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Biomedical subjects

Ting Wang

Publications and source records attributed to Ting Wang.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Expression of transforming growth factor-beta1 and basic fibroblast growth factor in articular process cartilages of adolescent idiopathic scoliosis].

OBJECTIVE: To investigate the characteristics of the expression of transforming growth factor-beta(1) (TGF-beta(1)) and basic fibroblast growth factor (bFGF) in the apical articular process cartilages of adolescent idiopathic scoliosis (AIS) patients. METHODS: The specimens of articular processes of 22 AIS patients and 18 congenital scoliosis (CS) patients were collected during operation. The pathology of the processes was observed with H.E staining. Immunohistochemistry and in situ hybridization were adopted to detect the expression of TGF-beta(1) and bFGF. The differences in the pathological changes, and expression of TGF-beta(1) and bFGF between the apical processes and the end processes, the convex processes and the concave processes, and the AIS processes and CS processes. The images of immunohistochemistry and in situ hybridization were input into the image analysis system and were analyzed semi-quantitatively. The SAS (8.01) software was adopted and (128.1 +/- 50.6 vs 165.4 +/- 59.2, 126.5 +/- 47.0 vs 168.3 +/- 46.8; 76.6 +/- 29.9 vs 96.4 +/- 28.4, 73.7 +/- 31.6 vs 101.8 +/- 39.4; 77.1 +/- 52.2 vs 114.4 +/- 59.4, and 69.5 +/- 40.1 vs 109.8 +/- 51.0 (P < 0.05) was defined as the significant levels. RESULTS: The expression of TGF-beta(1) and the expression of bFGF were not significantly different between the AIS patients and the CS patients. The TGF-beta(1) expression in the concave side of the apical vertebrae of the AIS group was 165.4 +/- 59.2, significantly higher than that in the convex sides (128.1 +/- 50.6, P = 0.03), and the TGF-beta(1) expression in the concave side of the apical vertebrae of the CS group was 168.3 +/- 46.8, significantly higher than that of the convex side (126.5 +/- 47.0, P = 0.02). However, there was no statistically significant differences in the TGF-beta(1) expression between the concave and convex sides of the upper and lower end vertebrae and between the upper and lower end vertebrae. The bFGF expression in the concave side of the apical vertebrae of the AIS group, and the bFGF expression in the concave side of the apical vertebrae of the CS group was 101.8 +/- 39.4, significantly higher than that of the convex side (73.7 +/- 31, P = 0.02). However, there were no statistically significant differences in the bFGF expression between the concave and convex sides of the upper and lower end vertebrae and between the upper and lower end vertebrae. CONCLUSION: The cartilages of the apical processes show some signs of regression and hypoplasia in AIS patients, especially at the concave side in comparison with the convex side. Increase of TGF-beta(1) and bFGF in the concave sides of apical processes in AIS may be the results of reconstruction of extracellular matrix and the compensation reactions which are caused by abnormal biomechanical forces, especially compressive stresses.

Adolescent↗
PubMed2006

Piezoelectric properties of human dentin and some influencing factors.

OBJECTIVES: The present study focused on the piezoelectricity of human dentin. The effects of moisture content and orientation of tubules were investigated. METHODS: Fresh human dentin was cut with two surfaces generally parallel to the occlusal surface. The potentials generated by specimens were detected, as the compression loads were respectively parallel and vertical to the tubules. Moreover, specimens were dried and rehydrated; piezoelectric coefficients d(33) of dentin with different moisture content were measured horizontally to, and vertically to, the tubules. RESULTS: The results showed that piezoelectricity of dentin increased with increasing moisture content. Furthermore, greater piezoelectricity was detected parallel to the tubules than vertical to the tubules. SIGNIFICANCES: This study indicated that the piezoelectric properties of dentin were significantly affected by both humidity and orientation of the tubules. Both structural and free water in dentin is attributed to its piezoelectric properties.

Analysis of Variance↗
PubMed2006

Open brain gene product Rab23: expression pattern in the adult mouse brain and functional characterization.

The gene mutated in the mouse open brain (opb) phenotype antagonizes sonic hedgehog-mediated signaling and encodes a small GTPase of the Rab family, Rab23. To date, the brain expression profile and exact mechanism of function of the Rab23 protein has remained unknown. Specific antibodies generated against Rab23 showed that the protein is highly enriched in the adult rodent brain and present in low levels in multiple tissues of the adult rodent. Rab23 is found in the cytosol as well as being associated with the plasma and endosomal membranes. In the adult mouse brain, Rab23 is found in betaIII tubulin (TuJ) positive neuronal cell bodies and are most prominent in the cortex, hypothalamus and the cerebellum. It is, however, absent from glial fibrillary acidic protein (GFAP) positive astrocytes or CNPase positive oligodendrocytes. Despite the plasma membrane/endosomal membrane localization of Rab23, neither overexpression of the GTP-restricted nor the GDP-bound mutant forms affect internalization of transferrin or epidermal growth factor. Exogenous overexpression of Rab23 or its mutants also did not affect the morphological differentiation of thalamic neurons in culture. Expression of Rab23 in the adult brain is suggestive, however, of having a postnatal function beyond its role in embryonic development.

