硒化紫球藻胞外多糖毒性及抗氧化活性的研究

目的 研究硒化紫球藻胞外多糖的毒性及抗氧化活性.方法 采用在培养液中添加亚硒酸,制备硒化紫球藻胞外多糖(Se-PSP);在体外培养条件下,测量其对细胞代谢活力的抑制率;建立小鼠动物模型,测量各项抗氧化功能指标.结果 Se-PSP对LO-2的半抑制浓度为80ìg·mL-1;Se-PSP(80,160 mg·kg-1)对小鼠不仅无毒性,而且还有促进其生长、抗氧化等保健功能.结论 Se-PSP在80,160 mg·kg-1低浓度范围内,可以发挥硒多糖的抗氧化等活性.     

硒化紫球藻胞外多糖体外诱导BEL-7402肿瘤细胞凋亡的实验研究

目的研究硒化紫球藻胞外多糖对BEL-7402等肿瘤细胞系的生长及凋亡的影响。方法采用在培养液中添加亚硒酸,制备硒化紫球藻(Porphyridiumsp.)胞外多糖(Se-PSP);在体外培养条件下,用不同浓度的紫球藻胞外多糖(PSP)及硒多糖(Se-PSP)处理肿瘤细胞,并用MTT,DNA ladder,Focus等方法测定。结果与结论Se-PSP(80mg.L-1)对BEL-7402肿瘤细胞系有极为显著的抑制作用,且能诱导BEL-7402细胞凋亡。     

硒化紫球藻(Porphyridium sp.)胞外多糖增强小鼠免疫功能的初步研究

目的研究硒化紫球藻胞外多糖对小鼠免疫功能的影响。方法采用在培养液中添加亚硒酸,制备硒化紫球藻胞外多糖(Se-PSP);小鼠分别腹腔注射紫球藻胞外多糖(PSP)及硒多糖(Se-PSP)(100 mg.kg-1.d-1),14d后进行外周血白细胞计数、免疫器官称重并且应用炭粒廓清法和溶血素测定法测定单核细胞吞噬功能和B淋巴细胞的体液免疫功能。结果与结论PSP对小鼠免疫功能无显著影响,而Se-PSP能明显增强小鼠的免疫功能。     

紫球藻胞外多糖的分离及体外抗乙肝病毒活性的初步研究

目的 研究紫球藻胞外多糖的分离及体外抗乙肝病毒活性。方法 紫球藻培养液通过离心、浓缩、透析、醇析、脱蛋白、冷冻干燥等步骤从中分离出胞外多糖；采用ELISA和MTT法测定紫球藻胞外多糖对2215细胞分泌e抗原（HBeAg）的影响。结果 元素分析表明，胞外多糖舍N：0．82％、C：32．91％、H：6．19％；氨基酸分析表明，含有17种氨基酸，含量为2．49％。红外光谱和紫外光谱分析表明，所分离的胞外多糖具有多糖的特征吸收峰，糖环为吡喃环，舍有硫酸酯基团。该胞外多糖对2215细胞分泌的HBeAg有不同程度的抑制作用，其治疗指数（TI）大于2。结论 紫球藻胞外多糖在体外具有抗乙肝病毒作用。     

硒在紫球藻蛋白质、多糖和脂类物质中的累积与分布

目的探讨硒对紫球藻的生长及其主要生化组成的影响,分析紫球藻累积同化硒的动态过程及其硒在细胞主要生化组成中的分布特点。方法利用添加0.5 mg.L-1硒的ASW培养基培养紫球藻(Porphyridium sp.),采用2,3-二氨基萘(DAN)荧光分光光度法测定藻体及各主要生化组成中的硒含量。结果与结论 (1)0.5 mg.L-1硒能够促进紫球藻的生长,最大干重可达到4.8 g.L-1,比对照组增加0.6 g.L-1,添加硒后紫球藻胞外分泌性多糖的产量明显提高,加硒组胞外分泌性多糖含量为180.7 mg.L-1,是对照组的1.69倍。添加硒培养紫球藻不会影响其生化组成和品质。(2)藻体硒含量在对数前期增加明显,由11.19μg.g-1增加到17.78μg.g-1;在培养中后期硒含量出现迅速升高,达到26.95μg.g-1,净增量为9.17μg.g-1;富硒紫球藻细胞的最高硒含量达到27.99μg.g-1,是对照组硒含量的14倍。每单位体积(L)培养物中,紫球藻富集硒的总量为140.16μg,硒的同化率达到28.03%。(3)添加硒后紫球藻培养物中胞外分泌性多糖的硒含量为31.02μg.g-1,,比藻体硒含量高3.03μg.g-1。藻体内硒主要分布在胞体多糖中,硒含量为7.08μg.g-1(DW),是细胞硒含量的25.3%,水溶性蛋白质和粗脂肪结合硒的量分别为5.84μg.g-1(DW)和0.89μg.g-1(DW),分别占细胞硒含量的20.9%和3.2%。     

