Phosphoproteomic analysis reveals changes in A-Raf-related protein phosphorylation in response to Toxoplasma gondii infection in porcine macrophages.

BACKGROUND: Toxoplasma gondii is an obligate intracellular protozoan parasite that causes severe threats to humans and livestock. Macrophages are the cell type preferentially infected by T. gondii in vivo. Protein phosphorylation is an important posttranslational modification involved in diverse cellular functions. A rapidly accelerated fibrosarcoma kinase (A-Raf) is a member of the Raf family of serine/threonine protein kinases that is necessary for MAPK activation. Our previous research found that knockout of A-Raf could reduce T. gondii-induced apoptosis in porcine alveolar macrophages (3D4/21 cells). However, limited information is available on protein phosphorylation variations and the role of A-Raf in macrophages infected with T. gondii. METHODS: We used immobilized metal affinity chromatography (IMAC) in combination with liquid chromatography tandem mass spectrometry (LC-MS/MS) to profile changes in phosphorylation in T. gondii-infected 3D4/21 and 3D4/21-ΔAraf cells. RESULTS: A total of 1647 differentially expressed phosphorylated proteins (DEPPs) with 3876 differentially phosphorylated sites (DPSs) were identified in T. gondii-infected 3D4/21 cells (p3T group) when compared with uninfected 3D4/21 cells (pho3 group), and 959 DEPPs with 1540 DPSs were identified in the p3T group compared with infected 3D4/21-ΔAraf cells (p3KT group). Venn analysis revealed 552 DPSs corresponding to 406 DEPPs with the same phosphorylated sites when comparing p3T/pho3 versus p3T/p3KT, which were identified as DPSs and DEPPs that were directly or indirectly related to A-Raf. CONCLUSIONS: Our results revealed distinct responses of macrophages to T. gondii infection and the potential roles of A-Raf in fighting infection via phosphorylation of crucial proteins.

Social Disconnectedness, Perceived Loneliness, and Cognitive Functioning: The Role of Neighborhood Environment.

Background and Objectives: Social disconnectedness and loneliness pose significant challenges for older Chinese immigrants. Yet, it remains unclear whether they are associated with an increased risk of cognitive decline in this population. This study aimed to investigate the association of social disconnectedness and loneliness with cognitive functioning and examine the moderation role of neighborhood contexts. Research Design and Methods: This longitudinal analysis examined a sample of individuals aged 60 years and older from the Population Study of Chinese Elderly in Chicago (N = 2,044). Global cognition was assessed using the averaged z-scores of cognitive performance tests. Social disconnectedness was constructed using 5 indicators about structural aspects of social relationships. Loneliness was assessed with the R-UCLA loneliness scale. Neighborhood socioeconomic status (NSES) and neighborhood segregation index were constructed using 2010-2014 American Community Survey data at the census tract level. Individual perceptions about neighborhood environments were used to construct neighborhood cohesion index and neighborhood disorder index (NDI). Latent growth curve models with adjusted cluster robust standard errors were estimated. Results: More loneliness was associated with a higher level of initial cognitive functioning (B = 0.030, p < .01), but also with a faster decline rate over time (B = -0.007, p < .01) after adjusting for covariates. High NSES and less neighborhood segregation buffered the negative effects of loneliness on cognitive decline, respectively. High NDI amplified the positive relationship between loneliness and initial functioning, but accelerated the rate of cognitive decline associated with loneliness. Discussion and Implications: The study revealed that perceived loneliness, but not social disconnectedness, is a risk factor for cognitive decline among older Chinese immigrants. Living in a neighborhood with low socioeconomic status, more segregation, and high disorder elevated the detrimental effect of loneliness on long-term cognitive decline. Further research needs to investigate the complex interplay between social relationships, neighborhood environment, and cognition.

Vascular endothelial glycocalyx shedding in ventilator-induced lung injury in rats.

