Protective effect of N-acetylcysteine against BDE-209-induced neurotoxicity in primary cultured neonatal rat hippocampal neurons in vitro

Globally, brominated diphenyl ether-209 (BDE-209) is the most widely used polybrominated diphenyl ether (PBDEs). It has been reported that BDE-209 induces developmental neurotoxicity in vivo. The purpose of this study was to use an antioxidant, N-acetylcysteine (NAC), as an antidote for the neurotoxic effect of BDE-209. We used primary hippocampal neurons from rats for the in vitro cultures. BDE-209 was added to the cultures in increasing concentrations and co-cultured with NAC in order to assess the effect of NAC on BDE-209-induced neurotoxicity. We measured cell viability, apoptosis, expression of phosphorylated p38 mitogen-activated protein kinases (MAPK), intracellular calcium content, and intracellular reactive oxygen species (ROS) levels. The difference between the BDE-209 groups without NAC and the blank control groups was significant (P < 0.05). The difference between the NAC treatment groups and the BDE-209 groups without NAC was also significant (P < 0.05), showing that BDE-209 increased apoptosis, the expression of p38 MAPK, the calcium ion concentration, and the ROS level and decreased cell viability. In contrast, NAC reduced the degree of cellular cytotoxicity induced by BDE-209. The results suggested that NAC may be able to attenuate BDE-209-induced neurotoxicity.     

Serial analysis of gene expression in a rat lung model of asthma

Background and objective: The pathogenesis and molecular mechanism underlying asthma remain undetermined. The purpose of this study was to identify genes and pathways involved in the early airway response (EAR) phase of asthma by using serial analysis of gene expression (SAGE). Methods: Two SAGE tag libraries of lung tissues derived from a rat model of asthma and controls were generated. Bioinformatic analyses were carried out using the Database for Annotation, Visualization and Integrated Discovery Functional Annotation Tool, Gene Ontology (GO) Tree Machine and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Results: A total of 26 552 SAGE tags of asthmatic rat lung were obtained, of which 12 221 were unique tags. Of the unique tags, 55.5% were matched with known genes. By comparison of the two libraries, 186 differentially expressed tags (P < 0.05) were identified, of which 103 were upregulated and 83 were downregulated. Using the bioinformatic tools these genes were classified into 23 functional groups, 15 KEGG pathways and 37 enriched GO categories. Conclusions: The bioinformatic analyses of gene distribution, enriched categories and the involvement of specific pathways in the SAGE libraries have provided information on regulatory networks of the EAR phase of asthma. Analyses of the regulated genes of interest may inform new hypotheses, increase our understanding of the disease and provide a foundation for future research.     

Establishment of a trinitrobenzene sulfonic acid‐induced rat colitis model

OBJECTIVE : To set up a trinitrobenzene sulfonic acid (TNBS)‐induced colitis model in the rat and to assess its value in research studies of inflammatory bowel disease (IBD). METHODS : A 0.85‐mL enema containing 30 mg TNBS dissolved in 50% ethanol was instilled into the rat colon to induce distal colitis. Control rats were instilled with 50% ethanol or TNBS/saline alone. Macroscopic histological changes of the colon and myeloperoxidase (MPO) activity of the mucosa were evaluated. RESULTS : One week after the TNBS/ethanol enema, hyperemia, edema and ulceration of the colonic mucosa appeared with predominant infiltration of polymorphonuclear leukocytes in the distal colon. Four weeks after TNBS/ethanol enema, ulcers had healed macroscopically and lymphocytes and plasma cells became predominant. The tissue MPO activity increased on the first day after the TNBS/ethanol enema and this increase in MPO activity lasted for 3 weeks, but declined 4 weeks after the TNBS/ethanol enema. In contrast, macroscopic, histological changes and MPO activity returned to normal levels in control rats within the first week. CONCLUSIONS : Trinitrobenzene sulfonic acid/ ethanol‐induced rat distal colitis is an ideal model of IBD and may serve as a tool for the investigation of the pathogenesis of and effects of pharmaceuticals on IBD.     