灰树花多糖脂质体的制备方法研究

目的:制备灰树花多糖脂质体。方法:用反向蒸发法、乙醚注入法、乙醇注入法、薄膜分散法制备灰树花多糖脂质体,根据包封率的高低确定制备方法;用葡聚糖凝胶层析法对灰树花多糖脂质体进行分离,硫酸-苯酚比色法测定游离灰树花多糖含量,负染色法观察其形态。结果:反向蒸发法、乙醚注入法、乙醇注入法、薄膜分散法制备灰树花多糖脂质体的包封率分别为20.15%、16.32%、10.26%、7.99%,形态为圆形或椭圆形,平均粒径为200nm。结论:采用反向蒸发法制备的灰树花多糖脂质体包封率较高,是多糖类药物制备脂质体较好的方法;葡聚糖凝胶层析法对灰树花多糖脂质体的分离效果较好。     

硒化玉米须多糖的工艺条件及硒含量测定研究

目的以玉米须多糖为原料,用亚硒酸钠进行玉米须多糖的硒化研究。方法利用单因素和正交试验确立硒化的最佳工艺条件;利用硒-硫氰酸钾-甲基紫萃取光度法测定硒多糖中的硒含量,并通过红外光谱对硒多糖进行了初步表征。结果最佳工艺条件为反应温度70℃,反应时间8 h,玉米须多糖与亚硒酸钠质量比为1∶1.2,硝酸体积分数为0.3%,玉米须硒多糖中硒含量为3.17 mg.g 1,平均收率为35.72%。红外光谱显示:玉米须硒多糖中含有Se=O键和Se C键。结论利用该工艺成功合成了玉米须硒多糖,为玉米须的开发和利用奠定基础。     

罗望子多糖硒酸酯的制备及表征

目的:合成罗望子多糖硒酸酯,并表征其结构特征。方法:在HNO3-BaCl2催化作用下,利用亚硒酸钠合成罗望子多糖硒酸酯,以硒含量为指标对合成工艺进行优选,采用红外吸收光谱、热重分析、GPC等方法对合成产物进行表征。结果:罗望子多糖硒酸酯最佳合成条件为硝酸浓度为0.5%,反应温度80℃,反应时间14 h,此条件下产物硒含量约为22 mg.g-1,结论:合成产物中硒以Se=O的形式存在,且与纯多糖比较,多糖硒酸酯热稳定性和相对分子质量稍有降低,可能是由于酸性反应体系下罗望子多糖稍有降解,同时引入的亚硒酸基对分子结构产生了影响。     

胀果甘草多糖的分离纯化及其理化性质

目的对新疆地产胀果甘草Glycyrrhiza inflataBat.中获得的一种水溶性多糖(GIP-2)进行分离纯化,并测定其部分理化参数。方法采用脱脂、回流提取、乙醇沉淀、Sevag法除蛋白,从胀果甘草药材中提取粗多糖,透析后经DEAE-52离子交换层析和Sepharose CL-6B、Sephadex G-50凝胶柱层析分离纯化得到一种水溶性多糖(GIP-2);UV及IR法检测其性质;自动旋光仪测定旋光度;高效凝胶渗透色谱法(HPGPC)分析其纯度和分子量范围;完全酸水解法鉴定多糖的单糖组分。结果胀果甘草多糖GIP-2为黄白色粉末,无甜味,易溶于水;UV检测192 nm处有明显吸收峰,260、280 nm处均无吸收峰,证明被测物为多糖,且不含核酸及蛋白质;IR分析结果显示,在3393、2932、1616、1423、1101 cm-1处表现为典型的多糖吸收峰;GIP-2分子量>2000 kDa,主要由葡萄糖、阿拉伯糖和半乳糖组成,其摩尔比为3.3:11.7:1.0。结论提取分离所得胀果甘草多糖GIP-2为单一、纯净的多糖。     

