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1.
Yen-Chu Huang Ho-Ling Liu Jiann-Der Lee Jen-Tsung Yang Hsu-Huei Weng Meng Lee Mei-Yu Yeh Yuan-Hsiung Tsai 《PloS one》2013,8(7)
Background
The aim of this study was to evaluate whether arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) can reliably quantify perfusion deficit as compared to dynamic susceptibility contrast (DSC) perfusion MRI.Methods
Thirty-nine patients with acute ischemic stroke in the anterior circulation territory were recruited. All underwent ASL and DSC MRI perfusion scans within 30 hours after stroke onset and 31 patients underwent follow-up MRI scans. ASL cerebral blood flow (CBF) and DSC time to maximum (Tmax) maps were used to calculate the perfusion defects. The ASL CBF lesion volume was compared to the DSC Tmax lesion volume by Pearson''s correlation coefficient and likewise the ASL CBF and DSC Tmax lesion volumes were compared to the final infarct sizes respectively. A repeated measures analysis of variance and least significant difference post hoc test was used to compare the mean lesion volumes among ASL CBF, DSC Tmax >4–6 s and final infarct.Results
Mean patient age was 72.6 years. The average time from stroke onset to MRI was 13.9 hours. The ASL lesion volume showed significant correlation with the DSC lesion volume for Tmax >4, 5 and 6 s (r = 0.81, 0.82 and 0.80; p<0.001). However, the mean lesion volume of ASL (50.1 ml) was significantly larger than those for Tmax >5 s (29.2 ml, p<0.01) and Tmax >6 s (21.8 ml, p<0.001), while the mean lesion volumes for Tmax >5 or 6 s were close to mean final infarct size.Conclusion
Quantitative measurement of ASL perfusion is well correlated with DSC perfusion. However, ASL perfusion may overestimate the perfusion defects and therefore further refinement of the true penumbra threshold and improved ASL technique are necessary before applying ASL in therapeutic trials. 相似文献2.
Objective
To evaluate the efficacy of continuous positive airway pressure (CPAP) on serum testosterone in men with obstructive sleep apnea (OSA).Methods
Two reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before June 2014. Information on characteristics of subjects, study design, pre- and post-CPAP treatment of serum total testosterone, free testosterone and sexual hormone blinding protein (SHBG) was extracted for analysis.Results
A total of 7 studies with 9 cohorts that included 232 men were pooled into meta-analysis. There was no change of total testosterone levels before and after CPAP treatment in OSA men (standardized mean difference (SMD) = −0.14, 95%CI: −0.63 to 0.34, z = 0.59, p = 0.558), even subdivided by CPAP therapeutic duration (>3 months). Meanwhile, no significant differences in free testosterone and SHBG were detected after CPAP treatment (SMD = 0.16, 95%CI: −0.09 to 0.40, z = 1.25, p = 0.211 and SMD = −0.58, 95%CI: −1.30 to 0.14, z = 1.59, p = 0.112, respectively).Conclusion
CPAP has no influence on testosterone levels in men with OSA, further large-scale, well-design interventional investigation is needed. 相似文献3.
4.
Background
Anemia is associated with poor prognosis in heart failure (HF) patients. Contributors to the risk of anemia in HF include hemodilution, renal dysfunction and inflammation. Hemoglobin levels may also be negatively affected by alterations in stress regulatory systems. Therefore, psychological distress characterized by such alterations may adversely affect hemoglobin in HF. The association between hemoglobin and Type D personality and affective symptomatology in the context of HF is poorly understood.Aim
To examine the relationship between Type D personality and affective symptomatology with hemoglobin levels at inclusion and 12-month follow-up, controlling for relevant clinical factors.Methods
Plasma levels of hemoglobin and creatinine were assessed in 264 HF patients at inclusion and at 12-month follow-up. Type D personality and affective symptomatology were assessed at inclusion.Results
At inclusion, hemoglobin levels were similar for Type D and non-Type D HF patients (p = .23), and were moderately associated with affective symptomatology (r = –.14, p = .02). Multivariable regression showed that Type D personality (β = –.15; p = .02), was independently associated with future hemoglobin levels, while controlling for renal dysfunction, gender, NYHA class, time since diagnosis, BMI, the use of angiotensin-related medication, and levels of affective symptomatology. Change in renal function was associated with Type D personality (β = .20) and hemoglobin at 12 months (β = –.25). Sobel mediation analysis showed significant partial mediation of the Type D – hemoglobin association by renal function deterioration (p = .01). Anemia prevalence increased over time, especially in Type D patients. Female gender, poorer baseline renal function, deterioration of renal function and a longer HF history predicted the observed increase in anemia prevalence over time, while higher baseline hemoglobin was protective.Conclusion
Type D personality, but not affective symptomatology, was associated with reduced future hemoglobin levels, independent of clinical factors. The relation between Type D personality and future hemoglobin levels was mediated by renal function deterioration. 相似文献5.
