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Biomedical subjects

Lin Yue

Publications and source records attributed to Lin Yue.

8 recordsLinked to original sources
PubMed2006

Polyethylene glycol fractionation improved detection of low-abundant proteins by two-dimensional electrophoresis analysis of plant proteome.

Poor detection of low-abundant proteins is a common problem in two-dimensional electrophoresis (2-DE) for separation of proteins in a proteome analysis. This is attributed partially, at least, to the existence of high-abundant proteins, e.g. ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in plants. They engage a large proportion of the whole-cell proteins and thus prevent low-abundant proteins from being up-taken by immobilized pH gradient (IPG) strip, consequently making the latter poorly detectable by 2-DE. In this work, we report a straightforward protocol for preparation of whole-cell proteins through differential polyethylene glycol (PEG) precipitation aiming at elimination of Rubisco from plant protein samples. In comparison with 2-DE analysis of protein samples prepared using a conventional TCA/acetone method, a relatively high reproducibility of proteins was achieved using a PEG fractionation protocol in terms of protein yield and protein species. As expected, the large subunit of Rubisco was precipitated predominantly in the 16% PEG fraction. This allowed proteins of the Rubisco-containing fraction to be analyzed separately from those of other PEG fractions. After taking into account the overlapping protein spots among 2-DE gels of all fractions through image and statistical analyses, we detected with this protocol a total 5077 protein spots, among which ca. 80% are proteins undetectable with the TCA/acetone method, while the rest of proteins exhibited a significant increase in their abundance. This protocol was developed using Arabidopsis as a source of protein and thus may also be applicable to protein preparations of other plants.

Arabidopsis↗
PubMed2006

Colloids seeded deposition: growth of titania nanotubes in solution.

The formation of titania nanotubes through CeO2 colloids seeded deposition process in solution has been demonstrated. The interactions among colloidal particles play important roles for the solution "VLS"-type growth of nanotubes. The observation has significance for understanding solution nucleation and for developing new methods for nanomaterials preparation via the disclosed colloids seeded deposition (CSD) mechanism.

Journal Article↗
PubMed2006

Cytochrome P450 gene induction in rats ex vivo assessed by quantitative real-time reverse transcriptase-polymerase chain reaction (TaqMan).

Drug-induced changes in expression of cytochrome P450 (P450) genes are a significant issue in the preclinical development of pharmaceuticals. For example, preclinically, P450 induction can affect safety studies by reducing the systemic exposure of a compound undergoing toxicological evaluation, thus limiting the exposure that can be safely investigated in patients. Therefore, the induction potential of candidate drugs has been studied as part of the drug development process, typically using protein and/or catalytic end points. However, measuring changes in the levels of mRNA using TaqMan technology offers the opportunity to investigate this issue with the advantages of better dynamic range and specific enzyme identification. Here, we describe the TaqMan application to study ex vivo the P450 gene induction in the rat. Initially, livers from rats dosed with the prototypic P450 inducers beta-napthoflavone (BNF), phenobarbital (PB), dexamethasone (DEX), and clofibric acid (CLO) were analyzed for mRNA levels of CYP1A1, 1A2, 2B1, 2B2, 2E1, 3A2, 3A23, and 4A1 and compared with control animals. The maximum fold induction of mRNA varied: 2500-fold for CYP1A1 with BNF, 680-fold for CYP2B1 with PB, 59-fold for CYP3A23 with DEX, and 16-fold for CYP4A1 with CLO. This method was then applied to estimate the inductive potential of putative drug candidates undergoing rodent toxicological evaluation. We present a summary of these data that demonstrates the sensitivity and specificity of the TaqMan assay to distinguish between inducers and noninducers and that offers a highly specific alternative to the quantification of drug effects on P450 expression using immunodetection and substrate metabolism.

Animals↗
PubMed2006

[Buffering effects of plaque solid, Streptococcus mutans and glucans].

OBJECTIVE: To investigate the buffer capacity of insoluble plaque mass including bacteria and glucans matrix. METHODS: Plaque samples (starved or incubated 1 h with 10% sucrose), Streptococcus mutans (S. mutans) mass, and insoluble/soluble glucans were titrated with 1 mmol/L HCl. Meanwhile, the density of bacteria was counted and related to buffer capacity. RESULTS: The bacteria density had significant effects on acid buffer capacity in dental plaque, but the effect reduced with consuming sugar. S. mutans mass with no sucrose incubating contributed to the buffer capacity of (0.609 +/- 0.202) mmol/L, and S. mutans mass with 2% sucrose had only the buffer capacity of (0.099 +/- 0.047) mmol/L. In the mean time, glucans had no effect on acid buffering (0.028 - 0.032 mmol/L). CONCLUSIONS: The bacteria including S. mutans may be the main contributor to acid buffering in plaque solid.

