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ABSTRACT: New hydrophilic monolithic columns were prepared with {[3-(methacryloylamino) propyl] dimethyl(3-sulfopropyl)ammonium hydroxide inner salt (SPP)} as monomer, pentaerythritol triacrylate (PETA) as crosslinking agent, azobisisobutyronitrile (AIBN) as initiator with two different porogens consisting of ethanol/ethylene glycol and methanol/1 ,4-butanediol, separately. In order to obtain monolithic columns with satisfactory efficiency, electroosmotic flow (EOF) velocity and permeability, the contents of the polymerization mixture were investigated and optimized. The performances of the two columns were compared in the permeability and separation performance. It was found that the monolithic column prepared with ethanol/ ethylene glycol had a better column efficiency and selectivity than that with methanol/1,4-butanediol, but was inferior to the latter in permeability. The effect of salt concentration (from 10 to 70 mmol/L ammonium formate) on the retention of nucleosides was investigated. It was observed that the retention factors of these nucleosides increased at first and then decreased. The columns were used in capillary liquid chromatography (cLC) and pressurized capillary electrochromatography (pCEC) for the separation of a test mixture of amines, phenols and nucleosides separately, and satisfactory separations for these samples were achieved. The column used in pCEC system showed better separation and higher speed of the mixture consisted of phenols and nucleosides compared to those used in cLC system.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 05/2012; 30(5):487-94.
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Xiaoying Zheng,
Mingming Su,
Lijun Pei,
Ting Zhang,
Xu Ma,
Yunping Qiu,
Hongfei Xia,
Fang Wang,
Xiaojiao Zheng, Xue Gu,
Xinming Song,
Xin Li,
Xin Qi,
Gong Chen,
Yihua Bao,
Tianlu Chen,
Yi Chi,
Aihua Zhao,
Wei Jia
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ABSTRACT: Neural tube defects (NTDs) are one of the most common types of birth defects, affecting approximately 1 of every 1000 pregnancies in the United States and an estimated 300 000 newborns worldwide each year. The metabolic signature of pregnant women with NTDs in offspring has not previously been characterized. In this paper, we report a profiling study that characterized the serum metabolome of 101 pregnant women affected with NTDs in offspring in comparison with 143 pregnant women with normal pregnancy outcomes in Lvliang prefecture, the area with the highest birth prevalence of NTDs in China. A serum metabonomic study was also conducted to identify significantly altered metabolites associated with di-n-butyl phthalate (DBP)-induced teratogenesis in mice. The metabolic signature of NTD in pregnant women is characterized by the impaired mitochondrial respiration, neurotransmitter γ-aminobutyric acid, and methionine cycle. Of interest, consistent findings from DBP-induced teratogenesis in mice demonstrated increased succinate and decreased fumarate, suggesting an inhibited succinic dehydrogenase implicated in the defective mitochondria. The characteristic disruption of maternal metabolism offers important insights into metabolic mechanisms underlying human NTDs as well as potential preventive strategies.
Journal of Proteome Research 09/2011; 10(10):4845-54. · 5.11 Impact Factor
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ABSTRACT: A 2-D separation platform was constructed using micro strong cation-exchange liquid chromatography (μ-SCXLC) and reversed-phase pressurized capillary electrochromatography (RP-pCEC) for the analysis of complex samples. Samples were fractionated by the first-dimension μ-SCXLC with a linear solvent gradient and then injected into the second-dimension RP-pCEC for further separation. The μ-SCXLC/RP-pCEC 2-D system with three separation mechanisms, namely strong cation-exchange, reversed-phase chromatography and electrophoresis, provided high selectivity, high resolution and high peak capacity compared to one-dimensional chromatographic approaches. Separation effectiveness of this 2-D system was demonstrated by the analysis of different kinds of complex samples, such as traditional Chinese medicine Cortex Phellodendri, bovine serum albumin (BSA) tryptic digest and real serum tryptic digest. A theoretical peak capacity of approximately 1200 was achieved, which proves its promising potential for the separation and analysis of complex samples.
