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Alzheimer's disease (AD) is associated with the impairment of white matter (WM) tracts. The current study aimed to verify the utility of WM as the neuroimaging marker of AD with multisite diffusion tensor imaging datasets [321 patients with AD, 265 patients with mild cognitive impairment (MCI), 279 normal controls (NC)], a unified pipeline, and independent site cross-validation. Automated fiber quantification was used to extract diffusion profiles along tracts. Random-effects meta-analyses showed a reproducible degeneration pattern in which fractional anisotropy significantly decreased in the AD and MCI groups compared with NC. Machine learning models using tract-based features showed good generalizability among independent site cross-validation. The diffusion metrics of the altered regions and the AD probability predicted by the models were highly correlated with cognitive ability in the AD and MCI groups. We highlighted the reproducibility and generalizability of the degeneration pattern of WM tracts in AD.
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Humans , White Matter/diagnostic imaging , Diffusion Tensor Imaging/methods , Alzheimer Disease/complications , Reproducibility of Results , Cognition , Cognitive Dysfunction/complications , Brain/diagnostic imagingABSTRACT
<p><b>OBJECTIVE</b>To investigate the clinical value of Physiologic Ability and Surgical Stress (E-PASS) and modified Estimation of Physiologic Ability and Surgical Stress (mE-PASS) scoring systems in predicting the mortality and surgical risk of gastric cancer patients, and to analyze the relationship between the parameters of E-PASS and early postoperative complications.</p><p><b>METHODS</b>Clinical data of 778 gastric cancer patients who underwent elective surgical resection in Tianjin Medical University General Hospital from Jan. 2010 to Jan. 2014 were analyzed retrospectively. E-PASS and mE-PASS scoring systems were used to predict the mortality of gastric cancer patients, respectively. Univariate and unconditioned logistic regression analyses were performed to assess the relationships between nine parameters of E-PASS system and early postoperative complications.</p><p><b>RESULTS</b>E-PASS and mE-PASS systems were used to predict the mortality in the death group and non-death group. The Z value was -5.067 and -4.492, respectively, showing a significant difference between the two groups (P<0.05). AUCs of mortality predicted by E-PASS and mE-PASS were 0.926 and 0.878 (P>0.05), and the prediction calibration of postoperative mortality showed statistically non-significant difference (P>0.05) between the E-PASS and mE-PASS prediction and actual mortality. Univariate analysis showed that age, operation time, severe heart disease, severe lung disease, diabetes mellitus, physical state index and ASA classification score are related to postoperative complications (P<0.05 for all). Unconditioned logistic regression analysis showed that severe lung disease, diabetes mellitus, ASA classification score and operation time are risk factors for early postoperative complications (P<0.05 for all).</p><p><b>CONCLUSIONS</b>Both mE-PASS and E-PASS scoring system have good consistency in the predicting postoperative mortality and actual mortality, and both are suitable for clinical application. Moreover, the mE-PASS scoring system is clinically more simple and convenient than E-PASS scoring system. Preoperative severe lung disease, diabetes mellitus, ASA classification score and operation time are independent factors affecting the early postoperative complications.</p>
Subject(s)
Humans , Age Factors , Area Under Curve , Diabetes Complications , Elective Surgical Procedures , Homeostasis , Lung Diseases , Operative Time , Postoperative Complications , Mortality , Postoperative Period , Predictive Value of Tests , Regression Analysis , Retrospective Studies , Risk Assessment , Methods , Risk Factors , Stomach Neoplasms , Mortality , General Surgery , Stress, PhysiologicalABSTRACT
