Abnormal changes in gray matter volume and structural covariate network in patients with chronic pontine infarction / 国际脑血管病杂志

Objective:To investigate the changes in gray matter volume (GMV) and abnormalities in structural covariant network (SCN) patterns in patients with chronic pontine infarction (PI).Methods:Patients with unilateral chronic PI (case group) with the first onset admitted to the First Affiliated Hospital of Zhengzhou University and Tianjin Medical University General Hospital from October 2014 to June 2021 were prospectively included. At the same time, healthy subjects matched with age, gender and education years (normal control group) were included. High-resolution three-dimensional T 1 structural MRI images and behavioral scores of the subjects were collected. The voxel-based morphometry and two-sample t test were used to explore the differences in GMV between the groups. Using GMV differential brain regions as seed points, SCN was constructed to explore the abnormality of structural covariant patterns in patients with PI. Spearman rank correlation analysis was used to analyze the correlation between GMV in differential brain regions and behavioral scores. Results:A total of 60 patients with PI were enrolled, including 33 left PI and 27 right PI, while 34 healthy controls were also enrolled. Compared with the normal control group, the GMV in bilateral posterior cerebellar lobe decreased significantly in the left PI group, and the GMV in left anterior and posterior cerebellar lobes and the right posterior cerebellar lobe decreased significantly in the right PI group (Gaussian random field correction with voxel level P<0.001 and cluster level P<0.05, cluster voxel >20), and there was a significant correlation between GMV values in the left anterior and posterior cerebellar lobes and the right posterior cerebellar lobe and the motor function score ( P<0.05). In addition, compared with the normal control group, the right PI group had broader covariate brain regions and a significant increase in the number of structural connections between covariate brain regions (family-wise error correction with voxel level P<0.05, cluster voxel >20). Conclusions:The GMV in bilateral posterior cerebellar lobe decreases significantly in patients with chronic PI, and were secondary to broader covariate brain regions and structural connections. This may be the neural mechanism of impaired behavioral function in patients with PI.

The alleviation effect of iron on cadmium phytotoxicity in mangrove A. marina. Alleviation effect of iron on cadmium phytotoxicity in mangrove Avicennia marina (Forsk.) Vierh.

Cd has high activity and bioavailability and is a poisonous element to plants. As a critical ecosysterm, mangroves are subjected to serious Cd pollution. In this research, the hypothesis was presented that improving Fe bioavailability would alleviate Cd phytotoxicity to Avicennia marina (Forsk.) Vierh. To test this, we examined the effect of four exogenous Fe and three Cd concentrations on A. marina. The results showed that a significant positive correlation excited between moderate exogenous Fe concentration and Cd tolerance of A. marina. Moderate exogenous Fe concentration directly or indirectly promoted the formation of Fe plaque, which immobilised more Cd on the root surface and decreased Cd absorption in roots. Furthermore, an exogenous Fe application increased plant biomass and Fe accumulation in A. marina tissues. This improved the competition between Fe and Cd within the plants. Therefore, an Fe application facilitated a decrease in Cd toxicity within A. marina. Simultaneously, a moderate Fe concentration caused an increase in low-molecular-weight organic acid (LMWOA) secretion from the roots. Meanwhile, Cd can be chelated/complexed by LMWOAs. It also played a crucial role in Cd detoxification in A. marina. In conclusion, Fe application accelerated the growth and enhanced Cd tolerance of A. marina. Therefore, improving Fe bioavailability will protect mangroves from Cd contamination.

