Induction of macrophage tumoricidal activity by granulocyte-macrophage colony-stimulating factor

Monocytes are a subpopulation of peripheral blood leukocytes, which when appropriately activated by the regulatory hormones of the immune system, are capable of becoming macrophages--potent effector cells for immune response to tumors and parasites. A complementary DNA for the T lymphocyte-derived lymphokine, granulocyte-macrophage colony-stimulating factor (GM-CSF), has been cloned, and recombinant GM-CSF protein has been expressed in yeast and purified to homogeneity. This purified human recombinant GM-CSF stimulated peripheral blood monocytes in vitro to become cytotoxic for the malignant melanoma cell line A375. Another T cell-derived lymphokine, gamma-interferon (IFN-gamma), also stimulated peripheral blood monocytes to become tumoricidal against this malignant cell line. When IFN-gamma activates monocytes to become tumoricidal, additional stimulation by exogenously added lipopolysaccharide is required. No such exogenous signals were required for the activation of monocytes by GM-CSF.     

急性冠状动脉综合征患者血浆M-CSF水平的检测及临床意义

目的 :观察急性冠状动脉综合征 (ACS)患者发病后各时间段血浆的巨噬细胞集落因子 (M- CSF)水平的变化及其临床意义。方法 :随机选择 ACS患者和健康成人各 30例 ,采用 ELISA法检测 ACS患者发病后第 1、2、3、7、1 4天血浆中的 M- CSF、肿瘤坏死因子α(TNF-α)和 C-反应蛋白 (CRP)的水平 ,同时检测 30例健康成人的 M- CSF、CRP和 TNF-α作为对照。结果 :ACS患者发病后第 1、2天血清M- CSF、CRP和 TNF- α的水平均较对照组高 (P<0 .0 1 ) ;但 ACS患者血清 CRP和 TNF- α的水平只在发病初期 (1～ 3d)增高 ,而 M- CSF在整个急性炎症过程中均显著增高 (P<0 .0 1 )。结论 :M- CSF是反映炎症过程的敏感指标 ,检测 M- CSF有助于临床医生判断 ACS急性炎症过程是否结束 ,对 ACS的诊断、治疗和预后具有重要的临床价值。     

Platelet-activating factor-induced aggregation of human platelets specifically inhibited by triazolobenzodiazepines

Platelet-activating factor (PAF), a naturally occurring phospholipid, is a potent activator of various biological processes, including platelet aggregation. The mechanisms by which PAF acts are largely unknown, partly because of the lack of specific inhibitors for PAF-elicited responses. It was found that in washed human platelets the psychotropic triazolobenzodiazepine drugs alprazolam and triazolam potently inhibited PAF-induced changes in shape, aggregation, and secretion. The effects were specific for PAF activation, since the responses of human platelets to adenosine diphosphate, thrombin, epinephrine, collagen, arachidonate, and the calcium ionophore A23187 were not inhibited by the triazolobenzodiazepines. These psychotropic drugs should be useful in investigating the possibility that PAF or PAF-like phospholipids play a role in neuronal function and in elucidating biochemical mechanisms activated specifically by PAF in a variety of cells.     

Inhibition of cell motility by interferon

Interferon derived from human leukocytes, human fibroblasts, and mouse fibroblasts was found to inhibit the motility of cultured cells. It inhibits the tumor-induced motility of capillary endothelial cells as well as the spontaneous migration of other cell types. The ability of a given preparation of interferon to inhibit the motility of a given cell type is proportional to its antiviral activity in that particular cell type. Antiserum to human leukocyte interferon neutralizes both the motility-inhibitory activity and the antiviral activity of this preparation.     

Tumor-specific antigens detected by inhibition of macrophage migration

Tumor-specific antigens of a guinea pig hepatoma induced by diethylnitrosamine were detected by the inhibition of migration of specifically sensitized macrophages from capillary tubes, and by the local passive transfer of delayed skin hypersensitivity and the suppression of growth of intradermally same injected tumor.     

