Mediterranean diet habits in older individuals: Associations with cognitive functioning and brain volumes

To examine the association between dietary habits, cognitive functioning and brain volumes in older individuals, data from 194 cognitively healthy individuals who participated in the Prospective Investigation of the Vasculature in Uppsala Seniors cohort were used. At age 70, participants kept diaries of their food intake for 1 week. These records were used to calculate a Mediterranean diet (MeDi) score (comprising dietary habits traditionally found in Mediterranean countries, e.g. high intake of fruits and low intake of meat), with higher scores indicating more pronounced MeDi-like dietary habits. Five years later, participants' cognitive capabilities were examined by the seven minute screening (7MS) (a cognitive test battery used by clinicians to screen for dementia), and their brain volumes were measured by volumetric magnetic resonance imaging. Multivariate linear regression analyses were constructed to examine the association between the total MeDi score and cognitive functioning and brain volumes. In addition, possible associations between MeDi's eight dietary features and cognitive functioning and brain volumes were investigated. From the eight dietary features included in the MeDi score, pertaining to a low consumption of meat and meat products was linked to a better performance on the 7MS test (P = 0.001) and greater total brain volume (i.e. the sum of white and gray matter, P = 0.03) when controlling for potential confounders (e.g. BMI) in the analysis. Integrating all dietary features into the total MeDi score explained less variance in cognitive functioning and brain volumes than its single dietary component meat intake. These observational findings suggest that keeping to a low meat intake could prove to be an impact-driven public health policy to support healthy cognitive aging, when confirmed by longitudinal studies. Further, they suggest that the MeDi score is a construct that may mask possible associations of single MeDi features with brain health domains in elderly populations.     

Effect of scanner acoustic background noise on strict resting-state fMRI

Functional MRI (fMRI) resting-state experiments are aimed at identifying brain networks that support basal brain function. Although most investigators consider a ‘resting-state’ fMRI experiment with no specific external stimulation, subjects are unavoidably under heavy acoustic noise produced by the equipment. In the present study, we evaluated the influence of auditory input on the resting-state networks (RSNs). Twenty-two healthy subjects were scanned using two similar echo-planar imaging sequences in the same 3T MRI scanner: a default pulse sequence and a reduced “silent” pulse sequence. Experimental sessions consisted of two consecutive 7-min runs with noise conditions (default or silent) counterbalanced across subjects. A self-organizing group independent component analysis was applied to fMRI data in order to recognize the RSNs. The insula, left middle frontal gyrus and right precentral and left inferior parietal lobules showed significant differences in the voxel-wise comparison between RSNs depending on noise condition. In the presence of low-level noise, these areas Granger-cause oscillations in RSNs with cognitive implications (dorsal attention and entorhinal), while during high noise acquisition, these connectivities are reduced or inverted. Applying low noise MR acquisitions in research may allow the detection of subtle differences of the RSNs, with implications in experimental planning for resting-state studies, data analysis, and ergonomic factors.     

Non-contact mapping in the treatment of ventricular tachycardia after myocardial infarction

The treatment of ventricular tachycardia (VT) in patients with underlying ischaemic heart disease (IHD) remains a challenge. Ablation of these arrhythmias may have a significant impact on quality of life for patients. For those patients with haemodynamically unstable VT, ablation success rates have been improved by the use of non-contact mapping. Care has to be taken in the analysis and interpretation of non-contact mapping studies, as chamber size and filter settings have a large effect on the appearance of the activation maps produced. Despite this limitation the majority of VT exit sites and part of the diastolic pathway can be identified with non-contact mapping techniques.     

基于纹理统计特征的医学图像颜色映射方法

为提高灰度医学图像颜色增强的有效性和视觉合理性,提出了一种基于纹理统计特征的颜色增强处理方法。此方法的颜色映射机理不是传统的在灰度级和颜色模型间经验性构筑一对一或多对一的映射关系函数,而是借助彩色可视化人体（VHP）解剖断层源图像数据,利用共生矩阵纹理统计特征信息,实现颜色在图像间的传输。实验结果证明了此方法的可行性,高维度、高阶数统计量的运用提高了颜色映射的准确性和有效性。     

脑CT及脑电地形图在急性进展性脑梗死中的应用研究

目的：观察脑CT及脑电地形图（BEAM）在急性进展性脑梗死（APCI）变化特点，为临床早期诊断和治疗提供客观依据。方法：对103例发病2．5～24小时、急性脑梗死患者进行前瞻性研究，其中APCI患者32例，分析脑CT和BEAM早期变化特点，并与71例非进展性脑梗死进行对比。结果：脑CT：103例患者，70例脑CT出现异常（68．0％）。进展组32例患者，27例（84．4％）出现脑梗死早期表现，明显高于非进展组（43例，60．6％），病情进展至高峰时，脑CT显示，16例（50％）出现梗死体积增大，5例（15．6％）有出血性梗死，3例（9．4％）有新部位的梗死，8例（25％）梗死体积无明显变化。BEAM检查：两组患者异常率为91．4％。进展组患者病变区8频带平均功率值高于非进展组，并且异常部位波及范围较大。结论：脑CT和BEAM可作为早期诊断APCI的预测指标。导致病情进展的直接原因可能与梗死体积增大、出血性脑梗死和再梗死有关。     