?árka Kaňková Lucie Procházková Jaroslav Flegr Pavel Calda Drahomíra Springer Eli?ka Potluková 《PloS one》2014,9(10)
Background
Toxoplasmosis, one of the most common zoonotic diseases worldwide, can induce various hormonal and behavioural alterations in infected hosts, and its most common form, latent toxoplasmosis, influences the course of pregnancy. Autoimmune thyroid diseases (AITD) belong to the well-defined risk factors for adverse pregnancy outcomes. The aim of this study was to investigate whether there is a link between latent toxoplasmosis and maternal AITD in pregnancy.Methods
Cross-sectional study in 1248 consecutive pregnant women in the 9–12th gestational weeks. Serum thyroid-stimulating hormone (TSH), thyroperoxidase antibodies (TPOAb), and free thyroxine (FT4) were assessed by chemiluminescence; the Toxoplasma status was detected by the complement fixation test (CFT) and anti-Toxoplasma IgG enzyme-linked immunosorbent assay (ELISA).Results
Overall, 22.5% of the women were positive for latent toxoplasmosis and 14.7% were screened positive for AITD. Women with latent toxoplasmosis had more often highly elevated TPOAb than the Toxoplasma-negative ones (p = 0.004), and latent toxoplasmosis was associated with decrease in serum TSH levels (p = 0.049). Moreover, we found a positive correlation between FT4 and the index of positivity for anti-Toxoplasma IgG antibodies (p = 0.033), which was even stronger in the TPOAb-positive Toxoplasma-positive women, (p = 0.014), as well as a positive correlation between FT4 and log2 CFT (p = 0.009).Conclusions
Latent toxoplasmosis was associated with a mild increase in thyroid hormone production in pregnancy. The observed Toxoplasma-associated changes in the parameters of AITD are mild and do not seem to be clinically relevant; however, they could provide new clues to the complex pathogenesis of autoimmune thyroid diseases. 相似文献6.
Isabelle Morard Sophie Clément Alexandra Calmy Alessandra Mangia Andrea Cerny Andrea De Gottardi Meri Gorgievski Markus Heim Raffaele Malinverni Darius Moradpour Beat Müllhaupt David Semela Stéphanie Pascarella Pierre-Yves Bochud Franco Negro 《PloS one》2014,9(9)
Background
The CCR5 receptor, expressed on Th1 cells, may influence clinical outcomes of HCV infection. We explored a possible link between a CCR5 32-base deletion (CCR5delta32), resulting in the expression of a non-functioning receptor, and clinical outcomes of HCV infection.Methods
CCR5 and HCV-related phenotypes were analysed in 1,290 chronically infected patients and 160 patients with spontaneous clearance.Results
Carriage of the CCR5delta32 allele was observed in 11% of spontaneous clearers compared to 17% of chronically infected patients (OR = 0.59, 95% CI interval 0.35–0.99, P = 0.047). Carriage of this allele also tended to be observed more frequently among patients with liver inflammation (19%) compared to those without inflammation (15%, OR = 1.38, 95% CI interval 0.99–1.95, P = 0.06). The CCR5delta32 was not associated with sustained virological response (P = 0.6), fibrosis stage (P = 0.8), or fibrosis progression rate (P = 0.4).Conclusions
The CCR5delta32 allele appears to be associated with a decreased rate of spontaneous HCV eradication, but not with hepatitis progression or response to antiviral therapy. 相似文献7.
