静注丙球低pH孵放灭活病毒效果验证

以水泡性口炎病毒（ＶＳＶ）为指示病毒,考察了低ｐＨ孵放不同时间对低温乙醇法生产的静注丙球（ＩＶＩＧ）中ＶＳＶ的灭活效果,并对不同厂家及不同批号ＩＶＩＧ中病毒灭活情况进行了比较。结果表明,液体ＩＶＩＧ在ＰＨ４．１±０．３,２０－２５℃,孵放２１天可灭活ＶＳＶ达６Ｌｏｇｓ以上（即低于实验检测限）,但不同厂家及不同批号的ＩＶＩＧ在病毒灭活的发生上有所不同     

S/D处理人纤维蛋白原的病毒灭活验证

在人纤维蛋白原制备工艺中增加Ｓ／Ｄ处理灭活病毒步骤,ＴＮＢＰ和Ｔｗｅｅｎ８０终浓度分别为０．３％和１％,在２５℃处理６小时能有效灭活指示病毒ＶＳＶ（〉３．７５Ｌｏｇ）、Ｓｉｎｄｂｉｓ（〉４．４６Ｌｏｇ）、ＨＩＶ（〉３．６７Ｌｏｇ）,盲传三代未检出病毒     

鸡传染性支气管炎病毒S1基因在昆虫细胞中表达水平初探

将含有鸡传染性支气管炎病毒 Ｓ１ 基因ｃ Ｄ Ｎ Ａ 的重组转移质粒ｐ Ｓ Ｘ Ｉ Ｖ Ｖ Ｉ＋ Ｘ３ Ｓ１ ． Ｈｏｌｔｅ 和ｐ Ｓ Ｘ Ｉ Ｖ Ｖ Ｉ＋ Ｘ３／４ Ｓ１ ． Ｈｏｌｔｅ 分别与粉纹夜蛾核型多角体病毒 Ｔｎ Ｎ Ｐ Ｖ Ｓ Ｖ Ｉ－ Ｇ Ｄ Ｎ Ａ（ Ｏ Ｃ Ｃ－ ,ｇａｌ＋ ） 共转染草地夜蛾（ Ｓｆ９） 细胞,经空斑纯化得到重组病毒 Ｔｎ Ｎ Ｐ Ｖ（ Ｘ３） Ｓ１ ． Ｈｏｌｔｅ Ｏ Ｃ Ｃ＋ 和 Ｔｎ Ｎ Ｐ Ｖ（ Ｘ３／４） Ｓ１ ． Ｈｏｌｔｅ Ｏ Ｃ Ｃ＋ 。将重组毒株分别感染 Ｔｎ５ Ｂ１ 细胞,并进行 Ｓ Ｄ Ｓ Ｐ Ａ Ｇ Ｅ 与 Ｗｅｓｔｅｒｎｂｌｏｔ 检测。结果表明, Ｔｎ Ｎ Ｐ Ｖ（ Ｘ３／４） Ｓ１ ． Ｈｏｌｔｅ Ｏ Ｃ Ｃ＋ 在感染的细胞中高效表达了 Ｓ１ 蛋白, Ｓ Ｄ Ｓ Ｐ Ａ Ｇ Ｅ 凝胶薄层色谱分析结果显示,感染病毒后７２ ｈ Ｓ１ 蛋白的表达量占细胞内总蛋白量的３５ ．８ ％ ,而 Ｔｎ Ｎ Ｐ Ｖ（ Ｘ３） Ｓ１ ． Ｈｏｌｔｅ Ｏ Ｃ Ｃ＋ 感染的细胞内检测不出 Ｓ１ 蛋白。经分析认为这一差异主要来自 Ｓ１ 基因翻译起始位点及其附近的周围环境。     

