抗消化淀粉对大鼠的胃损伤预防效果

本文以抗消化淀粉(RS3)为研究对象,采用动物模型,研究其对盐酸/乙醇诱导SD大鼠胃损伤的预防效果。研究结果表明:10%RS3和15%RS3组大鼠的血清IL-6和TNF-α水平均低于胃损伤对照组大鼠;且胃损伤程度显著低于胃损伤对照组大鼠、而抑制率显著高于胃损伤对照组大鼠;均能减少胃液分泌量、增加胃液pH,表现出一定的胃损伤预防效果;其中15%RS3对胃损伤预防效果最佳。     

下关生沱茶的成分分析以及对SD大鼠的盐酸/乙醇诱导胃损伤预防效果

为弄清下关生沱茶（Xiaguan raw Tuocha,XRT）的成分和其体内胃损伤预防效果,本实验利用LC-MS和细胞因子分析,同时还测定了胃液量和胃液的pH值。结果表明：XRT具有12 种成分,这些成分使XRT具有胃损伤预防效果。高质量浓度的XRT相比低质量浓度的XRT,细胞因子IL-6 和TNF-α下降。1 000 mg/kg的XRT处理时小鼠显示出和正常小鼠接近的低胃液量（2.0 mL）和高的pH值（3.1）。由此可知,下关生沱茶包含很多功能性成分并且表现出强有力的胃损伤预防效果。     

抗消化淀粉对盐酸/乙醇诱导大鼠胃损伤的影响

以3种抗消化淀粉(RS2、RS3、RS4)为研究对象,采用动物试验法,研究其对盐酸/乙醇诱导大鼠胃损伤的影响。结果表明,3种RS组大鼠的血清IL-6和TNF-α水平、胃损伤程度均低于胃损伤对照组大鼠,而抑制率显著高于胃损伤对照组大鼠,均能减少胃液分泌量、增加胃液pH值,表现出一定的降低胃损伤程度的效果,并且RS3的效果最优。     

抗性淀粉对SD大鼠的胃损伤预防效果研究

以抗性淀粉（RS2）为研究对象,构建动物模型,通过酶联免疫法、逆转录-聚合酶链式反应等方法研究其对HCl-乙醇诱导SD大鼠胃损伤的预防效果。结果表明：10% RS2、15% RS2和20% RS2均能降低大鼠的血清IL-6和TNF-α水平,大鼠的胃损伤程度,显著提高胃损伤的抑制率,均能减少胃液分泌量、增加胃液pH值,表现出一定的胃损伤预防效果。其中20% RS2对胃损伤预防效果最佳。     

干酪乳杆菌Qian增强京尼平苷对盐酸/乙醇诱导小鼠胃损伤的预防效果

为探讨最近新发现的干酪乳杆菌Qian（Lactobacillus casei Qian,LC-Qian）和京尼平苷组合对胃损伤预防效果的增强作用,比较分析LC-Qian（0.5×108?CFU/kg,以体质量计,下同）、京尼平苷（50?mg/kg）以及LC-Qian（0.5×108?CFU/kg）＋京尼平苷（50?mg/kg）对盐酸/乙醇诱导胃损伤的预防效果。LC-Qian＋京尼平苷（组合组）能减少胃损伤面积和胃液量,同时提高胃液pH值,能使这些指标接近正常组并且与模型组显著不同。相对于模型组,组合组能降低细胞因子白细胞介素-6（interleukin-6,IL-6）、IL-12、肿瘤坏死因子α和γ-干扰素的水平,同时降低血清胃动素、P物质、内皮素-1的水平和提高生长激素抑制素、血管活性肠肽的水平。相比模型组,在心脏、肝脏、肾脏和胃组织中组合组表现出更高的NO含量,但是这些含量低于正常组。通过逆转录聚合酶链式反应分析观察到：相对于对照组小鼠,组合组能够上调神经元型一氧化氮合酶、内皮型一氧化氮合酶、核因子κB抑制蛋白α的mRNA表达和下调诱导型一氧化氮合成酶、核因子κB表达,同时以上这些表达强度与正常组较为接近。通过这些结果可以看到LC-Qian和京尼平苷联合使用具有最好的胃损伤预防效果,LC-Qian能够提高京尼平苷的胃损伤预防效果,该组合可作为一种新的参考方法用于预防胃损伤。     