Anders Boyd Jean-Luc Meynard Laurence Morand-Joubert Adrien Michon Franck Boccara Jean-Philippe Bastard Assia Samri Nabila Haddour Ziad Mallat Jacqueline Capeau Mo?se Desvarieux Pierre-Marie Girard for the Collaboration in HIV Inflammation Cardiovascular Disease Study 《PloS one》2014,9(11)
Background
While residual plasma viremia is commonly observed in HIV-infected patients undergoing antiretroviral treatment (ART), little is known about its subclinical consequences.Methods
This cross-sectional study included 47 male, never-smoking, non-diabetic patients with ≥4 years of ART and controlled HIV-replication (HIV-viral load, VL <20 copies/mL for ≥1 year). Residual HIV-VL was measured using an ultrasensitive assay (quantification limit: 1 copy/ml). Patients were categorized as having detectable (D; 1-20 copies/mL, n = 14) or undetectable (UD; <1 copies/mL, n = 33) HIV-VL. Linear regression was used to model the difference in total carotid intima-media thickness [c-IMT, measures averaged across common carotid artery (cca), bifurcation, and internal carotid artery] and cca-IMT alone across detection groups. Multivariable models were constructed for each endpoint in a forward-stepwise approach.Results
No significant differences were observed between viremia groups with respect to median ART-duration (9.6 years, IQR = 6.8–10.9), nadir CD4+T-cell (208/mm3, IQR = 143–378), and CD4+T-cell count (555/mm3, IQR = 458–707). Median adjusted inflammatory markers tended to be higher in patients with D- than UD-viremia, with differences in IL-10 being significant (p = 0.03). After adjustment on age, systolic blood pressure, and insulin resistance, mean cca-IMT was significantly lower in patients with undetectable (0.668 mm±0.010) versus detectable viremia (0.727 mm±0.015, p = 0.002). Cca-IMT was also independently associated with age and insulin resistance. Mean adjusted total c-IMT was no different between viremia groups (p = 0.2), however there was large variability in bifurcation c-IMT measurements.Conclusions
Higher cca-IMT was observed in patients with detectable, compared to undetectable, HIV-VL in never-smoking ART-controlled patients, suggesting that residual HIV viremia may be linked to atherosclerosis. 相似文献8.
Purpose
This study sought to evaluate factors associated with hospital length of stay in cancer patients with febrile neutropenia.Methods
A prospective cohort study was performed at a single tertiary referral hospital in southern Brazil from October 2009 to August 2011. All adult cancer patients with febrile neutropenia admitted to the hematology ward were evaluated. Stepwise random-effects negative binomial regression was performed to identify risk factors for prolonged length of hospital stay.Results
In total, 307 cases of febrile neutropenia were evaluated. The overall median length of hospital stay was 16 days (interquartile range 18 days). According to multiple negative binomial regression analysis, hematologic neoplasms (P = 0.003), high-dose chemotherapy regimens (P<0.001), duration of neutropenia (P<0.001), and bloodstream infection involving Gram-negative multi-drug-resistant bacteria (P = 0.003) were positively associated with prolonged hospital length of stay in patients with febrile neutropenia. The condition index showed no evidence of multi-collinearity effect among the independent variables.Conclusions
Hematologic neoplasms, high-dose chemotherapy regimens, prolonged periods of neutropenia, and bloodstream infection with Gram-negative multi-drug-resistant bacteria are predictors of prolonged length hospital of stay among adult cancer patients with febrile neutropenia. 相似文献9.
Background
Human personality consists of two fundamental elements character and temperament. Character allays automatic and preconceptual emotional responses determined by temperament. However, the neurobiological basis of character and its interplay with temperament remain elusive. Here, we examined character-temperament interplay and explored the neural basis of character, with a particular focus on the subgenual anterior cingulate cortex extending to a ventromedial portion of the prefrontal cortex (sgACC/vmPFC).Methods
Resting brain glucose metabolism (GM) was measured using [18F] fluorodeoxyglucose positron emission tomography in 140 healthy adults. Personality traits were assessed using the Temperament and Character Inventory. Regions of interest (ROI) analysis and whole-brain analysis were performed to examine a combination effect of temperament and character on the sgACC/vmPFC and to explore the neural correlates of character, respectively.Results
Harm avoidance (HA), a temperament trait (i.e., depressive, anxious, vulnerable), showed a significant negative impact on the sgACC/vmPFC GM, whereas self-transcendence (ST), a character trait (i.e., intuitive, judicious, spiritual), exhibited a significant positive effect on GM in the same region (HA β = −0.248, p = 0.003; ST: β = 0.250, p = 0.003). In addition, when coupled with strong ST, individuals with strong HA maintained the sgACC/vmPFC GM level comparable to the level of those with low scores on both HA and ST. Furthermore, exploratory whole-brain analysis revealed a significant positive relationship between ST and sgACC/vmPFC GM (peak voxel at x = −8, y = 32, z = −8, k = 423, Z = 4.41, corrected p FDR = 0.030).Conclusion
The current findings indicate that the sgACC/vmPFC might play a critical role in mindful awareness to something beyond as well as in emotional regulation. Developing a sense of mindfulness may temper exaggerated emotional responses in individuals with a risk for or having anxiety and depressive disorders. 相似文献10.
