molecular weights (M_n) and thicknesses of dry polystyrene (PS) brushes on their glass transition temperature (T) were investigated by ellipsometry. The results show that T strongly depends on the grafting density of the PS brushes. The T of the PS brushes with σ_p > 0.30 increases with decreasing M_n (or brush thickness) and is mainly dominated by entropic effects, in which the grafted chains are highly extended along the film thickness direction resulting in a sharp reduction in configurational entropy. The T of PS brushes with σ_p < 0.30 decreases with decreasing M_n (or brush thickness) which is mainly dominated by surface effects. For intermediate-density brushes (σ_p = 0.30), T becomes independent of M_n or brush thickness. The reason for this grafting density dependence of T is attributed to the transition of the PS brush conformation from mushroom-to-brush.

PPE38 Protein of Mycobacterium tuberculosis Inhibits Macrophage MHC Class I Expression and Dampens CD8+ T Cell Responses

Suppression of CD8⁺ T cell activation is a critical mechanism used by Mycobacterium tuberculosis (MTB) to escape protective host immune responses. PPE38 belongs to the unique PPE family of MTB and in our previous study, PPE38 protein was speculated to participate in manipulating macrophage MHC class I pathway. To test this hypothesis, the function of mycobacterial PPE38 protein was assessed here using macrophage and mouse infection models. Decreased amount of MHC class I was observed on the surface of macrophages infected with PPE38-expressing mycobacteria. The transcript of genes encoding MHC class I was also inhibited by PPE38. After infection of C57BL/6 mice with Mycobacterium smegmatis expressing PPE38 (Msmeg-PPE38), decreased number of CD8⁺ T cells was found in spleen, liver, and lungs through immunohistochemical analysis, comparing to the control strain harboring empty vector (Msmeg-V). Consistently, flow cytometry assay showed that fewer effector/memory CD8⁺ T cells (CD44^highCD62L^low) were activated in spleen from Msmeg-PPE38 infected mice. Moreover, Msmeg-PPE38 confers a growth advantage over Msmeg-V in C57BL/6 mice, indicating an effect of PPE38 to favor mycobacterial persistence in vivo. Overall, this study shows a unique biological function of PPE38 protein to facilitate mycobacteria to escape host immunity, and provides hints for TB vaccine development.

Intraspinal bronchogenic cyst: Series of case reports and literature review

PURPOSE

Spinal bronchogenic cysts (SBCs) are rare congenital lesions. The clinical and imaging characteristics and treatment of SBCs are not well known. We studied three cases of SBCs retrospectively, which were registered in our department and analyzed eight case reports which were all published in English, focusing on providing a deeper knowledge of SBCs.

METHODS

Three patients with SBCs registered in our department were retrospectively reviewed. Eight reported SBCs cases published from 1992 to 2015 were enrolled in our study. Imaging diagnosis was confirmed by computed tomography (CT), MRI, and computed tomography angiography (CTA). All of our patients and reviewed cases had undergone surgical resection and the final diagnosis was made by pathological examination.

RESULTS

Five lesions were located at the cervical spinal canal. Most patients presented with pain in the limbs and back, which might be related to compression of the spinal cord and the reduced blood supply of the anterior spinal artery. The signal intensity on MRI was correlated with cystic fluid traits to a large extent. Seven lesions were partially removed because of the adhesions to the nearby spinal cord. All reported cases had no recurrence in the later follow-up.

CONCLUSIONS

SBCs can occur anywhere in the spinal canal, but they are more likely to present at the cervical canal and might be present along with some developmental malformations of the spine. We emphasize the role of CT and MRI findings in the disease diagnosis. It is recommended that the lesion should be removed as completely as possible.