涟波振荡与大鼠颞叶癫癎发作关系的研究

目的探讨脑电中的涟波振荡与大鼠颞叶癫癎发作的关系。方法10只SD大鼠,在双侧齿状回和海马分别置入深部电极,用氯化锂-毛果芸香碱腹腔注射诱发大鼠颞叶癫癎,记录癫癎发作前后的深部脑电(采样频率10KHz,低通为5000Hz)。用小波变换提取脑电中的涟波和快速涟波成分,并用能量法对癫癎发作前后的涟波成分进行分析。结果涟波和快速涟波的能量变化与癫癎发作的状态十分符合。癫癎发作时,快速涟波和涟波的能量都有明显增加,累积速率大。给予地西泮后,两者的能量都有所减小,累积速率趋于稳定,但快速涟波的能量累积速度降低得更快。结论脑电中的涟波振荡成分对癫癎发作有指示性作用。     

Epitope mapping and biological function analysis of antibodies produced by immunization of mice with an inactivated Chinese isolate of severe acute respiratory syndrome-associated coronavirus (SARS-CoV)

Inactivated severe acute respiratory syndrome-associated coronavirus (SARS-CoV) has been tested as a candidate vaccine against the re-emergence of SARS. In order to understand the efficacy and safety of this approach, it is important to know the antibody specificities generated with inactivated SARS-CoV. In the current study, a panel of twelve monoclonal antibodies (mAbs) was established by immunizing Balb/c mice with the inactivated BJ01 strain of SARS-CoV isolated from the lung tissue of a SARS-infected Chinese patient. These mAbs could recognize SARS-CoV-infected cells by immunofluorescence analysis (IFA). Seven of them were mapped to the specific segments of recombinant spike (S) protein: six on S1 subunit (aa 12-798) and one on S2 subunit (aa 797-1192). High neutralizing titers against SARS-CoV were detected with two mAbs (1A5 and 2C5) targeting at a subdomain of S protein (aa 310-535), consistent with the previous report that this segment of S protein contains the major neutralizing domain. Some of these S-specific mAbs were able to recognize cleaved products of S protein in SARS-CoV-infected Vero E6 cells. None of the remaining five mAbs could recognize either of the recombinant S, N, M, or E antigens by ELISA. This study demonstrated that the inactivated SARS-CoV was able to preserve the immunogenicity of S protein including its major neutralizing domain. The relative ease with which these mAbs were generated against SARS-CoV virions further supports that subunit vaccination with S constructs may also be able to protect animals and perhaps humans. It is somewhat unexpected that no N-specific mAbs were identified albeit anti-N IgG was easily identified in SARS-CoV-infected patients. The availability of this panel of mAbs also provided potentially useful agents with applications in therapy, diagnosis, and basic research of SARS-CoV.     

一个原发性痛风家系致病易感基因染色体定位

目的 对一原发性痛风家系进行致病基因的染色体定位。方法 收集痛风家系成员的临床资料及血液样本。选择其中一典型家系为研究对象（包括6例患者，9例正常人），抽提外周血基因组DNA，进行全基因组扫描和连锁分析，初步明确致病基因所在的染色体区段。结果 在微卫星引物D4S1572处获得最大LOD值（θ=0．00时LOD=1．50），表明该痛风家系的致病基因与该位点连锁。结论 由于D4S1572位于4q25，因此该家系致病基因位于4q25附近。     

Progressive remodeling of the atrial substrate--a novel finding from consecutive voltage mapping in patients with recurrence of atrial fibrillation after catheter ablation

Background: Atrial substrate properties have been demonstrated to be related to atrial arrhythmias. This study investigated whether the atrial substrate exhibits progressive remodeling in patients with recurrence of atrial fibrillation (AF) after catheter ablation.
Methods and Results: Fifteen consecutive AF patients (52 ± 12 years old, 12 males) underwent the same mapping technique (NavX, St. Jude Medical, Minnetonka, MN, USA) and same ablation technique for primary AF and recurrence of AF (170 ± 66 days after the first procedure). The bipolar mean peak-to-peak voltage (PPV) of the global left atrium during sinus rhythm significantly decreased in the second procedure (2.25 ± 0.62 vs. 1.79 ± 0.60 mV, P = 0.008). Also, the percentage of the surface area of the low voltage zone (LVZ; less than 0.5 mV) in the left atrium increased from 6 ± 4% to 13 ± 6% (P = 0.001) in the second procedure. There was no significant change in the right atrial bipolar mean PPV or surface area of the LVZ in the second procedure.
Conclusion: Atrial substrate remodeling with a progressive decrease in the left atrial voltage was demonstrated in patients with recurrent AF.     

Normal atrial activation and voltage during sinus rhythm in the human heart: an endocardial and epicardial mapping study in patients with a history of atrial fibrillation

Background: The three-dimensional contributions to human atrial activation in sinus rhythm have not been specifically characterized. We evaluated the sequence of endocardial and epicardial activation and voltage of the atria during normal sinus rhythm.
Methods and Results: The study group includes 35 patients with history of symptomatic atrial fibrillation. Prior to catheter ablation of atrial fibrillation, we performed multielectrode electroanatomic mapping during sinus rhythm, endocardially of the RA, LA, and coronary sinus (CS) and, in 10 patients, epicardially of the transverse sinus and oblique sinus. Following activation of the atrial region of the sinus node, the epicardial transverse sinus was activated 11 ± 18 msec later, while the earliest endocardial LA activation occurred in the region of Bachmann's bundle at 31 ± 13 msec, significantly earlier than the earliest epicardial LA activation of the oblique sinus at 54 ± 10 msec (P < 0.002). The posterior LA revealed complex types of activation in 66% of patients analyzed, due to the convergence of wavefront propagation from the CS, oblique sinus, and endocardial LA. Bipolar voltage measurements revealed significantly higher values for the epicardium (mean 3.05 ± 1.31 mv) than for the endocardium (mean 1.65 ± 0.75 mv), P < 0.0001 between both groups.
Conclusions: In sinus rhythm, we have characterized endocardial and epicardial atrial activation and voltage, and provide an analysis and understanding of the genesis of the P wave complex in humans.