Endothelial permeability deterioration is involved in ventilator-induced lung injury (VILI). The integrality of vascular endothelial glycocalyx (EG) is closely associated with endothelial permeability. The hypothesis was that vascular EG shedding participates in VILI through promoting endothelial permeability. In the present study, male Sprague-Dawley (SD) rats were ventilated with high tidal volume (VT =40 ml/kg) or low tidal volume (VT =8 ml/kg) to investigate the effects of different tidal volume and ventilation durations on EG in vivo. We report disruption of EG during the period of high tidal volume ventilation characterized by increased glycocalyx structural components (such as syndecan-1, heparan sulfate, hyaluronan) in the plasma and decreased the expression of syndecan-1 in the lung tissues. Mechanistically, the disruption of EG was associated with increased proinflammatory cytokines and matrix metalloproteinase in the lung tissues. Collectively, these results demonstrate that the degradation of EG is involved in the occurrence and development of VILI in rats, and the inflammatory mechanism mediated by activation of the NF-κB signaling pathway may be partly responsible for the degradation of EG in VILI in rats. This study enhances our understanding of the pathophysiological processes underlying VILI, shedding light on potential therapeutic targets to mitigate VILI.

Toxoplasma gondii infection regulates apoptosis of host cells via miR-185/ARAF axis.

BACKGROUND: Toxoplasmosis is a zoonosis with a worldwide presence that is caused by the intracellular parasite Toxoplasma gondii. Active regulation of apoptosis is an important immune mechanism by which host cells resist the growth of T. gondii or avoid excessive pathological damage induced by this parasite. Previous studies found that upregulated expression of microRNA-185 (miR-185) during T. gondii infection has a potential role in regulating the expression of the ARAF gene, which is reported to be associated with cell proliferation and apoptosis. METHODS: The expression levels of miR-185 and the ARAF gene were evaluated by qPCR and Western blot, respectively, in mice tissues, porcine kidney epithelial cells (PK-15) and porcine alveolar macrophages (3D4/21) following infection with the T. gondii ToxoDB#9 and RH strains. The dual luciferase reporter assay was then used to verify the relationship between miR-185 and ARAF targets in PK-15 cells. PK-15 and 3D4/21 cell lines with stable knockout of the ARAF gene were established by CRISPR, and then the apoptosis rates of the cells following T. gondii infection were detected using cell flow cytometry assays. Simultaneously, the activities of cleaved caspase-3, as a key apoptosis executive protein, were detected by Western blot to evaluate the apoptosis levels of cells. RESULTS: Infection with both the T. gondii ToxoDB#9 and RH strains induced an increased expression of miR-185 and a decreased expression of ARAF in mice tissues, PK-15 and 3D4/21 cells. MiR-185 mimic transfections showed a significantly negative correlation in expression levels between miR-185 and the ARAF gene. The dual luciferase reporter assay confirmed that ARAF was a target of miR-185. Functional investigation revealed that T. gondii infection induced the apoptosis of PK-15 and 3D4/21 cells, which could be inhibited by ARAF knockout or overexpression of miR-185. The expression levels of cleaved caspase-3 protein were significantly lower in cells with ARAF knockout than in normal cells, which were consistent with the results of the cell flow cytometry assays. CONCLUSIONS: Toxoplasma gondii infection could lead to the upregulation of miR-185 and the downregulation of ARAF, which was not related to the strain of T. gondii and the host cells. Toxoplasma gondii infection could regulate the apoptosis of host cells via the miR-185/ARAF axis, which represents an additional strategy used by T. gondii to counteract host-cell apoptosis in order to maintain survival and reproduce in the host cells.

Smoke exposure associated with higher urinary benzene biomarker muconic acid (MUCA) in Golestan Cohort Study participants.

Background. Benzene is a known human carcinogen. Human exposure to benzene can be assessed by measuring trans, trans-muconic acid (MUCA) in urine. Golestan Province in northeastern Iran has been reported to have high incidence of esophageal cancer linked to the use of tobacco products. This manuscript evaluates the urinary MUCA concentrations among the participants of the Golestan Cohort Study (GCS).Methods. We analyzed MUCA concentration in 177 GCS participants' urine samples and performed nonparametric pairwise multiple comparisons to determine statistically significant difference among six different product use groups. Mixed effects model was fitted on 22 participants who exclusively smoked cigarette and 51 participants who were classified as nonusers. The urinary MUCA data were collected at the baseline and approximately five years later, and intraclass correlation coefficient (ICC) was calculated from the model.Results. Compared with nonusers, tobacco smoking was associated with higher urinary MUCA concentrations. Based on the nonparametric test of pairwise multiple comparisons, MUCA concentrations among participants who smoked combusted tobacco products were statistically significantly higher compared to nonusers. Urinary MUCA collected five years apart from the same individuals showed moderate reliability (ICC = 0.41), which was expected given the relatively short half-life (∼6 h) of MUCA.Conclusion. Our study revealed that tobacco smoke was positively associated with increased levels of urinary MUCA concentration, indicating that it is a significant source of benzene exposure among GCS participants.

