Effects of aerosols from nontoxic Stachybotrys chartarum on murine airways

Acute effects on the upper and lower respiratory tract due to inhalation exposure to Stachybotrys chartarum (Sc) extract were investigated in mice. In addition, the capacity of the Sc exposure to activate immune system and cause inflammation in the respiratory tract was studied. The inhalation of Sc extract aerosols was observed to provoke sensory irritation in the airways of both naive and Sc-immunized mice. In contrast, exposure to aerosolized ovalbumin or phosphate buffered saline did not cause this effect. Exposure to Sc twice a week for 3 wk increased significantly the serum total immunoglobulin E (IgE) levels in BALB/c mice immunized with Sc as well as in nonimmunized mice. A slight presence of inflammatory cells was observed in the alveoli 3 days after the last exposure to Sc. In conclusion, Sc extract has the capacity to provoke sensory irritation in the murine airways and to activate the murine immune system.     

3种牙髓生物活性材料对小鼠间充质干细胞骨向分化的影响

目的 评估3种牙髓生物活性材料——三氧化聚合物（MTA）、Bioaggregate（BA）和Biodentine（BD）的生物相容性并观察其各自对小鼠间充质干细胞（MSCs）向成骨分化的影响。方法 采用XTT实验和ALP染色检测小鼠MSCs生存能力、分化矿化能力,观察MTA、BA及BD对小鼠MSCs向成骨分化的影响。结果 BD的细胞生存能力在浓度1、1/2、1/4时明显低于MTA和BA（P<0.001）,3种材料的细胞生存能力在材料浓度降至1/10和1/50时,差异无统计学意义（P>0.05）。MTA、BA和低浓度BD在显示分化矿化能力的ALP染色检测方面,与对照组相比染色值均升高,差异有统计学意义（P<0.05）。结论 MTA、BA以及低浓度BD与小鼠MSCs有良好的生物相容性;MTA、BA和低浓度BD在小鼠MSCs向成骨方向分化过程中有促进分化矿化作用,可以作为根管的根尖封闭材料。     

Effects of sulfur oxides on eicosanoids

Ultrafine metal oxides and SO2 react during coal combustion or smelting operations to form primary emissions coated with an acidic SOx layer. Ongoing work in this laboratory has examined the effects of sulfur oxides on pulmonary functions of guinea pigs. We have previously reported that 20 micrograms/m3 acidic sulfur oxide as a surface layer on ultrafine ZnO particles decreases lung volumes, decreases carbon monoxide diffusing capacity, and causes lung inflammation in guinea pigs after 4 daily 3-h exposures. It also produces bronchial hypersensitivity following a single 1-h exposure. The importance of this surface layer is demonstrated by our observation that 200 micrograms/m3 of sulfuric acid droplets of equivalent size are needed to produce the same degree of hypersensitivity. This study characterized the concentration-dependent effects of in vivo exposures to sulfur oxides on arachidonic acid metabolism in the guinea pig lung, and investigated the time course and the relation between eicosanoid composition and pulmonary functions. We focused specifically on four cyclooxygenase metabolites of arachidonic acid, that is, prostaglandins (PG) E1, F2 alpha, 6-keto prostaglandin F1 alpha, and thromboxane (Tx) B2, and two groups of sulfidopeptide leukotrienes (C4, D4, E4, and F4). Guinea pigs were exposed to ultrafine ZnO aerosol (count median diameter = 0.05 microns, sigma g = 1.80) with a layer of acidic sulfur oxide on the surface of the particles. Lung lavage was collected after exposures, and the levels of arachidonic acid metabolites were determined using radioimmunoassay (RIA). Concentration-dependent promotion of PGF2 alpha and concentration-dependent suppression of LtB4 were observed. The increased PGF2 alpha was associated with depressed vital capacity and diffusing capacity of the lungs measured in guinea pigs exposed to the same atmosphere described in a previous study. There is no causal relationship between the levels of other arachidonic acid metabolites and the pulmonary functional changes after exposures to these aerosols.     

