动态比浊法测定13N-氨水的细菌内毒素含量

目的建立快速准确测定PET示踪剂13N-氨水中的细菌内毒素含量的方法.评估动态比浊法在半衰期短的PET临床用药中的实用价值. 方法通过制备5.0 Eu/ml、0.5 Eu/ml、0.05 Eu/ml的标准内毒素溶液进行测定,制出LogT-LogC 标准曲线图,根据样品的反应时间代入曲线方程得出13N-氨水中细菌内毒素的含量. 结果标准曲线在标准内毒素浓度范围为0.05Eu/ml～5.0Eu/ml时线性关系良好(γ=0.99969),精密度和样品阳性对照的回收率都比较满意.样品阳性对照的回收率一般为75%～120%,阳性样品回收率越接近100%,则表明此次检验的准确性越高.此方法最低检测范围为0.05Eu/ml. 结论与传统内毒素检测方法凝胶法相比,动态比浊法具有快速、准确、有效、定量地测定13N-氨水中的细菌内毒素含量的优势.     

动态比浊法测定^13N—氨水的细菌内毒素含量

目的：建立快速准确测定PET示踪剂^13N-氨水中的细菌内毒素含量的方法。评估动态比浊法在半衰期短的PET临床用药中的实用价值。方法：通过制备5．0Eu/ml、0．5Eu/ml、0．05Eu/ml的标准内毒素溶液进行测定，制出LogT-LogC标准曲线图，根据样品的反应时间代入曲线方程得出^13N－氨水中细菌内毒素的含量。结果：标准曲线在标准内毒素浓度范围为0．05Eu/ml-5.0Eu/ml时线性关系良好（γ＝0．99969),精密度和样品阳性对照的回收率都比较满意。样品阳性对照的回收率一般为75％－120％，阳性样品回收率越接近100％，则表明此次检验的准确性越高。此方法最低检测范围为0．05Eu/ml。结论：与传统内毒素检测方法凝胶法相比，动态比浊法具有快速、准确、有效、定量地测定^13N－氨水中的细菌内毒素含量的优势。     

细菌内毒素定量检测的影响因素分析及对策

细菌内毒素检查法(简称鲎试验)是利用鲎血变形细胞制成的鲎试剂与微量内毒素产生凝集反应的现象,作为判断样品中细菌内毒素含量是否符合规定的一种方法。其基本原理是利用微量内毒素激活、活化鲎试剂中的C因子和B因子,使凝固酶原转化为凝固酶,成为凝胶样的凝固蛋白,具有简便、迅速、特异性高及灵敏度高等优点。中国药典1995年板已收载,并对鲎试剂、内毒素标准、试验程序、判断标准等作了规定。 我科引进的EDS-99细菌内毒素检测系统可进行动态比浊法和显色基质法检测内毒素,分别利用细菌内毒素与鲎试剂形成凝胶过程中的浊度变化以及反应过程中产生的凝固酶使特     

动态比浊法鲎试验定量分析催化剂的细菌内毒素

目的通过定量检测催化剂的细菌内毒素含量,为控制药品质量及筛选最佳生产工艺提供参考。方法应用动态比浊法及凝胶法鲎试验对催化剂的细菌内毒素进行定量和半定量检测。结果动态比浊法鲎试验定量检测了4批催化剂,其原液(原瓶加5.0mL水)细菌内毒素含量依次为20EumL-1-50EumL-1不等,样品在256倍稀释时其添加内毒素(2.0EumL-1)的回收率在75%-125%之间,此时对鲎试验反应无干扰作用,与凝胶法的检查结果一致。结论动态比浊法鲎试验可用来定量检测催化剂的细菌内毒素含量。     

过滤和离心对热原实验影响的初步研究

目的了解医疗器械和生物材料的浸提液能否过滤或离心后再进行热原实验。方法采用《中国药典》2010年版(二部)附录检测细菌内毒素的动态浊度法,进行定量测定浓度为0.2 EU/mL的原液中的细菌内毒素含量,并在过滤和离心后分别测定溶液中细菌内毒素的含量。结果溶液中的细菌内毒素含量过滤后大大减少,甚至小于0.040 EU/mL。离心则不会影响溶液中的细菌内毒素含量,与原液中含量相近,为0.260 EU/mL。结论为除去医疗器械和生物材料的浸提液中的悬浮颗粒,可以离心后再进行热原实验。     