超高效液相色谱法测定柑橘果肉中四种植物性内源激素的含量

利用超高效液相色谱法同时测定柑橘(Citrus reticulate Bance)果肉中的玉米素、赤霉素、吲哚乙酸和脱落酸的含量。以C8色谱柱,甲醇-0.1%冰乙酸为流动相梯度洗脱,检测波长为262nm,流速0.22mL/min。结果表明,玉米素含量在0.14～0.38μg/mL间线性关系良好,R2为0.999 5,平均回收率为98.7%,RSD为0.99%;赤霉素含量在0.67～1.79μg/mL间线性关系良好,R2为0.999 3,平均回收率为98.6%,RSD为0.70%;吲哚乙酸含量在0.25～0.67μg/mL间线性关系良好,R2为0.999 6,平均回收率为99.0%,RSD为0.68%;脱落酸含量在0.036～0.096μg/mL间线性关系良好,R2为0.999 9,平均回收率为99.1%,RSD为0.61%。该方法简便、快速、精密度高、准确性好,可用于植物样品中激素含量的测定。     

Suppression of gamma interferon production by inactivated feline leukemia virus

Supernatants from cultures of normal feline lymphocytes stimulated with Staphylococcus enterotoxin A showed antiviral activity, characterized as a gamma-like interferon. With the addition of inactivated feline leukemia virus, markedly less interferon was produced. The reduction in interferon production was not attributable to lowered lymphocyte viability or reduced mitogenic properties of Staphylococcus enterotoxin A and appears to be a direct retroviral effect. This finding may reflect clinically relevant events that may contribute to the development of the feline or human states of acquired immunodeficiency.     

鱼类内源消化酶系改性豆粕工艺初探

[目的]探索鱼类内源酶系对豆粕中大豆抗原蛋白的降解效果,为建立鱼内脏改性豆粕体系提供理论依据。[方法]采用SDS-PAGE电泳分析方法初步考察了初始pH、前处理条件、鱼类品种对鱼类内源复合酶系对豆粕中大豆抗原蛋白降解的影响。[结果]在50℃酶解温度下,初始pH 4.0条件下酶解效果最佳,其次为初始自然pH条件,初始中性和碱性条件下酶解效果不佳;加热前处理对酶解过程有明显促进作用,80～100℃范围内,随前处理温度升高,对酶解的促进逐渐加强;在自然pH环境及50℃酶解温度条件下,带鱼内源消化酶系酶解豆粕的效果明显比花鲢和鳗鱼内源酶系酶解豆粕的效果强,其中鳗鱼内源酶系的酶解作用相对较弱。[结论]研究显示,鱼类内源消化酶是一种潜在的豆粕抗营养因子改性酶原料。     

黄土暗穴扩展诱发地面沉降分析

【目的】应用随机介质理论分析黄土暗穴扩展诱发地面沉降的科学规律,为黄土地区公路工程地基设计、施工以及灾害防治提供科学依据。【方法】针对黄土暗穴扩展趋势,借助数值分析软件MATLAB,从暗穴的扩展机理出发研究其扩展形态及过程,并对暗穴扩展诱因进行量化,结合暗穴的临界厚度来判断暗穴的稳定性态,最后利用随机介质理论计算暗穴扩展对地面沉陷的影响。【结果】暗穴抬升、扩容及黄土湿陷诱发地面沉降的分析表明,暗穴抬升过程中,当上覆土体厚度小于临界高度时暗穴会发生坍塌,地面发生约0.25m的最大沉陷,影响范围约为方圆8.0m左右;暗穴扩容比暗穴抬升引起的地面沉降量及影响范围更大;随着黄土自重湿陷系数的增大,暗穴引起的地面沉陷量也呈线性增大。【结论】基于随机介质理论的黄土暗穴扩展诱发的地面沉降分析,能够初步预测暗穴塌陷过程对地面的影响;不同深度处黄土的湿陷性差异是黄土暗穴形成的重要原因,黄土的崩解性是诱发地面塌陷的关键因素。     

NaCl处理对酸枣幼苗内源激素含量的影响

【目的】研究不同浓度NaCl处理对酸枣幼苗叶和根系内源激素含量的影响。【方法】利用高效液相色谱法,测定不同NaCl浓度处理及不同时间下,酸枣幼苗叶、根中脱落酸、生长素、赤霉素、玉米素4种内源激素的含量。【结果】与0 mmol/L NaCl处理相比,处理时间相同时,酸枣幼苗叶和根在50、100、150、200 mmol/L NaCl处理下ABA含量显著增加,IAA、ZT、GA₃的含量、IAA/ABA、GA₃/ABA的比值整体显著下降。与处理0 h相比,不同浓度NaCl处理下,随着处理时间的延长,酸枣叶,根的ABA含量显著升高,IAA/ABA、GA₃/ABA的比值均显著降低;100 mmol/L NaCl处理下,酸枣叶和根的GA₃、IAA、ZT含量显著下降。【结论】NaCl处理下,处理时间相同时,酸枣幼苗通过增加叶和根ABA含量,降低叶和根IAA、ZT、GA₃含量、IAA/ABA和GA₃/ABA的比值适应盐胁迫。     