Acids↗
PubMed2005

[Synthesis and crystal structure of a porous coordination polymer [Nd2 (C6H8O4)3 (H2O)2]n x n (4,4'-bpy)].

A novel porous coordination polymer [Nd2 (C6H8O4)3 (H2O)2]n x n (4,4'-bpy) was synthesized by hydrothermal synthesis reaction of hexyl acid, 4,4'-bpy with NdCl3 x XH2O. The structure was characterized by elemental analysis, thermal gravimetric analysis, IR spectroscopy, and X-ray single crystal analysis. The crystal data are of an orthorhombic crystal system, Pbcn space group. Crystallographic data are: a = 2.201 2 nm(6), b = 0.777 8 nm(2), c = 1.972 4 nm(5), alpha = beta = gamma = 90 degrees, V = 337.70 nm(15)3, Z = 4, D(c) = 1.796 g x cm(-3), mu = 3.108 mm(-1), F(000) = 1 800, R = 0.043 0 and wR2 = 0.056 0. X-ray analysis reveals that three-dimensional porous nets were formed between Nd3+ and Nd3+ by carboxyl of hexyl acid.

Crystallization↗
PubMed2002

Plaque minerals in the prediction of caries activity.

BACKGROUND/AIMS: Attempts to identify subjects who will develop caries lesions in future years have been only moderately successful, suggesting that one or more important risk factors are being overlooked. The aim of this study was to validate the use of plaque calcium, phosphate and fluoride concentrations as significant risk factors in caries. METHODS: DMFS and DMFT rates were measured three times over 2 years in a group of rural Chinese schoolchildren initially aged 12 years and not living in a high-fluoride area. At the baseline and year 1 examinations, dental plaque was accumulated for 3 days and, after collection, was analysed for Ca, P and F. Plaque scores, dental health behaviour and parents' occupation data were also recorded. RESULTS: The mean DMFS increment over 2 years was 1.14 with a range of -2 to +9. Regression analysis taking all factors into account identified only plaque Ca concentration, baseline DMFS score and toothbrushing frequency as significant factors in identifying high-risk individuals. Plaque Ca also showed predictive ability on its own. For example, when high caries was defined as 3+ new DMFS and a Ca cut-off value of 200 nmol/mg dry wt was selected, sensitivity was 0.84 and specificity 0.38. However, with this cut-off value the percentage predicted to have high caries risk was unrealistically high at 66%. As in several other studies, baseline caries score was a useful predictor of future caries. CONCLUSION: Low plaque Ca concentration showed a modest ability to predict future caries, and since it is implicated directly in the chain of events leading to caries, its use in caries prediction should be considered further. Plaque P and F showed no predictive ability in this study.

Calcium↗
PubMed2002

[Proteins in saliva and dental plaque fluid in relation to caries susceptibility].

OBJECTIVE: To investigate the relationship of the levels of proteins in parotid saliva, whole saliva and dental plaque fluid with caries susceptibility. METHODS: Sixty-six of university students were selected as subjects, 39 in caries-free group (CF, DMFS = 0) and 27 in caries-susceptible group (CS, DMFS >/= 8 and DT >/= 3). Total protein concentration was detected with Lowry method. Protein compositions were separated with SDS-PAGE and alkaline electrophoresis. The gels were analyzed using an image evaluation system. RESULTS: Total protein level in dental plaque fluid was about 10-fold higher than that in saliva. Whole saliva was closely related to dental plaque fluid in terms of proteins only in CF group (r = 0.804), but there was little relation in CS group. The proteins that occurred in all three fluids were 14 000, 66 000 and 76 000 proteins. The 14 000, 15 000 and 38 000 proteins level in dental plaque fluid and 14 000 protein level in whole saliva were significantly lower in CS group than in CF group. CONCLUSIONS: The proteins of dental plaque fluid are influenced significantly by whole saliva in CF group. The results suggest some kinds of proteins in dental plaque fluid and in whole saliva might play important roles against caries.

Dental Caries↗