鲎试验测定注射用头孢雷特中细菌内毒素的方法学研究

目的：检测注射用头孢雷特中的细菌内毒素。方法：供试品干扰试验后,采用凝胶鲎试验对样品中细菌内毒素进行检测。结果：三批注射用头孢雷特浓度为2mg·ml^-1对细菌内毒素的检测无干扰作用,所测样品的头孢雷特细菌内毒素含量均小于0.5EU.mg-1。结论：所建立方法检查注射用头孢雷特中的细菌内毒素可行。     

两种方法测定灯盏细辛注射液中细菌内毒素含量

目的：建立灯盏细辛注射液细菌内毒素的定性和定量检测方法。方法：按照《中国药典》2010年版一部附录细菌内毒素检查法项下凝胶法和动态浊度法对灯盏细辛注射液进行试验。结果：灯盏细辛注射液注射液稀释25倍（凝胶法）和200倍（动态浊度法）后对鲎试剂及内毒素反应无干扰作用。结论：用凝胶法和动态浊度法检测灯盏细辛注射液中细菌内毒素的含量是可行的。     

鲎试验测定复方氨基酸(15)双肽(2)注射液中的细菌内毒素

目的:检测复方氨基酸(15)双肽(2)注射液中的细菌内毒素。方法:供试品干扰试验后,采用凝胶鲎试验对样品中的细菌内毒素进行检测。结果:三批复方氨基酸(15)双肽(2)注射液稀释至28倍时对细菌内毒素的检测无干扰作用,所测样品的细菌内毒素含量均小于7 EU.ml-1。结论:所建立方法检查复方氨基酸(15)双肽(2)注射液中的细菌内毒素可行。     

鲎试验测定长链脂肪乳注射液中细菌内毒素的方法学研究

目的：确定长链脂肪乳注射液中细菌内毒素鲎试验检查法的可行性。方法：供试品干扰试验后，采用凝胶鲎试验对样品中细菌内毒素进行检测。结果：三批长链脂肪乳注射液稀释至2倍时对细菌内毒素的检测无干扰作用，所测样品的细菌内毒素含量均小于0．5EU·ml^-1。结论：所建立方法检查长链脂肪注射液中的细菌内毒素可行。     

脱细胞粘膜基质的热原试验研究

目的 考察脱细胞粘膜基质的热原试验方法的可行性。方法 依据《中华人民共和国药典》2010年版二部附录XIE细菌内毒素检查法和ISO10993.12 Biological evaluation of medical devices-Part 12:Sample preparation and reference materials,使用离心法消除样品浸提液的悬浮颗粒,使用动态浊度法验证离心条件是否会影响浸提液中细菌内毒素的检测。依据《中华人民共和国药典》2010年版三部附录XIID热原检查法检测脱细胞粘膜基质的热原试验是否合格。结果 本实验中采用的离心条件不会影响样品浸提液中细菌内毒素的检测,热原试验合格。结论该产品可以采用此离心条件进行热原检测。     

Endotoxin and bacterial contamination of dialysis center water and dialysate; a cross sectional survey

The bacterial and endotoxin levels of purified water and effluent dialysate were examined in a cross section of dialysis centers in the central United States. All samples were collected within a four-hour drive of the University of Louisville and were collected, processed and analyzed by our personnel, to eliminate variability in sample handling. A medium capable of higher bacteria recovery from aqueous environments than those ordinarily employed in clinical assays was used. Endotoxins were determined by a quantitative colorimetric assay. By the more sensitive bacterial assay 53% of the centers had bacterial counts above the AAMI standard of 200 colony-forming units per ml (CFU/ml) for water and 35% of the centers had bacterial counts above the 2000 CFU/ml standard for dialysate in at least one sampling period. The samples showed 35% and 19% of water and dialysate above the standards, respectively. While there are no standards for endotoxin concentrations in water used to prepare dialysate, 2% of the centers had endotoxin levels in their water above five endotoxin units per ml (5 EU/ml = 1 ng/ml in our assay kit), the limit set by the AAMI standards for reprocessor water. Both bacterial and endotoxin levels tended to be elevated in dialysate, with the highest levels of endotoxin in dialysates posing an obvious potential risk when high-flux dialyzers are used.     

