Biomedical subjects

Sheng Xie

Publications and source records attributed to Sheng Xie.

8 recordsLinked to original sources

PubMed2025

Causal relationships between antibody-mediated immune responses and acute pancreatitis: Evidence from a genetic study.

Certain specific antibody-mediated immune responses may be associated with acute pancreatitis (AP), but their causal relationship remains uncertain. Therefore, we used bidirectional two-sample Mendelian randomization (MR) to investigate their causal link and potential mediation by inflammatory cytokines. Data for this study were sourced from a large-scale Genome Wide Association Study (GWAS) communal data pool. To explore the causality between antibody-mediated immune responses and AP, we performed two-sample bidirectional MR analyses using 5 approaches: inverse-variance weighted (IVW), MR-Egger, weighted mode, weighted median, and simple mode. We also studied the potential mediating effect of 91 circulating inflammatory cytokines using a two-step MR method. Additionally, sensitivity analyses were conducted using MR-Egger intercept test and Cochran Q test to ensure the robustness of the outcomes. The results of forward MR analysis showed that anti-Epstein-Barr virus (anti-EBV) IgG seropositivity [OR = 0.941; 95% CI, 0.893-0.992; P = .023] and human herpes virus (HHV) 6 IE1A antibody levels [OR = 0.894; 95% CI, 0.816-0.981; P = .017] significantly reduced the risk of AP. The results of the reverse MR analysis revealed a negative correlation between AP and anti-EBV IgG seropositivity [OR = 0.775; 95% CI, 0.605-0.992; P = .043]. Furthermore, none of the 91 circulating inflammatory cytokines could mediate the causal relationship between HHV-6 IE1A antibody levels and the risk of AP. The results of sensitivity analysis confirmed the robustness of these causalities. The current study suggests that HHV-6 IE1A antibody levels are a protective factor against AP, and there is a bidirectional causality between AP and anti-EBV IgG seropositivity. In addition, the mediation analysis results showed that the 91 circulating inflammatory cytokines could not serve as mediators between the 46 antibody-mediated immune responses and AP.

Humans↗

PubMed2006

Detection of abnormal visual cortex in children with amblyopia by voxel-based morphometry.

PURPOSE: To detect the abnormalities of gray matter in children with amblyopia by voxel-based morphometry (VBM). DESIGN: Prospective, nonrandomized clinical trial. METHODS: Thirteen children with amblyopia and 14 normally sighted children underwent magnetic resonance (MR) examination. The two groups were age-matched with a mean age of 5.8 years. In the amblyopia group, five children had strabismus amblyopia, and eight had anisometropic amblyopia. We analyzed the original 3-dimensional T1 brain images using the VBM module within the widely used analysis software package SPM2 (Welcome Department of Cognitive Neurology, London, United Kingdom). After normalization, segmentation, and smoothing of the images, comparison between amblyopic and control groups was derived for the gray matter of the entire brain using parametric statistics. RESULTS: The results of VBM analysis indicated that the amblyopic group had decreased gray matter density in the middle frontal gyrus, parahippocampal gyrus, fusiform gyrus, inferior temporal gyrus of the left hemisphere, and the bilateral calcarine cortices. The radii of these regions ranged from 12 to 36 voxels. These abnormalities were consistent with morphologic changes in brain regions related to visual function. CONCLUSIONS: Using MR and VBM analysis, we detected morphologic changes in the visual cortex of children with amblyopia, which may indicate developmental abnormalities of visual cortex during the critical growth period.

Amblyopia↗

PubMed2006

Handedness-related functional connectivity using low-frequency blood oxygenation level-dependent fluctuations.

Functional neuroimaging studies of handedness have traditionally focused on exploring regionally activated discrepancies, yet little is known regarding the effect of handedness on functional connections of brain regions. Here, we reported the relationship between cerebellar functional connectivity patterns and handedness by low-frequency blood oxygenation level-dependent fluctuations. Compared with the right-handers, the left-handers show higher cerebellar-prefrontal, cerebellar-parietal, and cerebellar-temporal functional connectivity, and lower cerebellar-limbic connectivity. Previous non-human primate studies have shown that these regions with known contributions to higher cognitive functions have afferent or efferent connections with the cerebellum. Our findings suggest that these observed low-frequency fluctuation correlations may reflect actually anatomic connections between the cerebellum and cerebral cortex, and the cerebellar involvement in higher function may be associated with handedness.

