肠缺血再灌注大鼠肺及血液白细胞介素6、白细胞介素8和肿瘤坏死因子α变化与辅酶Q10的干预

目的:观察大鼠肠缺血再灌注时肺及血液白细胞介素6、白细胞介素8和肿瘤坏死因子α的变化以及辅酶Q10的影响。方法:实验于2006-12/2007-02在滨州医学院药理学实验室和免疫学实验室(山东省重点学科三级实验室)完成。①实验分组:清洁级健康Wistar大鼠30只,体质量290～390g,随机数字表法分为假手术组、肠缺血再灌注组,辅酶Q10处理组(缺血再灌注 辅酶Q10),每组10只。②实验方法:建立肠缺血再灌注模型,钝性分离肠系膜上动脉的根部,假手术组不作其他处理;肠缺血再灌注组再灌前30min时经股静脉注入生理盐水10mL/kg;辅酶Q10处理组再灌前30min时经股静脉注入辅酶Q1010mg/kg。③实验评估:酶联免疫吸附法(ELISA)检测各组动物血液、肺组织匀浆及肺泡灌洗液中的白细胞介素6、白细胞介素8和肿瘤坏死因子α含量;光镜下观察肺组织形态学变化。肺泡灌洗液沉渣进行白细胞计数和分类。结果:纳入大鼠30只,均进入结果分析。①肺组织形态学变化:假手术组肺组织无病理改变;肠缺血再灌注组肺间质明显水肿,中性粒细胞浸润,有少量的出血和纤维蛋白渗出;辅酶Q10处理组肺间质轻度水肿,少量的中性粒细胞。②肺泡灌洗液白细胞计数组间无显著性差异,多形核细胞分类肠缺血再灌注组明显高于假手术组(P<0.05),而辅酶Q10处理组与其他两组间差异无显著性意义(P>0.05)。③各组动物血液、肺组织匀浆及肺泡灌洗液中的白细胞介素6、白细胞介素8和肿瘤坏死因子α含量:与假手术组比较,肠缺血再灌注组血液、肺组织匀浆及肺泡灌洗液中白细胞介素6、白细胞介素8和肿瘤坏死因子α显著升高(P<0.05或P<0.01)。与肠缺血再灌注组比较,辅酶Q10处理组血液、肺组织匀浆和肺泡灌洗液中白细胞介素6含量显著降低(P<0.05);白细胞介素8和肿瘤坏死因子α含量在血液中显著降低(P<0.05);而在肺组织匀浆中含量未见显著降低(P>0.05);在肺泡灌洗液中含量亦未见显著降低(P>0.05)。结论:辅酶Q10可能通过抑制白细胞介素6、白细胞介素8和肿瘤坏死因子α炎性因子的释放,对大鼠肠缺血再灌后肺损伤有一定的保护作用。     

山茱萸化学成分的研究

从山茱萸(Cornus officinalis Sieb.et Zucc.)的果实中分得一新的双环烯醚萜甙化合物,命名为山茱萸新甙(cornuside)。通过波谱分析(IR,MS,¹HNMR和¹³CNMR)和理化常数测定,确定了它的结构。     

Clinical isolates of Staphylococcus aureus have osteolytic surface proteins and a proportion of the population have antibodies that block this activity: is this of prognostic significance?

Staphylococcus aureus is directly implicated in the bone destruction associated with infected orthopaedic implants and bacterial arthritis. The Oxford (laboratory) strain of this organism has surface-associated proteins (SAPs) which have potent osteolytic activity. In this study, we have examined the osteolytic activity of SAPs from clinical isolates and also investigated the role of the humoral immune response to such proteins. Nine patients with infected orthopaedic prostheses or infective arthritis, and six volunteers not suffering from overt S. aureus infection, were examined. The sera from 5/9 patients and 4/6 volunteers were able to neutralize the osteolytic activity of the SAPs. The SAPs were extracted from four clinical isolates and were found to have osteolytic activity, but with a wide range of efficacies and potencies. All four patients from whom the clinical isolates were obtained had serum IgG antibodies to the surface proteins from their autologous isolates as determined by ELISA. In conclusion, clinical isolates of S. aureus contain osteolytic SAPs which may be responsible for bone destruction. Apparently disease-free individuals and patients have antibodies able to block this activity. However, since the capacity of patients' sera to neutralize the activity of the SAPs derived from their own S. aureus isolate was not investigated, it is unclear whether these findings are of prognostic value.      