肾康注射液细菌内毒素检查法的研究

目的建立肾康注射液细菌内毒素检查方法,以期能够替代家兔热原法控制产品的热原,达到快速尧高效尧可靠尧简便的 目的遥方法按叶中国药典2015 年版四部曳通则1143 细菌内毒素检查法进行试验遥采用两个不同厂家的的鲎试剂,对7 个不同 批次的样品开展干扰试验,确定最小不干扰稀释倍数,并对样品进行了细菌内毒素检查遥结果供试品4倍稀释液无干扰作用, 细菌内毒素限值定为1.0 Eu/ml遥结论用细菌内毒素检查法代替热原法是可行的遥     

双黄连注射液细菌内毒素检查法的应用

目的:建立双黄连注射液的细菌内毒素检查方法.方法:按照《中国药典》2005年版附录细菌内毒素检查法进行试验.结果:双黄连注射液对鲎试剂与内毒素反应无干扰作用.结论:双黄连注射液采用细菌内毒素检查方法可靠,简单可行,可以考虑代替热原检查.     

Plasma endotoxin assay by supersensitive reagent for the diagnosis of gram-negative bacteremia

With a novel supersensitive reagent, we evaluated the utility of measuring plasma endotoxin level for the rapid and sensitive diagnosis of gram-negative bacteremia. Subjects were 112 febrile(more than 38 degrees C) patients suspected of having bacterial infection and 170 samples were collected. Venous blood was obtained aseptically before administering antibiotics. Blood culture and endotoxin assays were performed simultaneously with these materials. Plasma endotoxin levels were positive in 64 samples when the cut off index was postulated at 0.35 pg/ml, while only 5 samples when the cut off index was postulated at 5 pg/ml. When the cut off index was at 0.35 pg/ml, sensitivity was 86%, while it was 14% when the cut off index was 5 pg/ml. Gram-negative rods(GNR) were detected by blood culture in 14 cases and the average period to detect GNR was 14.8 hours. The presence of circulating viable bacteria is diagnosed by blood culture, but because of the serious consequence of bacterial sepsis, treatment is initiated even in the absence of an identifiable organism. Since plasma endotoxin level can be assayed in about 2 hours, it will be more practical if we adjust the cut off index according to the clinical situation.     

Detection of endotoxin in the plasma of patients with gram-negative bacterial sepsis by the Limulus amoebocyte lysate assay.

A total of 120 Limulus amoebocyte lysate (LAL) determinations were made on plasma obtained from normal, healthy human blood donors. Results demonstrated a mean endotoxin level in blood of 0.02 to 1.57 pg/ml. The amount of Escherichia coli endotoxin added to human plasma samples can be quantitated by both nephelometry and turbidimetry. Endotoxin-spiked samples were shown to be significantly different from unspiked samples. When plasma samples were collected from 45 patients hospitalized at three centers, a strong association was demonstrated between a positive Limulus amoebocyte lysate assay and a septic condition. Sensitivity, specificity, and false-positive and false-negative rates for the Limulus amoebocyte lysate assay as a diagnostic test for gram-negative bacteremia were estimated.     

Effect of methylprednisolone on bacterial clearance and endotoxin liberation during experimental sepsis induced by gram-negative bacteria.