Effect of perioperative goal-directed fluid therapy on postoperative complications after thoracic surgery with one-lung ventilation: a systematic review and meta-analysis.

BACKGROUND: An understanding of the impact of goal-directed fluid therapy (GDFT) on the outcomes of patients undergoing one-lung ventilation (OLV) for thoracic surgery remains incomplete and controversial. This meta-analysis aimed to assess the effect of GDFT compared to other fluid therapy strategies on the incidence of postoperative complications in patients with OLV. METHODS: The Embase, Cochrane Library, Web of Science, and MEDLINE via PubMed databases were searched from their inception to November 30, 2022. Forest plots were constructed to present the results of the meta-analysis. The quality of the included studies was evaluated using the Cochrane Collaboration tool and Risk Of Bias In Non-Randomized Study of Interventions (ROBINS-I). The primary outcome was the incidence of postoperative complications. Secondary outcomes were the length of hospital stay, PaO2/FiO2 ratio, total fluid infusion, inflammatory factors (TNF-α, IL-6), and postoperative bowel function recovery time. RESULTS: A total of 1318 patients from 11 studies were included in this review. The GDFT group had a lower incidence of postoperative complications [odds ratio (OR), 0.47; 95% confidence interval (95% CI), 0.29-0.75; P = 0.002; I 2, 67%], postoperative pulmonary complications (OR 0.48, 95% CI 0.27-0.83; P = 0.009), and postoperative anastomotic leakage (OR 0.51, 95% CI 0.27-0.97; P = 0.04). The GDFT strategy reduces total fluid infusion. CONCLUSIONS: GDFT is associated with lower postoperative complications and better survival outcomes after thoracic surgery for OLV.

Residential Segregation, Perceived Neighborhood Environment, and All-Cause Mortality Among Community-Dwelling Older Chinese Americans.

OBJECTIVES: Residential segregation profoundly affects mental and physical health. However, impacts of residential segregation and other neighborhood characteristics on health among older Asian Americans are not fully understood. This study aimed to close this gap by examining effects of residential segregation, perceived neighborhood cohesion, and neighborhood disorder on all-cause mortality among older Chinese immigrants, as well as testing whether the association between residential segregation and mortality would be mediated by perceived neighborhood cohesion and neighborhood disorder. METHODS: Data were drawn from a subsample of 3,094 older Chinese Americans aged 60 and older (mean age = 72.8 years) from the Population Study of Chinese Elderly in Chicago. Residential segregation was derived using 2010-2014 American Community Survey data. Participants completed surveys on perceived neighborhood cohesion and neighborhood disorder between 2011 and 2013. All-cause mortality was tracked until December 2021. RESULTS: Residential segregation was associated with elevated all-cause mortality risk; this association, however, was no longer statistically significant after controlling for sociodemographic, behavioral, and health covariates. Perceived neighborhood cohesion, but not neighborhood disorder, was significantly associated with decreased mortality risks. There were no indirect effects of residential segregation on all-cause mortality through perceived neighborhood cohesion or neighborhood disorder. These effects were consistent across male and female participants. DISCUSSION: These results suggest the importance of neighborhood social environment, specifically perceptions of neighborhood cohesion, in influencing mortality risk among older Chinese immigrants. The findings also indicate the need to conduct further research to examine the health impact of residential segregation among this population.

Effects of acute stress on risky decision-making are related to neuroticism: An fMRI study of the Balloon Analogue Risk Task.