海洋生物活性肽研究进展

综述几种海洋天然生物活性肽的研究进展，阐明酶解生物活性肽的理论基础和海洋生物活性肽的吸收理论。对活性肽在养殖业中的作用、当前海洋生物活性肽研究的不足及研究前景作了评述。     

水蛭活性肽的纯化工艺

目的：对水蛭活性肽进行纯化,并对水蛭活性肽进行树脂纯化条件考察。方法：采用DA201-C大孔吸附树脂进行极性分离,后经D201阴离子交换树脂进行电荷分离,最终得到纯化的水蛭活性肽组分。结果：DA201-C大孔树脂,上样肽浓度20 mg·mL^-1,流速1.0 BV·h^-1,依次用25%乙醇、50%乙醇和75%乙醇溶液洗脱,各洗脱部位得率及活力较高,但总体活性成分被分散,以上各洗脱部位经D201离子交换树脂,pH 4.0,上样肽浓度30 mg·mL^-1,流速3.0 BV·h^-1,分别用2.5%氯化钠的25%乙醇、2.5%氯化钠的50%乙醇、2.5%氯化钠的75%乙醇溶液洗脱,2.5%氯化钠的25%乙醇和2.5%氯化钠的50%乙醇洗脱部位有明显的抗凝活性,经过分析性RP-HPLC验证后,基线平稳,各组分分离度良好。结论：经DA201-C大孔树脂和D201离子交换树脂纯化后的水蛭活性肽,2.5%氯化钠的25%乙醇和2.5%氯化钠的50%乙醇洗脱部位活力较高,分离度好。     

Role of eicosanoids in PAF-induced increases of the vascular permeability in rat airways.

1. Platelet activating factor (PAF; 1.0 and 5.0 micrograms kg-1) injected in the tail vein of unanaesthetized rats dose-dependently increased the vascular permeability of the trachea, upper and lower bronchi (up to 400%) as measured by the extravasation of Evans blue dye. The permeability of the parenchyma was not affected by PAF treatment. 2. Pretreatment of the animals with an intravenous injection of the PAF antagonist BN-52021 (10 mg kg-1) abolished almost totally the vascular permeability changes elicited by PAF injection (5.0 micrograms kg-1). 3. Pretreatment of the animals with intravenous injections of inhibitors of thromboxane formation, indomethacin (10 mg kg-1) and compound OKY-046 (10 mg kg-1), and thromboxane antagonist, compound L-655,240 (5 mg kg-1), partially reduced PAF effects in the airways (from 28 to 69%). The thromboxane mimic U-44069 (5.0 micrograms kg-1) did not modify the vascular permeability of rat airways. The effect of a low dose of PAF (0.1 microgram kg-1) on the vascular permeability of the trachea and bronchi (but not of the parenchyma) was potentiated by compound U-44069 (5.0 micrograms kg-1) or noradrenaline (400 ng kg-1) whereas the effect of a high dose of PAF (5.0 micrograms kg-1) was not affected. 4. Neither the peptidoleukotriene antagonist MK-571 (10 mg kg-1) nor the 5-lipoxygenase inhibitor, L-663,536 (10 mg kg-1) given before the injection of PAF (5.0 micrograms kg-1) affected the protein extravasation in rat lung tissues.(ABSTRACT TRUNCATED AT 250 WORDS)     

生物活性肽的抗肿瘤作用及其机理研究进展

生物活性肽是一类天然存在于动、植物和微生物等生物体内,或动、植物蛋白质经蛋白酶酶解以及人工化学合成或生物工程方法而得,且具有特殊生理活性的生物物质,具有较显著的抗肿瘤作用。此文介绍了生物活性肽的分类与特性、抗肿瘤作用,并简述了生物活性肽增强机体特异性和非特异性免疫功能、抗自由基与辐射损伤、诱导肿瘤细胞凋亡和直接作用于肿瘤细胞等多种作用机理,并简述了生物活性肽实现抗癌以及临床抗肿瘤药用等内容。     

Cytotoxic and allergenic potential of bioactive proteins and peptides

This review article deals with the assessment of cytotoxic and allergenic potential of bioactive proteins and peptides. It is evident that 'novel' foods or nutraceuticals containing bioactive proteins and peptides must fulfill their proposed "health claim". Furthermore, there is a need to assess their potential to exert adverse effects before they can be made widely available to consumers. A brief overview of compounds (i.e. proteins and peptides of animal and plant origin) and mechanisms involved in cytotoxic and allergenic (adverse) reactions is given along with some recent results obtained from ongoing studies. There are numerous proteins and peptides of plant and animal origin that are known to exhibit cytotoxic effects. There is evidence that many cytotoxic compounds described in the literature exclusively affect malignant cells leading to the assumption that a cancer protective effect could exist for such bioactive proteins and peptides. All the constituents that are responsible for the allergenicity of foods (as well as of pollens) are proteinaceous in nature. Some protein breakdown products, i.e. peptide fragments, may conserve part of the allergenicity of the native protein and thus can also be considered as allergens. The molecular basis of IgE recognition underlying cow's milk protein allergy is described. Some results from studies on volunteers fed caseinophosphopeptides or potentially hypotensive milk protein hydrolysates illustrate the major difference between allergenicity and immunogenicity. The data presented on the relationship between the structure of food proteins and peptides and their allergenicity shows the difficulty in trying to assess the "non-allergenicity" of products derived from an allergenic source, even if the process used involved extensive hydrolysis of the native protein(s). A 'weight of evidence approach' for assessing the potential allergenicity of a novel protein with no history of prior allergenicity is also presented with regard to the current EU Regulations.     

