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We used resting-functional magnetic resonance imaging data from 98 healthy older adults to analyze how local and global measures of functional brain connectivity are affected by age, and whether they are related to differences in memory performance. Whole-brain networks were created individually by parcellating the brain into 90 cerebral regions and obtaining pairwise connectivity. First, we studied age-associations in interregional connectivity and their relationship with the length of the connections. Aging was associated with less connectivity in the long-range connections of fronto-parietal and fronto-occipital systems and with higher connectivity of the short-range connections within frontal, parietal, and occipital lobes. We also used the graph theory to measure functional integration and segregation. The pattern of the overall age-related correlations presented positive correlations of average minimum path length (r = 0.380, p = 0.008) and of global clustering coefficients (r = 0.454, p < 0.001), leading to less integrated and more segregated global networks. Main correlations in clustering coefficients were located in the frontal and parietal lobes. Higher clustering coefficients of some areas were related to lower performance in verbal and visual memory functions. In conclusion, we found that older participants showed lower connectivity of long-range connections together with higher functional segregation of these same connections, which appeared to indicate a more local clustering of information processing. Higher local clustering in older participants was negatively related to memory performance.  相似文献   
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IntroductionThe current paradigm of the management of rheumatoid arthritis (RA) recommends achieving a state of remission or low disease activity through the treat-to-target strategy. Our study assesses adherence to this strategy.MethodPatients with RA (ACR-EULAR 2010 criteria) were included. From each centre, 19 patients were randomly selected. Clinical histories (CH) were assessed by independent auditors, checking compliance with predefined quality criteria. The study was approved by ethics committees.ResultsWe included 856 patients (mean age 54 years; 71% women). The use of a combined index (CI) was recorded in 61% of cases. Visits were recorded every 4 weeks using a CI in 4% of CH while attempts were made to achieve remission. Monitoring of disease activity every 6–8 months after reaching the target was recorded in 73% of cases.ConclusionsThe implementation of the treat-to-target strategy is barely recorded in patients with RA in routine clinical practice.  相似文献   
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Many studies have demonstrated a strong association between elevated plasma total homocysteine (tHcys) levels and vascular disease. The aim of the present study was to determine the plasma levels of tHcys in pediatric recipients of renal transplants, to establish possible correlations with renal function, lipid profile, and folate and vitamin B12 status, and to assess whether the C677T and A1298C polymorphisms in the 5, l0-methylenetetrahydrofolate reductase (MTHFR) gene were associated with a particular risk. A total of 26 transplanted children and adolescents were investigated. tHcys levels were elevated in transplanted patients (12.9+/-4.8 micro mol/l) and 73% of these displayed values above the 97th percentile of healthy children. Plasma tHcys correlated negatively with creatinine clearance ( r=-0.58, P<0.001) and plasma vitamin B(12) ( r=-0.40, P<0.05) and positively with plasma triglycerides ( r=0.53, P<0.005). No significant correlations were found between plasma tHcys level and age, gender, time elapsed after transplantation and plasma values of glucose, insulin, folic acid, total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, apolipoprotein B, and apolipoprotein A-1. Plasma tHcys level was clearly increased in 3 patients with a MTHFR 677TT/1298AA genotype. In a multiple stepwise regression model plasma creatinine and triglyceride levels and MTHFR 677TT/1298 AA genotype accounted for 60% of the observed plasma tHcys variability. The MTHFR 677CT/1298 AC genotype was not a significant predictor of tHcys plasma levels. We conclude that a moderate degree of hyperhomocysteinemia is often present in renal transplant children and that folate supplementation must be considered in this population.  相似文献   
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Journal of Neurology - MRI atrophy predicts cognitive status in AD. However, this relationship has not been investigated in early-onset AD (EOAD, &lt; 65&nbsp;years) patients...  相似文献   
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