Journal of Separation Science 03/2011; 34(9):1027-34. · 2.73 Impact Factor
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ABSTRACT: The application of pressurized capillary electrochromatography (pCEC) coupled with ultra violet (UV) detection has been investigated for the production of global metabolite profiles from human plasma, and its capabilities of classifying pancreatic cancer patients. The pCEC separation of plasma samples was performed on a RP column with gradient elution. The applied voltage, detection wavelength and type of acid modifiers on separation of plasma samples were optimized with pooled quality control (QC) sample. The stability and the repeatability of the methodology were also determined by the repeat analysis of QC sample. The effects of different scaling methods on the results of orthogonal partial least-squares discrimination analysis (OPLS-DA) based on pCEC-UV data set were also investigated. The results of the current study clearly showed the different phenotypes of metabolites of pancreatic cancer patients and healthy controls based on pCEC-UV plasma profiles. OPLS-DA data are shown to provide a valuable means of convenient classification. This work indicated that pCEC-UV method can be used as a cost-effective and information-rich, while relatively simple and inexpensive approach for plasma profiling on disease metabolomics studies.
Electrophoresis 02/2011; 32(3-4):340-7. · 3.30 Impact Factor
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ABSTRACT: A novel on-line 2-D system was developed for peptide and protein mapping. The system combines capillary IEF (cIEF) with pressurized CEC (pCEC) using a micro-injection valve as the interface. Sample fractions, which were focused and separated in the first-dimension cIEF based on their differences in pIs, were electrically mobilized and further successively resolved by their differences in size, hydrophobicity, and electrophoretic mobility in the second-dimension pCEC. In the presented system, the valve interface was free of the external electric field in two dimensions for the purpose of stabilization, safety, and facilitating manipulation. In the first dimension, cIEF separation was executed by a one-step method to simplify the operation procedure. Moreover, a home-made electrical decoupler was introduced to isolate the micro-injection valve from the cIEF electric field. For the second dimension, taking advantage of the combination of hydrodynamic flow with EOF, reversed-phase pCEC not only offers on-column refocusing the effluent fractions, but also brings enhanced separation resolution and elution speed. Separation effectiveness of this 2-D system was demonstrated by the analysis of tryptic digest of BSA and human red blood cell lysate. A theoretical peak capacity of approximately 24,000 has been achieved for BSA digest, which proves its promising potential for the application in proteomics.
Electrophoresis 01/2011; 32(2):230-7. · 3.30 Impact Factor
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ABSTRACT: Pressurized capillary electrochromatography (pCEC) combines capillary electrophoresis (CE) with high performance liquid chromatography (HPLC), resulting in high separation efficiency, high selectivity, high resolution and fast speed. In addition, it provides a solvent gradient capability. Based on pCEC, a two-dimensional chromatography was constructed using micro strong cation exchange liquid chromatography and reversed phase pressurized capillary electrochromatography (micro-SCXLC/RP-pCEC) for the analysis of Cortex Phellodendri extract. A sample was separated by the first dimensional SCX column with a linear salt gradient elution into 11 plugs. Each plug was collected and injected into the second dimensional RP-pCEC column with a linear gradient for further separation. Compared with one-dimensional liquid chromatography, it has higher resolution and larger peak capacity. The two-dimensional chromatographic system is suitable for the separation and analysis of complex samples.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 03/2010; 28(3):226-30.
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ABSTRACT: The hydrophilic monolithic column was prepared in 100 microm i. d. capillary in situ using ethylene dimethacrylate as crosslinker, butyl methacrylate and 3-[dimethyl-[2-(2-methyl-prop-2-enoyloxy) ethyl] azaniumyl] propane-1-sulfonate as monomers. In the study, the hydrophilic interaction behavior of the monolithic column was demonstrated. The application of the column in pressurized capillary electrochromatography (pCEC) for the separation of melamine with ultraviolet detection has been studied. The effects of the composition of mobile phase, pH value, the concentration of the buffer, the flow rate of pump and voltage were investigated. The optimum separation for melamine was achieved with the mobile phase of 10 mmol/L phosphate buffer (pH 3.0) and acetonitrile (20: 80, v/v), voltage at 3 kV and UV detection at 215 nm. The limits of detection (LODs) (S/N = 3) for melamine standard was 0.05 mg/L. The method is simple, accurate and works well without using the ion-pairing agent. The powdered milk and liquid milk were analyzed quantitatively by pCEC using the hydrophilic interaction monolithic column. It is shown that this method is promising in the routine analysis of melamine in dairy products.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 03/2010; 28(3):231-5.
