Effects of diets enriched in linoleic acid and its peroxidation products on brain fatty acids,oxylipins, and aldehydes in mice

Background

Linoleic acid (LA) is abundant in modern industrialized diets. Oxidized LA metabolites (OXLAMs) and reactive aldehydes, such as 4-hydroxy-2-nonenal (4-HNE), are present in heated vegetable oils and can be endogenously synthesized following consumption of dietary LA. OXLAMs have been implicated in cerebellar degeneration in chicks; 4-HNE is linked to neurodegenerative conditions in mammals. It unknown whether increasing dietary LA or OXLAMs alters the levels of oxidized fatty acids (oxylipins), precursor fatty acids, or 4-HNE in mammalian brain.

2月龄和4月龄大鼠制备心肺复苏模型后神经功能评价及亚组评分的比较

目的：本研究旨在选择适合的大鼠,对比2月龄大鼠与4月龄大鼠CPR后神经功能评分及亚组评分,摸索利用不同月龄的大鼠CPR的可行性。方法通过严格监测SD大鼠制备模型过程中的心电、血压生理指标、测定各组大鼠不同时间点的神经功能缺失评分以及神经功能亚组评分、对比制备4月龄和2月龄大鼠心肺复苏模型的稳定性。结果电刺激致室颤,4月龄组大鼠的成模率为87.5％,远高于2月龄组大鼠,而死亡率无差异;在电刺激诱发CA过程中造成的血压变化,4月龄组大鼠明显低于2月龄组大鼠,存在极显著性差异（ P ＜0.01）;4月龄组大鼠与2月龄组大鼠CPR后各时间点的神经功能评分无统计学差异,而4月龄组大鼠与2月龄组大鼠的神经功能亚组评分在不同时间点,存在显著差异（P ＜0.05）,4月龄大鼠与2月龄大鼠对比,心肺复苏后脑损伤的程度加重。结论4月龄大鼠更适合制备心肺复苏模型,该月龄组的大鼠制备模型成模率高,脑损伤程度重,更适合于用于心肺复苏的基础研究及治疗评价。     

Evidence for an Astrocyte-Derived Vasorelaxing Factor with Properties Similar to Nitric Oxide

To determine whether astrocytes release nonprostanoid vasodilators, cells on microcarrier beads were superfused with various agents in the presence of indomethacin, and the effluent was bioassayed and also analyzed for nitric oxide by a chemiluminescence technique. Bradykinin and A23187 induced release of a factor that relaxed arterial rings, an effect that was blocked by hemoglobin. The effluent contained either nitric oxide or a related compound that could be reduced to nitric oxide. Production of this factor was competitively inhibited by the arginine analogs NG-nitro-L-arginine and NG-methyl-L-arginine and could be restored with L-arginine. Quisqualate and norepinephrine were also effective in causing the release of nitric oxide from astroglial cells. Thus, astrocyte-derived relaxing factor has properties similar to those of an endothelium- and neuron-derived relaxing factor.     

The hazardous effects of formalin and alcoholic fixative in mice: A public health perspective study

Formalin is used for different purposes due to its preservation capability. But continuous exposure to formalin may result various health related issues leading to cancer and death. A new alcohol-based fixative, EMA (ethanol, methanol and acetic acid = 3:1:1) could be a safer option in this regard. To compare the health hazards of formalin and EMA, a total 15 adult male mice were randomly distributed into three groups- exposure groups (formalin and EMA) and control group. The mice were subjected to natural inhalation exposure of the fixatives followed by behavioral depression test (forced swimming test), histopathology and serum biochemical tests. Our results showed that the hazardous effects of formalin were remarkably higher than that of EMA. Formalin exposed group showed severe depression (P < 0.001) in the forced swimming test compared to EMA and control groups. Histopathologically, diffuse lymphocytic infiltrations around the lung alveoli and bronchioles and severe inflammation with accumulation of reactive cells in the cerebral cortex were detected in the formalin exposed group, whereas little or no inflammation with fibrinous exudates in the bronchioles was reported in the EMA group and no inflammatory cells were detected in the cerebral tissues. The serum biochemical analysis of the inflammatory mediators (Interleukin-6 and C-reactive protein) revealed that both significantly (P < 0.001) increased in the formalin exposed group compared to EMA and control groups. These results confer that EMA could be a safer option to reduce health hazards of formalin in the workplace environment.     