Objective To study the functional connectivity (FC) pattern of thalamus in patients with Alzheimer' s disease (AD).Methods In the present study,resting state functional magnetic resonance imaging (MRI) data were obtained from 30 patients with AD and 26 subjects with normal cognition (NC).The altered functional connectivity pattern in AD was evaluated by comparing to NC.Then a correlation analysis was performed between the strength of FC of the identified regions and various clinical variables for evaluating the relationships between the strength of FC and the cognitive abilities (MMSE,immediate recall and delayed recall of Auditory Verbal Learning Test) of the AD patients.Results The MMSE(19.7 ± 4.1),immediate recall (2.8 ± 1.7) and delayed recall (0.7 ± 1.3) of Auditory Verbal Learning Test in AD patients were lower than NC group (28.8 ± 1.0,5.9 ± 1.2,5.7 ± 2.2 ; t =11.09,8.09,10.51,all P <0.05).Compared to NC,AD patients showed decreased FC between the left thalamus and several regions of brain including right posterior/middle cingulate cortex (PCC/MCC.R),left medial prefrontal cortex (MPFC.L) and right superior frontal gyms/medial prefrontal cortex (SFG/MPFC.R).For the right thalamus,decreased FC was found in SFG/MPFC.R,PCC/MCC.R and right hippocampus.We also found increased FC between the bilateral thalamus and many regions of brain including inferior temporal gyrus,medial temporal gyrus,SFG,postcentral gyrus,paracentral lobule,inferior frontal gyms and insula.Significant correlations between the fitted FC strength and clinical variables were also detected.Conclusions FC pattern of thalamus in AD group is impaired.Increased FC in AD may indicate the presence of a compensatory mechanism.The alteration is related with cognitive function in AD.
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ObjectiveTo investigate the characteristics of spontaneous activities throughout the whole brain with Alzheimer's disease (AD) by resting state functional magnetic resonance imaging ( fMRI ).Methods The subjects included 23 AD patients and 21 normal controls (NC),who underwent a neuropsychological test battery including MMSE and Auditory Verbal Learning Test (AVLT) and restingstate fMRI using GE Signa 3.0 T MR scanner.The neuropsychological scores were compared between two groups.Regional homogeneity (ReHo) method was used to explore the different regional spontaneous activities throughout the brain between normal controls and patients with AD.Results In AD group,clinical variables (MMSE scores:20 ±4,AVLT-Immediate Recall:2.6 ± 1.6,AVLT-Delay Recall:0.4 ±0.7,AVLT-Recognition:5.8 ± 3.7 ) were lower than NC group( 29 ± 1,5.9 ± 1.2,5.5 ± 2.0,9.2 ± 1.1,T =10.58,7.21,10.99,3.96,all P < 0.01 ).With the threshold of P < 0.01 for each voxel and a cluster size of at least 100 voxels,decreased ReHo indexes were found in default mode network (DMN) including the medial prefrontal cortex,posterior cingulate gyrus/precuneus,right superior temporal gyrus and bilateral superior parietal lobule/inferior parietal lobule in AD,while increased ReHo indexes were found in left putamen and thalamus compared with controls.ConclusionThe DMN are damaged in AD and spontaneous activities of putamen and thalamus are reinforced as compensation response of subcortical structures.
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Objective To determine the efficacy of individual cognitive training (CT) in the treatment of cognitive and neuropsychiatric symptoms in patients with mild to moderate Alzheimer disease ( AD). Methods A randomized, controlled, rater-blind clinical trial recruited 32 AD patients. AH patients were assigned to a CT group (n = 16) or a control group (a time and attention control, n = 16) for 10 weeks. All outcome measures were administered at baseline and follow-up. The cognitive status was evaluated using the Mini Mental State examination (MMSE) , a clock-drawing test (CDT) , Fuld's object memory evaluation (FOME) , a rapid verbal retrieval (RVR) , digit span assessments (DS) , block designing (BD), and the A version of the trail making test (TMTA). The patients' functional status was evaluated using an activities of daily living (ADL) scale. Any psychological and behavioural disorders were evaluated with the Neuropsychiatry Inventory ( NPI). Results Patients receiving CT showed greater average improvements in NPI total score, TMT-A score and MMSE total score than the controis at week 10. There was no statistically significant benefit for CT-treated patients in terms of ADL score. Conclusions Cognitive training can raise the NPI total scores and MMSE total scores of patients with mild to moderate AD.