异紫草酸纯化提取工艺及抗氧化活性研究

探究丹参多酚酸中异紫草酸的最佳分离纯化方法及其体外抗氧化活性。通过MCI Gel色谱柱、LH-20凝胶色谱柱、动态轴向加压制备液相联用分离得到高纯度异紫草酸,并与传统硅胶柱层析法分离效果进行对比。通过·OH清除实验、DPPH自由基清除实验和铁氰化钾还原实验测定异紫草酸的体外抗氧化活性。所建立方法分离得到的异紫草酸纯品归一化法百分含量达到98.7%,传统硅胶柱层析法无法分离得到异紫草酸纯品。异紫草酸对·OH和DPPH的半数清除率浓度(IC50)分别为0.277 mg·mL^-1、17.43μg·mL^-1,其抗氧化能力与浓度剂量呈现依赖关系。MCI-Gel/LH-20凝胶/C18键合填料柱层析法可用于高纯度异紫草酸的分离。异紫草酸具有清除自由基及抗氧化活性,可用于治疗心脑血管疾病药物的开发。     

A fatal case of gun blue ingestion in a toddler

Acute selenium poisoning occurs infrequently. The form of selenium encountered plays a great role in toxicity. Several fatalities have been reported and all but I involved ingestion of selenious acid or selenium dioxide. A healthy 22-mo-old male ingested up to 15 ml of Gun Blue solution (selenious acid). Initially he was pink, alert, and combative in the ambulance but his condition rapidly deteriorated. There was no measurable blood pressure, his oxygen saturation was 84% by pulse oximetry, and his mental status deteriorated to require hand ventilation. The child was cyanotic, unresponsive, and without palpable pulses upon presentation. Cardiopulmonary resuscitation was initiated unsuccessfully and was terminated after 35 minutes.     

Absorption, distribution, and retention of inhaled selenious acid and selenium metal aerosols in beagle dogs

We studied the distribution and retention of inhaled selenious acid and selenium metal aerosols which were similar in size and chemical form to selenium aerosols that may be produced during fossil fuel combustion. Beagle dogs were given 10 to 61 micrograms Se/kg of body weight by inhalation. Aerosols generated for the inhalation exposures were also collected and instilled into the upper respiratory tracts or stomachs of additional dogs to measure systemic absorption at these sites. Selenium-75, incorporated into the aerosols, was used to determine the Se content in the whole animal, excreta, and individual tissues as a function of time. Virtually all of the inhaled selenious acid aerosol was rapidly absorbed into the blood from the lungs, gastrointestinal tract, and the nasal membranes. Selenium metal aerosols were less rapidly absorbed. Selenium that was absorbed into the blood was translocated to the liver, kidney, spleen, and heart. Selenium-75 in these organs had a biological half-life of 30 to 40 days. Approximately 50% of the deposited Se was eliminated with a biological T1/2 of 1.2 days. Urine was the major route of excretion, accounting for 70 to 80% of the excreted Se. The long-term component of the whole-body retention function for both inhaled aerosols had a half-life of about 34 days and accounted for about 20% of the initial Se dose. The data suggested that although absorption of selenious acid into blood following inhalation was more rapid than absorption of selenium metal, once absorbed the disposition of both compounds was similar.     

Acute poisoning by selenious acid

A 2 yo male child ingested approximately 15 ml of a Gun Blue solution containing selenious acid, nitric acid and copper nitrate. He was immediately given milk and vomited spontaneously blood-stained food with a garlic smell. He was admitted to our Centre less than 3 hr following ingestion. An esophago-gastroscopy showed a second degree burn of both esophagus and stomach. He became comatose and had to be ventilated mechanically. Metabolic acidosis, leucocytosis, hyperglycemia and hemoconcentration were also observed. During the following day he developed a severe intestinal distension, a cardiomyopathy (CPK = 1,302, cardiac arrhythmia), and moderate hepatic, renal and pulmonary dysfunctions. Plasma selenium concentration was 285 micrograms/L and the maximum urinary concentration was 28,459 micrograms/L. After 4 days, his condition had improved considerably and he was about to be extubated when he suddenly developed acute respiratory distress. A similar episode occurred 24 hr later. His lung function progressively deteriorated; later he required the use of an extracorporeal membrane lung. Legionella dumofii was found the causative agent. He died 17 d after ingestion despite aggressive treatment. Acute selenious acid poisoning and its relation to Legionnaire's disease is discussed.     

Fluorescence characteristics of benzodiazepines in strong acid.

The fluorescence characteristics of 10 substituted 1,4-benzodiazepines in strong acid solution were investigated. The compounds that fluoresce in the Hammett acidity region possess, or can form by enolization, an azomethine linkage in the 1,2- or 4,5-position. All benzodiazepines that fluoresce in strong acid show increases in fluorescence intensity with corresponding blue shifts as acidity increases. Two pKa's in the Hammett acidity region were observed for both the fluorometric and absorptiometric titrations of the benzodiazepines possessing a carbonyl in the 2-position. No evidence of excited state prototropism was observed.     