11.
Tomàs M. Pérez-Porcuna Carlos Ascaso Adriana Malheiro Rosa Abellana Marilaine Martins José Felipe Jardim Sardinha Patricia Quincó Irineide Assump??o Antunes Marlucia da Silva Garrido Samira Bührer-Sékula Flor Ernestina Martinez-Espinosa 《PloS one》2014,9(5)
Objective
This study evaluated the performance of the Tuberculin Skin Test (TST) and Quantiferon-TB Gold in-Tube (QFT) and the possible association of factors which may modify their results in young children (0–6 years) with recent contact with an index tuberculosis case.Materials and Methods
A cross-sectional study including 135 children was conducted in Manaus, Amazonas-Brazil. The TST and QFT were performed and the tests results were analyzed in relation to the personal characteristics of the children studied and their relationship with the index case.Results
The rates of positivity were 34.8% (TST) and 26.7% (QFT), with 14.1% of indeterminations by the QFT. Concordance between tests was fair (Kappa = 0.35 P<0.001). Both the TST and QFT were associated with the intensity of exposure (Linear OR = 1.286, P = 0.005; Linear OR = 1.161, P = 0.035 respectively) with only the TST being associated with the time of exposure (Linear OR = 1.149, P = 0.009). The presence of intestinal helminths in the TST+ group was associated with negative QFT results (OR = 0.064, P = 0.049). In the TST− group lower levels of ferritin were associated with QFT+ results (Linear OR = 0.956, P = 0.036).Conclusions
Concordance between the TST and QFT was lower than expected. The factors associated with the discordant results were intestinal helminths, ferritin levels and exposure time to the index tuberculosis case. In TST+ group, helminths were associated with negative QFT results suggesting impaired cell-mediated immunity. The TST−&QFT+ group had a shorter exposure time and lower ferritin levels, suggesting that QFT is faster and ferritin may be a potential biomarker of early stages of tuberculosis infection. 相似文献12.
Ari D. Johnson Dana R. Thomson Sidney Atwood Ian Alley Jessica L. Beckerman Ichiaka Koné Djoumé Diakité Hamed Diallo Boubacar Traoré Klenon Traoré Paul E. Farmer Megan Murray Joia Mukherjee 《PloS one》2013,8(12)
Background
In 2012, 6.6 million children under age five died worldwide, most from diseases with known means of prevention and treatment. A delivery gap persists between well-validated methods for child survival and equitable, timely access to those methods. We measured early child health care access, morbidity, and mortality over the course of a health system strengthening model intervention in Yirimadjo, Mali. The intervention included Community Health Worker active case finding, user fee removal, infrastructure development, community mobilization, and prevention programming.Methods and Findings
We conducted four household surveys using a cluster-based, population-weighted sampling methodology at baseline and at 12, 24, and 36 months. We defined our outcomes as the percentage of children initiating an effective antimalarial within 24 hours of symptom onset, the percentage of children reported to be febrile within the previous two weeks, and the under-five child mortality rate. We compared prevalence of febrile illness and treatment using chi-square statistics, and estimated and compared under-five mortality rates using Cox proportional hazard regression. There was a statistically significant difference in under-five mortality between the 2008 and 2011 surveys; in 2011, the hazard of under-five mortality in the intervention area was one tenth that of baseline (HR 0.10, p<0.0001). After three years of the intervention, the prevalence of febrile illness among children under five was significantly lower, from 38.2% at baseline to 23.3% in 2011 (PR = 0.61, p = 0.0009). The percentage of children starting an effective antimalarial within 24 hours of symptom onset was nearly twice that reported at baseline (PR = 1.89, p = 0.0195).Conclusions
Community-based health systems strengthening may facilitate early access to prevention and care and may provide a means for improving child survival. 相似文献13.