干酪乳杆菌Qian增强京尼平苷对盐酸/乙醇诱导小鼠胃损伤的预防效果（英文）

为探讨最近新发现的干酪乳杆菌Qian(Lactobacillus casei Qian,LC-Qian)和京尼平苷组合对胃损伤预防效果的增强作用,比较分析LC-Qian(0.5×10~8 CFU/kg,以体质量计,下同)、京尼平苷(50 mg/kg)以及LC-Qian(0.5×10~8 CFU/kg)+京尼平苷(50 mg/kg)对盐酸/乙醇诱导胃损伤的预防效果。LC-Qian+京尼平苷(组合组)能减少胃损伤面积和胃液量,同时提高胃液pH值,能使这些指标接近正常组并且与模型组显著不同。相对于模型组,组合组能降低细胞因子白细胞介素-6(interleukin-6,IL-6)、IL-12、肿瘤坏死因子α和γ-干扰素的水平,同时降低血清胃动素、P物质、内皮素-1的水平和提高生长激素抑制素、血管活性肠肽的水平。相比模型组,在心脏、肝脏、肾脏和胃组织中组合组表现出更高的NO含量,但是这些含量低于正常组。通过逆转录聚合酶链式反应分析观察到:相对于对照组小鼠,组合组能够上调神经元型一氧化氮合酶、内皮型一氧化氮合酶、核因子κB抑制蛋白α的mRNA表达和下调诱导型一氧化氮合成酶、核因子κB表达,同时以上这些表达强度与正常组较为接近。通过这些结果可以看到LC-Qian和京尼平苷联合使用具有最好的胃损伤预防效果,LC-Qian能够提高京尼平苷的胃损伤预防效果,该组合可作为一种新的参考方法用于预防胃损伤。     

海南苦丁茶多糖的降血糖功效评价

以常规降糖药盐酸二甲双胍(125 mg/kg·d)为阳性对照,通过对正常小鼠和四氧嘧啶致高血糖小鼠、去甲肾上腺素致糖尿病小鼠进行降血糖治疗试验及葡萄糖耐量实验,研究了海南苦丁茶多糖(100、150、300 mg/kg·d)的降血糖作用。结果显示,苦丁茶多糖能较好地降低糖尿病小鼠血糖水平,表现出一定的量效关系,高剂量组接近药物组的治疗水平,同时能够提高糖尿病模型小鼠的葡萄糖耐量;但并不影响正常小鼠的血糖水平。     

小叶苦丁茶多酚提取物对盐酸/乙醇诱导小鼠胃损伤的预防效果

本研究以小叶苦丁茶多酚提取物为研究对象,测定其在体外清除DPPH自由基、ABTS自由基、羟自由基的能力,并以60%酒精和40% 150 mmol/L盐酸混合液为诱导剂构建盐酸/乙醇诱导胃损伤小鼠模型,通过检测小鼠血清和胃组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,观察组织病理切片的变化,测定内皮型一氧化氮合酶(eNOS)、神经型一氧化氮合酶(nNOS)、环氧合酶-2(COX-2)的mRNA表达,从而对小叶苦丁茶多酚对小鼠盐酸/乙醇性胃损伤的预防效果进行综合评价。结果表明,小叶苦丁茶多酚类物质具有较强的还原能力,能够有效清除DPPH自由基、ABTS自由基、羟自由基,随着浓度的增加,清除能力逐渐增强。动物试验结果表明,小叶苦丁茶多酚提取物在一定浓度下可降低小鼠的胃损伤程度,提高胃损伤抑制率,减少胃液分泌量,增加胃液pH;与模型组相比,小叶苦丁茶多酚提取物能显著(p<0.05)提高超氧化物歧化酶(SOD)活性和谷胱甘肽(GSH)含量,降低丙二醛(MDA)的生成,缓解胃组织病理症状,能显著(p<0.05)上调铜/锌-超氧化物歧化酶(Cu/Zn-SOD)、锰-超氧化物歧化酶(Mn-SOD)、过氧化氢酶(CAT)、内皮型一氧化氮合酶(eNOS)、神经型一氧化氮合酶(nNOS)的mRNA相对表达量,降低诱导型一氧化氮合酶(iNOS)、环氧合酶-2(COX-2)的mRNA相对表达量,且高浓度(200 mg/kg)的小叶苦丁茶多酚提取物效果比低浓度(100 mg/kg)的小叶苦丁茶多酚提取物更明显。由此可见,小叶苦丁茶多酚提取物能有效缓解盐酸/乙醇诱导的小鼠胃损伤程度,是一类具有胃损伤改善作用的活性成分,具有较好的应用前景。     