Age Factors↗
PubMed2006

Viral and therapeutic control of IFN-beta promoter stimulator 1 during hepatitis C virus infection.

Viral signaling through retinoic acid-inducible gene-I (RIG-I) and its adaptor protein, IFN promoter-stimulator 1 (IPS-1), activates IFN regulatory factor-3 (IRF-3) and the host IFN-alpha/beta response that limits virus infection. The hepatitis C virus (HCV) NS3/4A protease cleaves IPS-1 to block RIG-I signaling, but how this regulation controls the host response to HCV is not known. Moreover, endogenous IPS-1 cleavage has not been demonstrated in the context of HCV infection in vitro or in vivo. Here, we show that HCV infection transiently induces RIG-I- and IPS-1-dependent IRF-3 activation. This host response limits HCV production and constrains cellular permissiveness to infection. However, HCV disrupts this response early in infection by NS3/4A cleavage of IPS-1 at C508, releasing IPS-1 from the mitochondrial membrane. Cleavage results in subcellular redistribution of IPS-1 and loss of interaction with RIG-I, thereby preventing downstream activation of IRF-3 and IFN-beta induction. Liver tissues from chronically infected patients similarly demonstrate subcellular redistribution of IPS-1 in infected hepatocytes and IPS-1 cleavage associated with a lack of ISG15 expression and conjugation of target proteins in vivo. Importantly, small-molecule inhibitors of NS3/4A prevent cleavage and restore RIG-I signaling of IFN-beta induction. Our results suggest a dynamic model in which early activation of IRF-3 and induction of antiviral genes are reversed by IPS-1 proteolysis and abrogation of RIG-I signaling as NS3/4A accumulates in newly infected cells. HCV protease inhibitors effectively prevent IPS-1 proteolysis, suggesting they may be capable of restoring this innate host response in clinical practice.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Effects of melatonin on orphanin FQ/nociceptin-induced hyperalgesia in mice.

The pain modulatory properties of melatonin (MT) are generally recognized but the detail of the interaction between melatonin and opioid system in pain regulation is not fully understood. The present study was undertaken to investigate the modulatory effect of melatonin (MT) on the hyperalgesic effect of Orphanin FQ/Nociceptin (OFQ/NC, NC), a member of opioid peptide family. Intracerebroventricular (i.c.v.) administration of NC (10 microg/mouse) induced significant hyperalgesic effect in tail-flick test in mice; i.c.v. (5, 10, 50 microg/mouse) or intraperitoneal (i.p.) (5, 10, 50 mg/kg) co-injection of melatonin dose-dependently reversed NC-induced hyperalgesia and showed a profound analgesic effect. The antihyperalgesia effect of MT could be significantly antagonized by i.c.v. co-injection of luzindole (10 microg/mouse) (an antagonist of MT receptor) or naloxone (10 microg/mouse) (antagonist of traditional opioid receptor). Taken together, all the results suggested that MT could produce a luzindole and naloxone sensitive reversing effect on NC-induced hyperalgesia at supraspinal and peripheral level in mice. The augmentation effect of MT on the traditional opioid system may be one of the mechanisms of this antihyperalgesia action induced by MT. The present work will help to elucidate the mechanism of the pain modulation effect of MT, and also will help to represent new interesting modulating therapeutic targets for the relief of pain.

Analysis of Variance↗
PubMed2006

Overexpression of the oncoprotein prothymosin alpha triggers a p53 response that involves p53 acetylation.

Activation of the tumor suppressor protein p53 is a critical cellular response to various stress stimuli and to inappropriate activity of growth-promoting proteins, such as Myc, Ras, E2F, and beta-catenin. Protein stability and transcriptional activity of p53 are modulated by protein-protein interactions and post-translational modifications, including acetylation. Here, we show that inappropriate activity of prothymosin alpha (PTMA), an oncoprotein overexpressed in human cancers, triggers a p53 response. Overexpression of PTMA enhanced p53 transcriptional activity in reporter gene assays for p53 target gene promoters hdm2, p21, and cyclin G. Overexpressed PTMA resulted in increased mRNA and protein levels for endogenous p53 target genes, hdm2 and p21, and in growth suppression. In contrast, reduction of endogenous PTMA through RNA interference decreased p53 transcriptional activity. Histone acetyltransferases (HATs) act as p53 coactivators and acetylate p53. PTMA, known to interact with HATs, led to increased levels of acetylated p53. PTMA did not increase the transcriptional activity of an acetylation-deficient p53 mutant, suggesting that p53 acetylation is an indispensable part of the p53 response to PTMA. Chromatin immunoprecipitation assays showed that excess PTMA associates with the p21 promoter and results in increased levels of acetylated p53 at the p21 promoter. Our findings indicate that overexpressed PTMA elicits a p53 response that involves p53 acetylation.