静脉注射免疫球蛋白制备中的病毒灭活

在静脉注射免疫球蛋白（ＩＶＩＧ）的制备中,采用有机溶剂结合表面活性剂（Ｓ／Ｄ）处理或６０℃１０小时液态加热（巴氏灭活法）的方法对组分Ⅱ（ＩｇＧ）进行病毒灭活处理,灭活效果用指示病毒进行了评价,结果表明：Ｓ／Ｄ法可有效灭活脂包膜病毒ＶＳＶ和Ｓｉｎｄｂｉｓ,巴氏灭活法则对上述病毒以及Ｖａｃｃｉｎｉａ和Ｅｃｈｏ病毒均有较好的灭活作用。经病毒灭活处理的免疫球蛋白,在理化及生物学特性上基本未受到不利影响,用两种方法分别处理组分Ⅱ后制备的ＩＶＩＧ,其主要特性指标均符合该制品的有关质量规定。     

麻蝇幼虫肠道蛋白酶BGP的分离纯化及性质

棕尾别麻蝇幼虫肠液经ＳＤＳ－ＰＡＧＥ后,Ｘ光片显影,呈现两条蛋白酶活性带．ＩＥＦ后,两条蛋白酶活性带的等电点分别为ｐＨ７．７和６．８．麻蝇幼虫肠液经５５％～７５％硫酸铵沉淀,以及连续两次制备等电聚焦,分离纯化出等电点约为ｐＨ７．７,分子量约为３５ｋＤ的蛋白酶ＢＧＰ．该酶能分解酪蛋白和类胰蛋白酶专一底物Ｂｚ－Ｐｈｅ－Ｖａｌ－ＡｒｇＮＡ,不能分解弹性蛋白酶专一底物ｅｌａｓｔｉｎ－ＣｏｎｇｏＲｅｄ和类胰凝乳蛋白酶专一底物Ｓｕｃ（Ａｌａ）２Ｐｒｏ－ＰｈｅＮＡ．ＳＢＢＩ,Ｌｅｕｐｅｐｔｉｎ和ＰＭＳＦ能强烈抑制其活性．专一底物和抑制剂的结果表明,ＢＧＰ是一种类胰蛋白酶．其最适反应温度为５０℃,最适作用ｐＨ为８．５．不耐高温,５０℃保温３０ｍｉｎ活性急剧下降．Ｈｇ２＋,Ｚｎ２＋和Ｃｕ２＋能抑制酶活性．Ｃａ２＋,Ｍｇ２＋对酶无激活作用,ＥＤＴＡ无抑制作用．     

假菠萝麻蛋白酶分离纯化及特性研究

从假菠萝麻叶汁中用乙醇分部沉淀法得到一种蛋白酶,对酪蛋白有强烈的水解活性,经Ｓｅｐｈａｄｅｘ Ｇ－１００柱层析和ＳＰ－Ｓｅｐｈａｄｅｘ Ｃ－５０离子交换柱层析等步骤纯化,可得到六角形结晶。结晶酶液经ＰＡＧＥ圆盘电泳,每条胶柱上只显示一条蛋白带,其活性在ｐＨ４。５－１０、５５℃范围内较稳定,最适ｐＨ８．５最适温度５０℃,Ｋｍ（酪蛋白）值为０．１８５％（Ｗ／Ｖ）。用ＳＤＳ－ＰＡＧＥ和Ｓｅｐｈａｄｅｘ     

Ca^2＋敏感性微电极在心肌胞浆Ca^2＋活度检测中的应用

改进的中性载体Ｃａ２＋敏感性微电极（Ｃａ－ＩＳＥ）在尖端直径为０．４—０．８μｍ时仍具有良好特性,可用于心肌胞浆Ｃａ２＋活度（αＣａｉ）的检测。测得豚鼠右心乳头肌、狗心室肌和浦肯野纤维静息时分别为０．１９±０．０１（ｎ＝２２）,０．２０±０．０２（ｎ＝１１）和０．４６±０．０７（ｎ＝１３）μｍｏｌ·Ｌ－１。毒毛旋花苷Ｇ３μｍｏｌ·Ｌ－１使静态及动态心肌分别增高０．１８±０．０２和６．６９±２．０９μｍｏｌ·Ｌ－１（ｎ＝２２）,并出现触发活动（ＴＡ）。１００μｍｏｌ·Ｌ－１蝙蝠葛碱可抑制毒毛旋花苷Ｇ引起的增高,同时使其ＴＡ消失。表明Ｃａ－ＩＳＥ技术可用于心肌组织ＴＡ与的同步检测。     

