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by
Z. Chen |
Total Records (
10 ) for
Z. Chen |
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R.J. Kain
,
Z. Chen
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T.S. Sonda
and
J.C. Abu-Kpawoh
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The effect of control variables involved in the extraction
of proteins and preparation of protein isolate from peanut meal flour
have been investigated and optimized. These control variables include:
temperature of the extraction medium, sample/water ratio, extraction time,
effect of successive extraction steps and centrifugal speed. The pH-dependent
protein solubility profile revealed that the region of minimum solubility
(isoelectric point) of the proteins was at pH 4.5. The solubility reduced
as the pH increased until it reached the isoelectric point which was followed
by progressive increase in solubility with further increase in pH. The
effect of temperature on the extraction of proteins indicated a slight
decrease in the protein yield of about 17.6 and 15.0% as the temperature
was increased from 40 to 60°C in both cold and heat pressed protein
isolates, respectively. Protein yields in both samples were adversely
affected at an increased temperature of 70°C. There was an increase
in the yield of proteins with decreasing solid-water ratio while the yield
of proteins increased as the centrifugal speed was increased. |
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S. L Gray
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A. Z LaCroix
,
J Larson
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J Robbins
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J. A Cauley
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J. E Manson
and
Z. Chen
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Background Proton pump inhibitor (PPI) medications have been inconsistently shown to be associated with osteoporotic fractures. We examined the association of PPI use with bone outcomes (fracture, bone mineral density [BMD]).
Methods This prospective analysis included 161 806 postmenopausal women 50 to 79 years old, without history of hip fracture, enrolled in the Women's Health Initiative (WHI) Observational Study and Clinical Trials with a mean (SD) follow-up of 7.8 (1.6) years. Analyses were conducted for 130 487 women with complete information. Medication information was taken directly from drug containers during in-person interviews (baseline, year 3). The main outcome measures were self-reported fractures (hip [adjudicated], clinical spine, forearm or wrist, and total fractures) and for a subsample (3 densitometry sites), 3-year change in BMD.
Results During 1 005 126 person-years of follow-up, 1500 hip fractures, 4881 forearm or wrist fractures, 2315 clinical spine fractures, and 21 247 total fractures occurred. The multivariate-adjusted hazard ratios for current PPI use were 1.00 (95% confidence interval [CI], 0.71-1.40) for hip fracture, 1.47 (95% CI, 1.18-1.82) for clinical spine fracture, 1.26 (95% CI, 1.05-1.51) for forearm or wrist fracture, and 1.25 (95% CI, 1.15-1.36) for total fractures. The BMD measurements did not vary between PPI users and nonusers at baseline. Use of PPIs was associated with only a marginal effect on 3-year BMD change at the hip (P = .05) but not at other sites.
Conclusion Use of PPIs was not associated with hip fractures but was modestly associated with clinical spine, forearm or wrist, and total fractures. |
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M. Y. Kan
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D. Z. Zhou
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D. Zhang
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Z. Zhang
,
Z. Chen
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Y. F. Yang
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X. Z. Guo
,
H. Xu
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L. He
and
Y. Liu
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Aims To investigate the two variants (rs1387153 and rs10830963) near/in the melatonin receptor 1B gene (MTNR1B) and to determine their association with Type 2 diabetes, as well as with the regulation of fasting plasma glucose (FPG) in Han Chinese subjects.Methods The two variants were genotyped in 1912 unrelated Type 2 diabetic patients and 2041 healthy individuals. Association with Type 2 diabetes was calculated by logistic regression with adjustments for sex, age and body mass index. The possible connection between the risk alleles and FPG was analysed by multiple linear regression. Results The two polymorphisms were associated with FPG levels in the healthy individuals (P = 0.003 and P = 0.002, respectively), and the G allele of rs10830963 was also associated with an increased risk of Type 2 diabetes in our patient sample (odds ratio, 1.12; 95% confidence interval, 1.02-1.23; P = 0.024). Moreover, the linkage disequilibrium degree of two single nucleotide polymorphisms was high (r2 = 0.66), which is similar to that of Europeans. Conclusions The common variant in MTNR1B confers the risk of Type 2 diabetes and modulates FPG in both the Han Chinese and European populations. |
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Y. Lin
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Y. Xu
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G. Chen
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B. Huang
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J. Yao
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Z. Chen
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L. Yao
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F. Lin
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Y. Qiao
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Z. Chen
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S. Zhu
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H. Huang
and
J. Wen