The impact of different infarction regions on functional connectivity in motor execution network / 中华行为医学与脑科学杂志

Objective@#To explore the influence of the location of the infarction lesion on the resting-state functional connectivity (rsFC) of the motor execution network.@*Methods@#A total of 144 patients with infarction of the motor pathway were involved in the study, including 97 patients with capsule stroke (CS) and 47 patients with pontine stroke (PS).50 age-matched healthy subjects were enrolled.After acquiring the structural images and the resting-state functional MRI data of all the subjects by 3.0-Tesla MR scanner, the functional connectivity was calculated in different regions of interest and the differences of the rsFC within the motor execution network among patients with different infarction location were compared.@*Results@#Left CS patients exhibited increased rsFC in L_PMd (MNI x, y, z: -22, -13, 57) -R_M1 (MNI x, y, z: 38, -22, 56) (F=3.951, P=0.022), the increased rsFC than healthy controls (P=0.031); Left CS patients exhibited increased rsFC in R_PMv (MNI x, y, z: 53, 0, 25)-L_SPL (MNI x, y, z: -22, -64, 54) than healthy controls (F=4.017, P=0.021), left CS patients exhibited decreased rsFC in R_PCG (MNI x, y, z: 37, -34, 53) -R_PMv (MNI x, y, z: 53, 0, 25) than healthy controls(F=-3.788, P=0.025). Right CS patients exhibited increased rsFC than healthy controls in R_PMd(MNI x, y, z: 28, -10, 54)-L_M1(MNI x, y, z: -38, -22, 56) (F=4.438, P=0.014), right CS patients exhibited increased rsFC than healthy controls in R_PMv(MNI x, y, z: 53, 0, 25)-R_PCG(MNI x, y, z: 37, -34, 53)(F=4.830, P=0.010), right CS patients exhibited decreased rsFC in L_M1(MNI x, y, z: -38, -22, 56)-L_SMA(MNI x, y, z: -5, -4, 57) than healthy controls (F=-5.102, P=0.007). And the left PS patients showed increased rsFC than healthy controls in R_DN -L_SMA (F=4.939, P=0.009), left PS patients exhibited increased rsFC than healthy controls in L_DN-R_SMA (F=3.431, P=0.036), left PS patients exhibited reduced rsFC than healthy controls in R_AICb -R_PMd (F=-4.114, P=0.019). Right PS patients showed increased rsFC compared with healthy controls in L_DN-R_M1(F=3.075, P=0.049), and increased rsFC compared with healthy controls in L_AICb-R_SCb (F=3.725, P=0.027).@*Conclusion@#The infarction location poses influence on the FC alteration of the motor network after stroke.

Accumulation and speciation of Cd in Avicennia marina tissues.

Avicennia marina is a high-Cd-tolerant species in the mangrove wetlands. A hydroponic experiment was carried out to research the accumulation and chemical form distribution of Cd in the tissues of A. marina under different concentrations and durations of Cd stress. It was found that the concentrations of Cd in plant tissues followed the order of root > stem > leaf. The data suggested that root activity decreased, Cd accumulation ability weakened in roots, and the translocation factor increased in stems and leaves with the increase of stress duration. With a proactive defense mechanism, most Cd was bound to pectates, organic acids, and protein, especially in roots and stems with the most proportion of 88.51 and 78.91%, respectively, having lower biological activities. The Cd bounded to water-soluble organic acid and free inorganic aminophenol-Cd showed the lowest concentration. The pectates, organic acids, and protein-integrated Cd seem the most important in affecting Cd detoxification for A. marina; this mechanism of change in Cd biological activities decreases the toxicity of this aggressive pollutant and presents new knowledge about the tolerance of mangrove plants.

The effects of sulfur amendments on the geochemistry of sulfur, phosphorus and iron in the mangrove plant (Kandelia obovata (S. L.)) rhizosphere.

P (phosphorus) and Fe (iron) are limiting elements and S (sulfur) is an important element of the biogeochemical cycle in the mangrove environment. To assess the effects of sulfur on the geochemical cycling of Fe and P at the sediment-plant interface, the speciation distributions of Fe, P and S in sediments were examined. The data showed that higher proportions of amorphous Fe, Fe-bound phosphate, chromium reducible sulfur and elemental sulfur were found in the rhizosphere, while more crystalline Fe, exchangeable phosphate and acid-volatile sulfide were determined in the non-rhizosphere. Sulfate application induced an increase in the Ex-P concentration, high P accumulation and high iron plaque deposition in the roots. In conclusion, sulfate applications had a significant influence on the geochemical cycling of Fe and P in the sediments. It significantly curtailed the Fe and P limit to plant growth and enhanced plant resistance to the rugged surroundings in mangrove.

cDNA sequence encoding metallothionein protein from Aegiceras corniculatum and its gene expression induced by Pb²âº and Cd²âº stresses.