系统感染TMV的番茄叶胞外β-1,3-葡聚糖酶

系统感染ＴＭＶ （ｔｏｂａｃｃｏ ｍ ｏｓａｉｃ ｖｉｒｕｓ）的番茄（Ｌｙｃｏｐｅｒｓｉｃｏｎ ｅｓｃｕｌｅｎｔｕｍ Ｍｉｌｌ．）叶胞外蛋白提取液经冰冻干燥浓缩、－ ２０℃丙酮沉淀、ＣＭ－Ｓｅｐｈａｄｅｘ Ｃ－２５离子交换层析、ＤＥＡＥ－Ｓｅｐｈａｄｅｘ Ａ－２５离子交换层析和Ｓｅｐｈａｄｅｘ Ｇ－７５凝胶层析纯化,获得ＰＡＧＥ均一的β－１,３－葡聚糖酶．ＳＤＳ－ＰＡＧＥ证明,它包含分子量为３６ ｋＤ 和２７ ｋＤ的两个同工酶．以昆布多糖为底物,酶的最适ｐＨ 在４．８—５．２之间,在ｐＨ ４—８稳定;酶的最适温度在３０—４０℃之间,在４０℃保温１ｈ 后酶活性不变;Ｋｍ 值为９．２ ｍ ｇ／ｍ Ｌ．在系统感染ＴＭＶ 的番茄叶胞外蛋白提取液中,有分子量为２２ ｋＤ、２７ ｋＤ和３６ ｋＤ的３个β－１,３－葡聚糖酶同工酶     

广西树萝卜属一新种

广西树萝卜属一新种方鼎（广西中医药研究所南宁５３００２２）ＡＮＥＷＳＰＥＣＩＥＳＯＦＴＨＥＧＥＮＵＳＡＧＡＰＥＴＥＳ（ＶＡＣＣＩＮＩＡＣＥＡＥ）ＦＲＯＭＧＵＡＮＧＸＩ,ＣＨＩＮＡＦＡＮＧＤｉｎｇ（ＧｕａｎｇｘｉＩｎｓｔｉｔｕｔｅｏｆＴｒａｄｉｔｉｏ...     

红苋R104种子谷蛋白的电泳分析

通过单向水平变性聚丙烯酰胺凝胶等电聚焦（ＩＥＦ）、十二烷基硫酸钠聚丙烯酰胺凝胶电泳（ＳＤＳ—ＰＡＧＥ）和双向电泳（ＩＥＦ×ＳＤＳ—ＰＡＧＥ）分析了红苋Ｒ１０４种子谷蛋白的亚基组成,亚基分子量和等电点分布。谷蛋白的双向电泳图谱可分辨出１００多个亚基成分．其主要亚基为：５４ｋＤ（ｐＩ７．１５）;３３ｋＤ（ｐＩ５．８２）;３１ｋＤ（ｐＩ６．９２;ｐＩ６．７０;ｐＩ６．６５）;２２ｋＤ（ｐＩ８．３４）;２０ｋＤ（ｐＩ６．９２;ｐＩ６５６）;１８ｋＤ（ｐＩ６．９２;ｐＩ７３５;ｐＩ７．７２;ｐＩ８．０５）。另外,还对ＩＥＦ方法进行了讨论。     

Sensitization of Listeria monocytogenes to Low pH, Organic Acids, and Osmotic Stress by Ethanol