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Objective It has been suggested that serum γ-glutamyltransferase is independently associated with cardiovascular mortality and atherosclerosis. The present study is to investigate the relationship between serum γ-glutamyltransferase and potential associated damage in an adult She Chinese population.Method A multistage, stratified, cluster, random sampling method was used to select an ethnically representative group of individuals aged 20-80 years in the general population. Brachial-ankle pulse-wave velocity was used to assess arterial stiffness in the general population and the Toronto Clinical Neuropathy Scoring System was used to detect diabetic peripheral polyneuropathy among populations with diabetes. Results A total of 5385 subjects were entered into the analysis. Serum γ-glutamyltransferase levels were classified into four groups using the 25th, 50th and 75th percentiles as cut points (males: < 20, 20-29, 29-52 and > 52 U/l; females: < 13, 13-18, 18-25 and > 25 U/l). As compared with the first quartile, the relative risks of arterial stiffness were 1.418, 1.667 and 2.394 in the other three categories, respectively (test for trend P < 0.05). After adjustment in five models, serum γ-glutamyltransferase was still a risk factor of arterial stiffness. We found inverted U-shape curves in both genders and the third quartile (male: 29 52 U/l; female: 18-25 U/l) had the highest odds ratios of 1.640 and 1.529, respectively. Conclusions We demonstrated that high serum γ-glutamyltransferase concentrations were directly associated with the increased risk of arterial stiffness, in general, and with peripheral polyneuropathy in subjects with diabetes in an ethnic She Chinese population. Alcohol use, gender, BMI and blood pressure were related to serum γ-glutamyltransferase and were involved in the relationship between serum γ-glutamyltransferase and brachial-ankle pulse-wave velocity. |
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F. Bragg
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L. Li
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M. Smith
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Y. Guo
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Y. Chen
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I. Millwood
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Z. Bian
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R. Walters
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J. Chen
,
L. Yang
,
R. Collins
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R. Peto
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Y. Lu
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B. Yu
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X. Xie
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Y. Lei
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G. Luo
and
Z. Chen
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AimsTo examine the relationship of self-reported diabetes, and of random blood glucose levels among individuals without known diabetes, with the prevalence of cardiovascular disease in Chinese adults. MethodsWe examined cross-sectional data from the China Kadoorie Biobank of 0.5 million people aged 30-79 years recruited from 10 diverse regions of China in the period 2004-2008. Logistic regression was used to estimate the odds ratios of prevalent cardiovascular disease associated with self-reported diabetes, and with measured random blood glucose levels among participants with no history of diabetes, adjusting simultaneously for age, sex, area, education, smoking, alcohol, blood pressure and physical activity. ResultsA total of 3.2% of participants had self-reported diabetes (men 2.9%; women 3.3%) and 2.8% had screen-detected diabetes (men 2.6%; women 2.8%), i.e. they had no self-reported history of diabetes but a blood glucose level suggestive of a diagnosis of diabetes. Compared with individuals without a history of diabetes, the odds ratios associated with self-reported diabetes were 2.18 (95% CI 2.06-2.30) and 1.88 (95% CI 1.75-2.01) for prevalent ischaemic heart disease and stroke/transient ischaemic attack, respectively. Among participants without self-reported diabetes there was a positive association between random blood glucose and ischaemic heart disease and stroke/transient ischaemic attack prevalence (P for trend <0.0001). Below the diabetic threshold (<11.1 mmol/l) each additional 1 mmol/l of random blood glucose was associated with 4% (95% CI 2-5%) and 5% (95% CI 3-7%) higher odds of prevalent ischaemic heart disease and stroke/transient ischaemic attack, respectively. ConclusionsIn this adult Chinese population, self-reported diabetes was associated with a doubling of the odds of prevalent cardiovascular disease. Below the threshold for diabetes there was still a modest, positive association between random blood glucose and prevalent cardiovascular disease. |
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Z.Y. Pan
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Z. Chen
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L. Liu
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Y.Z. Cao
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K.Z. Xie
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J.S. Yang
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X.G. Huang
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S.L. Wu
and
W.B. Bao
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Toll Like Receptors (TLRs) play an important role in innate and adaptive immunity, however the expression of TLR4 in piglets of different ages is still unknown. In this study, the tissue samples of 11 organs including heart, liver, spleen and so on were collected from 32 piglets of 4 different ages (8, 18, 30 and 35 days old). Real-time PCR was used to compare and analyze the expression of TLR4 both in different tissues and growing periods of piglets which aimed at discussing the function of TLR4 in immune responses in the piglets of development periods as well as showing the relationship between the expression level and piglets sensitivity to different subtypes E. coli. The results showed that TLR4 gene was expressed in all the tissues and high levels of expression were detected in immune organs such as lung, lymph node, thymus gland and spleen. In addition in 8 days old piglets, the expression level of TLR4 in immune organs such as lung, spleen, kidney and thymus gland was relatively high. Then the whole expression quantity continually increased reaching the highest level in 35 days old of weaning period, especially in thymus gland and lung. The expression of TLR4 in thymus gland in 35 days old piglets was significantly higher than that in piglets of other ages (p<0.05) and the expression in lung was significantly higher than that in 8 days old piglets (p<0.05). The results indicated that TLR4 played the extremely important role in connecting the natural immunity and specific immunity. Besides, TLR4 not only played an important role in both immune response and general resistance to lung diseases but also could have a significant control function in preventing weaning piglets from being infected by E. coli F18. |
