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Purpose To determine longitudinal relationships between lumbar vertebral bone marrow permeability and marrow adipose tissue in a rabbit diabetes model by using quantitative dynamic contrast agent-enhanced (DCE) magnetic resonance (MR) imaging and iterative decomposition of water and fat with the echo asymmetry and least-squares estimation quantitation (IDEAL IQ) sequence. Materials and Methods Twenty rabbits were randomly assigned to the diabetic (n = 10) or control (n = 10) group. All rabbits underwent sagittal MR imaging of the lumbar region at fixed time points (0, 4, 8, 12, and 16 weeks after alloxan injection). A linear mixed-effects model was used to analyze fat fraction (FF) and permeability parameter changes for 16 months after baseline. These parameters were compared between the two groups by using an independent-samples t test. Correlation of DCE MR imaging parameters with FF and with microvessel density (MVD) was analyzed by using the Spearman correlation coefficient. All statistical analyses were performed with software. Results Twelve weeks after injection, transfer constant (Ktrans) and rate constant (Kep) were markedly and significantly increased, while fractional plasma volume (Vp) significantly decreased. The volume of extravascular extracellular space (Ve) decreased significantly after 16 weeks in the diabetic group. MVD was negatively correlated with Ktrans and Kep and positively correlated with Ve and Vp, while FF was positively correlated with Ktrans and Kep and negatively correlated with Ve and Vp (P < .05 for all). Conclusion DCE MR imaging and the IDEAL IQ sequence can be used for quantitative evaluation of changes in vertebral microvascular permeability and vertebral fat deposition in alloxan-induced diabetic rabbits. This variation is highly associated with increased vertebral fat deposition. © RSNA, 2017 Online supplemental material is available for this article.

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Motor impairment after stroke is related to the integrity of the corticospinal tract (CST). However, considerable variability in motor impairment remains unexplained. To increase the accuracy in evaluating long-term motor function after ischemic stroke, we tested the hypothesis that combining diffusion tensor imaging (DTI) and gray matter (GM) volumetry can better characterize long-term motor deficit than either method alone in patients with chronic stroke. We recruited 31 patients whose Medical Research Council strength grade was ≤ 3/5 in the extensor muscles of the affected upper extremity in the acute phase. We used the Upper Extremity Fugl-Meyer (UE-FM) assessment to evaluate motor impairment, and as the primary outcome variable. We computed the fractional anisotropy ratio of the entire CST (CSTratio) and the volume of interest ratio (VOIratio), between ipsilesional and contralesional hemispheres, to explain long-term motor impairment. The results showed that CSTratio, VOIratio of motor-related brain regions, and VOIratio in the temporal lobe were correlated with UE-FM. A multiple regression model including CSTratio and VOIratio of the caudate nucleus explained 40.7% of the variability in UE-FM. The adjusted R2 of the regression model with CSTratio as an independent variable was 29.4%, and that of using VOIratio of the caudate nucleus as an independent variable was 23.1%. These results suggest that combining DTI and GM volumetry may achieve better explanation of long-term motor deficit in stroke patients, than using either measure individually. This finding may provide guidance in determining optimal neurorehabilitative interventions.

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Structural integrity of the corticospinal tract (CST) after stroke is closely linked to the degree of motor impairment. However, current methods for measurement of fractional atrophy (FA) of CST based on region of interest (ROI) are time-consuming and open to bias. Here, we used tract-based spatial statistics (TBSS) together with a CST template with healthy volunteers to quantify structural integrity of CST automatically. Two groups of patients after ischemic stroke were enrolled, group 1 (10 patients, 7 men, and Fugl-Meyer assessment (FMA) scores ⩽ 50) and group 2 (12 patients, 12 men, and FMA scores = 100). CST of FA(ipsi), FA(contra), and FA(ratio) was compared between the two groups. Relative to group 2, FA was decreased in group 1 in the ipsilesional CST (P < 0.01), as well as the FA(ratio) (P < 0.01). There was no significant difference between the two subgroups in the contralesional CST (P = 0.23). Compared with contralesional CST, FA of ipsilesional CST decreased in group 1 (P < 0.01). These results suggest that the automated method used in our study could detect a surrogate biomarker to quantify the CST after stroke, which would facilitate implementation of clinical practice.

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BACKGROUND: Rh blood group system is the most complex and immunogenetic blood group system. Prevalent RHD alleles varied in different populations. The purpose of this study is to determine the molecular basis of weak D and DEL phenotype in Anhui Chinese Han population. METHODS: The D antigen was determined with IgM monoclonal anti-D conformed to the guidelines for donor testing in China. Weak D samples were identified by an indirect antiglobulin test. DEL phenotype was determined by adsorption and elution test. All the RHD 10 exons were screened by PCR with sequence-specific priming or sequenced for the first-time donors who typed weak D, DEL or D negative by serologic test. RESULTS: Of all the 30 799 blood donors, 155 blood samples were found D negative with IgM anti-D; 34 blood samples were found D positive by indirect antiglobulin test or absorption elution test. RHD alleles were identified by nucleotide sequencing. Total 4 RHD alleles were found including two new. One hundred and twenty of 155 (77.4%) of the serologically D negative samples lacked the RHD gene. One D negative was RHD(615del2). Thirty-two of 155 (20.6%) carried RHD(K409K) among them one carrying 1227G > A and 845G > A. Two of 155 (1.3%) was weak D type 15. CONCLUSIONS: In this study at the molecular level, all DEL phenotype is RHD(K409K); weak D type 15 is the prevalent weak D allele in Anhui Chinese Han population. Additionally, an improved more efficient method was adopted to amplify all the RHD exons in one PCR program. Our study added to the understanding of molecular mechanisms underlying D antigen expression in Anhui Han population and provided useful information for adopting suitable genotyping strategies in routine use.

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OBJECTIVE: To investigate spatial and temporal patterns of event-related potentials (ERP) evoked by facial expression. METHODS: ERP was recorded in 25 healthy subjects while they performed facial recognition task. Repeated-measure one-way ANOVA was adopted to compare the subjects' responses to stimulation by 3 different expressions (positive, neutral and negative) with statistical parametric mapping (SPM). RESULTS: Significant facial expression effects occurred separately in the left parietal and bilateral occipital regions (280-340 ms), left frontal region (400-420 ms), and right prefrontal region (480-500 ms). In 4 time periods, significant difference was observed between positive and neutral emotion wave in the right frontoparietotemporal and left prefrontal regions (60-80 ms), right occipital region (120-140 ms), left occipital region (280-320 ms), and left frontoparietal region (400-440 ms). Significant difference between negative and neutral emotion waves was observed in 5 time periods in the right occipital region (120-140 ms), central frontoparietal region (220-240 ms), central parietal region (280-300 ms), left parietal and right temporopartial regions (320-340 ms) and frontopartial occipitotemporal region (480-500 ms). CONCLUSIONS: The spatiotemporal patterns of ERP suggest that the information processing of facial expression involves extensive brain regions dynamically.

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