Diverse effects of mycobacterial proline-proline-glutamic acid proteins upon interaction with host macrophages

The proline-proline-glutamic acid (PPE) family proteins are abundant only in pathogenic Mycobacteria, but their general functions are far from unveiled. To investigate their roles in how Mycobacterium tuberculosis (Mtb) resists killing by the host, 25 PPE recombinant Mycobacterium smegmatis strains that overexpress Mtb PPE proteins were constructed. During phagocytosis, a similar amount of intracellular bacteria was observed at 2 h post-infection (hpi) for 24 PPE recombinants, while a 50% reduction of entrance was observed for the PPE29 recombinant. In addition, we found that 20 ppe genes significantly influenced the survival of mycobacteria within macrophage cells. Mycobacterial survival was promoted by overexpression of 18 of these genes and inhibited by the other two. Highest survival was observed for the PPE27 recombinant. We also measured the levels of proinflammatory cytokines tumor necrosis factor-alpha and interleukin-6 secreted by macrophages. The overall effects varied among the different PPE recombinants. Moreover, we also found that various PPE recombinants exhibited increased resistance against oxidative, acidic and sodium dodecyl sulfate stresses that could be encountered in vivo. Together, our results indicate that PPE proteins play distinct roles in mycobacterial survival in macrophages. The findings described here broaden our understanding of mycobacterial pathogenicity.

Wash-free colorimetric homogeneous immunoassay for Zygosaccharomyces rouxii

A rapid and convenient AuNP-based method for detecting large microbes was developed.

Iron oxide nanoparticles functionalized with nisin for rapid inhibition and separation of Alicyclobacillus spp

One-step synthesis of iron oxide magnetic nanoparticles with nisin based on electrostatic adsorption for inhibition and separation ofAlicyclobacillusspp.

Identification and characterization of epiphytic yeasts on apples in China

The first report regarding yeast diversity on apples from the two largest producing areas in China.

Radiographic findings of a well-differentiated sinonasal neuroendocrine neoplasm: Case report and review of the literature

Typical carcinoid is a rare tumor among other neuroendocrine neoplasms that occur in the nasal cavity. Only a few cases of typical carcinoids in the nasal cavity have been reported. We report a case of typical carcinoid of the nasal cavity in a 61-year-old man who had a history of persistent nasal obstruction and epistaxis for approximately 17 years. Computed tomography revealed a huge, lobulated mass in the nasal cavity with extension into the posterior sphenoid sinus. Extensive bone destruction could be seen in the neighboring sphenoid sinus. MR imaging suggested that the tumor was close to the dura. The final histologic evaluation of the excised biopsy specimen yielded a diagnosis of a well-differentiated neuroendocrine neoplasm (typical carcinoid). In this article, the relevant reports in the literature are reviewed, and the role of radiographic findings on tumor diagnosis and on the establishment of a surgery plan is emphasized.

[Quantitative proteomic analysis of mkl gene function in Mycobacterium marinum using iTRAQ]

OBJECTIVE

To identify differentially expressed proteins in Mycobacterium marinum wild-type (WT) and mkl::Tn mutant strains, and provide new clues for exploring the functions of mkl gene.

METHODS

Cellular proteins were extracted from cultures of M. marinum WT and mkl::Tn strains, and labelled with isobaric tags for relative and absolute quantitation (iTRAQ) 4-plex. Differentially expressed proteins were identified with LC-MS/MS and subjected to biological information analysis.

RESULTS

A total of 566 differentially expressed proteins were revealed, among which 232 proteins were up-regulated (ratio≥1.4) and 334 proteins were down-regulated (ratio≤0.7). These proteins are mainly associated with lipid metabolism, cell wall and cell processes, intermediary metabolism and respiration, and hypothetical proteins. The most down-regulated protein DesA3, is a fatty acid desaturase and involved in the synthesis of oleic acid. Further experiments showed that the growth of mkl::Tn strain was attenuated on 7H10-ADC agar plate without oleic acid, suggesting that mkl may play a role in the biosynthesis of oleic acid.

CONCLUSION

Differentially expressed proteins were identified in M. marinum mkl::Tn compared to WT, and these results shed light on the mechanisms of mkl gene in mycobacterial pathogenesis.