BACKGROUND: Decision making under acute stress is frequent in daily life. While evidence suggests for a modulatory role of neuroticism on risky decision-making behaviors, the neural correlates underlying the association between neuroticism and risky decision-making under acute stress remain to be elucidated. METHODS: Based on a modified Balloon Analogue Risk Task (BART) with concurrent functional magnetic resonance imaging, we evaluated the effect of acute stress on risk-taking behavior in 27 healthy male adults, and further assessed stress-induced changes in brain activation according to the individual differences in neuroticism. RESULTS: Higher trait neuroticism levels positively correlated with increased stress-modulated activation of the right dorsal anterior cingulate cortex during risk-taking, and negatively correlated with decreased stress-modulated activation of the right dorsolateral prefrontal cortex during cash-outs. LIMITATIONS: Only male participants were recruited. CONCLUSIONS: We found a positive correlation between neuroticism and greater risk-taking behavior under acute stress. These results extend our understanding of the increased risk-taking propensity in high neurotic individuals under acute stress.

Effect of Driving Pressure-Oriented Ventilation on Patients Undergoing One-Lung Ventilation During Thoracic Surgery: A Systematic Review and Meta-Analysis.

Background: Hypoxemia and fluctuations in respiratory mechanics parameters are common during one-lung ventilation (OLV) in thoracic surgery. Additionally, the incidence of postoperative pulmonary complications (PPCS) in thoracic surgery is higher than that in other surgeries. Previous studies have demonstrated that driving pressure-oriented ventilation can reduce both mortality in patients with acute respiratory distress syndrome (ARDS) and the incidence of PPCS in patients undergoing general anesthesia. Our aim was to determine whether driving pressure-oriented ventilation improves intraoperative physiology and outcomes in patients undergoing thoracic surgery. Methods: We searched MEDLINE via PubMed, Embase, Cochrane, Web of Science, and ClinicalTrials.gov and performed a meta-analysis to compare the effects of driving pressure-oriented ventilation with other ventilation strategies on patients undergoing OLV. The primary outcome was the PaO2/FiO2 ratio (P/F ratio) during OLV. The secondary outcomes were the incidence of PPCS during follow-up, compliance of the respiratory system during OLV, and mean arterial pressure during OLV. Results: This review included seven studies, with a total of 640 patients. The PaO2/FiO2 ratio was higher during OLV in the driving pressure-oriented ventilation group (mean difference [MD]: 44.96; 95% confidence interval [CI], 24.22-65.70.32; I 2: 58%; P < 0.0001). The incidence of PPCS was lower (OR: 0.58; 95% CI, 0.34-0.99; I 2: 0%; P = 0.04) and the compliance of the respiratory system was higher (MD: 6.15; 95% CI, 3.97-8.32; I 2: 57%; P < 0.00001) in the driving pressure-oriented group during OLV. We did not find a significant difference in the mean arterial pressure between the two groups. Conclusion: Driving pressure-oriented ventilation during OLV in patients undergoing thoracic surgery was associated with better perioperative oxygenation, fewer PPCS, and improved compliance of the respiratory system. Systematic Review Registration: PROSPERO, identifier: CRD42021297063.

Influence of wind and light on the floating and sinking process of Microcystis.

The vertical migration and accumulation of Microcystis colonies is a critical process in algal bloom formation. This work explored the effect of wind and light intensity on the vertical migration of Microcystis colonies. The wind-driven currents, light-driven changes in mass density of colonies, and the effect of colony size was coupled to simulate the vertical motion of colonies via Ansys Fluent and MATLAB. Results showed that light causes Microcystis to exhibit a 'day-sinking and night-floating' (d-n) phenomenon, however, wind weakens the phenomenon by forming a turbulent drag force that inhibits the vertical movement of Microcystis. This study proposed a kinetic ratio-based method, that there is a specific equilibrium turbulent kinetic energy and when turbulent kinetic energy of the water body is greater than the equilibrium turbulent kinetic energy, the d-n phenomenon does not occur. For Lake Taihu, the wind-driven turbulent kinetic energy is usually greater than the equilibrium turbulent kinetic energy. Therefore, Microcystis colonies may not exhibit the d-n phenomenon. Our findings provide a new theoretical basis for current process-based models in simulating algal blooms in large shallow lakes.

Acute High Level Noise Exposure Can Cause Physiological Dysfunction in Macaque Monkeys: Insight on the Medical Protection for Special Working Environmental Personnel.