海洋动物功能蛋白及活性肽研究进展

海洋动物中含有丰富的蛋白质、多糖、多肽、脂肪酸等活性物质,具有来源丰富、功能多样、活性显著、毒副作用小等优点,已经成为当前医药卫生和功能食品研究的热点。本文主要对海洋动物来源的抗氧化、抗菌、抗肿瘤和免疫调节等活性的功能蛋白和多肽进行综述,介绍其可能的作用机制,并就海洋生物功能蛋白及活性肽开发利用前景作出展望。     

Effects of platelet-activating factor on rat airways

Effects of platelet-activating factor (PAF) on the rat airways were investigated. Male Wistar rats were anesthetized, and PAF was inhaled into the lungs through a tracheal cannula for 5 min using an ultrasonic nebulizer. The bronchomotor response was measured with a modified Konzett-R?ssler method in rats immobilized with decamethonium bromide. The inhalation of PAF caused a marked bronchoconstriction, dose-dependently, in a concentration range of 0.0001 to 0.01%. The bronchoconstrictor potency of PAF was about ten times higher than that of ACh. On the other hand, histamine inhalation gave only a slight bronchoconstriction even at the high concentration of 0.1%. The bronchomotor response to PAF was accompanied by a marked, sustained decrease in systemic blood pressure, in a dose-dependent manner. Repeated inhalations of PAF (0.001%) at an interval of 60 min resulted in a pronounced tachyphylaxis in the bronchoconstrictor response, but not in the hypotensive response. Combined inhalations of PAF with ACh or histamine did not produce a potentiation by PAF of the bronchoconstrictor responses to ACh and histamine. These findings show that PAF is a strong bronchoconstrictor agent in rats and that there is no interaction between PAF and other mediators in the acute bronchoconstrictor response.     

Functional characterization of muscarinic receptors in murine airways.

1. The effects of muscarinic receptor antagonists considered to be selective for M1 receptors (pirenzepine; PZ), M2 receptors (AFDX-116), and for M3 receptors (4-diphenyl acetoxy N-methyl-piperidine (4-DAMP)) were used to investigate the existence of muscarinic receptors subtypes in murine airways. Atropine was used as a nonselective antagonist. The effects of these antagonists were studied upon tracheal contractions induced either by EFS (electric field stimulation) or by application of an exogenous cholinoceptor agonist (arecoline). 2. The muscarinic receptor antagonists tested inhibited arecoline-induced tracheal contractions with the following rank order of potency: 4-DAMP = atropine > pirenzepine = AFDX-116. The rank order of potency of the muscarinic antagonists used in inhibiting EFS-induced tracheal contractions was: 4-DAMP = atropine > PZ > AFDX-116. The pA2 values for these antagonists were similar when compared to the pA2 values determined in guinea-pig and bovine airway smooth muscle. 3. In addition to in vitro studies, the effects of inhalation of the different muscarinic antagonists on lung function parameters in vivo were investigated. Inhalation of 4-DAMP induced a decrease in airway resistance and an increase in lung compliance. In contrast, inhalation of AFDX-116 induced an increase in airway resistance and almost no change in lung compliance. Apart from some minor effects of atropine on airway resistance, atropine, PZ, and pilocarpine failed to induce changes in lung mechanics as determined by in vivo lung function measurements. 4. The results provide evidence for the existence of M3 receptors on murine tracheae that are involved in the contraction of tracheal smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)     

海洋生物活性肽及其生物活性研究进展

概述存在于海绵、海鞘等海洋低等生物和海洋鱼贝类中的生物活性肽，以及这些活性肽的抗肿瘤、抗菌、抗高血压及抗氧化等生物活性的研究进展。     

Smoking, eicosanoids and ulcerative colitis

In this study, which is the first of its kind using normal tissue samples that are very difficult to obtain, we have investigated the hypothesis that smoking protects against ulcerative colitis by altering the colonic mucosal formation of prostaglandins and related substances. Colonic mucosa biopsied from healthy young men produced prostaglandin E, 6-keto-PGF1 alpha (formed from PGI2), leukotriene B4 and leukotriene C4/D4/E4 as determined by radioimmunoassay. With each substance, the median yield was lower in the group of smokers who smoked 3 cigarettes in the 2 h before biopsy, than in the non-smokers. However, with each eicosanoid the statistical probability approached only the 10% level, but the fact that the trend was the same for all eicosanoids somewhat strengthens the possibility of a real difference between the groups.     