To determine the effect of methylprednisolone administration on the clearance of bacteremia and the release and clearance of endotoxin during antibiotic therapy of gram-negative bacterial sepsis, Escherichia coli K1 sepsis was induced in paired rabbits. Moxalactam and either methylprednisolone or placebo were administered to infected rabbits 1.5 h after intraperitoneal administration of live bacteria. Serial blood samples were obtained for quantitation of bacteremia and endotoxemia, arterial blood gases, and complete blood count. Arterial blood pressure, heart rate, and core body temperature were also monitored. There were no significant differences between the methylprednisolone-treated and placebo-treated groups in either the levels of bacteremia or endotoxemia or in the physiologic, metabolic, or hematologic parameters that were measured. We conclude that methylprednisolone administration has no acute effect on bacterial clearance or on the kinetics of endotoxin release and clearance during antibiotic therapy of gram-negative bacterial sepsis in this experimental model.     

Clearance of endotoxin from blood of rabbits injected with staphylococcal toxic shock syndrome toxin-1.

This study was undertaken to examine some of the properties of staphylococcal toxic shock syndrome toxin 1 (TSST-1) with regard to the clearance of endotoxin from blood. The concentration of endotoxin in blood was measured by using a chromogenic limulus test and modified perchloric acid method. When TSST-1, which produces fever in rabbits, was injected (100 ng/ml or 100 micrograms/ml per kg) intravenously (i.v.) into the animals, no measurable level of endotoxin was detected in the blood. In control animals, which were given 5 micrograms of endotoxin per ml per kg i.v., endotoxin could be detected in the blood at rapidly declining levels. These results suggested that TSST-1 might not lead bacterial endotoxin from other body sites into the blood. When the animals were given TSST-1 (1 to 100 ng/ml per kg) i.v. and then endotoxin (5 micrograms/ml per kg) i.v. 4 h later, endotoxin was detected in the blood at a high level, depending on the dose of TSST-1 injected. These results showed that TSST-1 inhibited the clearance of endotoxin in the blood; this clearance is thought to be mainly done by the reticuloendothelial system. In the animals given TSST-1 (100 ng/ml per kg) and endotoxin (5 micrograms/ml per kg) simultaneously, the endotoxin level in the blood was found to be higher than that in control animals given endotoxin only but lower than that in the animals given TSST-1 and then endotoxin at the same doses.     

Development of fever in the newborn lamb.

Newborn lambs do not become febrile in response to intravenous (iv) bacterial endotoxin in moderate doses. Newborn lambs were tested to see if they could become febrile to large doses of endotoxin or to endogenous pyrogen. At 5 h of age lambs do not become febrile to relatively large doses of endotoxin or to endogenous pyrogen, but rather become hypothermic. At 32 h and all subsequent times, fevers could be elicited. Onset time of fevers in lambs was short initially and gradually lengthened over 9 days, at which time it was similar to the onset time of the adult fever. With respect to the febrile response, newborn lambs showed varying degrees of tolerance after 10 days of daily injections of endotoxin, as compared to the ewe which becomes tolerant in 2 or 3 days.     

Evaluation of hygiene and safety controls for on-line paired hemodiafiltration (PHF)

BACKGROUND: On-line hemodiafiltration is gaining popularity due to increasing evidence of clinical benefits however it also requires strict attention to hygiene and safety as notable quantities of liquid are reinfused into the patient. Although most centers are improving their attention to water quality, a frequent concern is the inadvertent or accidental contamination of water and whether the redundant safety controls are sufficient to protect the patient. In the present study, in order to simulate a worst-case safety condition, we tested in vitro the reliability of paired hemodiafiltration - (PHF), under low, moderate and high bacterial contamination of the water supply. Tests were performed using various bacterial concentrations (range 85-2000 cfu/mL) of Pseudomonas Aeruginosa. Samples were analyzed from different sites throughout the entire on-line hemodiafiltration circuit for bacteria endotoxin, fungus and ability to stimulate whole blood production of TNFalfa. RESULTS: In the in vitro contamination study, with the three bacterial concentrations tested at various points of the circuit, bacteria were below the level of detection and endotoxins were < 0.01 UE/mL. Addition of dialysate samples taken after the first stage of microfiltration, as well as after the first and second stage of ultrafiltration and incubated with whole blood were not associated with stimulated production of TNFalfa . CONCLUSIONS: PHF appeared to be a safe and feasible method for on-line hemodiafiltration even in the unforeseen presence of bacterial contamination of the feed water or water distribution system.