The role of BDNF methylation and Val66Met in amygdala reactivity during emotion processing

Epigenetic alterations of the brain‐derived neurotrophic factor (BDNF) gene have been associated with psychiatric disorders in humans and with differences in amygdala BDNF mRNA levels in rodents. This human study aimed to investigate the relationship between the functional BDNF‐Val⁶⁶Met polymorphism, its surrounding DNA methylation in BDNF exon IX, amygdala reactivity to emotional faces, and personality traits. Healthy controls (HC, n = 189) underwent functional MRI during an emotional face‐matching task. Harm avoidance, novelty seeking and reward dependence were measured using the Tridimensional Personality Questionnaire (TPQ). Individual BDNF methylation profiles were ascertained and associated with several BDNF single nucleotide polymorphisms surrounding the BDNF‐Val⁶⁶Met, amygdala reactivity, novelty seeking and harm avoidance. Higher BDNF methylation was associated with higher amygdala reactivity (x = 34, y = 0, z = ?26, t₍₁₆₆₎ = 3.00, TFCE = 42.39, p_(FWE) = .045), whereby the BDNF‐Val⁶⁶Met genotype per se did not show any significant association with brain function. Furthermore, novelty seeking was negatively associated with BDNF methylation (r = ?.19, p = .015) and amygdala reactivity (r = ?.17, p = .028), while harm avoidance showed a trend for a positive association with BDNF methylation (r = .14, p = .066). The study provides first insights into the relationship among BDNF methylation, BDNF genotype, amygdala reactivity and personality traits in humans, highlighting the multidimensional relations among genetics, epigenetics, and neuronal functions. The present study suggests a possible involvement of epigenetic BDNF modifications in psychiatric disorders and related brain functions, whereby high BDNF methylation might reduce BDNF mRNA expression and upregulate amygdala reactivity.     

膝关节前外侧韧带的研究进展

目的对膝关节前外侧韧带（anterolateral ligament，ALL）的研究进展进行综述，为临床诊治提供参考。方法广泛查阅近年来国内外有关 ALL 损伤诊断及治疗的文献，总结膝关节 ALL 解剖形态、生物力学以及 ALL 损伤机制、治疗现状。结果膝关节 ALL 具有限制胫骨内旋及前移作用，影响膝关节轴移。ALL 损伤后可结合患者体征和 MRI 检查诊断。膝关节 ALL 手术指征尚未统一，但多数学者倾向于对需进行前交叉韧带（anterior cruciate ligament，ACL）重建或翻修且伴有高度轴移试验阳性的患者进行 ALL 重建。目前 ALL 重建方式较多，但尚无最佳治疗术式。此外，由于缺乏高质量的术后长期随访研究，远期临床疗效仍不明确。结论ALL 在维持膝关节稳定性方面具有一定作用，但 ALL 重建技术及临床疗效仍待进一步研究。     

新型纳米根管充填材料对成骨细胞生长的影响

通过体外培养的成骨细胞,采用二甲基噻唑二苯基四唑溴盐比色法和流式细胞术对新型纳米根管充填材料(nHA-PA66)作用下的成骨细胞生长情况的变化进行研究,评价其对成骨细胞生长的影响。以该材料的细胞培养基浸提液作用于实验组细胞,对照组采用培养基本身。实验组和对照组成骨细胞的生长情况和细胞周期无显著性差异,表明该新型纳米材料对成骨细胞的生长和细胞周期无不良影响。提示新型纳米根管充填材料的成骨细胞相容性较好,具有用作根充材料的基础。     

外围由小分子修饰的树枝状聚酰胺的合成及其荧光性能研究

合成了1－5代外围由小分子荧光体修饰的树枝状聚酰胺，通过红外，紫外，核磁等表征了其结构，并对其荧光性能进行了研究，修饰后的固体产物的荧光较修饰前粘稠体产物的荧光强得多，树枝状高分子荧光受组分比，代数，溶液浓度，溶剂等因素的影响，有机硅对树状高分子的端氨基与3，5二羟基苯甲酸按1／1摩尔比反应时，其产物荧光最强，对于端氨基与3，5－二羟基苯甲酸摩尔比为1／1的不同代树枝状聚酰胺而言，2代产物荧光最强。     

Brain-derived neurotrophic factor Val66Met and psychiatric disorders: meta-analysis of case-control studies confirm association to substance-related disorders, eating disorders, and schizophrenia.

BACKGROUND: There is an increasing recognition that the pathophysiology of mental disorders could be the result of deregulation of synaptic plasticity with alterations of neurotrophins. The valine (Val)66-to-methionine (Met) variant, located in the pro brain-derived neurotrophic factor (BDNF) sequence, has been extensively studied through linkage and association approaches in several psychiatric disorders. METHODS: We performed a meta-analysis restricted to individual case-control studies in different categories of mental disorders and BDNF Val66Met polymorphism. We included data from 39 case-control studies encompassing psychiatric phenotypes: eating disorders, substance-related disorders, mood disorders, and schizophrenia, among others. RESULTS: The association of Val66Met was confined to three diagnoses: substance-related disorders, eating disorders, and schizophrenia. The Val/Met and the Met/Met genotypes increase the risk for eating disorders up to 33%, while these same genotypes confer a 21% protective effect in substance-related disorders. The homozygous carriers Met/Met showed a 19% increased risk of schizophrenia with respect to the heterozygous state. CONCLUSIONS: The study confirms the association of Val66Met to substance-related disorders, eating disorders, and schizophrenia. It remains to be determined if other variants in tight linkage disequilibrium with Val66Met could configure an extended functional haplotype that would explain observed discrepancies in risk estimations across studies.     

