A multimodal approach using TMS and EEG reveals neurophysiological changes in Parkinson's disease

IntroductionAlterations in large scale neural networks leading to neurophysiological changes have been described in Parkinson's disease (PD). The combination of transcranial magnetic stimulation (TMS) and electroencephalography (EEG) has been suggested as a promising tool to identify and quantify neurophysiological mechanisms. The aim of this study was to investigate specific changes in electrical brain activity in response to stimulation of four brain areas in patients with PD.Methods21 healthy controls and 32 patients with PD underwent a combined TMS-EEG assessment that included stimulation of four brain areas: left M1, right M1, left dorso-lateral prefrontal cortex (DLPFC), and right DLPFC. Six measures were calculated to characterize the TMS evoked potentials (TEP) using EEG: (1) wave form adherence (WFA), (2) late phase deflection (LPD), (3) early phase deflection (EPD), (4) short-term plasticity (STP), (5) inter-trial adherence, and (6) connectivity between right and left M1 and DLPFC. A Linear mixed-model was used to compare these measures between groups and areas stimulated.ResultsPatients with PD showed lower WFA (p = 0.052), lower EPD (p = 0.009), lower inter-trial adherence (p < 0.001), and lower connectivity between homologs areas (p = 0.050), compared to healthy controls. LPD and STP measures were not different between the groups. In addition, lower inter-trial adherence correlated with longer disease duration (r = −0.355, p = 0.050).ConclusionsOur findings provide evidence to various alterations in neurophysiological measures in patients with PD. The higher cortical excitability along with increased variability and lower widespread of the evoked potentials in PD can elucidate different aspects related to the pathophysiology of the disease.     

Pattern of milk feeding and family size as risk factors for iron deficiency anemia among poor Egyptian infants 6 to 24 months old

Infants between 6 and 24 months of age are at the highest risk of development of iron deficiency anemia (IDA) in developing countries. Consuming unmodified cow's milk, delayed introduction of solid foods after 6 months, and high birth order could be predictors of the presence of IDA. Three hundred infants between the ages of 6 and 24 months (mean, 13.94 ± 6.17 months) from Ain Shams University Children's Hospital were enrolled in the study. Data collected included demographic information and dietary assessment including the type of milk feeding, introduction of solid foods, and daily iron intake. The infants were examined, and anthropometric measurements were recorded. Anemic infants (hemoglobin level <11 g/dL) were further evaluated by complete blood count, hemoglobin electrophoresis, and iron profile. Anemia was diagnosed among 198 infants (66%), of whom 129 (43%) had IDA. Red cell distribution width at a cutoff value of 15.8% was 86% sensitive and 74% specific in predicting IDA. The main risk factors for IDA included being between 6 and 18 months of age, of the male sex, birth order above the second order, consuming cow's milk, predominant breast-feeding beyond 6 months of age, and low daily iron intake. We conclude that IDA is the most common cause of anemia among Egyptian infants 6 to 24 months old of low socioeconomic standard. Independent clinical predictors were consuming cow's milk during the first 6 months, delayed introduction of solid foods after 6 months, and birth order beyond the second order.     

醉茄素A对非小细胞肺癌A549细胞增殖、凋亡及PI3K／Akt信号通路的影响

目的 探讨醉茄素A（WFA） 对非小细胞肺癌（NSCLC）A549细胞增殖、凋亡及PI3K／Akt信号通路的影响。方法 采用0、2.5、5.0、10.0、20.0μmol／L WFA 处理A549细胞,采用四甲基偶氮唑盐（MTT）比色法检测上述浓度处理24、48、72和96h的细胞增殖抑制率,Hoechst染色和磷酯酰丝氨酸结合蛋白 异硫氢酸荧光素／碘化丙啶双染法（Annexin V-FITC／PI）检测各浓度组48h的细胞凋亡情况,流式细胞仪检测各浓度组48h的细胞周期分布情况,免疫印迹检测各浓度组48h凋亡相关基因（Bcl-2、Bax和Cleaved caspase-3）和PI3K／Akt信号通路重要蛋白Akt及其磷酸化形式p-Akt的蛋白水平。结果 WFA 可抑制细胞增殖,并呈剂量和时间依赖性（P＜0.05）;0、2.5、5.0、10.0、20.0μmol／L WFA作用48h后A549细胞的凋亡指数分别为2.75±0.64、4.61±1.36、9.75±2.78、12.92±3.42和18.68±4.31,组间差异有统计学意义（P＜0.05）。除2.5μmol／L外,其余浓度组的早、晚期凋亡率、凋亡促进基因（Bax和Cleaved caspase-3）水平及G0／G1期细胞比例均高于0μmol／L,凋亡抑制基因Bcl-2水平及S期和G2／M期细胞比例均低于0μmol／L（P＜0.05）; 2.5、5.0、10.0、20.0μmol／L的组间差异有统计学意义（P＜0.05）。随着浓度升高,p-Akt／Akt值呈降低趋势,差异有统计学意义（P＜0.05）。结论 WFA能够抑制A549细胞的增殖及凋亡,可能通过抑制PI3K／Akt通路激活实现。     

Proposal of a predictive model for advanced fibrosis containing Wisteria floribunda agglutinin‐positive Mac‐2‐binding protein in chronic hepatitis C

Aim

We aimed to construct a predictive model for advanced fibrosis containing Wisteria floribunda agglutinin‐positive Mac‐2‐binding protein (WFA⁺‐M2BP) level in patients with chronic hepatitis C (CHC) and to validate its accuracy in an independent cohort.