Constructing various green wetland examples for mangrove wetland systems is a useful way to use natural power to remediate the polluted wetlands at intertidal zones. Metallothioneins (MT) are involved in heavy metal tolerance, homeostasis, and detoxification of intracellular metal ions in plants. In order to understand the mechanism of heavy metal uptake in Aegiceras corniculatum, we isolated its metallothionein gene and studied the MT gene expression in response to heavy metals contamination. Here, we report the isolation and characterization of MT2 genes from young stem tissues of A. corniculatum growing in the cadmium (Cd) and lead (Pb) polluted wetlands of Quanzhou Bay, southeast of China. The obtained cDNA sequence of MT is 512 bp in length, and it has an open reading frame encoding 79 amino acid residues with a molecular weight of 7.92 kDa and the theoretical isoelectric point of 4.55. The amino acids include 14 cysteine residues and 14 glycine residues. It is a non-transmembrane hydrophilic protein. Sequence and homology analysis showed the MT protein sequence shared more than 60% homology with other plant type 2 MT-like protein genes. The results suggested that the expression level of MT gene of A. corniculatum young stems induced by a certain range concentration of Cd(2+) and Pb(2+) stresses (0.2 mmol L(-1) Pb(2+), 1 mmol L(-1) Pb(2+), 0.2 mmol L(-1) Pb(2+), and 40 µmmol L(-1) Cd(2+); 1 mmol L(-1) Pb(2+) and 40 µmol L(-1) Cd(2+)) compared with control might show an adaptive protection. The expression levels of MT gene at 20 h stress treatment were higher than those at 480 h stress treatment. The expression levels of MT gene with 0.2 mmol L(-1) Pb(2+) stress treatment were higher than those with 0.2 mmol L(-1) Pb(2+) and 40 µmol L(-1) Cd(2+) stress treatment, and the MT gene expression levels with 1 mmol L(-1) Pb(2+) treatment were higher than those with 1 mmol L(-1) Pb(2+) and 40 µmol L(-1) Cd(2+) treatment. There exists an antagonistic action between Pb(2+) and Cd(2+) in the MT metabolization of A. corniculatum.

The distribution of acid-volatile sulfide and simultaneously extracted metals in sediments from a mangrove forest and adjacent mudflat in Zhangjiang Estuary, China.

The distribution of acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) were studied in sediments collected from mangrove forest, forest fringe and adjacent mudflat in the Zhangjiang Estuary, China. The aim was to examine the spatial distribution of AVS and SEM in sediments of the Estuary and determine the influence of mangrove trees on AVS and SEM concentrations in the sediments. The results indicated that AVS concentrations in forest sediments were significantly lower than those in mudflat sediments. There was a significant positive correlation between AVS values and moisture contents in forest sediments, while LOI played an important role in AVS concentrations of mudflat sediments. In the forest sediment core, the peak value of AVS appeared deeper in the sediment profile compared to it appeared in the mudflat core. The distribution of SEM showed different trends from that of AVS, and potential toxicity existed in the upriver forest sediments.

Speciation changes of cadmium in mangrove (Kandelia candel (L.)) rhizosphere sediments.

The speciation distribution of cadmium (Cd) in mangrove (Kandelia candel (L.) Druce) rhizosphere sediment was investigated after different contents of Cd being loaded. The study results indicated that root induced changes of Cd bioavailability in the rhizosphere. Exchangeable and carbonate bound Cd in the rhizosphere sediments were lower than these in the bulk sediments, whilst an increase in Fe-Mn oxides bound and O.M/sulfide bound fractions occurred in the rhizosphere sediment. Increased levels of Cd in sediments resulted in higher Cd concentrations in mangrove plants, and the order of accumulation was: roots > hypocotyls > stems and leaves.