Michaela Defrancesco Karl Egger Josef Marksteiner Regina Esterhammer Hartmann Hinterhuber Eberhard A. Deisenhammer Michael Schocke 《PloS one》2014,9(8)
Background
Mild cognitive impairment (MCI) may represent an early stage of dementia conferring a particularly high annual risk of 15–20% of conversion to Alzheimer’s disease (AD). Recent findings suggest that not only gray matter (GM) loss but also a decline in white matter (WM) integrity may be associated with imminent conversion from MCI to AD.Objective
In this study we used Voxel-based morphometry (VBM) to examine if gray matter loss and/or an increase of the apparent diffusion coefficient (ADC) reflecting mean diffusivity (MD) are an early marker of conversion from MCI to AD in a high risk population.Method
Retrospective neuropsychological and clinical data were collected for fifty-five subjects (MCI converters n = 13, MCI non-converters n = 14, healthy controls n = 28) at baseline and one follow-up visit. All participants underwent diffusion weighted imaging (DWI) and T1-weighted structural magnetic resonance imaging scans at baseline to analyse changes in GM density and WM integrity using VBM.Results
At baseline MCI converters showed impaired performance in verbal memory and naming compared to MCI non-converters. Further, MCI converters showed decreased WM integrity in the frontal, parietal, occipital, as well as the temporal lobe prior to conversion to AD. Multiple regression analysis showed a positive correlation of gray matter atrophy with specific neuropsychological test results.Conclusion
Our results suggest that additionally to morphological changes of GM a reduced integrity of WM indicates an imminent progression from MCI stage to AD. Therefore, we suggest that DWI is useful in the early diagnosis of AD. 相似文献14.
Bradley J. MacIntosh David E. Crane Michael D. Sage A. Saeed Rajab Manus J. Donahue William E. McIlroy Laura E. Middleton 《PloS one》2014,9(1)
Purpose
Despite the generally accepted view that aerobic exercise can have positive effects on brain health, few studies have measured brain responses to exercise over a short time span. The purpose of this study was to examine the impact within one hour of a single bout of exercise on brain perfusion and neuronal activation.Methods
Healthy adults (n = 16; age range: 20–35 yrs) were scanned using Magnetic Resonance Imaging (MRI) before and after 20 minutes of exercise at 70% of their age-predicted maximal heart rate. Pseudo-continuous arterial spin labeling (pcASL) was used to measure absolute cerebral blood flow (CBF) prior to exercise (pre) and at 10 min (post-10) and 40 min (post-40) post-exercise. Blood oxygenation level dependent (BOLD) functional MRI (fMRI) was performed pre and post-exercise to characterize activation differences related to a go/no-go reaction time task.Results
Compared to pre-exercise levels, grey matter CBF was 11% (±9%) lower at post-10 (P<0.0004) and not different at post-40 (P = 0.12), while global WM CBF was increased at both time points post-exercise (P<0.0006). Regionally, the hippocampus and insula showed a decrease in perfusion in ROI-analysis at post-10 (P<0.005, FDR corrected), whereas voxel-wise analysis identified elevated perfusion in the left medial postcentral gyrus at post-40 compared to pre (pcorrected = 0.05). BOLD activations were consistent between sessions, however, the left parietal operculum showed reduced BOLD activation after exercise.Conclusion
This study provides preliminary evidence of regionalized brain effects associated with a single bout of aerobic exercise. The observed acute cerebrovascular responses may provide some insight into the brain’s ability to change in relation to chronic interventions. 相似文献15.