江苏地产浒苔多糖对大鼠急性酒精性胃黏膜损伤的保护作用

为研究江苏地产浒苔多糖对酒精性大鼠胃黏膜损伤的保护作用和机制,将Wistar大鼠随机分成生理盐水组、模型组、浒苔多糖各剂量组(100,200,400 mg/kg)以及阳性对照组(奥美拉唑,300 mg/kg),每组各10只。采用酒精灌胃致胃黏膜损伤模型。给予浒苔多糖7 d后,观察胃黏膜组织的大体和病理组织改变,测定胃液分泌量、胃酸浓度,胃组织中黏液蛋白、丙二醛(MDA)、氧化物歧化酶(SOD)、谷胱甘肽还原酶(GSH-Px)、大鼠白细胞介素1β(IL-1β)、肿瘤坏死因子(TNF-α)、以及环氧酶(COX-2)等生化指标的活力或含量。结果表明:浒苔多糖能明显改善胃黏膜组织损伤情况,降低损伤积分(p0.01),提高酒精性损伤抑制率;在高剂量组能显著降低胃液量的分泌(p0.05),提高胃组织GSH-Px,降低炎性因子IL-1β和TNF-α的释放(p0.01);各剂量组均能降低胃组织中MDA的含量和COX-2的活力(p0.05或p0.01),显著提高SOD的活力以及胃黏液蛋白的浓度(p0.05或p0.01)。江苏地产浒苔多糖对大鼠急性酒精性胃黏膜损伤具有一定保护作用,其机制可能与增强胃黏膜保护因子,提高抗氧化、降低脂质过氧化、抑制炎症因子释放的能力有关。     

大豆异黄酮对β淀粉样肽诱导的大鼠脑组织炎症相关因子表达的影响

目的研究大豆异黄酮(SIF)对β淀粉样肽1-42(Aβ1-42)诱导的大鼠脑炎症损伤的作用。方法将健康雄性Wistar大鼠按体重随机分成对照组、Aβ模型组,SIF干预组(SIF+Aβ组)和SIF组(SIF单独处理组)。SIF干预组和SIF组大鼠每日给予大豆异黄酮(80 mg/kg)灌胃处理,共14 d。然后Aβ模型组和SIF干预组采用微型注射泵在大鼠侧脑室区持续注射Aβ1-42 14 d,建立大鼠脑炎症损伤模型。采用RT-PCR方法和Western blot方法检测脑组织白介素-1β(IL-1β)、诱导型一氧化氮合成酶(iNOS)以及白介素-10(IL-10)基因和蛋白水平的表达。结果与模型组比较,SIF干预组大鼠脑组织IL-1β、iNOS及IL-10基因和蛋白表达水平显著下调(P<0.05)。结论大豆异黄酮可能是通过影响大鼠脑组织炎症相关因子及酶基因/蛋白水平的表达来拮抗Aβ1-42介导的脑炎症反应。     

Regulation of inflammation,antioxidant production,and methyl-carbon metabolism during methionine supplementation in lipopolysaccharide-challenged neonatal bovine hepatocytes

Supplementation of methionine (Met) may improve immunometabolic status, specifically during a period of inflammatory stress. The aim of the present study was to establish an inflammation model using primary neonatal bovine hepatocytes and to examine the effects of increasing concentrations of dl-Met and a maintained Met to lysine (Lys) ratio on hepatocyte inflammatory responses, antioxidant production, and Met metabolism during lipopolysaccharide (LPS) challenge. Hepatocytes isolated from 4 calves were maintained as monolayer cultures and exposed to 0, 10, or 40 µMdl-Met and 100 µM Lys (0Met100Lys, 10Met100Lys, or 40Met100Lys) or 10 µMdl-Met and 25 µM Lys (10Met25Lys). Cells were exposed to each treatment for 16 h and then challenged with either 0 or 100 ng/mL of LPS for 8 h. In the absence of LPS, glutathione (GSH) was not altered by 10Met100Lys or 10Met25Lys but was increased by 40Met100Lys. With LPS challenge, GSH concentration was decreased with 40Met100Lys and tended to be decreased with 10Met100Lys. Hepatocytes receiving 10Met100Lys treated with 100 ng/mL of LPS showed an inflammatory response with increased mRNA expression of tumor necrosis factor (TNFα), IL-6, IL-1β, and interferon gamma, which was accompanied by increased nuclear factor κB inhibitor and serum amyloid A3 mRNA. The treatment 40Met100Lys was effective for preventing the LPS-induced increase in expression of the above genes except TNFα. Similar preventative effects were observed for 10Met25Lys; however, it did not prevent the LPS-induced increase in TNFα or IL-6 mRNA. Lipopolysaccharide challenge decreased mRNA expression of key genes controlling the transmethylation and Met regeneration pathways, which was not prevented by Met supplementation. The data suggest that bovine hepatocyte cultures can be used as a biological model to study the inflammatory cascade via an LPS challenge. Supplementation of Met prevents the LPS-induced hepatocyte cytokine expression and is associated with elevated intracellular GSH concentration.     