Enhanced co-stimulatory ability of synovial fluid accessory cells in rheumatoid arthritis

We have established in vitro assays that allow the examination of co- stimulatory function of rheumatoid arthritis (RA) antigen-presenting cells (APC). Synovial fluid (SF) and peripheral blood (PB) APC co- stimulatory ability was compared in the activation of peptide-specific human T-cell clones. T-cell receptor (TCR) stimulation by peptide or anti-CD3 antibody allowed the direct comparison of SF and PB APC co- stimulatory activity, separately from their ability to process antigen. SF APC from 15 RA patients consistently enhanced T-cell proliferation when compared to their PB counterparts. Moreover, increasing the numbers of PB APC present resulted in only a minor increase in T-cell proliferation, failing to achieve levels stimulated by SF APC. We propose that the enhanced co-stimulatory function of synovial APC may be a significant factor in the persistence of local immune responses in RA.      

博莱霉素致肺纤维化大鼠肺组织表面活性物质蛋白A B C mRNA的表达

目的观察博莱霉素致肺纤维化大鼠肺组织表面活性物质蛋白（ＳＰ）Ａ、Ｂ、ＣｍＲＮＡ的表达。方法气管内灌注博莱霉素Ａ５，复制肺纤维化模型，分别于３、７、１４和２８天处死动物，提取肺组织总ＲＮＡ，进行Ｎｏｒｔｈｅｒｎ杂交。结果肺纤维化大鼠肺泡Ⅱ型上皮细胞数量增加。灌注博莱霉素后第３天ＳＰＡ、ＳＰＢ及ＳＰＣｍＲＮＡ的表达即开始下降，７天时降至最低点，而后于１４天时开始回升，至２８天时上升最明显。但仍低于正常。结论博莱霉素致纤维化大鼠肺组织ＳＰＡ、ＳＰＢ及ＳＰＣｍＲＮＡ的表达减低。肺泡Ⅱ型上皮细胞功能的改变可能参与肺纤维化的发病过程。     

An essential role for lysophosphatidylcholine in the inhibition of platelet aggregation by secretory phospholipase A2

The release of secretory phospholipase A2 (sPLA2) into the mammalian circulation may contribute to the development of hemorrhagic and inflammatory diseases. sPLA2 has previously been shown to alter the behavior of platelets, leukocytes, and endothelial cells, although the molecular basis for these cellular effects has not been established. Our studies indicate that the inhibition of platelet aggregation by snake, bee venom, and pancreatic sPLA2 is dependent on a plasma cofactor. This cofactor resides within the lipoprotein fraction of plasma, with 54%, 31%, and 11% of the activity present in the high- density lipoprotein (HDL), low-density lipoprotein (LDL), and very low density lipoprotein (VLDL) fractions, respectively. Delipidation of HDL and LDL was associated with the complete loss of platelet-inhibitory activity. Incubation of purified sPLA2 with the HDL fraction of plasma resulted in the time-dependent generation of lysophosphatidylcholine (lysoPC). The formation of lysoPC correlated with the inhibition of platelet aggregation. Purified lysoPC (10 to 100 micrograms/mL) inhibited platelet aggregation and dense granule release induced by thrombin (0.05 U/mL), collagen (1 micrograms/mL), ionophore A23187 (2 mumol/L), ADP (12.5 mumol/L), and adrenaline (3.2 mumol/L). The inhibition of platelet aggregation by lysoPC was dose-dependent and correlated with decreased fibrinogen binding to glycoprotein IIb-IIIa. Our studies indicate that the enzymatic generation of lysoPC from plasma lipoproteins is essential for the sPLA2-mediated inhibition of platelet activation in the presence of albumin. These results raise the possibility that the toxic effects of circulating sPLA2 may be due in part to the generation of the bioactive lysophospholipid, lysoPC.     

Preventive and curative effect of methanolic extract of Gardenia gummifera Linn. f. on thioacetamide induced oxidative stress in rats

ObjectiveTo evaluate the antioxidant and antihepatotoxic effect of methanolic extract of Gardenia gummifera Linn. f. root (MEGG) on thioacetamide (TAA) induced oxidative stress in male Wistar rats.MethodsIn the preventive study, rats were administered with 125 and 250 mg/kg of MEGG for 9 days prior to TAA administration (100 mg/kg s.c.). In post-treatment groups, rats were treated with MEGG at doses of 125 and 250 mg/kg, 2, 24 and 48 h after TAA intoxication. Silymarin was used as a standard drug control (100 mg/kg). Hepatotoxicity was assessed by quantifying the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant potential of MEGG was evaluated by the estimation of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH) and lipid peroxidation [thiobarbituric acid reactive substances (TBARS)] in hepatic and renal tissues. Histopathological changes were also evaluated.ResultsMEGG significantly (P≤0.05) prevented the elevation of serum AST, ALT, ALP, LDH and tissue malondialdehyde levels in both experimental groups, when compared to the TAA alone treated groups. The rats receiving TAA plus MEGG exhibited significant (P≤0.05) increases in hepatic and renal antioxidant activities including GSH, GST, GR, GPx and CAT levels. Quantification of histopathological changes also supported the dose dependent protective effects of MEGG.ConclusionsThese observations suggest that MEGG has dose dependent hepatoprotective and antioxidant effect against TAA induced oxidative stress.     