The high level noise caused by intense acoustic weapons and blasting is a common source of acute acoustic trauma faced by some special environmental personnel. Studies have shown that high level noise can cause auditory and non-auditory effects. However, there are few reports on the biological effects, especially the non-auditory effects of acute high level noise exposure in simulated special working environments, and the great differences between experimental animals and human beings make it difficult to extrapolate from research conclusions. In this study, macaque monkeys were used to detect the effects of acute high level noise exposure on hearing, cognition, and cardiovascular function. Auditory brainstem response, auditory P300, and electrocardiogram (ECG) of macaque monkeys were measured. Results showed that acute high level noise exposure caused permanent hearing threshold shifts; partial hearing loss which couldn't recover to normal levels in the detection period; pathological changes in T wave and QRS complexes; and large fluctuations in cognitive ability after exposure, which finally recovered to normal. These alterations may be a combination of effects caused by stress-induced neuroendocrine dysfunction and mechanical damage of auditory organs. To elaborate the exact mechanism, further studies are still needed. Meanwhile, positive measures should be taken to reduce the incidence of acute high level noise injury.

Brain structural plasticity in visual and sensorimotor areas of airline pilots: A voxel-based morphometric study.

BACKGROUND AND PURPOSE: Airline pilot is a highly specialized profession that requires to response quickly and accurately in the presence of a wide variety of visual information. Although functional imaging studies have employed virtual simulation to identify brain areas that underlie various flying-related tasks, little is known about the specific patterns of structural plasticity in the airline pilot's brain. MATERIALS AND METHODS: In this study, we examined differences of gray matter and white matter volumes between 42 airline pilots and 39 non-pilots by using voxel-based morphometry, and further assessed the association between magnitude of structural alterations and flight time in the pilots. RESULTS: We found significantly increased white matter volume in the cuneus area in the pilot group compared to the non-pilot group (p < 0.05, FWE corrected). Using a relaxed threshold, it was also observed that the pilots had increased gray matter volume in the lingual gyrus, inferior frontal gyrus, supramarginal gyrus, cuneus, and postcentral gyrus, and increased white matter volume in the postcentral area (p < 0.001, uncorrected). Moreover, the pilots' flight time was positively correlated with gray matter volume in the postcentral gyrus and white matter volume in the cuneus area (p < 0.001, uncorrected). CONCLUSIONS: The morphological changes in specific visual and sensorimotor areas may provide airline pilots with neural efficiency in the visuo-motor processing related to flight.

Discriminative Analysis of Symptom Severity and Ultra-High Risk of Schizophrenia Using Intrinsic Functional Connectivity.

Past studies have consistently shown functional dysconnectivity of large-scale brain networks in schizophrenia. In this study, we aimed to further assess whether multivariate pattern analysis (MVPA) could yield a sensitive predictor of patient symptoms, as well as identify ultra-high risk (UHR) stage of schizophrenia from intrinsic functional connectivity of whole-brain networks. We first combined rank-based feature selection and support vector machine methods to distinguish between 43 schizophrenia patients and 52 healthy controls. The constructed classifier was then applied to examine functional connectivity profiles of 18 UHR individuals. The classifier indicated reliable relationship between MVPA measures and symptom severity, with higher classification accuracy in more severely affected schizophrenia patients. The UHR subjects had classification scores falling between those of healthy controls and patients, suggesting an intermediate level of functional brain abnormalities. Moreover, UHR individuals with schizophrenia-like connectivity profiles at baseline presented higher rate of conversion to full-blown illness in the follow-up visits. Spatial maps of discriminative brain regions implicated increases of functional connectivity in the default mode network, whereas decreases of functional connectivity in the cerebellum, thalamus and visual areas in schizophrenia. The findings may have potential utility in the early diagnosis and intervention of schizophrenia.

Amplification and Preparation of Cellular O-Glycomes for Functional Glycomics.