Background
New effective interventions to attenuate age-related cognitive decline are a global priority. Computerized cognitive training (CCT) is believed to be safe and can be inexpensive, but neither its efficacy in enhancing cognitive performance in healthy older adults nor the impact of design factors on such efficacy has been systematically analyzed. Our aim therefore was to quantitatively assess whether CCT programs can enhance cognition in healthy older adults, discriminate responsive from nonresponsive cognitive domains, and identify the most salient design factors.Methods and Findings
We systematically searched Medline, Embase, and PsycINFO for relevant studies from the databases'' inception to 9 July 2014. Eligible studies were randomized controlled trials investigating the effects of ≥4 h of CCT on performance in neuropsychological tests in older adults without dementia or other cognitive impairment. Fifty-two studies encompassing 4,885 participants were eligible. Intervention designs varied considerably, but after removal of one outlier, heterogeneity across studies was small (I 2 = 29.92%). There was no systematic evidence of publication bias. The overall effect size (Hedges'' g, random effects model) for CCT versus control was small and statistically significant, g = 0.22 (95% CI 0.15 to 0.29). Small to moderate effect sizes were found for nonverbal memory, g = 0.24 (95% CI 0.09 to 0.38); verbal memory, g = 0.08 (95% CI 0.01 to 0.15); working memory (WM), g = 0.22 (95% CI 0.09 to 0.35); processing speed, g = 0.31 (95% CI 0.11 to 0.50); and visuospatial skills, g = 0.30 (95% CI 0.07 to 0.54). No significant effects were found for executive functions and attention. Moderator analyses revealed that home-based administration was ineffective compared to group-based training, and that more than three training sessions per week was ineffective versus three or fewer. There was no evidence for the effectiveness of WM training, and only weak evidence for sessions less than 30 min. These results are limited to healthy older adults, and do not address the durability of training effects.Conclusions
CCT is modestly effective at improving cognitive performance in healthy older adults, but efficacy varies across cognitive domains and is largely determined by design choices. Unsupervised at-home training and training more than three times per week are specifically ineffective. Further research is required to enhance efficacy of the intervention. Please see later in the article for the Editors'' Summary 相似文献16.
Jun-Xia Cao Xiao-Yan Zhang Jin-Long Liu Duo Li Jun-Li Li Yi-Shan Liu Min Wang Bei-Lei Xu Hai-Bo Wang Zheng-Xu Wang 《PloS one》2014,9(9)
Background
The effectiveness of immunotherapy for high-grade glioma (HGG) patients remains controversial. To evaluate the therapeutic efficacy of dendritic cells (DCs) alone in the treatment of HGG, we performed a systematic review and meta-analysis in terms of patient survival with relevant published clinical studies.Materials and methods
A total of 409 patients, including historical cohorts, nonrandomized and randomized controls with HGG, were selected for the meta-analysis.Results
The treatment of HGG with DCs was associated with a significantly improved one-year survival (OS) (p<0.001) and 1.5-, 2-, 3-, 4-, and 5-year OS (p<0.001) compared with the non-DC group. A meta-analysis of the patient outcome data revealed that DC immunotherapy has a significant influence on progression-free survival (PFS) in HGG patients, who showed significantly improved 1-,1.5-, 2-, 3- and 4-year PFS (p<0.001). The analysis of Karnofsky performance status (KPS) demonstrated no favorable results for DC cell therapy arm (p = 0.23).The percentages of CD3+CD8+ and CD3+CD4+ T cells and CD16+ lymphocyte subset were not significantly increased in the DC group compared with the baseline levels observed before treatment (p>0.05), whereas CD56+ lymphocyte subset were significantly increased after DC treatment (p = 0.0001). Furthermore, the levels of IFN-γ in the peripheral blood of HGG patients, which reflect the immune function of the patients, were significantly increased after DC immunotherapy (p<0.001).Conclusions
Thus, our meta-analysis showed that DC immunotherapy markedly prolongs survival rates and progression-free time, enhances immune function, and improves the efficacy of the treatment of HGG patients. 相似文献17.