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Z Xiao
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G Li
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Y Chen
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M Li
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F Peng
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C Li
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F Li
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Y Yu
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Y Ouyang
and
Z. Chen
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Formalin-fixed, paraffin-embedded (FFPE) tissue specimens represent a potentially valuable resource for protein biomarker investigations. In this study, proteins were extracted by a heat-induced antigen retrieval technique combined with a retrieval solution containing 2% SDS from FFPE tissues of normal nasopharyngeal epithelial tissues (NNET) and three histological types of nasopharyngeal carcinoma (NPC) with diverse differentiation degrees. Then two-dimensional liquid chromatography-tandem mass spectrometry coupled with isobaric tags for relative and absolute quantification (iTRAQ) labeling was employed to quantitatively identify the differentially expressed proteins among the types of NPC FFPE tissues. Our study resulted in the identification of 730 unique proteins, the distributions of subcellular localizations and molecular functions of which were similar to those of the proteomic database of human NPC and NNET that we had set up based on the frozen tissues. Additionally, the relative expression levels of cathepsin D, keratin8, SFN, and stathmin1 identified and quantified in this report were consistent with the immunohistochemistry results acquired in our previous study. In conclusion, we have developed an effective approach to identifying protein changes in FFPE NPC tissues utilizing iTRAQ technology in conjunction with an economical and easily accessible sample preparation method. (J Histochem Cytochem 58:517–527, 2010) |
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T.X. Li
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K. Kuwana
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K. Saito
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H. Zhang
and
Z. Chen
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We have conducted experimental and numerical studies on flame synthesis of carbon nanotubes (CNTs) to investigate the effects of three key parameters – selective catalyst, temperature and available carbon sources – on CNT growth. Two different substrates were used to synthesize CNTs: Ni-alloy wire substrates to obtain curved and entangled CNTs and Si-substrates with porous anodic aluminum oxide (AAO) nanotemplates to grow well-aligned, self-assembled and size-controllable CNTs, each using two different types of laminar flames, co-flow and counter-flow methane–air diffusion flames. An appropriate temperature range in the synthesis region is essential for CNTs to grow on the substrates. Possible carbon sources for CNT growth were found to be the major species CO and those intermediate species C2H2, C2H4, C2H6, and methyl radical CH3. The major species H2, CO2 and H2O in the synthesis region are expected to activate the catalyst and help to promote catalyst reaction. |
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C. Liu
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X. Wang
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Z. Chen
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L. Zhang
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Y. Wu
and
Y. Zhang
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Background: The effects of hepatic ischemia-reperfusion (I/R) on insulin signaling remain unclear. We observed changes in insulin secretion and signal protein expression during the early steps in insulin signaling after hepatic I/R in rats. Materials and Methods: Eighty healthy Wistar rats were randomly divided into an I/R group and a control (C) group. After we exposed the hepatic hilum, ischemia was induced by clamping the hepatic artery and portal vein for 30 minutes and then the liver was reperfused for 2 hours in the I/R group; a show procedure was done in the C group. Blood samples were obtained after exposure of the hepatic hilum (T1) and 2 hours after reperfusion in the I/R group (T2) and 2.5 hours after T1 in the C group (T2). We measured glucose and insulin plasma concentrations. We determined the expressions of insulin signaling proteins, including insulin receptor (IR) β unit (IR β), IR substrate 1 (IRS-1), IRS-2, and P85 in phosphatidylinositol 3-kinase (PI3K) and tyrosine phosphorylation of these proteins in liver and skeletal muscle.Results: Plasma glucose concentrations increased in both groups at T2 (P < .01) and were higher in the I/R group (P < .01). Insulin concentrations in the I/R group did not change significantly at T2. Insulin concentrations at T2 were higher than those at T1 in the C group (P < .05). Expressions of insulin signal proteins showed no significant difference between the 2 groups; however, tyrosine phosphorylation of IR β, IRS-1, IRS-2, and the interactions between IRS-1 in skeletal muscle or IRS-2 in liver and PI3K were significantly lower in the I/R group than the C group.Conclusion: Hepatic I/R inhibited insulin secretion and induced insulin resistance via down-regulation during the early steps in insulin signaling in rats. |
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