Cyclotron production of carrier-free 66Ga as a positron emitting label of albumin colloids for clinical use

A method for producing carrier free ⁶⁶Ga (T_1/2:9.4h; ⁺) by ⁴He bombardment of natural copper targets is presented. ⁶⁶Ga is formed by means of the ⁶³Cu (⁴He, n) ⁶⁶Ga reaction. Production yields are given in the 17.5 to 8 MeV ⁴He energy range. Chemical purification of ⁶⁶Ga from the copper target is described. The only radionuclidic impurity found in the final product was ⁶⁷Ga. Albumin colloids from commercially available kits designed for use with ^99mTc could easily be labeled with ⁶⁶Ga and employed for studies of the lymphatic system by positron emission tomography.     

原位检测新基因SNC66在胃癌组织与正常胃粘膜中的表达

目的: 观察新基因SNC66在胃癌组织中的表达水平,分析SNC66表达水平与胃癌发生的相关性。 方法:以β-actin为对照,对20例胃癌组织及其配对正常胃粘膜的石蜡切片,进行原位cRNA/mRNA分子杂交和原位RT-PCR扩增。 结果:两种检测方法表明,SNC66在正常胃粘膜组织中都呈强阳性表达。而在胃癌组织中,原位分子杂交检测表明,20例标本SNC66不表达和弱阳性表达各8例,强阳性表达4例。原位RT-PCR检测表明,当循环数为10时,此20例胃癌标本中不表达、弱阳性和呈强阳性表达数分别为6,9和5;而当循环数为25时,则4例不表达,16例呈强阳性表达。 结论:SNC66基因在胃癌组织中存在明显的表达降低和表达缺陷。SNC66可以作为一个胃癌负相关基因加以进一步研究。     

Reactive Compatibilization of PA6/LDPE Blends with Glycidyl Methacrylate Functionalized Polyolefins

Summary: Blends of polyamide‐6 (PA6) and low density polyethylene (LDPE) were compatibilized by melt mixing with various polyolefins functionalized with glycidyl methacrylate (GMA), i.e., GMA grafted LDPE (LDPE‐g‐GMA), GMA grafted styrene‐ethylene/butylene‐styrene block copolymer (SEBS‐g‐GMA) and ethylene‐co‐glycidyl methacrylate copolymer (E‐GMA). Blends with PA6/LDPE composition ratios of 25/75 and 75/25 wt.‐%/wt.‐% were prepared in a Brabender internal mixer and their properties were evaluated by SEM, rheological measurements and DSC. Morphological investigation by SEM showed a neat improvement of phase dispersion and interfacial adhesion in all compatibilized blends when compared to PA6/LDPE binary blends. The variation of the dispersed phase size was analyzed as a function of blend composition, compatibilizer concentration and GMA content. The emulsification curves of compatibilized blends showed that the equilibrium size of dispersed particles at the saturation concentration of copolymer was lower when PA6 was the major component. The finest dispersion of the LDPE phase (<0.25 μm) was observed in the presence of SEBS‐g‐GMA copolymer. LDPE‐g‐GMA and E‐GMA displayed a similar compatibilizing efficiency. In all cases, the blends with a polyamide matrix presented a marked rise in torque and melt viscosity with increasing compatibilizer content. These effects were accounted for by a reaction between the epoxide groups of LDPE‐g‐GMA and the carboxyl/amine end‐groups of PA6, leading to the formation of an interchain graft copolymer. The phase transition processes of PA6 in the blends were influenced by the compatibilizer content and the interfacial interactions between the polymer components, suggesting a different role for the compatibilizer at the PA6/LDPE interface.

SEM micrograph of PA6/LDPE 25/75 blend compatibilized with 2.5 phr SEBS‐g‐GMA.     

Morphology and Thermal Properties of MCPA6/ABS by in situ Polymerization of ε‐Caprolactam

Summary: In this work, blends of monomer casting polyamide 6 (MCPA6) and acrylonitrile‐butadiene‐styrene (ABS) were successfully prepared by in situ polymerization via the application of ε‐caprolactam as a reactive solvent. The morphology and thermal properties of MCPA6/ABS were investigated by means of wide angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. The domain sizes of the ABS phase in MCPA6/ABS blends were much finer than those in corresponding polyamide 6 (PA6)/ABS blends prepared by simple melt blending. With an increased amount of ABS in MCPA6, the melt enthalpy (ΔH_f), the rate of crystallization (T_c) and the degree of crystallinity (X_c(DSC)) of MCPA6 in MCPA6/ABS blends were all decreased. The degree of supercooling (ΔT_d) showed a contrary trend. However, the melting temperatures of these blends were almost unchanged. All the results could be attributed to in situ polymerization and the hydrolysis reaction of ABS that occurred during the polymerization process. Furthermore, WAXD results showed that only α‐form crystals existed in the MCPA6/ABS blends, despite the ABS content and heat treatment.

SEM micrograph of the fractured surface of an MCPA6/ABS blend with an ABS content of 20 wt.‐% (×10 000).