牡蛎天然活性肽BPO-1诱导人胃腺癌BGC-823细胞凋亡的形态与超微结构观察

目的观察BPO-1对人胃腺癌BGC-823细胞形态与超微结构的影响,以探索BPO-1对胃癌细胞的作用机制。方法采用酸抽提、凝胶柱层析等方法,从牡蛎体内分离提取到牡蛎天然活性多肽组分BPO-1,以细胞凋亡诱导物姜黄素和癌细胞分化诱导物HMBA为平行对照,用光镜、透射电镜观察BPO-1处理细胞的形态和超微结构变化。结果经处理后的BGC-823细胞体积缩小、染色质凝聚、线粒体空泡化、内质网腔扩大和出现凋亡小体等多种典型的细胞凋亡形态和超微结构特征。结论牡蛎天然活性肽BPO-1对人胃腺癌BGC-823细胞凋亡的诱导具有显著作用。     

Effects of ATP and VIP on guinea pig airways

The bronchodilator effects of vasoactive intestinal peptide (VIP) and adenosine triphosphate (ATP), putative neurotransmitters of nonadrenergic, noncholinergic innervation, were compared with those of isoproterenol (ISP) in guinea pig airways by in vivo and in vitro techniques. In both studies, the test agents produced dose-dependent relaxations. The response of airway smooth muscle to ISP was significantly greater than the responses to the test agents. In the in vivo studies, the test agents produced statistically equieffective responses. However, in the in vitro studies, VIP produced complete relaxation of the precontracted tissues to the baseline, whereas ATP could not, suggesting VIP as a more effective relaxant than ATP.     

Flavonoids, leucocyte migration and eicosanoids

Quercetin reduced the concentration of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) in the pleural exudate induced in rats by 1% carrageenan given intrapleurally. Leucocyte migration in the exudate was also reduced by the flavonoid. Inhibition of eicosanoids and leucocytes in the exudate was dose-related. Quercetin also reduced LTB4 synthesis in cells stimulated with ionophore A23187, either ex-vivo or in-vitro. A similar, though less active, mode of action was found with quercitrin, while apigenin and luteolin reduced leucocyte accumulation and PGE2 formation, but not LTB4-formation.     

Antihypertensive effect of soybean bioactive peptides: A review

Hypertension is a global disease that is extremely harmful to humans. Timely lowering of blood pressure is necessary in order to avoid the occurrence of corresponding complications. This review shows that soy peptides are beneficial in resisting hypertension. One of the advantages is the abundance of raw materials for producing soybean peptides. Secondly, there are no reports of adverse reactions due to soy peptides. Moreover, they exert protective effect against hypertension-induced complications such as long-term memory impairment and kidney damage. However, there are still some obstacles associated with the development of soybean peptides. Therefore, this review is focused on statistical analysis of peptide sequences, amino acid residues, and possible targets of anti-hypertensive soybean peptides. Eventually, it proposes that application of genetic engineering technology to specifically modify the N- and C-terminal of the soybean peptides, and possible targets in identifying the likely drug targets involved in the antihypertensive effects of these peptides.     

Bucindolol: Effects on blood pressure,airways resistance and serum creatine phosphokinase

Summary The effect of bucindolol on pulse, blood pressure and airways resistance was studied in eight patients. One hour after 150 mg bucindolol, a significant decrease in supine, standing and post-exercise blood pressure was observed. No change in blood pressure occurred 10 to 14 h after doses ranging from 50–150 mg indicating that bucindolol has a relatively short duration of action. A dose related inhibition of excercise induced tachycardia was observed consistant with beta-receptor blocking activity. However, there was no change in the resting pulse indicating partial sympathomimetic activity. There was no increase in airways resistance at all doses of bucindolol. Serum creatine phosphokinase increased beyond normal limits in 3 out of 6 patients studied, probably due to a direct effect upon skeletal muscle.