The killing of Listeria monocytogenes following exposure to low pH, organic acids, and osmotic stress was enhanced by the addition of 5% (vol/vol) ethanol. At pH 3, for example, the presence of this agent stimulated killing by more than 3 log units in 40 min of exposure. The rate of cell death at pH 3.0 was dependent on the concentration of ethanol. Thus, while the presence 10% (vol/vol) ethanol at pH 3.0 stimulated killing by more than 3 log units in just 5 min, addition of 1.25% (vol/vol) ethanol resulted in less than 1 log unit of killing in 10 min. The ability of 5% (vol/vol) ethanol to stimulate killing at low pH and at elevated osmolarity was also dependent on the amplitude of the imposed stress, and an increase in the pH from 3.0 to 4.0 or a decrease in the sodium chloride concentration from 25 to 2.5% led to a marked reduction in the effectiveness of 5% (vol/vol) ethanol as an augmentative agent. Combinations of organic acids, low pH, and ethanol proved to be particularly effective bactericidal treatments; the most potent combination was pH 3.0, 50 mM formate, and 5 % (vol/vol) ethanol, which resulted in 5 log units of killing in just 4 min. Ethanol-enhanced killing correlated with damage to the bacterial cytoplasmic membrane.     

Assessment of viral inactivation during pH 3.3 pepsin digestion and caprylic acid treatment of antivenoms

Antivenoms are manufactured by the fractionation of animal plasma which may possibly be contaminated by infectious agents pathogenic to humans. This study was carried out to determine whether pre-existing antivenom production steps, as carried out by EgyVac in Egypt, may reduce viral risks. Two typical manufacturing steps were studied by performing down-scaled viral inactivation experiments: (a) a pH 3.3 pepsin digestion of diluted plasma at 30 degrees C for 1h, and (b) a caprylic acid treatment of a purified F(ab')2 fragment fraction at 18 degrees C for 1h. Three lipid-enveloped (LE) viruses [bovine viral diarrhoea virus (BVDV), pseudorabies virus (PRV), and vesicular stomatitis virus (VSV)] and one non-lipid-enveloped (NLE) virus [encephalomyocarditis virus (EMC)] were used as models. Kinetics of inactivation was determined by taking samples at 3 time-points during the treatments. The pH 3.3 pepsin digestion resulted in complete clearance of PRV (>7.0 log(10)) and in almost complete reduction of VSV (>4.5 but < or =6.4 log(10)), and in a limited inactivation of BVDV (1.7 log(10)). EMC inactivation was > or =2.5 but < or =5.7 log(10). The caprylic acid treatment resulted in complete inactivation of the 3 LE viruses tested: BVDV (>6.6 log(10)), PRV (>6.6 log(10)), and VSV (>7.0 log(10)). For EMC no significant reduction was obtained (0.7 log(10)). Cumulative reduction was >13.6, >11.5, >8.3 and > or =2.5 for PRV, VSV, BVDV and EMC, respectively. Therefore the current manufacturing processes of at least some animal antisera already include production steps that can ensure robust viral inactivation of LE viruses and moderate inactivation of a NLE virus.     

The phytoplankton productivity of an acidic lake

The phytoplankton productivity over two years in a lake heavily loaded by acid mine drainage was very low. Algal assays indicated that below pH 5.5 the water, if buffered and fertilized with phosphorus, resulted in log growth. Above pH 5.5 algal log growth could be induced with phosphorus addition only. However, an in situ bag experiment was done in the lake and immediate bloom conditions of the indigenous algae resulted from phosphorus addition only, despite pH values below 5.     

Sensitization of Listeria monocytogenes to low pH, organic acids, and osmotic stress by ethanol

The killing of Listeria monocytogenes following exposure to low pH, organic acids, and osmotic stress was enhanced by the addition of 5% (vol/vol) ethanol. At pH 3, for example, the presence of this agent stimulated killing by more than 3 log units in 40 min of exposure. The rate of cell death at pH 3.0 was dependent on the concentration of ethanol. Thus, while the presence 10% (vol/vol) ethanol at pH 3.0 stimulated killing by more than 3 log units in just 5 min, addition of 1.25% (vol/vol) ethanol resulted in less than 1 log unit of killing in 10 min. The ability of 5% (vol/vol) ethanol to stimulate killing at low pH and at elevated osmolarity was also dependent on the amplitude of the imposed stress, and an increase in the pH from 3.0 to 4.0 or a decrease in the sodium chloride concentration from 25 to 2.5% led to a marked reduction in the effectiveness of 5% (vol/vol) ethanol as an augmentative agent. Combinations of organic acids, low pH, and ethanol proved to be particularly effective bactericidal treatments; the most potent combination was pH 3.0, 50 mM formate, and 5 % (vol/vol) ethanol, which resulted in 5 log units of killing in just 4 min. Ethanol-enhanced killing correlated with damage to the bacterial cytoplasmic membrane.     