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ABSTRACT: Neural tube defect (NTD) prevalence in northern China is among the highest worldwide. Dealing with the NTD situation is ranked as the number one task in China's scientific development plan in population and health field for the next decade. Physical and social environments account for much of the disease's occurrence. The environmental determinants and their effects on NTD vary across geographical regions, whereas factors that play a significant role in NTD occurrence may be buried by global statistics analysis to a pooled dataset over the entire study area. This study aims at identification of the local determinants of NTD across the study area and exploration of the epidemiological implications of the findings.
NTD prevalence rate is represented in terms of the random field theory, and Rushton's circle method is used to stabilize NTD rate estimation across the geographical area of interest; NTD determinants are represented by their measurable proxy variables and the geographical weighted regression (GWR) technique is used to represent the spatial heterogeneity of the NTD determinants.
Informative maps of the NTD rates and the statistically significant proxy variables are generated and rigorously assessed in quantitative terms.
The NTD determinants in the study area are investigated and interpreted on the basis of the maps of the proxy variables and the relationships between the proxy variables and the NTD determinants. No single determinant was found to dominate the NTD occurrence in the study area. Villages where NTD rates are significantly linked to environmental determinants are identified (some places are more closely linked to certain environmental factors than others). The results improve current understanding of NTD spread in China and provide valuable information for adequate disease intervention planning.
BMC Public Health 01/2010; 10:52. · 2.00 Impact Factor
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International Journal of Geographical Information Science. 01/2010; 24:107-127.
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Gong Chen,
Li-Jun Pei,
Jian Huang,
Xin-Ming Song,
Liang-Ming Lin, Xue Gu,
Jian-Xin Wu,
Fang Wang,
Ji-Lei Wu,
Jia-Peng Chen,
Ju-Fen Liu,
Ruo-Lei Xin,
Ting Zhang,
Xiao-Ying Zheng
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ABSTRACT: To study the prevalence of different types of neural tube defects (NTDs) in Luliang Prefecture, Shanxi province, where the prevalence of NTDs is unusually high and the correlation between NTDs prevalence and patterns.
A surveillance population-based birth defects was performed in Luliang Prefecture, Shanxi province.
The results of our study showed that the prevalence of NTDs was 2-fold higher in Luliang Prefecture than in other areas of Shanxi province. Unusual patterns of NTDs were found, however, multiple NTDs were relatively common in Luliang Prefecture, accounting for over 13% of all NTDs cases in China.
The prevalence of NTDs is associated with its patterns.
Biomedical and Environmental Sciences 08/2009; 22(4):340-4. · 1.35 Impact Factor
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ABSTRACT: Gold microspheres modified with octadecanethiol as chromatographic stationary phase were prepared. The particles were characterized by the scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (FT-IR), elemental analysis and nitrogen adsorption analysis. The average diameter, the surface area and the average pore diameter were 3.5 microm, 49.0 m2/g and 5.0 nm, respectively. The IR spectra demonstrated that C18 was bonded to the surface of gold microspheres with the carbon content of 0.56%. Using these microspheres as stationary phase, a 19 cm section of a total length of 36 cm capillary (100 microm i. d.) was packed electrokinetically, and the evaluations in capillary liquid chromatography and pressurized capillary electrochromatography were performed. The mobile phases (80% methanol) with extreme pH values (pH 1.0 or pH 12.0) were used to flush the column for 140 h. In order to investigate the chemical stability of the column, the retention factors before and after flushing were calculated and compared based on the experimental results. There was no remarkable deterioration on the retention factors after flushing, which demonstrated the column was stable pounds were separated using capillary liquid chromatography to examine the retention behavior of the column, and over 50,000 theoretical plates per meter and acceptable symmetry peaks were obtained. The pressurized capillary electrochromatographic properties of the column were investigated using a separation of the mixture of aniline and benzoic acid, and the separation was obtained when a 5 kV positive or negative voltage was applied. The research work confirmed the feasibility of using the octadecanethiol modified gold microspheres as a novel stationary phase for capillary liquid chromatography and pressurized capillary electrochromatography.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 07/2009; 27(4):431-5.
