Detection of IgG antibody affinity in suspected cases of measles and rubella in Beijing / 中华微生物学和免疫学杂志

Objective:To investigate the causes of immune failure in the population with high vaccination rate of measles and rubella vaccine in Beijing by detecting the IgG antibody affinity in suspected cases of measles and rubella.Methods:Serum samples of 276 suspected cases of measles and rubella were tested for IgM and IgG antibodies by enzyme-linked immunosorbent assay (ELISA). The affinity of IgG antibody was detected, and the relative affinity index was calculated.Results:Among the 276 suspected cases, 104 were measles and 108 were rubella. Six measles cases had vaccination history and were caused by primary immunization failure ( n=3) and secondary immunization failure ( n=3). Twelve rubella cases had vaccination history and were due to primary immunization failure ( n=4) and secondary immunization failure ( n=8). Specific high-affinity antibodies were detected in nine measles cases and seven rubella cases without vaccination history, which indicated that these cases were reinfected. In the cases without measles or rubella, other pathogenic infections including mixed infections were detected, which were mainly caused by EB virus. Conclusions:Both primary and secondary immunization failure occurred in the population with immunization history. Reinfection was found in the patients who had not received vaccination against measles or rubella. Other pathogenic infections were existed among the cases without measles or rubella. Thus, misdiagnosis was responsible for the increased proportion of measles and rubella patients with immunization history in suspected cases in recent years. Full-course vaccination was conducive to produce high-affinity antibodies against measles and rubella. A supplementary vaccination campaign should be launched to consolidate the immune barrier against measles and rubella in key population or high-risk population, aiming to block the circulation of measles virus and achieve the goal of eliminating measles.

Human amniotic fluid influenced by different sampling methods during 1H NMR-based metabonomics analysis / 生物医学工程学杂志

To assess the influence of different sampling methods on Human Amniotic Fluid (HAF) during metabonomics analysis, and to establish a metabolite profile database for normal human amniotic fluid, four experimental groups (the group of freeze-drying, of freeze-thawing, of storage at -20 degrees C, and of keeping in room temperature) and a control group were investigated by use of 1H-NMR spectroscopy, respectively; the data of H-NMR spectroscopy was treated by principal components analysis (PCA). The results showed that, by comparison with the control, there were distinct differences in the experimental groups except the group of storage at -20 degrees C. Therefore, It is possible to use 1H-NMR-based metabonomics technique for analysis of HAF; moreover, during the tests, careful treatments of HAF should be institued to minimize the influence on the samples.

Impact of experimental conditions on the results of NMR-based metabononmics study / 生物医学工程学杂志

In the process of preparing and analyzing the metabonomics samples, there are lots of influential factors such as sample individual differences, environmental factors and human factors. Here we report a study on 3 healthy male SD rats of different samples carried out by different operators (n=4). It was a two-way experiment designed to explore the impact factors and lay the foundation for future experiments. The cluster analysis was employed in comparing 12 samples. The results showed that the differences of rats between the sample groups had a certain influence on the metabonomics data, and there was relatively little variability between the 4 operators. That is to say, whilst the sample are rather different from one another, a given sample is generally quite similar to itself in metabonomics study.

Investigation on Dexamethasone induced cleft palate in embryos of C57BL/6J mice by 1H-NMR pattern recognition of metabolites group / 生物医学工程学杂志

Metabonomics approach is a science that systematically studies the regularity of changes of metabolites and reveals the nature of metabolic activities of the lives in the dynamic process of metabolism. In this study, pregnant C57BL/6J mice were randomly divided into two groups with 15 mice in each. The ones in the experimental group were intraperitoneally injected with Dexamethasone and the others in the control group with isotonic Na chloride from 10th to 12th day of gestational period. On 17.5th day, all the mice were executed. The livers were extracted and prepared into aqueous soluble liver tissue extracts. The technology of nuclear magnetic resonance (NMR) was used to detect the endogenous small molecule metabolites. Finally, through the method of principal component analysis (PCA), changes of metabolites ingredients could be determined. The experimental results showed that there was significant difference in PCA scores plot between the two groups. Furthermore, the difference was in line with that of incidence of cleft palate in the embryos between the two groups. Therefore, metabonomics results can be used to reflect the changes of metabolites group interfered by Dexamethasone in the course of pregnancy of C57BL/6J mice and this method opens up a new way for further study of pathogenic mechanism of cleft lip with or without palate.

Microdiffraction measurements of natural tooth by high resolution X-ray diffraction equipment / 生物医学工程学杂志

The main mineral component of natural tooth was determined as calcium apatite many years ago; most of them exist in the form of hydroxyapatite with different crystallites. If a tooth decayed, the crystalline of hydroxyapatite would be changed and decomposed. In our experiment, a natural tooth with caries was measured by high resolution XRD equipment: X'pert Pro. Three spots which included normal enamel, normal dentin and caries tissue were analyzed. The results showed that tooth was a kind of biological mixed crystal composed of many crystal phases, the main crystal phase was hydroxyapatite. From normal enamel to normal dentin and to caries tissue, the length of the a-axis of hydroxyapatite crystallite increased, the length of the c-axis of hydroxyapatite crystallite remained unchanged. The crystal sizes were: normal enamel D002 = 27.600 nm; normal dentin D002 = 16.561 nm; caries tissue D002 = 13.163 nm. Crystallinity: normal enamel>normal dentin>caries tissue. According to our experiment, tooth could be conveniently studied by high resolution microdiffracion XRD equipment.