Activity of glutaraldehyde at low concentrations (less than 2%) against poliovirus and its relevance to gastrointestinal endoscope disinfection procedures.

The activity of glutaraldehyde (GTA) at low concentrations (less than 2%) against poliovirus was assessed by a suspension procedure. The inactivation kinetics showed that concentrations of less than or equal to 0.10% were effective against purified poliovirus at pH 7.2; a 1 log10 reduction was obtained in 70 min with 0.02% GTA, and a 3 log10 reduction was obtained in 30 min with 0.10% GTA. GTA activity at low concentrations was greatly enhanced at alkaline pH, but was completely abolished at acid pH. In contrast, the inactivation assays on poliovirus RNA showed that it was highly resistant to GTA at concentrations up to 1.0% at pH 7.2. At pH 8.3 a low inactivation was noticed with 1.0% GTA. Our results are of relevance to hospital practice in digestive endoscopy investigations because there has been an increasing tendency to use low concentrations of GTA and very short contact times in disinfection procedures.     

Activity of glutaraldehyde at low concentrations (less than 2%) against poliovirus and its relevance to gastrointestinal endoscope disinfection procedures.

The activity of glutaraldehyde (GTA) at low concentrations (less than 2%) against poliovirus was assessed by a suspension procedure. The inactivation kinetics showed that concentrations of less than or equal to 0.10% were effective against purified poliovirus at pH 7.2; a 1 log10 reduction was obtained in 70 min with 0.02% GTA, and a 3 log10 reduction was obtained in 30 min with 0.10% GTA. GTA activity at low concentrations was greatly enhanced at alkaline pH, but was completely abolished at acid pH. In contrast, the inactivation assays on poliovirus RNA showed that it was highly resistant to GTA at concentrations up to 1.0% at pH 7.2. At pH 8.3 a low inactivation was noticed with 1.0% GTA. Our results are of relevance to hospital practice in digestive endoscopy investigations because there has been an increasing tendency to use low concentrations of GTA and very short contact times in disinfection procedures.     

Electrical Properties of Neurospora crassa : Effects of external cations on the intracellular potential

Glass micropipette electrodes have been employed to study the transsurface potential difference of Neurospora crassa. For mature hyphae grown in agar cultures, the internal potential is large and negative, often exceeding -200 mv. The potential is sensitive to the concentrations of extracellular potassium, sodium, hydrogen, and calcium ions, but does not vary in a manner which is readily explained by ionic diffusion potentials. With extracellular solutions containing only potassium chloride (or sulfate) and sucrose, the internal potential shifts toward zero (becomes less negative) at 45 mv per tenfold increase of potassium, over the range 0.1 to 10 mM. A similar result has been found with sodium, though the slope is only 33 mv/log unit. Calcium (1 mM) diminishes the influence of potassium and sodium by 60 to 70 per cent. As potassium or sodium is raised above 20 mM, the slope of the internal potential increases sharply to 85 to 90 mv/log unit, both in the presence and absence of calcium. With increasing hydrogen ion concentration, too, the internal potential shifts toward zero; in this case the slope is about 12 mv/pH unit at pH 9 and rises smoothly to 33 mv/pH unit at pH 3. All these phenomena are probably properties of the plasma membrane. The polysaccharide cell wall contains few fixed negative charges, has a low transverse resistance, and supports very little potential difference when separated from the plasma membrane.     