Mucin-type O-glycans play key roles in many cellular processes, and they are often altered in human diseases. A major challenge in studying the role of O-glycans through functional O-glycomics is the absence of a complete repertoire of the glycans that comprise the human O-glycome. Here we describe a cellular O-glycome preparation strategy, Preparative Cellular O-Glycome Reporter/Amplification (pCORA), that introduces 4-N3-Bn-GalNAc(Ac)3 as a novel precursor in large-scale cell cultures to generate usable amounts of O-glycans as a potential O-glycome factory. Cultured human non-small cell lung cancer (NSCLC) A549 cells take up the precursor, which is extended by cellular glycosyltransferases to produce 4-N3-Bn-α-O-glycans that are secreted into the culture medium. The O-glycan derivatives can be clicked with a fluorescent bifunctional tag that allows multidimensional HPLC purification and production of a tagged glycan library, representing the O-glycome of the corresponding cells. We obtained ∼5% conversion of precursor to O-glycans and purified a tagged O-glycan library of over 100 O-glycan derivatives, many of which were present in >100 nmol amounts and were sequenced by sequential MS fragmentation (MSn). These O-glycans were successfully printed onto epoxy glass slides as an O-glycome shotgun microarray. We used this novel array to explore binding activity of serum IgM in healthy persons and NSCLC patients at different cancer stages. This novel strategy provides access to complex O-glycans in significant quantities and may offer a new route to discovery of potential diagnostic disease biomarkers.

Cyanobacterial bloom expansion caused by typhoon disturbance in Lake Taihu China.

It remains unclear why the area of a cyanobacterial bloom increases in a shallow lake after a typhoon passes. In this study, the mechanisms of cyanobacterial bloom expansion were investigated by studying meteorological factors, water quality, algal biomass, and bloom area in Lake Taihu before and after typhoons (2007-2016). Our results showed that typhoon-induced sediment resuspension caused a short-term increase in nutrients, but nutrients returned to pre-typhoon levels after the typhoon passages. The short-term nutrient release during a typhoon did not result in an obvious increase in Microcystis cell density in two bays of Lake Taihu (Gonghu and Meiliang). Under strong winds, Microcystis aggregates were uniformly distributed in the water column downwind and then dispersed into different directions by wind-driven currents. In particular, Microcystis in the surface water were transported to the center of Lake Taihu. After a typhoon, dispersed Microcystis refloated and formed blooms. Thus, the bloom area was enlarged compared with before a typhoon. Several days after a typhoon, the bloom area gradually reduced as a result of a steady breeze on the horizontal accumulation of Microcystis.

Endogenous cortisol-related alterations of right anterior insula functional connectivity under acute stress.

BACKGROUND: Previous studies have suggested that the right anterior insula (rAI) plays a vital role in salience processing and stress-related disorders. In this study, we aimed to investigate the relationship between rAI functional connectivity changes and individual differences in cortisol responses after acute stress, in order to provide insights into psychiatric illness vulnerabilities. METHODS: Thirty-five young men were enrolled in a randomized, counterbalanced two-session study, with aversive movie clip combined with electrical shocks as stress stimulation and the neutral movie clip as control stimulation. Resting-state fMRI data was acquired after movie exposure. The rAI was chosen as seed for functional connectivity analysis. We then examined the effect of acute stress on rAI functional connectivity and its association with individuals' cortisol response. RESULTS: We found decreased rAI functional connectivity in the fronto-parietal regions, but increased functional connectivity in the visual and somatosensory areas following acute stress. Moreover, stress-induced cortisol response was significantly positively correlated with the rAI functional connectivity in the medial prefrontal cortex, and negatively correlated with the orbital-frontal cortex, lingual gyrus, and middle temporal gyrus. LIMITATIONS: Only young Chinese males without any trauma experience were recruited in this study. CONCLUSIONS: The results suggested tight link between specific rAI functional connectivity alterations and individual stress reactivity, which may help elucidate the potential neurobiological mechanism underlying vulnerability to stress-related disorders.

Preparative scale purification of natural glycans by closed-loop recycle HPLC.

While glycoscience has become well recognized as an indispensable area in biomedical research, studies on the function of individual glycans remains a great challenge due to the lack of tools and methods. One of the greatest impediments to progress in this area is the lack of biomedically relevant complex glycans in sufficient quantity and purity for structural and functional analysis. Despite recent advances in chemoenzymatic synthesis of complex glycans, generating significant amounts of pure glycans is limited to laboratories with specialized expertise. We have previously reported the oxidative release of natural glycans (ORNG) using household bleach, which provides large quantities of biologically relevant glycans that can be a source of glycans in quantities (>mg scale) suitable for functional studies. However, the preparative scale separation of complicated glycan mixtures has not been studied due largely to the fact that gram quantities of starting glycans have not been available until now. Here we report the adoption of closed-loop, recycle HPLC to resolve closely related glycan structures, including complex glycan isomers at preparative scale (10-100 mg).