紫球藻生物活性物质及其应用

紫球藻（Porphyridium)是一种海水单细胞红藻，其在培养繁殖过程中，能够合成藻胆蛋白，高不饱和脂肪酸，硫酸酯多糖等生物活性物质，具有广阔的应用前景。本文综述了分类，形态，及其活性物质的生物应用研究。     

Toxicité de l'étain: Action sur les propriétés électriques et mécaniques de la fibre musculaire squelettique

The toxicity of tin on the excitation-contraction coupling of skeletal muscle fibers was studied in “nonpolluted” and in “polluted” crabs. In fibers obtained from “non-polluted” crabs living in artificial seawater (ASW): (i) the resting membrane potential of muscle fibers decreased irreversibly from the control value of ?67.0 ± 3.1 to ?59.8 ± 3.9 mV after 10 min of exposure to tin (10^?4m); (ii) the action potential rapidly (5 min) and irreversibly changed from an all-or-none type to a graded response in the presence of tin; (iii) the twitch tension decreased in 4 min from a mean value of 0.92 ± 0.29 kg·cm^?2 in ASW to a new value of 0.50 ± 0.32 kg·cm^?2 in ASW + tin. The crabs which were housed in ASW + tin did not survive beyond 15 days. In the fibers from these “polluted” crabs: (i) the resting membrane potential fell to ?59.6 ± 2.4 mV after 18 hr of exposure of the crabs to ASW + tin; the value after 24 hr was ?51.5 ± 3.9 mV and the membrane potential was stable at that value until the ninth day of life in ASW + tin; (ii) the action potentials were all of the graded type after 18 hr in ASW + tin; (iii) the twitch tension was 0.61 ± 0.21 kg·cm^?2 after 24 hr. It was still 0.55 ± 0.30 after 9 days. The potassium contracture decreased from the control value of 2.7 ± 0.1 to 0.97 ± 0.52 kg·cm^?2 after 4 days of life in ASW + tin. At the concentration of 10^?4m, tin is a toxic lethal substance which depresses electrical and mechanical activity of the crustacean skeletal muscle fiber.     

二氢杨梅素的稳定性研究

目的:研究二氢杨梅素在不同条件下的稳定性。方法:考察二氢杨梅素在不同pH值、温度、光线、金属离子影响下的稳定性,用反相高效液相色谱法测定其含量。结果:在pH值≤4的弱酸性条件下二氢杨梅素能稳定存在,随着pH值的增加,会加速氧化,特别是在pH值≥9的碱性条件下会立即反应而氧化变黄。温度的升高,Fe3 ,Al3 ,Cu2 等金属离子的存在以及光线均可以加速二氢杨梅素的氧化。结论:为使二氢杨梅素能较长时间稳定存在,需保证其生理活性的条件是弱酸性、避免接触Fe3 ,Al3 ,Cu2 等金属离子、避光低温保存。     

Effect of hyperosmotic xylitol on gastric secretion in the rat: lack of influence of cyclooxygenase inhibitors

The effects of hyperosmotic solutions of xylitol were tested on acid and bicarbonate outputs from the rat stomach as well as on acid back-diffusion. Hyperosmotic solutions were instilled into anesthetized rats by an esophageal cannula and drained through a duodenal catheter. Spontaneously secreting and histamine-stimulated rats were used in different experiments. Hyperosmotic xylitol solutions at concentrations of 18.4% or higher produced graded inhibitions of the histamine-induced acid secretion. A 34.5% xylitol solution also inhibited spontaneous acid secretion. The same solution also caused a certain degree of acid back-diffusion and increased output of bicarbonate. Neither the inhibition acid secretion nor stimulation of bicarbonate output were affected by cyclooxygenase inhibitors indomethacin or flufenamic acid. It is concluded that hyperosmotic xylitol reduces gastric acidity by three mechanisms namely inhibition of acid secretion, increased bicarbonate output and increased back-diffusion of acid. None of these mechanisms seem to depend on prostaglandin biosynthesis.     

乳酶生质量标准中酸度试验的影响因素探讨

摘 要 目的：考察乳酶生现行质量标准中酸度试验的影响因素。方法: 测定不同来源牛奶、不同接菌量、不同保存条件下的酸度值。结果: 采用不同品牌、不同批次牛奶测定的酸度值不稳定;现行质量标准无法真实反映保存条件对样品质量的影响。结论:牛奶培养基的质量问题和现行标准方法欠合理,导致酸度试验结果缺乏可靠性。