Metabolic regulation of brain Abeta by neprilysin

Amyloid beta peptide (Abeta), the pathogenic agent of Alzheimer's disease (AD), is a physiological metabolite in the brain. We examined the role of neprilysin, a candidate Abeta-degrading peptidase, in the metabolism using neprilysin gene-disrupted mice. Neprilysin deficiency resulted in defects both in the degradation of exogenously administered Abeta and in the metabolic suppression of the endogenous Abeta levels in a gene dose-dependent manner. The regional levels of Abeta in the neprilysin-deficient mouse brain were in the distinct order of hippocampus, cortex, thalamus/striatum, and cerebellum, where hippocampus has the highest level and cerebellum the lowest, correlating with the vulnerability to Abeta deposition in brains of humans with AD. Our observations suggest that even partial down-regulation of neprilysin activity, which could be caused by aging, can contribute to AD development by promoting Abeta accumulation.     

Temperature regulation by the inflorescence of philodendron

The inflorescence of Philodendron selloum temporarily maintains a core temperature of 38 degrees to 46 degrees C, despite air temperatures ranging from 4 degrees to 39 degrees C, by means of a variable metabolic rate. The heat is produced primarily by small, sterile male flowers that are capable of consuming oxygen at rates approaching those of flying hummingbirds and sphinx moths.     

高效液相色谱法分离和测定油茶茎尖组织中4种内源激素

建立了高效液相色谱法测定油茶茎尖组织中生长素(IAA)、赤霉素(GA3)、玉米核苷(ZR)、脱落酸(ABA)4种内源激素的方法。应用反相C18色谱柱,以甲醇-水(含0.75%冰乙酸,35∶65,V/V)为流动相,流速为0.8 ml/min,进样量10μl,检测波长254 nm,柱温30℃,该方法各峰分离效果理想。IAA、GA3、ZR、ABA的最低检出限分别为0.05、0.01、0.02、0.01 mg/L,回收率分别为98.2%、97.9%、96.3%、93.4%。该方法易操作且准确性高。     

蛋鸡白血病的PCR检测和序列分析

采用PCR方法对某蛋鸡场送检感染鸡进行实验室诊断,针对禽白血病病毒逆转录酶3’区域设计鉴定内外源病毒共同下游引物H5,针对ALV-J亚群gp85囊膜糖蛋白基因保守区域设计上游引物H7,A-E亚群gp85囊膜糖蛋白基因保守区域设计上游引物AD1,提取肝脏病料中核酸进行PCR扩增,测序分析结果表明为内源性禽白血病病毒感染。     

Regulation of interferon regulatory factor-3 by the hepatitis C virus serine protease

Persistent infections with hepatitis C virus (HCV) are likely to depend on viral inhibition of host defenses. We show that the HCV NS3/4A serine protease blocks the phosphorylation and effector action of interferon regulatory factor-3 (IRF-3), a key cellular antiviral signaling molecule. Disruption of NS3/4A protease function by mutation or a ketoamide peptidomimetic inhibitor relieved this blockade and restored IRF-3 phosphorylation after cellular challenge with an unrelated virus. Furthermore, dominant-negative or constitutively active IRF-3 mutants, respectively, enhanced or suppressed HCV RNA replication in hepatoma cells. Thus, the NS3/4A protease represents a dual therapeutic target, the inhibition of which may both block viral replication and restore IRF-3 control of HCV infection.     

The endocrine regulation of aging by insulin-like signals

Reduced signaling of insulin-like peptides increases the life-span of nematodes, flies, and rodents. In the nematode and the fly, secondary hormones downstream of insulin-like signaling appear to regulate aging. In mammals, the order in which the hormones act is unresolved because insulin, insulin-like growth factor-1, growth hormone, and thyroid hormones are interdependent. In all species examined to date, endocrine manipulations can slow aging without concurrent costs in reproduction, but with inevitable increases in stress resistance. Despite the similarities among mammals and invertebrates in insulin-like peptides and their signal cascade, more research is needed to determine whether these signals control aging in the same way in all the species by the same mechanism.