Changes occurring in immune responsiveness of single- and twin-bearing Comisana ewes during the transition period

Changes induced by twin and single lambing in the immune response of 16 periparturient Comisana ewes were studied. Cell-mediated immune responses were evaluated by means of skin tests performed from 3 wk before and up to d 35 after parturition. At d 21 and 7 before lambing, the sheep received an intramuscular injection of the antigen keyhole limpet hemocyanin (KLH), to which the animals had not been previously exposed, to determine their humoral immune response. Starting 3 wk before lambing and up to d 35 postlambing, the ewes were sampled to determine the plasma concentrations of anti-KLH antibody (IgG), IL-6, and IL-1 β. From parturition through d 35 postpartum, individual milk samples were collected for determination of anti-KLH IgG titers and IL-6 and IL-1β concentrations by means of a capture ELISA. The number of lambs born affected IL-6 concentrations in ewe plasma; IL-6 secretion always was higher in ewes birthing twins than in single-lambing ewes. Apart from the number of lambs born, the concentrations of plasma IL-6 in ewes were higher at lambing than at d 21 antepartum and at d 35 postpartum. An interaction of number of lambs born × time of sampling was observed for plasma antibody titers to KLH. The IgG concentrations were significantly higher in single-bearing ewes than in twin-bearing ewes before parturition and were very similar across groups after parturition. A time effect was found for the cell-mediated immune response and for anti-KLH IgG concentrations in milk, such that at parturition, cellular responses were lowest, and the anti-KLH IgG concentration was highest. A significant correlation was found for IgG titers to KLH in plasma and milk. Results indicate that IL-6 concentrations in blood can be considered a reliable indicator of stress connected to lambing and that the mammary gland is a microenvironment unrelated to blood stream with respect to interleukins expression. In contrast, a relationship was found for the IgG secretions in milk and blood, which suggests that the assessment of humoral immune status may be combined with milking routine in dairy animals.     

褪黑素对脂多糖刺激小鼠体内炎症反应

研究脂多糖(LPS)刺激时,褪黑素对小鼠炎症反应的影响。用脂多糖建立炎症反应模型,检测肝脏中白介素-1(IL-1)、白介素-10(IL-10)水平,血清中一氧化氮(NO)、一氧化氮合酶(NOS)以及小肠髓过氧化物酶(MPO)的活性变化。在LPS刺激后4 h时,灌胃褪黑素的小鼠IL-1和小肠MPO明显低于灌胃生理盐水组和正常组,而IL-10高于灌胃生理盐水组和正常组,刺激后16 h时,IL-1、IL-10和MPO均较刺激后4 h有所降低。褪黑素对LPS所诱导的炎症反应有明显的抑制作用,有助于维持机体炎症/抗炎症平衡,保护机体免受炎症损伤。     

产胞外多糖乳杆菌的筛选及多糖功能的研究

本论文从大连地区海产品消化腺中筛选产胞外多糖(EPS)的乳杆菌属菌株,并研究其所产EPS的功能特性,选出一株目标菌,对其EPS分离纯化,测定纯化后各多糖组分的相对分子量。获得EPS产量相对较高的菌株经16S r RNA序列测定鉴定为Lactobacillus plantarum subsp.plantarum-4,Lactobacillus plantarum-12,Lactobacillus plantarumsubsp.plantarum-49;对3株植物乳杆菌及其EPS进行清除DPPH自由基的测定,Lactobacillus plantarum-12的EPS浓度为0.5 mg/mL时,清除率为48.82±3.88%,显著高于另外2株菌(p0.05);测定植物乳杆菌的EPS抑制E.coli ATCC25922在HT-29细胞上的粘附效果,Lactobacillus plantarum-12的EPS浓度为0.2mg/mL时,抑制率为78.23%±2.46%,显著高于另外两株菌(p0.05);Lactobacillus plantarum-12的EPS可显著抑制E·coli ATCC25922刺激HT-29细胞产生IL-8(p0.05)。Lactobacillus plantarum-12的EPS经DEAE-Sepharose Fast Flow离子交换柱、Sepharose CL-6B凝胶柱和Sephacryl HR S200凝胶柱层析分离得到两组分,测定两组分的相对分子质量分别为8.5×10~4 u和7.4×10~4 u。     