Background
There are few reports on total body skeletal muscle mass (SM) in Chinese. The objective of this study is to establish a prediction model of SM for Chinese adults.Methodology
Appendicular lean soft tissue (ALST) was measured by dual energy X-ray absorptiometry (DXA) and SM by magnetic resonance image (MRI) in 66 Chinese adults (52 men and 14 women). Images of MRI were segmented into compartments including intermuscular adipose tissue (IMAT) and IMAT-free SM. Regression was used to fit the prediction model . Age and gender were adjusted in the fitted model. The piece-wise linear function was performed to further explore the effect of age on SM. ‘Leave-One-Out Cross Validation’ was utilized to evaluate the prediction performance. The significance of observed differences between predicted and actual SM was tested by t test and the level of agreement was assessed by the method of Bland and Altman.Results
Men had greater ALST and IMAT-free SM than women. ALST was the primary predictor and highly correlated with IMAT-free SM (R2 = 0.94, SEE = 1.11 kg, P<0.001). Age was an additional predictor (SM prediction model with age adjusted R 2 = 0.95, SEE = 1.05 kg, P<0.001). There was a piece-wise linear relationship between age and IMAT-free SM: IMAT-free SM = 1.21×ALST−0.98, (Age <45 years) and IMAT-free SM = 1.21×ALST−0.98−0.04× (Age−45), (Age ≥45years). The prediction performance of this age-adjusted model was good due to ‘Leave-One-Out Cross Validation’. No significant difference between measured and predicted IMAT-free SM was detected.Conclusion
Previous SM prediction model developed in multi-ethnic groups underestimated SM by 2.3% and 3.4% for Chinese men and women. A new prediction model by DXA has been established to predict SM in Chinese adults. 相似文献18.
Stéphanie Giezendanner Melanie Sarah Fisler Leila Maria Soravia Jennifer Andreotti Sebastian Walther Roland Wiest Thomas Dierks Andrea Federspiel 《PloS one》2016,11(3)
Background
White matter (WM) fibers connect different brain regions and are critical for proper brain function. However, little is known about the cerebral blood flow in WM and its relation to WM microstructure. Recent improvements in measuring cerebral blood flow (CBF) by means of arterial spin labeling (ASL) suggest that the signal in white matter may be detected. Its implications for physiology needs to be extensively explored. For this purpose, CBF and its relation to anisotropic diffusion was analyzed across subjects on a voxel-wise basis with tract-based spatial statistics (TBSS) and also across white matter tracts within subjects.Methods
Diffusion tensor imaging and ASL were acquired in 43 healthy subjects (mean age = 26.3 years).Results
CBF in WM was observed to correlate positively with fractional anisotropy across subjects in parts of the splenium of corpus callosum, the right posterior thalamic radiation (including the optic radiation), the forceps major, the right inferior fronto-occipital fasciculus, the right inferior longitudinal fasciculus and the right superior longitudinal fasciculus. Furthermore, radial diffusivity correlated negatively with CBF across subjects in similar regions. Moreover, CBF and FA correlated positively across white matter tracts within subjects.Conclusion
The currently observed findings on a macroscopic level might reflect the metabolic demand of white matter on a microscopic level involving myelination processes or axonal function. However, the exact underlying physiological mechanism of this relationship needs further evaluation. 相似文献19.
Objective
To investigate the underlying physiological mechanisms of the structural differences in gray matter (GM) and white matter (WM) associated with obesity in young Chinese adults.Materials and Methods
A total of 49 right-handed obese or overweight (n = 22, mean age 31.72±8.04 years) and normal weight (n = 27, mean age 29.04±7.32 years) Han Chinese individuals were recruited. All participants underwent voxel-based morphometry analysis of T1-weighted MRI and tract-based spatial statistics analysis of diffusion tensor imaging. Partial correlation analysis was performed between the physiological data obtained and the abnormal structural alterations.Results
In the OO group, GM atrophy occurred in the left prefrontal cortex, bilateral cingulate gyrus, and the right temporal lobe, while enlargement was observed in the bilateral putamen. WM atrophy was observed predominantly in the regions that regulate food intake, such as the bilateral basal ganglia, the right amygdala, and the left insula. The OO group exhibited lower fractional anisotropy (FA) in bilateral frontal corticospinal tracts and the right brainstem. Significant negative correlations were observed between FA values of those three clusters and BMI, and waist circumference, while the volume of bilateral putamen positively correlated with both BMI and waist circumference. High plasma LDL levels were correlated with low FA values in the right frontal corticospinal tract. Interestingly, the negative correlation was limited to male participants.Conclusions
Obesity-related alterations of GM and WM volumes were observed predominantly in food reward circuit, which may motivate abnormal dietary intake. Further, early elevated plasma LDL might contribute to low right frontal FA values of male adults, which requires further demonstration by larger-scale and longitudinal studies. 相似文献20.
Min Wang Jun-Xia Cao Jian-Hong Pan Yi-Shan Liu Bei-Lei Xu Duo Li Xiao-Yan Zhang Jun-Li Li Jin-Long Liu Hai-Bo Wang Zheng-Xu Wang 《PloS one》2014,9(11)