Hematopoietic supportive functions of mouse bone marrow and fetal liver microenvironment: dissection of granulocyte, B-lymphocyte, and hematopoietic progenitor support at the stroma cell clone level

We dissected the functions of the microenvironment of bone marrow (BM) and fetal liver (FL) at the cellular level by cloning individual stromal calls and characterizing their phenotypical and functional features. Stromal cell clones derived from FL are large in size (mean forward light scatter intensity [mFSC] of 450), express the surface antigen Thy-1 but not Sca-1 and 6 out of 6 are able to differentiate into fat accumulating adipocytes. BM derived stromal cell clones are either small (mFSC of 250) or large (mFSC of 450), express Sca-1 but not Thy-1 and only 2 out of 7 differentiate towards adipocytes. Heterogeneity in terms of vascular adhesion molecule-1, intracellular adhesion molecule-1 and heat stable antigen expression was found among the different cell clones. Functional assays using long- and short-term cocultures of stromal and hematopoietic calls revealed: (1) the capacity of 8 out of 12 stromal cell clones to support the expansion of primitive hematopoietic progenitors (colony forming unit spleen day 12) more than 10 weeks. Fat accumulation but not expression of stem cell factor by stromal cells did correlate with this supportive function. (2) Better support of granulocyte maturation and proliferation by BM- compared to FL-derived stromal cell clones. However, stromal cell clones from both organs expressed macrophage-colony stimulating factor. (3) The ability of 4 out of 12 stromal cell clones (derived from both, FL and BM) to support the expansion of Interleukin-7 dependent pre-B cells from the BM. Pre-B cell growth stimulating factor was not restricted to supporters. (4) Mutual exclusiveness of myeloid and lymphoid support in that a given stromal cell clone supported either pre B-cell or granulocyte expansion. Experiments comparing the support of BM- and FL-derived hematopoietic progenitors showed identical responses of late (B220+/c-kit-) but strikingly different responses of early (B220+/c-kit+) pre-B cells, revealing different proliferation requirements for FL- versus BM- derived early pre-B cells in vitro.     

Helicobacter pylori stimulates inducible nitric oxide synthase expression and activity in a murine macrophage cell line

BACKGROUND & AIMS: Helicobacter pylori uniquely colonizes the human stomach and produces gastric mucosal inflammation. High-output nitric oxide production by inducible nitric oxide synthase (iNOS) is associated with immune activation and tissue injury. Because mononuclear cells comprise a major part of the cellular inflammatory response to H. pylori infection, the ability of H. pylori to induce iNOS in macrophages was assessed. METHODS: H. pylori preparations were added to RAW 264.7 murine macrophages, and iNOS expression was assessed by Northern blot analysis, enzyme activity assay, and NO2- release. RESULTS: Both whole H. pylori and French press lysates induced concentration-dependent NO2- production, with peak levels 20-fold above control. These findings were paralleled by marked increases in iNOS messenger RNA and enzyme activity levels. iNOS expression was synergistically increased with interferon gamma, indicating that the H. pylori effect can be amplified by other macrophage-activating factors. Studies of lipopolysaccharide (LPS) content and polymyxin B inhibition of LPS suggested that the H. pylori effect was attributable to both LPS- dependent and -independent mechanisms. CONCLUSIONS: iNOS expression in macrophages is activated by highly stable H. pylori products and may play an important role in the pathogenesis of H. pylori-associated gastric mucosal disease. (Gastroenterology 1996 Dec;111(6):1524-33)     

Expression of tissue factor and factor VIIa/tissue factor inhibitor activity in endotoxin or phorbol ester stimulated U937 monocyte-like cells

Previously, unstimulated cells of the human monocytic tumor cell line U937 have been shown to possess a negligible cell-surface tissue factor (TF) activity, and to secrete a small amount of factor VIIa/tissue factor (VIIa/TF) inhibitor activity. On stimulation with endotoxin or with phorbol myristate acetate (PMA), TF of these cells is known to be increased approximately fourfold. In this report, we demonstrate that VIIa/TF inhibitor is also increased on stimulation of U937 cells with endotoxin (approximately equal to threefold) or with PMA (approximately equal to 20-fold). Notably, the secretion of the inhibitor persisted after the cell surface TF had started to decline. Further, when serum- free media from PMA stimulated cells was electrophoresed on a sodium dodecyl sulfate (SDS) gel, we eluted two inhibitor activity peaks corresponding to Mr approximately equal to 47,000 and Mr approximately equal to 36,000. The molecular weights of these peaks are similar to those obtained earlier from human plasma for this inhibitor(s).