O-Benzylhydroxylamine (BHA) as a Cleavable Tag for Isolation and Purification of Reducing Glycans.

Glycoscience has been recognized as an important area in biomedical research. Currently, a major obstacle for glycoscience study is the lack of diverse, biomedically relevant, and complex glycans in quantities sufficient for exploring their structural and functional aspects. Complementary to chemoenzymatic synthesis, natural glycans could serve as a great source of biomedically relevant glycans if they are available in sufficient quantities. We have recently developed oxidative release of natural glycans (ORNG) for large-scale release of N-glycans as free reducing glycans. While free reducing glycans can be readily derivatized with ultraviolet or fluorescent tags for high-performance liquid chromatography (HPLC) and mass spectrometry (MS) analysis, it is difficult to remove tags for the regeneration of free reducing glycans without affecting the structural integrity of glycans. To address this inconvenience, we explored the use of a cleavable tag, O-benzylhydroxylamine (BHA). Free reducing glycans are easily and efficiently labeled with BHA under mild conditions, enabling UV detection during HPLC purification. Individual glycan-BHA conjugates can then be separated using multidimensional HPLC and characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and MS/MS. The BHA tag can then be easily removed by palladium-on-carbon (Pd/C)-catalyzed hydrogenation to efficiently regenerate free reducing glycans with little effect on glycan structures. This procedure provides a simple and straightforward way to tag free reducing glycans for purification at a preparative scale using multidimensional HPLC and subsequently recover purified free reducing glycans.

Manifold Learning of Dynamic Functional Connectivity Reliably Identifies Functionally Consistent Coupling Patterns in Human Brains.

Most previous work on dynamic functional connectivity (dFC) has focused on analyzing temporal traits of functional connectivity (similar coupling patterns at different timepoints), dividing them into functional connectivity states and detecting their between-group differences. However, the coherent functional connectivity of brain activity among the temporal dynamics of functional connectivity remains unknown. In the study, we applied manifold learning of local linear embedding to explore the consistent coupling patterns (CCPs) that reflect functionally homogeneous regions underlying dFC throughout the entire scanning period. By embedding the whole-brain functional connectivity in a low-dimensional manifold space based on the Human Connectome Project (HCP) resting-state data, we identified ten stable patterns of functional coupling across regions that underpin the temporal evolution of dFC. Moreover, some of these CCPs exhibited significant neurophysiological meaning. Furthermore, we apply this method to HCP rsfMR and tfMRI data as well as sleep-deprivation data and found that the topological organization of these low-dimensional structures has high potential for predicting sleep-deprivation states (classification accuracy of 92.3%) and task types (100% identification for all seven tasks).In summary, this work provides a methodology for distilling coherent low-dimensional functional connectivity structures in complex brain dynamics that play an important role in performing tasks or characterizing specific states of the brain.

Altered resting-state functional connectivity of the insula in individuals with clinical high-risk and patients with first-episode schizophrenia.

OBJECTIVES: Abnormalities in insular functional connectivity have been implicated in many clinical features of schizophrenia. The aim of this study was to determine to what degree such abnormalities occur in individuals with clinical high risk for psychosis (CHR), and whether which is associated with symptom severity. METHODS: Resting-state fMRI data were collected from 47 healthy controls, 24 CHR individuals and 19 patients with first-episode schizophrenia. Using the posterior, dorsal and ventral insular subregions as separate seeds, we examined resting-state functional connectivity differences between different groups and the association between concurrent symptom severity and dysconnectivity. RESULTS: Compared with healthy controls, both CHR individuals and schizophrenia patients showed hypoconnectivity between posterior insula (PI) and somatosensory areas, and between dorsal anterior insula (dAI) and putamen. Schizophrenia patients also showed dAI and ventral anterior insula(vAI) hyperconnectivity with visual areas relative to controls and CHR individuals. Correlation analysis revealed that dAI functional connectivity with superior temporal gyrus was positively correlated with positive symptoms of CHR, and vAI connectivity with dorsolateral prefrontal cortex was negatively correlated with the severity of the symptoms of first-episode schizophrenia. CONCLUSIONS: Our findings suggest that insular functional dysconnectivity with the sensory cortex may be a system-level neural substrate preceding the onset of psychosis.