Fermentation characteristics of exopolysaccharide-producing lactic acid bacteria from sourdough and assessment of the isolates for industrial potential

Lactic acid bacteria (LAB) with antimicrobial activity and high exopolysaccharide (EPS) production ability isolated from sourdough were studied for their fermentation characteristics as potential new starter cultures. The values of pH, titratable acidity, and viable cell counts were 4.06+/-0.009-4.50+/- 0.015, 0.787+/-0.020%-1.172+/-0.018%, and 8.78+/-0.08-8.98+/- 0.06 log CFU/ml, respectively. In order to select probiotics with a high survival rate in the gut, isolates were tested to assess resistance against the artificial gastric acid and bile juice. Viable LAB counts were significantly (p<0.05) affected by the acidity. At pH 2.0, the total declines in the initial bacterial counts were 4.52+/-0.07 log for S. thermophilus St-Body-1, >7.98+/-0.03 log for E. flavescens DU-10, >7.95+/-0.05 log for E. faecium DU-12, and 3.15+/- 0.06 log for L. amylovorus DU-21. Among the strains, L. amylovorus DU-21 was the only strain that had bile tolerance under simulated gastrointestinal conditions. In order to improve EPS production by L. amylovorus DU- 21, the influence of carbon source was studied. When glucose was used as a carbon source, EPS production dramatically increased to 17.19+/-0.28 g/l (p<0.05). The maximum cell growth (10.012+/-0.012 log CFU/ml) and EPS production (18.71+/-0.19 g/l) were achieved when 15 g/ l of glucose was employed as the carbon source.     

The passive permeability of the red blood cell in cations

The efflux of salt from human red blood cells suspended in isotonic sucrose plus low concentrations of salt, was measured under steady-state conditions. The relationship between the efflux and the log of the salt concentration can be fitted by two straight lines with a sharp inflection point, the steeper slope occurring at concentrations below 0.2 mM NaCl. The determining factor in the rate of efflux is the ionic strength rather than the specific monovalent cations or anions and the effects are completely reversible. With an increase in temperature, the effects of reduced ionic strength are more pronounced and the inflection point is shifted toward higher salt concentrations. An increase in pH leads to an increased efflux at a given ionic strength, but the size of the pH effect is small at low ionic strength. At a given pH, the data can be fitted by a simplified form of the Goldman equation suggesting that with reduction in ionic strength, the permeability remains constant until the inflection point is reached. At that ionic strength, a sharp reversible transition to a new permeability state occurs. The permeability increases with an increase in the external but not the internal pH.     

Inactivation of caliciviruses

The viruses most commonly associated with food- and waterborne outbreaks of gastroenteritis are the noroviruses. The lack of a culture method for noroviruses warrants the use of cultivable model viruses to gain more insight on their transmission routes and inactivation methods. We studied the inactivation of the reported enteric canine calicivirus no. 48 (CaCV) and the respiratory feline calicivirus F9 (FeCV) and correlated inactivation to reduction in PCR units of FeCV, CaCV, and a norovirus. Inactivation of suspended viruses was temperature and time dependent in the range from 0 to 100 degrees C. UV-B radiation from 0 to 150 mJ/cm(2) caused dose-dependent inactivation, with a 3 D (D = 1 log(10)) reduction in infectivity at 34 mJ/cm(2) for both viruses. Inactivation by 70% ethanol was inefficient, with only 3 D reduction after 30 min. Sodium hypochlorite solutions were only effective at >300 ppm. FeCV showed a higher stability at pH <3 and pH >7 than CaCV. For all treatments, detection of viral RNA underestimated the reduction in viral infectivity. Norovirus was never more sensitive than the animal caliciviruses and profoundly more resistant to low and high pH. Overall, both animal viruses showed similar inactivation profiles when exposed to heat or UV-B radiation or when incubated in ethanol or hypochlorite. The low stability of CaCV at low pH suggests that this is not a typical enteric (calici-) virus. The incomplete inactivation by ethanol and the high hypochlorite concentration needed for sufficient virus inactivation point to a concern for decontamination of fomites and surfaces contaminated with noroviruses and virus-safe water.