Methods

A total of 386 patients with CHC were retrospectively analyzed. For the purpose of this study, we formed a training set (n = 210) and a validation set (n = 176). In the training set, we investigated variables linked to the presence of advanced fibrosis using univariate and multivariate analyses. We constructed a formula for predicting advanced fibrosis and validated its accuracy in the validation cohort. Receiver operating characteristic curve (ROC) analysis was carried out for calculating the area under the ROC (AUROC).

Results

In multivariate analyses, WFA⁺‐M2BP (P = 0.029) and prothrombin time (PT) (P = 0.018) were found to be significant predictive factors linked to the presence of advanced fibrosis; platelet count (P = 0.098) and hyaluronic acid (P = 0.078) showed borderline statistical significance for the presence of advanced fibrosis. Using these four variables (with the initials MPPH), we constructed the following formula: MPPH score = −3.584 − (0.275 × WFA⁺‐M2BP) + (0.068 × platelet count) + (0.042 × PT) − (0.005 × hyaluronic acid). In the training and validation sets, MPPH score yielded the highest AUROCs (0.87 and 0.83) for predicting advanced fibrosis among eight serum liver fibrosis markers. Similarly, in the training and validation sets, MPPH score had the highest diagnostic accuracies for predicting advanced fibrosis among eight serum variables (81.4% and 74.4%).

Conclusion

Our proposed MPPH scoring system can be useful for predicting advanced fibrosis in patients with CHC.

     

Distribution of Aquaporin 4 in rodent spinal cord: relationship with astrocyte markers and chondroitin sulfate proteoglycans

Water balance between cells and extracellular compartments is essential for proper functioning of the central nervous system, as demonstrated by its perturbations in pathological conditions. Aquaporin 4 (AQP4) is the predominant water channel in brain and spinal cord, where it is present mainly on astrocytic endfeet contacting vessels. A role in water homeostasis control has been proposed also for the extracellular matrix, that in brain consists mainly of chondroitin sulfate proteoglycans (CSPGs). Using cytochemical and immunocytochemical techniques, we investigated their distribution in rodent spinal cord, to better understand the role of these two classes of molecules. The results show that in spinal gray matter AQP4 labeling is intense in all perivascular profiles and (1) displays a marked dorsoventral gradient in the neuropil; and (2) coexists extensively with glial glutamate transporter-1 (GLT-1) but scarcely with glial fibrillary acidic protein (GFAP). In white matter the overlap between AQP4, GLT-1, and GFAP is almost complete. Ultrastructural examination shows that AQP4-labeled astrocytic processes surround blood vessels, neuronal perikarya and processes, and both asymmetric and symmetric synapses, indicating that the protein may be involved in the regulation of water fluxes around both inhibitory and excitatory synapses. CSPGs, visualized by labeling with Wisteria floribunda agglutinin, show a distribution complementary to that of AQP4, being absent or weekly expressed in AQP4-enriched areas. These findings suggest that different mechanisms may contribute to the regulation of water homeostasis in different spinal cord regions.     

Morphology of perineuronal nets in tenascin-R and parvalbumin single and double knockout mice

Recently identified chondroitin sulphate proteoglycans in perineuronal nets include neurocan and phosphacan. However, the function and assembly of these components has yet to be resolved. In this study we show morphological alteration in Wisteria floribunda labelled nets around cortical interneurones both in tenascin-R knockout and tenascin-R/parvalbumin double knockout mice. This alteration reflects the loss of phosphacan and neurocan from cortical nets in mice deficient in tenascin-R. No effect on the membrane related cytoskeleton, as revealed by ankyrin(R), was observed in any of the mice. These results on mice lacking tenascin-R substantiate previously reported in vitro interactions between tenascin-R and phosphacan and neurocan.     

Molecular heterogeneity of aggrecan‐based perineuronal nets around five subclasses of parvalbumin‐expressing neurons in the mouse hippocampus

Subsets of GABAergic neurons are surrounded by perineuronal nets (PNNs), which play a critical role in the regulation of neural plasticity and neuroprotection. Although the plant lectin Wisteria floribunda agglutinin (WFA) has been commonly used to label PNNs, WFA only detects N‐acetyl‐d ‐galactosamine on aggrecan, a member of the lectican family. In this study, we used WFA and the antibody against the core protein of aggrecan (ACAN) to investigate the molecular heterogeneity of aggrecan‐based PNNs around five subclasses of parvalbumin‐expressing (PV+) γ‐aminobutyric acid (GABA)ergic neurons in the CA1 and CA3 regions of the mouse hippocampus. The vast majority of ACAN+ PNNs were colocalized with WFA in the stratum pyramidale, whereas a substantial population of ACAN+ PNNs lacked WFA labeling in the stratum oriens. We then defined the subclasses of PV+ neurons based on their cellular locations, molecular expression, and septal projection. Like the WFA+ PNNs, ACAN+ PNNs surrounded PV+ basket cells and bistratified cells but not axo‐axonic cells. Unlike the WFA+ PNNs, ACAN+ PNNs frequently surrounded PV+ oriens‐lacunosum moleculare cells and hippocampo‐septal cells. Interestingly, the relative densities of GABAergic synapses were higher around PV+ neurons with ACAN+ PNNs than around those without ACAN+ PNNs. Degradation of WFA+ PNNs by chondroitinase ABC did not affect the GABAergic synaptic densities around PV+ neurons. Our findings suggest that the molecular composition of aggrecan‐based PNNs around PV+ neurons may differ in a subclass‐specific manner, and also might help determine the functional involvement of PNNs in the regulation of GABAergic synapses around PV+ neurons in the hippocampus. J. Comp. Neurol. 525:1234–1249, 2017. © 2016 Wiley Periodicals, Inc.