Rat Strain Differences in Pulmonary Artery Smooth Muscle Ca2+ Entry Following Chronic Hypoxia

Effects of chronic hypoxia (CH) on store‐ and receptor‐operated Ca²⁺ entry (SOCE, ROCE) in pulmonary vascular smooth muscle (VSM) are controversial, although whether genetic variation explains such discrepancies in commonly studied rat strains is unclear. Since protein kinase C (PKC) can inhibit Ca²⁺ permeable nonselective cation channels, we hypothesized that CH differentially alters PKC‐dependent inhibition of SOCE and ROCE in pulmonary VSM from Sprague‐Dawley and Wistar rats. To test this hypothesis, we examined SOCE and endothelin‐1 (ET‐1)‐induced ROCE in endothelium‐disrupted, pressurized pulmonary arteries from control and CH Sprague‐Dawley and Wistar rats. Basal VSM Ca²⁺ was elevated in CH Wistar, but not Sprague‐Dawley, rats. Further, CH attenuated SOCE in VSM from Sprague‐Dawley rats, while augmenting this response in Wistar rats. CH reduced ROCE in arteries from both strains. PKC inhibition restored SOCE in CH Sprague‐Dawley arteries to control levels, while having no effect on SOCE in Wistar arteries or on ROCE in either strain. We conclude that effects of CH on pulmonary VSM SOCE are strain dependent, whereas inhibitory effects of CH on ROCE are strain independent. Further, PKC inhibits SOCE following CH in Sprague‐Dawley, but not Wistar, rats but does not contribute to ET‐1‐induced ROCE in either strain.     

Embryonic stem cells produce neurotrophins in response to cerebral tissue extract: Cell line-dependent differences

In the present study, we compare the capacity of two different embryonic stem (ES) cell lines to secrete neurotrophins in response to cerebral tissue extract derived from healthy or injured rat brains. The intrinsic capacity of the embryonic cell lines BAC7 (feeder cell-dependent cultivation) to release brain-derived neurotrophic factor (BDNF) or neurotrophin-3 (NT-3) exceeded the release of these factors by CGR8 cells (feeder cell-free growth) by factors of 10 and 4, respectively. Nerve growth factor (NGF) was secreted only by BAC7 cells. Conditioning of cell lines with cerebral tissue extract derived from healthy or fluid percussion-injured rat brains resulted in a significant time-dependent increase in BDNF release in both cell lines. The increase in BDNF release by BAC7 cells was more pronounced when cells were incubated with brain extract derived from injured brain. However, differences in neurotrophin release associated with the origin of brain extract were at no time statistically significant. Neutrophin-3 and NGF release was inhibited when cell lines were exposed to cerebral tissue extract. The magnitude of the response to cerebral tissue extract was dependent on the intrinsic capacity of the cell lines to release neurotrophins. Our results clearly demonstrate significant variations in the intrinsic capability of different stem cell lines to produce neurotrophic factors. Furthermore, a significant modulation of neurotrophic factor release was observed following conditioning of cell lines with tissue extract derived from rat brains. A significant modulation of neurotrophin release dependent on the source of cerebral tissue extract used was not observed.     

环磷酸腺苷反应元件结合蛋白在吗啡依赖及戒断大鼠脑区的表达

目的　研究吗啡依赖及吗啡戒断时环磷酸腺苷反应元件结合蛋白 (CREB)在大鼠脑内的表达。方法　将 1 5只雄性Sprague Dawley大鼠随机分为正常对照组、吗啡依赖组和吗啡戒断组 ,每组各 5只。于大鼠背部皮下注射吗啡 ,第 1天注射 2 0mg/kg ,逐日递增剂量 ,至第 5天达 1 0 0mg/kg ,形成大鼠吗啡依赖模型。吗啡戒断组大鼠在末次注射吗啡后 1 6h皮下注射纳洛酮 1mg/kg。采用免疫印迹法观察各组大鼠的前额叶皮质、伏隔核和海马等脑区CREB的表达。结果　 (1 )在前额叶皮质 ,吗啡依赖组和吗啡戒断组CREB的含量 (为相对光密度值 )分别为 [(1 31± 1 1 ) % ]和 [(1 33± 1 5) % ] ,均高于正常对照组 [(1 0 0± 1 4 ) % ] ,差异有显著性 (P <0 0 5) ;(2 )在伏隔核 ,三组CREB的差异无显著性(P >0 0 5) ;(3)在海马 ,吗啡戒断组CREB的含量 [(1 4 1± 1 8) % ]高于正常对照组 [(1 0 0± 1 4 ) % ] ,差异有非常显著性 (P <0 0 1 )。结论　大鼠处于吗啡依赖和戒断时CREB的表达在前额叶皮质和海马发生改变 ,表明多个脑区CREB表达的调节参与了阿片类物质依赖的形成     