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ABSTRACT: A quantitative CE (qCE) system with high precision has been developed, in which a 4-port nano-valve was isolated from the electric field and served as sample injector. The accurate amount of sample was introduced into the CE system with high reproducibility. Based on this system, consecutive injections and separations were performed without voltage interruption. Reproducibilities in terms of RSD lower than 0.8% for retention time and 1.7% for peak area were achieved. The effectiveness of the system was demonstrated by the quantitative analysis of caffeine, theobromine, and theophylline in real samples, such as tea leaf, roasted coffee, coca cola, and theophylline tablets.
Journal of Separation Science 01/2009; 32(2):267-74. · 2.73 Impact Factor
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ABSTRACT: To examine the association between the risk of neural tube defects (NTD) and maternal serum vitamin B12, folate and homocysteine in a high-risk area of China.
A case-control study was carried out in Luliang mountain area of Shanxi Province.
A total of eighty-four NTD pregnancies and 110 matched controls were included in the study; their serum vitamin B12 and folate concentrations were measured by chemiluminescent immunoenzyme assay and total homocysteine concentrations by fluorescent polarisation immunoassay.
Serum vitamin B12 and folate concentrations were lower in NTD-affected pregnant women than in controls (P < 0.01). Serum total homocysteine was higher in the NTD group than in controls at less than 21 weeks of gestation (P < 0.01). Adjusted odds ratios revealed that women with lower vitamin B12 (adjusted OR=4.96; 95 % CI 1.94, 12.67) and folate (adjusted OR=3.23; 95 % CI 1.33, 7.85) concentrations had a higher risk of NTD compared to controls. Based on dietary analysis, less consumption of meat, egg or milk, fresh vegetables and fruit intake would increase the risk of NTD.
Lower serum concentrations of folate and vitamin B12 are related to the increased risk of NTD in high-risk populations. Both folate and vitamin B12 intake insufficiency could contribute to the increased risk of NTD. A dietary supplement, combining folate and vitamin B12, might be an effective measure to decrease the NTD incidence in these areas.
Public Health Nutrition 06/2008; 12(5):680-6. · 2.17 Impact Factor
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ABSTRACT: This research was to compare the occurrence levels of birth defect, to describe the distribution of primary birth defects in different range of monitored ages and to provide data to China birth-defect monitoring system.
A retrospective study on birth defect was conducted in two counties, Shanxi province, China, which covered birth defects among fetuses after 20 weeks' gestational age from 2002 through 2004. Data collected on birth defect cases mainly included extrinsic and visceral anomaly.
The occurrence rates of the monitored structural birth defects significantly increased with the increase of age. The occurrence rates were 17.6, 34.0, 43.6, and 53.7 per 1000 births, for different statistical range, from 20-week to 27-week gestational age, 7 days, 1 year and 3 years after birth, respectively. The range from 28-week gestational age to 7 days after birth was usually regarded as the routinely monitored range. If the occurrence rate was calculated from the 20-week gestational age, it appeared a 2.1-time increase. However, if the range was changed to 1 or 3 years after birth, the occurrence rate increased to 2.7 or 3.3 times high, respectively. The distribution of time when birth-defect was identified was significantly different by categories with majority of neural tube defect cases diagnosed at antepartum or 7 days after birth. Visceral defects were mainly found at 7 days after birth but increased with age, even some were diagnosed at 1 year after birth.
