Purpose To investigate white matter alterations in post-stroke cognitive impairment (PSCI) patients at the subacute stage employing diffusion kurtosis and tensor imaging. Methods Thirty PSCI patients at the subacute phase and 30 healthy controls (HC) underwent diffusion kurtosis imaging (DKI) scans and neuropsychological assessments. Based on the tract-based spatial statistics and atlas-based ROI analysis, fractional anisotropy (FA), mean diffusivity (MD), mean kurtosis (MK), kurtosis fractional anisotropy (KFA), axial kurtosis (AK), and radial kurtosis (RK) were compared in specific white matter fiber bundles between the groups (with family-wise error correction). Adjusting for age and gender, a partial correlation was conducted between neurocognitive assessments and DKI metrics in the PSCI group. Results In comparison with the HC, PSCI patients significantly showed decreased MK, RK, and FA and increased MD values in the genu of corpus callosum, anterior limb internal capsule, and left superior corona radiata. In addition, DKI detected more white matter region changes in MK (31/48), KFA (40/48), and RK (25/48) than DTI with FA (28/48) and MD (21/48), which primarily consisted of the right cingulum, right superior longitudinal fasciculus, and left posterior limb of internal capsule. In the left anterior limb of internal capsule, MK and RK values were significantly negatively correlated with TMT-B ( r = −0.435 and −0.414, P < 0.05), and KFA values ( r = −0.385, P < 0.05) of corpus callosum negatively associated with TMT-B. Conclusion Combing DTI, DKI, and neuropsychological tests, we found extensive damaged white matter microstructure and poor execution performance in subacute PSCI patients. DKI could detect more subtle white matter changes than DTI metrics. Our findings provide added information for exploring the mechanisms of PSCI and conducting cognitive rehabilitation in the subacute stage.

Purpose Methamphetamine use may cause severe neurotoxicity and cognitive impairment, leading to addiction, overdose, and high rates of relapse. However, few studies have systematically focused on functional impairments detected by neuroimaging in methamphetamine abstainers (MAs) during short-term abstinence. This study aimed to investigate effective connectivity, resting-state networks, and internetwork functional connectivity in MA brains to improve clinical treatment. Methods Twenty MAs and 27 age- and education-matched healthy controls underwent resting-state functional magnetic resonance imaging. The amplitude of low-frequency fluctuations and Granger causality were analyzed to investigate disrupted brain regions and effective connectivity, respectively. Independent component analysis and functional network connectivity were used to identify resting-state networks and internetwork functional connectivity, respectively. Results Compared with healthy controls, MAs demonstrated abnormal amplitudes of low-frequency fluctuations in the bilateral precuneus, left posterior cingulate cortex (PCC), left middle frontal gyrus (MFG), left superior parietal lobule, left supplementary motor area (SMA), and left inferior parietal lobule (IPL). Moreover, MAs showed decreased effective connectivity from the left PCC to the left precuneus, increased effective connectivity from the left precuneus to the left MFG and from the right precuneus to the left SMA, and altered functional connectivity within the default mode network (DMN), frontoparietal network, sensorimotor network, ventral attention network, cerebellar network, and visual network. Importantly, hyperconnectivity between the DMN and ventral attention network and hypoconnectivity between the DMN and cerebellar network as well as the DMN and frontoparietal network were demonstrated in MAs. Conclusion Our study implies that in short-term methamphetamine abstinence, disruptions to the DMN and executive network may a play key role, providing new insights for early rehabilitation.

Background: Thyroid cancer is the most prevalent malignancy and one of the leading causes of cancer-related deaths. Recent studies have revealed that microRNAs (miRNAs) play an important role in tumorigenesis in various cancer types by affecting the expression of its targets. However, the role of miR-32-5p in thyroid cancer remains limited. Methods: In this study, we attempt to explore the role of miR-32-5p in thyroid cancer and elucidate the underlying mechanism. Expression of miR-32-5p was determined by quantitative reverse transcription PCR. Functional assays were performed by CCK-8 assay, cell colony assay, cell apoptosis assay, cell migration and invasion assays, cell cycle assay and luciferase assay. Protein expression was analyzed by Western blot.Results: In the present study, the role of miR-32-5p in thyroid cancer was firstly explored. It is found that miR-32-5p was downregulated in thyroid cancer tissues and cells. Overexpression of miR-32-5p inhibited thyroid cancer cells proliferation, migration, invasion and epithelial‐mesenchymal transition process; while suppression of miR-32-5p exhibited an opposite effect on thyroid cancer cells. In addition, In addition, a luciferase assay showed Twist1 was identified as a direct target of miR-32-5p in thyroid cancer, and further study showed that restoration of Twist1 attenuated the biological effect of miR-32-5p on thyroid cancer cells. Conclusion: In conclusion, our results demonstrated miR-32-5p functions as a tumor suppressor by targeting Twist1 in thyroid cancer, providing a novel insight into thyroid cancer therapy.

No abstract