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Objective To investigate the neural representations of long-term digital memory in human brain by functional magnetic resonance imaging (fMRI) technique. Methods 22 right-handed normal volunteers were recruited to participate in a test of long-term digital memory while the fMRI data were recorded. Control tasks were performed for the block-design. SPM 99 was used to analyze the data and to obtain the activated brain regions.Numbers of activated voxels were used to calculate lateralization index (LI). Results When the threshold was set as P<0. 0001 ,using a one-sample t -test,the middle gyrus of the left frontal lobe(t=9.68) and the right cerebellum ( t = 9.85 ) were activated remarkably during the memory task. The subcortical structures including the thalamus (t=6.72) and the caudate (t=6.58) were also obviously activated during the memory task. LI of the numbers of activated voxels was 0.51. Conclusions The subcortical structures and the cerebellum as well as the cerebral cortex are collaborative to contribute to long-term digital memory function in human brain. The results also reveal that the functional areas of long-term digital memory in human brain are localized with the functional lateralization in the left hemisphere.
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Objective To evaluate the effect of laparoscopic adrenalectomy for adrenal tumors by transperito-neal or retroperitoneal approaches. Methods Atotal of 41 laparoscopic adrenalectomy for adrenal tumor patients were pertormed,inchiding 16 patients by transperitoneal approach and 25 patients by retroperitoneal approach. The tumor size,operative time,intraoperative blood loss, postoperative hospital stay, postoperative ambulatory day and postopera-tive complications were observed. Results Of the 41 cases ,3 cases were transferred to open surgery and the other 38 cases were achieved successful operations. No significant differences( all P>0.05) were found in tumor size,intraop-erative blood loss, postoperative hospital stay, postoperative ambulatory day between the transperitoneal group and ret-roperitoneal group ,but there were significant differences( P<0.05) in operative time and intraoperative blood loss be-tween the two group. Conclusion Both the transperitoneal and retroperitoneal laparoscopic approaches are feasible and safe for adrenal tumors, and the latter has more advantages in operative time, but the operative approach still should be chosen based on the pathological changes,tumor size and position as well as the individual conditions of the patients.
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Objective To examine whether the marginal division of the striatum(MrD)is involved in the associative learning and memory function of human brain with the help of functional magnetic resonance imaging(fMRI)technique.Methods Sixteen right-handed normal volunteers participated in a test of paired-word associative learning and memory,while the fMRI data were recorded.Control tasks were performed for the block-design.Statistcs parameter mapping 99 was used to analyze the data and to obtain the activated brain regions.Results When the threshold was set as P<0.005.using a one-sample T-test,the left occipital lobe and the superior and middle gyrus of the left frontal lobe were activated remarkably during the encoding process of the paired-word associative learning and memory task,with the maximum intensity T value being 13.87 and 9.36.respectively.The left MrD was also obviously activated during this stage(T value was 5.46).But during the retrieval process,the left parietal lobe was prominently activated(T value was 8.73).Conclusion The resuhs of this study reveal that the subcortical structures such as MrD as well as the cerebral cortex are involved in the associative learning and memory of paired-word in human brain.
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Objective To compare the characteristics and differences of the activation of the brain regions between the digital memory span task and digital working memory task.Methods 12 right-handed volunteers participated in a test of 7-digit memory span and a test of 2-digit working memory respectively, while the functional MR imaging (fMRI) data were recorded by a Seimens 1.5 T MR machine. Two control tasks were performed respectively and stimulation paradigms was block-design. SPM 99 was used to analyze the data and to localize the activated brain regions.Results The Brodmann area (BA) 6, 9 and 47 regions in the frontal lobe, the BA 7 and 40 regions in the parietal lobe, the cingulate gyrus, the hippocampus structures, the striatum and the cerebellum were activated by both tasks in comparison to their control tasks. Bilateral BA 18 and 19 regions of the occipital lobe without hemisphere predominance were the most activated regions by the digital memory span task, and the BA 37 region of the temporal lobe was also activated. However, the frontal lobe with left predominance was the most activated region by the digital working memory.Conclusion Different brain regions play distinct roles in different short-term digital memory tasks, and might be involved in different stages. The fMRI is a good tool for exploring the process of digits in the brain.