The routine Chinese monitoring program might detect approximately 1/3 of those structural birth defects with the base of current technique and monitoring range from 28-week gestational age to 7 days after birth. The result of our findings should be of help to other related studies.
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 04/2008; 29(3):220-3.
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Bao-Yuan Zhang,
Ting Zhang,
Liang-Ming Lin,
Fang Wang,
Ruo-Lei Xin, Xue Gu,
Yu-Na He,
Dong-Mei Yu,
Pei-Zhen Li,
Qing-Shan Zhang,
Jin Zhao,
Yu-Fu Qin,
Xiu-Feng Yang,
Gong Chen,
Ju-Fen Liu,
Xin-Ming Song,
Xiao-Ying Zheng
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ABSTRACT: To investigate the association between birth defects and dietary nutrient intake in a high risk area of China.
A dietary survey was performed and serum folic acid was measured in women whose pregnancy was affected by neural tube defects (NTDs) or unaffected by any birth defects (BDs) in Zhongyang and Jiaokou Counties in Shanxi Province of China.
The local average consumption of foods including dark green vegetables, fruits, fat and meat, and nutrient intake (e.g., energy, protein, retinol, riboflavin, vitamin E, and selenium) were lower than the national average level. In women of childbearing age, these regions, the intake of nutrients was much lower than the recommended nutrient intake (9%-77%). The case-control dietary nutrition study of women whose pregnancy was affected by BDs (including NTDs and congenital heart defects) demonstrated that, in early pregnancy, adequate nutrition (i.e., eating meat, fresh vegetables, fruit more than once a week) was a protective factor, while eating germinated potatoes was a risk factor. The geometrical mean (p5-p95) of serum folic acid in women with NTD birth defects was 9.6 nmol/L (3.6, 23.03), which was significantly lower than that in normal women (14.03 nmol/L).
Women of childbearing age in the two counties of Shanxi Province, China, have a marked insufficient intake of some nutrients, especially folic acid, zinc, vitamins A and B12. This nutrient deficiency may be an important risk factor for the high prevalence of birth defects in these regions. Therefore, adequate dietary nutrition in early pregnancy can prevent BDs.
Biomedical and Environmental Sciences 03/2008; 21(1):37-44. · 1.35 Impact Factor
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ABSTRACT: A new approach for the metabolomic study of urinary samples using pressurized CEC (pCEC) with gradient elution is proposed as an alternative chromatographic separation tool with higher degree of resolution, selectivity, sensitivity, and efficiency. The pCEC separation of urinary samples was performed on a RP column packed with C(18), 5 microm particles with an ACN/water mobile phase containing TFA. The effects of the acid modifiers, applied voltage, mobile phase, and detection wavelength were systematically evaluated using eight spiked standards, as well as urine samples. A typical analytical trial of urine samples from Sprague Dawley (S.D.) rats exposed to high-energy diet was carried out following sample pretreatment. Significant differences in urinary metabolic profiles were observed between the high energy diet-induced obesity rats and the healthy control rats at the 6th wk postdose. Multivariate statistical analysis revealed the differential metabolites in response to the diet, which were partially validated with the putative standards. This work suggests that such a pCEC-based separation and analysis method may provide a new and cost-effective platform for metabolomic study uniquely positioned between the conventional chromatographic tools such as HPLC, and hyphenated analytical techniques such as LC-MS.
Electrophoresis 01/2008; 28(23):4459-68. · 3.30 Impact Factor
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Xue Gu,
Liangming Lin,
Xiaoying Zheng,
Ting Zhang,
Xinming Song,
Jinfeng Wang,
Xinhu Li,
Peizhen Li,
Gong Chen,
Jilei Wu,
Lihua Wu,
Jufen Liu
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ABSTRACT: Shanxi Province has historically reported a high prevalence of NTDs. In order to establish baseline rates for NTDs and discuss the risk factors associated with sociodemographic, maternal characteristics, and geographic factors, we performed the present study using an approach combining population and hospital-based methodologies.
We used chi(2) and Fisher's exact tests to evaluate variation in the prevalence by selected covariates and computed crude ORs and 95% CIs. Adjusted odds ratios (AORs) were performed using logistic regression with all the covariates included in the model.