The FBPase Encoding Gene glpX Is Required for Gluconeogenesis, Bacterial Proliferation and Division In Vivo of Mycobacterium marinum

Lipids have been identified as important carbon sources for Mycobacterium tuberculosis (Mtb) to utilize in vivo. Thus gluconeogenesis bears a key role for Mtb to survive and replicate in host. A rate-limiting enzyme of gluconeogenesis, fructose 1, 6-bisphosphatase (FBPase) is encoded by the gene glpX. The functions of glpX were studied in M. marinum, a closely related species to Mtb. The glpX deletion strain (ΔglpX) displayed altered gluconeogenesis, attenuated virulence, and altered bacterial proliferation. Metabolic profiles indicate an accumulation of the FBPase substrate, fructose 1, 6-bisphosphate (FBP) and altered gluconeogenic flux when ΔglpX is cultivated in a gluconeogenic carbon substrate, acetate. In both macrophages and zebrafish, the proliferation of ΔglpX was halted, resulting in dramatically attenuated virulence. Intracellular ΔglpX exhibited an elongated morphology, which was also observed when ΔglpX was grown in a gluconeogenic carbon source. This elongated morphology is also supported by the observation of unseparated multi-nucleoid cell, indicating that a complete mycobacterial division in vivo is correlated with intact gluconeogenesis. Together, our results indicate that glpX has essential functions in gluconeogenesis, and plays an indispensable role in bacterial proliferation in vivo and virulence of M. marinum.

Assessing Region of Interest Schemes for the Corticospinal Tract in Patients With Brain Tumors

Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) techniques are widely used for identifying the corticospinal tract (CST) white matter pathways as part of presurgical planning. However, mass effects in patients with brain tumors tend to cause anatomical distortions and compensatory functional reorganization of the cortex, which may lead to inaccurate mapping of white matter tracts. To overcome these problems, we compared different region-of-interest (ROI) selection schemes to track CST fibers in patients with brain tumors. Our study investigated the CSTs of 16 patients with intracranial tumors. The patients were classified into 3 subgroups according to the spatial relationships of the lesion and the primary motor cortex (PMC)/internal capsule. Specifically, we investigated the key factors that cause distorted tractography in patients with tumors. We compared 3 CST tractography methods that used different ROI selection schemes. The results indicate that CST fiber tracking methods based only on anatomical ROIs could possibly lead to distortions near the PMC region and may be unable to effectively localize the PMC. In contrast, the dual ROI method, which uses ROIs that have been selected from both blood oxygen level-dependent functional MRI (BOLD-fMRI) activation and anatomical landmarks, enabled the tracking of fibers to the motor cortex. The results demonstrate that the dual ROI method can localize the entire CST fiber pathway and can accurately describe the spatial relationships of CST fibers relative to the tumor. These results illustrate the reliability of using fMRI-guided DTT in patients with tumors. The combination of fMRI and anatomical information enhances the identification of tracts of interest in brains with anatomical deformations, which provides neurosurgeons with a more accurate approach for visualizing and localizing white matter fiber tracts in patients with brain tumors. This approach enhances surgical performance and perserves brain function.

A novel method to quantify the activity of alcohol acetyltransferase Using a SnO2-based sensor of electronic nose

Alcohol acetyltransferase (AATFase) extensively catalyzes the reactions of alcohols to acetic esters in microorganisms and plants. In this work, a novel method has been proposed to quantify the activity of AATFase using a SnO2-based sensor of electronic nose, which was determined on the basis of its higher sensitivity to the reducing alcohol than the oxidizing ester. The maximum value of the first-derivative of the signals from the SnO2-based sensor was therein found to be an eigenvalue of isoamyl alcohol concentration. Quadratic polynomial regression perfectly fitted the correlation between the eigenvalue and the isoamyl alcohol concentration. The method was used to determine the AATFase activity in this type of reaction by calculating the conversion rate of isoamyl alcohol. The proposed method has been successfully applied to determine the AATFase activity of a cider yeast strain. Compared with GC-MS, the method shows promises with ideal recovery and low cost.