Adult↗

PubMed2005

Side and handedness effects on the cingulum from diffusion tensor imaging.

In order to explore the microstructure of bilateral cingulum bundles associated with side and handedness, fractional anisotropy was extracted from diffusion tensor imaging. Distinguished from the conventional region of interest-based method, a fiber-based analysis method called scale-invariant parameterization method was employed to ascertain the anisotropy along the cingulum bundle in 31 normal right-handers and 14 normal left-handers. The statistical results showed a remarkable left-greater-than-right asymmetry pattern of anisotropy in most segments of cingulum bundles except the most posterior segment, for both right-handers and left-handers. Interestingly, higher anisotropy of the right-hander than the left-hander was found in the bilateral cingulum bundles. No significant handedness-by-side interaction was obtained in the present study, however.

Adult↗

PubMed2005

Evaluation of bilateral cingulum with tractography in patients with Alzheimer's disease.

A fiber-tracking algorithm was used to extract fractional anisotropy of bilateral cingulum bundles in patients with probable Alzheimer's disease and normal aging controls. In addition, their hippocampal volumes were measured manually. Relative to normal controls, Alzheimer's disease patients showed a significant reduction of fractional anisotropy and hippocampal volumes. Significant correlation was observed between fractional anisotropy values and volumes of hippocampi and mini-mental state examination scores. This study suggests that lower anisotropy of cingulum bundles is associated with cognitive dysfunction and atrophy of the limbic system.

Aged↗

PubMed2005

Asymmetry analysis of cingulum based on scale-invariant parameterization by diffusion tensor imaging.

Current analysis of diffusion tensor imaging (DTI) is based mostly on a region of interest (ROI) in an image dataset, which is specified by users. This method is not always reliable, however, because of the uncertainty of manual specification. We introduce an improved fiber-based scheme rather than an ROI-based analysis to study in DTI datasets of 31 normal subjects the asymmetry of the cingulum, which is one of the most prominent white matter fiber tracts of the limbic system. The present method can automatically extract the quantitative anisotropy properties along the cingulum bundles from tractography. Moreover, statistical analysis was carried out after anatomic correspondence specific to the cingulum across subjects was established, rather than the traditional whole-brain registration. The main merit of our method compared to existing counterparts is that to find such anatomic correspondence in cingulum, a scale-invariant parameterization method by arc-angle was proposed. It can give a continuous and exact description on any segment of cingulum. More interestingly, a significant left-greater-than-right asymmetry pattern was obtained in most segments of cingulum bundle (-50-25 degrees), except in the most posterior portion of cingulum (25-50 degrees).

Adult↗

PubMed2003

[The fMRI study of the calculation tasks in normal aged volunteers].

OBJECTIVE: To investigate the feasibility and cortex activation of fMRI in aged volunteers during the performance of calculation tasks. METHODS: Internal mental calculation tasks including simple tasks and complicated tasks were conducted in 11 normal aged volunteers. The fMRI data was postprocessed using SPM99 to reveal the activated cortex. RESULTS: The simple calculation tasks were fulfilled satisfactorily in all aged subjects. Cortex in the bilateral Superior parietal lobule, inferior parietal lobule and bilateral occipital lobes showed activation. We found a selective enhancement of fMRI signal in Brodmann regions 9, 10 and 46 in the complicated tasks. CONCLUSION: fMRI tasks are feasible in aged people and more cortex of the left frontal lobe shows activation in complicated calculation tasks.

Aged↗

PubMedDate not supplied

Patterns of brain activation in patients with mild Alzheimer's disease during performance of subtraction: an fMRI study.

We performed a functional MRI (fMRI) study to compare the difference of activation between healthy aged people and patients with mild Alzheimer's disease (AD) during performance of subtraction. Nine patients with mild AD and nine healthy aged volunteers were recruited in this study. The analysis of fMRI data revealed that brain activation is decreased in several regions in AD patients in comparison with healthy participants. But in the right inferior prefrontal lobe, activation is greater in patients than in the controls. We believe that our findings will help the understanding mechanism of neuronal activity in AD.

Aged↗