Brain expansion and comparative prenatal ontogeny of the non-hominoid primate cranial base

The basicranium is the keystone of the primate skull, and understanding its morphological interdependence on surrounding soft-tissue structures, such as the brain, can reveal important mechanisms of skull development and evolution. In particular, several extensive investigations have shown that, across extant adult primates, the degree of basicranial flexion and petrous orientation are closely linked to increases in brain size relative to cranial base length. The aim of this study was to determine if an equivalent link exists during prenatal life. Specific hypotheses tested included the idea that increases in relative endocranial size (IRE5), relative infratentorial size (RIE), and differential encephalization (IDE) determine the degree of basicranial flexion and coronal petrous reorientation during non-hominoid primate fetal development. Cross-sectional fetal samples of Alouatta caraya (n=17) and Macaca nemestrina (n=24) were imaged using high-resolution magnetic resonance imaging (hrMRI). Cranial base angles (CBA), petrous orientations (IPA), base lengths, and endocranial volumes were measured from the images. Findings for both samples showed retroflexion, or flattening, of the cranial base and coronal petrous reorientation as well as considerable increases in absolute and relative brain sizes. Although significant correlations of both IRE5 and RIE were observed against CBA and IPA, the correlation with CBA was in the opposite direction to that predicted by the hypotheses. Variations of IDE were not significantly correlated with either angle. Correlations of IPA with IRE5 and RIE appeared to support the hypotheses. However, partial coefficients computed for all significant correlations indicated that changes to the fetal non-hominoid primate cranial base were more closely related to increases in body size than the hypothesized influence of relative brain enlargement. These findings were discussed together with those from a previous study of modern human fetuses.     

猪大脑皮层突触质膜糖皮质激素结合位点的测定

利用放射配体结合测定法,测得猪大脑皮层突触质膜上存在有皮质酮特异结合位点,该皮质酮膜结合位点的最大结合量（Ｂｍａｘ）为３３１．８±３６．９ｆｍｏｌ／ｍｇ蛋白,平衡解离常数（Ｋｄ）为１８５．０±６２．７ｎｍｏｌ／Ｌ。竞争取代实验表明,它具有较高的甾体结合特异性,按亲和力大小排列为：皮质酮＞孕酮＞１７β－雌二醇≈醛固酮＞睾酮。     

毛冠鹿大脑组织全长cDNA文库构建

运用SMART技术构建了毛冠鹿(Elaphodus cephalophus)大脑组织全长cDNA文库。提取大脑组织总RNA,Oligotex mRNA Kit纯化、获得poly(A) RNA,以CDSⅢ/3′PCR引物进行逆转录,LD-PCR扩增获得全长双链cDNA,经SfiⅠ酶切及柱层析分离后,500 bp以上的片段与载体λTripIEx2连接,体外包装得到cDNA文库。经鉴定原始文库滴度为5.1×105pfu/ml,扩增后文库滴度为1.5×109pfu/ml,重组率达到85%以上,插入片断平均长度约为1.0 kb,说明构建文库质量符合要求,可用于大脑特异表达基因的筛选。从该文库中克隆到了rig基因全长,包含5′和3′非编码区,从第43至477个核苷酸为一完整阅读框(ORF),此阅读框可编码一个145氨基酸的rig蛋白。     

3Development-Dependent Regulation of N-Acetyl-β-d-Hexosaminidase of Cerebellum and Cerebrum of Normal and Staggerer Mutant Mice

Distinctive activities of various glycosidases were expressed in the cerebellum and cerebral cortex of mice during their development. In particular, N-acetyl-beta-D-hexosaminidase (EC 3.2.1.30) appeared to be developmentally regulated. A transient peak of enzyme activity at postnatal day 7 was characteristic for the cerebellum, whereas the activity in the cerebral cortex gradually increased through the 1st postnatal month and was maintained at a high level of activity throughout adulthood. The regulation of N-acetylhexosaminidase activity in the developing cerebellum of the staggerer mouse deviated clearly from enzyme activities in the wild-type, whereas the activity pattern in the staggerer cerebral cortex remained unaffected. In experiments mixing wild-type and staggerer cerebellum homogenates, the specific activity was additive. Thus, involvement of inhibitors or activating molecules can be excluded. This developmentally controlled regulation or disregulation in staggerer appears to be enzyme specific, sine beta-glucosidase, alpha-glucosidase, and beta-galactosidase did not exhibit such a pattern in either normal or staggerer mice. In the mutation weaver that, like staggerer, loses the majority of its cerebellar granule cells, N-acetyl-beta-hexosaminidase activity of the cerebellum was not elevated, indicating a specific defect in staggerer rather than a general effect on lysosomal enzymes due to cell death.     

Occurrence of phosphatidyl-d-serine in the rat cerebrum

Phosphatidylserine (PS), a relatively abundant component of mammalian cell membranes, plays important roles in biological processes including apoptosis and cell signaling. It is believed that phosphatidyl-l-serine is the only naturally occurring PS. Here, we describe for the first time the occurrence of phosphatidyl-d-serine (d-PS) in rat cerebrum. Quantitative HPLC analysis of the derivatives of serine liberated from PS by hydrolysis revealed that the amount of d-PS was approximately 1% of the total PS in the cerebrum. Enzymatic cleavage of cerebrum PS with phospholipase D and phospholipase C resulted in the release of both isomers of serine and phosphoserine, respectively, providing additional evidence for the existence of d-PS. Free d-serine was incorporated into PS in an in vitro system using a cerebrum extract, and this activity was inhibited by EDTA, suggesting the occurrence of a divalent cation-dependent enzyme that synthesizes d-PS by a base-exchange reaction.