植物血凝素及淋巴因子激活的杀伤细胞体外抗肿瘤作用的MTT比色法分析

目的　检测植物血凝素及淋巴因子激活的杀伤细胞（ＰＨＡ－ＬＡＫ）的体外广谱抗肿瘤作用。方法 用ＭＴＴ比色法测定 ＰＨＡ－ＬＡＫ对体外培养的Ｋ５６２、ＭＧｃ８０－３、１４３ＴＫ－、ＨｅＬａ、ＬｏＶｏ等５种肿瘤细胞的杀伤活性。结果ＰＨＡ－ＬＡＫ对５种不 同组织器官来源的肿瘤细胞均有明显杀伤活性,在效靶比为７．５：１．０时,ＰＨＡ－ＬＡＫ对１４３ＴＫ－细胞的杀伤率可高达 ５７．３％,杀伤效应随效靶比增加而升高;但在效靶比为１５：１时,杀伤效应不随效靶比增加而增高数。结论　（１）来自健康献血 员的ＰＨＡ－ＬＡＫ对肿瘤细胞具非特异性杀伤活性,能较好解决传统过继免疫治疗中免疫效应细胞的数量和活性问题; （２）在一定的条件下,ＭＴＴ法用于检测免疫效应细胞的杀瘤作用时才具灵敏、可靠的优点。     

Interlaboratory Comparison as a Source of Information for the Product Evaluation Process. Case Study of Ceramic Tiles Adhesives

In this study, the results obtained by 19 laboratories participating in 2 editions of the interlaboratory comparison (ILC) determining 2 properties of ceramic tiles adhesives (CTAs), i.e., initial tensile adhesion strength and tensile adhesion strength after water immersion following EN 12004, were analyzed. The results show that participating laboratories maintain a constant quality of their work. The use of z-score analysis, under ISO 13528, allows for classifying 89.5% to 100% of laboratories as satisfactory, depending on the measurement’s kind and edition. The remaining laboratories are classified as questionable. The investigation of the predominant mode of failure of the CTA’s samples tested in the two editions shows significant differences. From the perspective of laboratories, the goal of the ILC has been achieved. From the standpoint of a manufacturer who evaluates a product’s properties when placing it on the market, the results indicate the necessity of a particular treatment of the product evaluation process because the variability of the obtained results is significant. It increases the possibility of the product failing to meet the assessment criteria verified by the construction market supervision authorities. The manufacturer must consider all possible variations in the risk analysis, including the ILC results, to improve the assessment process of CTAs.     

Implementation of a blood irradiation program at a community cancer center

BACKGROUND: Blood component irradiation is an accepted method of preventing transfusion-associated GVHD. Previous publications have largely focused on the technical aspects of the irradiation process itself, but relatively little attention has been paid to the details associated with the implementation of a blood irradiation program at the level of a community cancer center. STUDY DESIGN AND METHODS: An observational study was performed, detailing the specific operational, documentation, and quality assurance measures employed in providing a blood component-irradiation service within the institutional context of a community cancer center. RESULTS: The Montgomery Cancer Center irradiated 589 units of blood components in 1998 and 1999 to provide a local blood bank with an alternative for procurement of irradiated blood components while complying with applicable quality assurance and regulatory requirements. CONCLUSION: Blood component irradiation is within the scope of most well-equipped and adequately staffed community cancer centers. Establishment of a blood component irradiation program requires scrupulous physics and dosimetry support, both to ensure the quality of the irradiated component and to satisfy governmental agency regulatory requirements.     

A totally synthetic lipopeptide-based self-adjuvanting vaccine induces neutralizing antibodies against heat-stable enterotoxin from enterotoxigenic Escherichia coli

ST-based lipopeptide vaccine candidates were constructed in which ST was chemically synthesized and folded into the correct conformation prior to ligation to a module containing a T-helper cell epitope (T(H)) and the Toll-like receptor 2 (TLR2) agonist, S-[2,3-bis(palmitoyloxy)propyl]cysteine (P2C). Two different chemistries, thioether-based and oxime-based, were then used to ligate ST to the lipidated T(H) epitope. The enterotoxic activity of synthetic ST and the ST-based lipopeptide vaccines was determined in mice followed by an evaluation of immunological efficacy. The importance of the fine detail in chemical composition used in vaccine design was demonstrated by the findings that (i) the oxime-based vaccine exhibited little or no toxicity but the thioether-based vaccine, exhibited residual toxicity in suckling mice, (ii) although each of the synthetic vaccines generated specific anti-ST antibodies, it was the low titer antibodies induced by the oxime-based vaccine that demonstrated better neutralizing activity suggesting that the chemical linkage also affects the specificity of antibodies, (iii) the geometric arrangement of ST within a vaccine can profoundly affect the specificity and biological function of the antibodies that are elicited, and (iv) the lipopeptide-based ST vaccine candidate assembled using oxime chemistry induced a better neutralizing antibody response to ST when administered by the mucosal (intranasal) route.     