绿原酸抑制JNK信号通路对非酒精性脂肪性肝病的防治作用

目的非酒精性脂肪性肝病(NAFLD)与胰岛素抵抗密切相关。绿原酸(CG)能调节糖脂代谢、改善胰岛素抵抗。探讨CG在NAFLD中的作用及其可能的分子基础。方法选取30只SD大鼠,随机分为正常饮食组(NG组)、高脂饮食组(HG组)和绿原酸干预组(CG组)。所有大鼠第1周采用普通饲料适应性喂养,第2周开始NG组喂饲普通饲料,HG组和CG组喂饲高脂饮食。第4周起NG组、HG组给予每周3次生理盐水灌胃,CG组给予每周3次灌胃CG。采用全自动生化仪和放射免疫法检测血清生化指标,采用全波长分光光度计测定超氧化物歧化酶(SOD)、丙二醛(MDA)和游离脂肪酸(FFA)。正常血糖高胰岛素钳夹试验技术测定胰岛素抵抗。Western Blot检测自噬及C-Jun氨基末端激酶(JNK)蛋白。计量资料多组间比较采用单因素方差分析,进一步两两比较采用LSD-t检验。相关分析采用Pearson相关性分析。结果与NG组相比,HG组体质量、肝指数、肝湿重、ALT、AST、TG、TC、TNFα及肝匀浆MDA、FFA均明显升高,而SOD明显低于NG组(P值均<0.05)。HG组与NG组相比,p-JNK1和JNK1的蛋白及自噬相关LC3-Ⅰ、LC3-Ⅱ、Beclin-1、Atg3和Atg5蛋白水平升高(P值均<0.05)。且JNK1蛋白的表达与胰岛素抵抗呈正相关。CG组体质量、肝湿重及肝指数显著低于HG组;ALT、AST、TG、TC、TNFα及肝匀浆MDA、FFA比HG组均明显降低,SOD高于HG组;LC3-Ⅰ、LC3-Ⅱ、Beclin-1、Atg3、Atg5表达均显著低于HG组,差异均有统计学意义(P值均<0.05)。结论 CG在NAFLD大鼠模型中通过JNK途径失活抑制自噬来改善肝损伤和胰岛素抵抗,CG可能为治疗NAFLD的潜在手段。     

Compliance behavior in a hospital setting: Employee and patients' reactions to no-smoking signs

Compliance behavior to no-smoking signs by hospital patients and employees was measured. Results showed initial compliance followed by a gradual return to pre-treatment smoking rate. The employees returned to baseline earlier than patients. The results seem to suggest that no-smoking signs by themselves (without enforcement of smoking policy) are not sufficient to produce compliance.     

The comparative study of Sprague–Dawley and Lewis rats in adjuvant-induced arthritis

The outbred Sprague–Dawley (SD) rats, similar to the inbred Lewis (LEW) rats, have been recently demonstrated to be highly susceptible to adjuvant-induced arthritis (AIA). We herein compared AIA in SD and LEW rats in terms of clinical, histological, radiological, and immuno-inflammatory features. The results showed that, following inoculation with a ground Mycobacterium tuberculosis (MT) suspension, SD and LEW rats manifested closely similar disease progression, with 100% incidence and similar severity. The development of arthritis was accompanied by significantly higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels than in control rats. Radiographic examination of the hind paws showed that both SD and LEW AIA rats manifested conspicuous soft tissue swelling, bone matrix resorption, periosteal new bone formation and bone erosion, while histopathological analysis of the synovial joints revealed marked cellular infiltration, angiogenesis, synovial hyperplasia, pannus formation, narrowing of joint space, and cartilage and bone destruction. Moreover, in relation to disease progression, serum tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 levels were markedly overexpressed in both SD and LEW AIA versus control rats, and SD and LEW AIA rats exhibited divergent profiles for the expression of TNF-α and IL-1β. Taken together, these results demonstrated that the SD rat AIA model shares several arthritic features with the comparable model in LEW rats. Hence, given the more favorable characteristics of SD rats than LEW rats (i.e., lower cost, wider availability, and heterogenic background), this SD rat AIA model is more cost effective and advantageous for screening and testing novel anti-arthritic agents.     

An EM-autoradiographic and EM-HRP study of the commissural projection of the superior colliculus in the cat

Terminals of the commissural projection in the cat were characterized ultrastructurally by autoradiographic and horseradish peroxidase methods. The results of the two studies are complementary. Terminals of commissural cells are present in the intermediate and deep layers of the cat superior colliculus. Two distinct populations of terminals are present: one containing mostly round vesicles and forming asymmetric specializations, and a second containing mostly pleomorphic vesicles and forming symmetric specializations. Both populations contact small dendrites or dendritic appendages. The two populations, mostly round and mostly pleomorphic, are present in the ratio of 2:1. Terminals measure approximately 1.1 micron in mean diameter and contact profiles ranging in size from 0.2 to 4.6 micron. There is no significant difference between the two populations in either pre- or postsynaptic profile size. The colocalization of terminals of commissural neurons with other afferent and efferent projections of the intermediate layers of the superior colliculus is discussed.