The overall NTD prevalence during the 3 year study period was 199.38 per 10,000 births, with a higher NTD prevalence clustered in 46 villages within this geographic area. However, no statistical significance was found between NTD prevalence and the elevation of the villages or their distance from coal plants. AORs revealed women aged 20 and above had a lower risk of NTDs compared to those younger than 20 (AOR range 0.4-0.5). A higher risk of NTDs was observed among female infants (AOR 1.50; 95% CI: 1.04-2.17), women with four or more previous births (AOR 2.80; 95% CI: 1.20-6.52), and a previous history of birth defects (AOR 3.23; 95% CI: 1.46-7.12).
This study has documented a high prevalence of NTDs in Shanxi. Similar variations to other reports were found in the risk of NTDs by maternal demographic characteristics and a clustering of NTDs in certain villages that require further exploration.
Birth Defects Research Part A Clinical and Molecular Teratology 11/2007; 79(10):702-7. · 2.27 Impact Factor
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ABSTRACT: Capillary electrochromatography (CEC) has attracted increasing interests in recent years. It combines the advantages of high efficiency of capillary electrophoresis (CE) with high selectivity of high performance liquid chromatography (HPLC). CEC also has a double retention mechanism of both CE and HPLC and, therefore, is suitable for simultaneous separation and analysis of neutral and charged compounds. In this paper, the preparation methods for various types of capillary columns for electrochromatography are reviewed in detail and their advantages and disadvantages are discussed.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 04/2007; 25(2):157-62.
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ABSTRACT: A high-throughput on-line capillary array-based two-dimensional liquid chromatography (2D-LC) system coupled with MALDI-TOF-TOF-MS proteomics analyzer for comprehensive proteomic analyses has been developed, in which one capillary strong-cation exchange (SCX) chromatographic column was used as the first separation dimension and 18 parallel capillary reversed-phase liquid chromatographic (RPLC) columns were integrated as the second separation dimension. Peptides bound to the SCX phase were "stepped" off using multiple salt pulses followed by sequentially loading of each subset of peptides onto the corresponding precolumns. After salt fractionation, by directing identically split solvent-gradient flows into 18 channels, peptide fractions were concurrently back-flushed from the precolumns and separated simultaneously with 18 capillary RP columns. LC effluents were directly deposited onto the MALDI target plates through an array of capillary tips at a 15-s interval, and then alpha-cyano-4-hydroxycinnamic acid (CHCA) matrix solution was added to each sample spot for subsequent MALDI experiments. This new system allows an 18-fold increase in throughput compared with serial-based 2D-LC system. The high efficiency of the overall system was demonstrated by the analysis of a tryptic digest of proteins extracted from normal human liver tissue. A total of 462 proteins was identified, which proved the system's promising potential for high-throughput analysis and application in proteomics.
Journal of Proteome Research 12/2006; 5(11):3186-96. · 5.11 Impact Factor
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ABSTRACT: Two-dimensional liquid chromatography (2D-LC) coupled on-line with electrospray ionization tandem mass spectrometry (2D-LC-ESI-MS/MS) is a new platform for analysis and identification of proteome. Peptides are separated by 2D-LC and then performed MS/MS analysis by tandem MS/MS. The MS/MS data are searched against database for protein identification. In one 2D-LC-ESI-MS/MS run, we obtained not only the structural information of peptides directly from MS/MS, but also the retention time of peptides eluted from LC. Information on the chromatographic behavior of peptides can assist protein identification in the new platform for proteomics. The retention time of the matching peptides of the identified protein was predicted by the hydrophobic contribute of each amino acid on reversed-phase liquid chromatography (RPLC). By using this strategy proteins were identified by four types of information: peptide mass fingerprinting (PMF), sequence query, and MS/MS ions searched and the predicted retention time. This additional information obtained from LC could assist protein identification with no extra experimental cost.
Journal of Chromatography B 12/2005; 826(1-2):122-8. · 2.89 Impact Factor