三氧化二砷对肺腺癌化学治疗敏感性的影响及其机制

目的　研究三氧化二砷 (As2 O3)对肺腺癌细胞生长过程及化学治疗 (简称化疗 )敏感性的影响。方法　应用四甲基偶氮唑蓝 (MTT)比色、免疫组织化学、流式细胞仪、逆转录 聚合酶链反应(RT PCR)等方法 ,观察不同浓度As2 O3 对人肺腺癌A549细胞株生长、化疗敏感性、细胞周期 ,及凋亡基因Fas/FasL、抗凋亡基因B淋巴细胞白血病 2 (bcl 2 )和多药耐药相关蛋白 (MRP)、肺耐药蛋白 (LRP)表达水平的影响。结果　 1、2 μmol/L的As2 O3 对人肺腺癌A549细胞株的生长抑制作用较弱 ,但能显著提高A549细胞对顺铂的敏感性 (P <0 .0 5)、提高A549在G1期细胞的比率 ,上调Fas、下调bcl 2及MRP、LRP的表达水平。 5μmol/L的As2 O3 对人肺腺癌A549细胞有一定的抑制作用 ,并可上调bcl 2、MRP、LRP的表达水平 ,但不能提高A549细胞对顺铂的敏感性。结论　低浓度的As2 O3 可能通过提高A549细胞在G1期的比率 ,上调Fas基因和下调bcl 2、MRP、LRP基因的表达水平 ,提高肺腺瘤细胞对化疗的敏感性     

The 21-aminosteroid U74389G prevents the down-regulation and decrease in activity of CYP1A1, 1A2 and 3A6 induced by an inflammatory reaction

In vivo, the 21-aminosteroid U74389G prevents the decrease in cytochrome P450 (P450) activity produced by a turpentine-induced inflammatory reaction (TIIR). To investigate the underlying mechanism of action, four groups of rabbits were used, controls receiving or not U74389G, and rabbits with the inflammatory reaction receiving or not U74389G. Hepatocytes were isolated 48h later and incubated for 4 and 24h with the serum of the rabbits. In vivo, the TIIR diminished CYP1A1/2 and 3A6 expression, and enhanced hepatic malondialdehyde (MDA) and nitric oxide (NO*) concentrations (p<0.05). U74389G prevented the increase in MDA, as well as the decrease in CYP1A1/2 amounts and activity, but increased CYP3A6 expression by 40% (p<0.05). In vitro, compared with serum from control rabbits (S(CONT)), incubation of serum from rabbits with TIIR (S(TIIR)) for 4 and 24h with hepatocytes from rabbits with TIIR (H(TIIR)) reduced CYP1A2 and CYP3A6 activity (p<0.05) and increased the formation of NO* and MDA. In rabbits with TIIR pretreated with U74389G, the S(TIIR+U) failed to reduce CYP1A2 activity or to increase MDA, although increased NO* and further reduced CYP3A6 activity. On the other hand, in hepatocytes harvested from rabbits with TIIR pretreated with U74389G, S(TIIR) did not decrease CYP1A2 activity and did not enhance MDA, but still increased NO*. In vitro, the reduction of CYP1A2 and CYP3A6 activity by S(TIIR) is not associated to NF-kappaB activation. In conclusion, U74389G prevents CYP1A1/2 down-regulation and decrease in activity by a double mechanism: hindering the release of serum mediators and by averting intracellular events, effect possibly associated with its antioxidant activity. On the other hand, U74389G up-regulates CYP3A6 but inhibits its catalytic activity.     

Sphingomyelinase in cultured skin fibroblasts from normal and Niemann-Pick type C patients

The spingomyelinase activities of extracts of normal cultured skin fibroblasts were compared with those obtained from Niemann-Pick disease Type A and B patients, and from a number of patients with a provisional clinical diagnosis of Niemann-Pick disease Type C. Even though fibroblasts from Type A and B patients were shown to be clearly deficient (<5% residual activity) the activity in Type C fibroblasts varied from approximately 50% of the lowest control value to normal activity.
Isoelectric focussing of extracts of normal cultured skin fibroblasts on polyacrylamide gels revealed the presence of sphingomyelinase heterogeneity. However, no characteristic change in the behaviour of the enzyme in corresponding extracts from Niemann-Pick Type C cells was observed, suggesting that, if the defect in this condition is expressed in fibroblasts, it does not manifest biochemically in the appearance or disappearance of a specific sphingomyelinase isoenzyme.
Our data suggest that the heterogeneity observed in fibroblast extracts may simply reflect an interaction of the enzyme either with itself or with other hydrophobic components present in the cellular extracts.     

Distribution of glucose-6-phosphatase and 5-nucleotidase in the digestive system of two teleost fishes.

The distribution and histochemical localization of G6Pase and 5-nucleotidase in the different parts of the alimentary canal of two teleost fishes, Heteropneustes fossilis and Barbus sophore have been studied. The major sites of activity of the two enzymes are intestinal mucosa and liver. G6Pase is localized in the cytoplasm of the absorptive cells of the intestinal mucosa while 5-nucleotidase is present in the cytoplasm as well as nucleus and cell membrane. In the intestine, the anterior portion shows more stronger activity than in the middle and posterior portions. Mild activity is also noticed in the mucosa and gastric glands of the stomach. G6Pase activity is stronger than 5-nucleotidase activity in all the portions. Weak 5-nucleotidase activity is found in the submucosal connective tissue and the nuclei of the intestine. The goblet cells, muscularis abd serosa are negative in all the portions. G6Pase activity is stronger in the herbivorous fish Barbus sophore than in the omnivorous form Heteropneustes fossilis. In the liver, stronger activity of two enzymes is localized in the hepatocytes surrounding the sinusoids. Connective tissue and endothelial lining are negative.     

Motor unit number estimation (MUNE): Where are we now?

Estimation of the number of motor units (MUNE) in specific muscles is important to monitor outcome in progressive neurogenic disorders, with potential application in clinical trials. However, in spite of recent developments to identify the most convenient technique for MUNE, all current methods have individual shortcomings. It is essential to understand the scientific concepts that support MUNE and the many methods already proposed. In particular, the core role of the compound muscle action potential (CMAP) size in the estimation process is undervalued. Operator-dependent variation in CMAP amplitude or area is the main factor underlying MUNE stability. At present, MUNIX, as standardized in many centers, is probably the best accepted method. Future developments should be based on full understanding of the neurophysiological concepts underlying the MUNE calculation, in order to find a quick, well-tolerated, operator-friendly and reliable method to apply more universally in clinical practice.