Strain-specific pathogenicity of putative host-adapted and nonadapted strains of Streptococcus uberis in dairy cattle

Streptococcus uberis is an important cause of intramammary infection in dairy cattle. Strains of Strep. uberis appear to differ in their ability to cause disease based on previous epidemiological studies. We explored the pathogenicity of 2 strains of Strep. uberis, where one strain represented a putatively host-adapted type based on its ability to cause persistent infection and to spread from cow to cow in a lactating herd. This type was part of a clonal complex that is commonly associated with bovine mastitis. The other strain, which was isolated from a transient infection in a single animal in the same herd and did not belong to any known clonal complex, was selected as putatively nonadapted type. Cows (6 per strain) were experimentally challenged in a single hind quarter and the adjacent hind quarter was used as mock challenged control quarter. Both strains showed an equal ability to grow in the milk of challenge animals in vitro. All cows that were challenged with the putatively host-adapted strain developed clinical signs of mastitis, including fever and milk yield depression as well as elevated somatic cell count due to influx of polymorphonuclear leucocytes and lymphocytes. The cytokine response followed a specific order, with an increase in IL-1β, IL-6, and IL-8 levels at the time of first SCC elevation, followed by an increase in IL-10, IL-12p40, and tumor necrosis factor-α levels approximately 6 h later. In 4 of 6 animals, IL-17A was detected in milk between 57 and 168 h postchallenge. The increase in IL-17A levels coincided with inversion of the prechallenge CD4⁺-to-CD8⁺ T lymphocyte ratio, which was observed from 96 h postchallenge. This was followed by normalization of the CD4⁺-to-CD8⁺ ratio due to continued increase of the CD8⁺ concentration up to 312 h postchallenge. Spontaneous resolution of infection was observed in 5 animals and coincided with a measurable IL-17A response in 4 animals, suggesting that IL-17 may be involved in the resolution of intramammary infection. With the exception of minor elevation of IL-8 levels, no clinical, cytological, or immunological response was detected in quarters challenged with the nonadapted strain. The observed strain-specific pathogenicity was consistent across animals, implying that it is determined by pathogen factors rather than host factors.     

Immunomodulatory properties of selectively processed prawn protein fractions assessed using human peripheral blood mononuclear cells

Prawn muscles were treated with acetic acid and high-pressure processing (600 MPa) separately to analyse their antigenicity and immunogenicity. The protein fractions were separated and isolated using preparative HPLC, and their antigenicity was analysed using Immunoglobulin G (IgG) ELISA kit. Out of thirty-nine protein fractions, only four (A10, A11, B10 and C9) were detected with antigenic potentials. The immunogenicity of these protein fractions was analysed using human PBMCs, and supernatants were collected at multiple times from 0 to 144 h. The treated fractions (B10 and C9) analysed using Immunoglobulin E (IgE) ELISA kit showed significantly (P < 0.05) lower pro- and anti-inflammatory cytokine production compared with control (A10). The allergenic fractions were characterised using an LC/MS/MS, which identified nine proteins. Among these, six proteins (tropomyosin, arginine kinase, haemocyanin, enolase, vitellogenin and 14-3-3 zeta) have been established as allergenic in prawn muscle and ovaries. Other three proteins (beta-1,3-glucan-binding protein, translationally controlled tumour protein and farnesoic acid O-methyltransferase short isoform protein) identified in this study need further investigation for their immunogenic properties.     

嗜酸乳杆菌NCFM对IL-6ST调控作用研究

研究了嗜酸乳杆菌NCFM作用于Caco-2和灌服小鼠后对免疫相关细胞因子白细胞介素6受体(IL-6ST)表达的影响,确定其免疫调节作用。在Caco-2细胞与嗜酸乳杆菌NCFM作用后,采用Real Time PCR方法检测il-6st基因的表达,il-6st基因的表达量呈现下降的趋势;嗜酸乳杆菌NCFM灌服小鼠后,肠道上皮细胞中il-6st基因短暂性上调后下降的趋势。通过特异性抑制剂PDTC证明il-6st基因的表达受到p38 MAPK途径的调控。因此,嗜酸乳杆菌NCFM能够诱导细胞因子il-6st短暂性的表达,进一步增加了其具有免疫调节作用的证据。