ABSTRACT
Early diagnosis and intervention is an important way to delay the progress of Alzheimer′s disease (AD).Compared with cerebrospinal fluid, blood sampling is not invasive and easy to be obtained in clinic practice.In this study, the serum samples of 9 controls, 10 AD and 12 mild cognitive dysfunction (MCI) patients were analyzed and compared through one by one analysis to screen potential markers for AD diagnosis.The experimental results showed that VGFYESDVMGR of α-2-macroglobulin peptide was closely related to the late stage of AD disease, and the large amount degradation of apolipoprotein C-Ⅲ, histone H1.2 and histone H1.4 was significantly related to early stages of AD progression.The characteristics of serum peptidome were different for the early and late AD, and these four proteins may be used as potential biomarkers of AD disease.In addition, the obvious ladder sequence characteristic was observed for apolipoprotein C-Ⅲ and histone H1, which could partly explain why the peptides distribution in different samples was somewhat contingent.On the contrary, the distribution at protein level was more stable.Finally, it was confirmed that the peptides of proteins such as fibrinogen α-chain, thymosin β-4 and patchy proteins were the dominant peptides in all serum samples.Overall, this study showed that the method of using serum peptidomics to diagnose AD was possible.The results may provide evidence and references for the large-scale clinical validation of AD.
ABSTRACT
By using the high resolution mass spectrometer TripleTOF 5600 , three kinds of standard proteins including bovine serum albumin ( BSA) , ovalbumin ( OVA) and lysozyme C( LYZC) were analyzed, and the correlationship between the ion intensity of mass spectrometry and the relative content of protein sample was investigated. The protein samples were digested by trypsion and diluted to 1-1024 fmol in 7 μL. The ion counts per second ( cps) were used to stand for the amounts of proteins and peptides. Then the correlation between sum of ion intensity ( cps) of all the peptides, number of peptides detected and the amount of proteins was investigated. By comparing the change of values of the same sample in three parallel experiments, a linear relationship between these indexes and the amount of proteins within 1-1024 fmol was found when the cps was more than 1000. Usually, the maximal ion intensity was no more than 1. 5 times of the minimum value for same peptide in triplicate experiments, which suggested that the 3 times or more change of ion intensity was the minimum threshold to determine the differences of proteins amounts in different samples. This study provides a relative quantitative analysis method using qualitative data of high resolution and high scan speed mass spectrometry, which can quickly and easily provide reference for biological and medical research.
ABSTRACT
One of significant characteristics of matrix-assisted laser desorption/ionization tandem time of flight mass spectrometry ( MALD-TOF/TOF ) high-energy collision induced dissociation ( CID ) is to produce abundant immonium ( IM ) ions that can offer a wealth of information for peptide composition. However, MALDI-TOF/TOF is generally used for routine protein identification based on database search or de novo sequencing combined with chemical derivation. Consequently, the characteristics of IM ions may not be fully explored and utilized. Here, a total of 239 MS/MS spectra are used to explore the fragmentation features of IM ions with MALDI TOF/TOF spectrometry and their application for peptide identification. IM ion signals can be observed for 14 kinds of amino acids including histidine etc with a positive rate of more than 50%. We have found that the chemical nature of the amino acids and position effects are the two main factors that affect the intensity of fragment ions. In addition, false positive IM ions are mainly derived from Arg, Lys, Leu and Ile residues or mixture peptides. Besides the compositional information, partial sequence information can also be obtained by a comparison of the relative intensity of IM ions. These findings are helpful when performing manual interpretations and could be useful for improving current peptide search algorithms.
ABSTRACT
Objective To evaluate the effect of the fast control scheme of schistosomiasis.Methods The fast control scheme of schistosomiasis was carried out,and the scheme mainly included dusting molluscicide,rapid immunodiagnosis screening and chemotherapy with praziquantel,environment modification,health education,etc.The control effects of the scheme were observed longitudinally.Results There were no infected snails found after the scheme was implemented from 2005 to 2008.The densities of living snails dropped from 1.48 snails/0.1 m~2 in 2004 to 0.71 snails/0.1 m~2 in 2008.The areas with snails dropped from 43.13 hm~2 in 2004 to 33.68 hm~2 in 2008.The infection rates of residents and cattle dropped to 0 in 2008.Conclusion The fast control scheme of schistosomiasis can control schistosomiasis fast.
ABSTRACT
Objective To evaluate the training effect of Public health emergencies.Methods The testing materials from the training course on public health emergencies in longgang district of Shenzhen in 2009 were analyzed.Results Of all 162 students,98.2% considered the training course was completely important,97.3% students considered the training was very necessary,after training,80% students considered the master degree of related knowledge was improved,93.8% students considered the effect of training on the role of dealing with public health emergency training was very well or average.Conclusions Emergency response training for dealing with the public health emergencies is very effective and completely necessary.