Acetylation↗
PubMed2006

An improved map of conserved regulatory sites for Saccharomyces cerevisiae.

BACKGROUND: The regulatory map of a genome consists of the binding sites for proteins that determine the transcription of nearby genes. An initial regulatory map for S. cerevisiae was recently published using six motif discovery programs to analyze genome-wide chromatin immunoprecipitation data for 203 transcription factors. The programs were used to identify sequence motifs that were likely to correspond to the DNA-binding specificity of the immunoprecipitated proteins. We report improved versions of two conservation-based motif discovery algorithms, PhyloCon and Converge. Using these programs, we create a refined regulatory map for S. cerevisiae by reanalyzing the same chromatin immunoprecipitation data. RESULTS: Applying the same conservative criteria that were applied in the original study, we find that PhyloCon and Converge each separately discover more known specificities than the combination of all six programs in the previous study. Combining the results of PhyloCon and Converge, we discover significant sequence motifs for 36 transcription factors that were previously missed. The new set of motifs identifies 636 more regulatory interactions than the previous one. The new network contains 28% more regulatory interactions among transcription factors, evidence of greater cross-talk between regulators. CONCLUSION: Combining two complementary computational strategies for conservation-based motif discovery improves the ability to identify the specificity of transcriptional regulators from genome-wide chromatin immunoprecipitation data. The increased sensitivity of these methods significantly expands the map of yeast regulatory sites without the need to alter any of the thresholds for statistical significance. The new map of regulatory sites reveals a more elaborate and complex view of the yeast genetic regulatory network than was observed previously.

Algorithms↗
PubMed2006

Preparation of submicron unilamellar liposomes by freeze-drying double emulsions.

A novel method is described for the preparation of sterile submicron unilamellar liposomes. The method is based on the lyophilization of double emulsions containing disaccharides as lyoprotectants in both the inner and outer aqueous phase. Using various phospholipids or mixtures of lipids as emulsifiers, the double emulsions can be prepared by a two-step emulsification, including hydrophilic agents in the inner aqueous phase or lipophilic agents in the oil phase. Then, the double emulsions are lyophilized after sterilization by passing them through a 0.22-microm pore filter. Rehydration of the lyophilized products results in liposomes with a relatively high encapsulation efficiency (for calcein, 87%; 5-fluorouracil, 19%; flurbiprofen, 93%) and a size below 200 nm measured by the dynamic light scattering technique (DLS) and the atomic force microscopy (AFM). The liposomes were found to be unilamellar from freeze-fracture electron micrographs and X-ray diffraction patterns. In addition, the liposomes can be reconstituted just before use by rehydration of the lyophilized products which are relatively stable. Thus, this reproducible and simple technique can be used to prepare sterilized, submicron unilamellar liposomes with a relatively high encapsulation efficiency, and excellent stability during long-term storage.

Emulsions↗
PubMed2006

Polyethersulfone dead-end tube as a scaffold for artificial lacrimal glands in vitro.

Polyethersulfone (PES) dead-end tubes were fabricated by means of a phase inversion technique, and then were used as scaffolds for artificial lacrimal glands. The wall of the dead-end tubes could allow nutrients such as ascorbic acid, L-tryptophan, and glucose to pass through, but prevents rat IgG from passing through. Lacrimal acinar epithelial cells of Sprague-Dawley rats were cultured in vitro, and cell-associated secretory component was detected with an immunofluorescence technique to identify the acinar cells. The second passage of the cells showed high degree of cellular differentiation, and was used to seed on the PES tubes. The results showed that the PES tube could support the attachment, the growth, and the proliferation of the rat lacrimal acinar cells. Thus, PES is a substrate for the growth of lacrimal acinar cells and may be a useful scaffolding biomaterial for tissue engineering, such as a scaffold for artificial lacrimal glands.

Animals↗
PubMed2006

Causes and consequences of mitochondrial reactive oxygen species generation in hepatitis C.

Hepatitis C virus has developed mechanisms to alter the redox state of hepatocytes and this is associated with changes in mitochondrial structure and function. Chronic hepatitis C patients manifest hepatic oxidative stress and this is exacerbated by alcohol consumption and associated with fibrosis progression. Several viral proteins, including core and NS5a appear to contribute to reactive oxygen species (ROS) generation by mechanisms that involve both mitochondria and endoplasmic reticulum (ER). Hepatitis C virus (HCV) core protein localizes to both ER and mitochondria and has effects at both sites. At the mitochondria a chain of events is initiated by core binding, which consists of increased Ca(2+) uptake, increased mitochondrial superoxide production, oxidation of the mitochondrial glutathione pool, inhibition of electron transport complex I activity, and sensitization of mitochondria to Ca(2+)- and ROS-induced membrane permeability transition. These effects have been observed in isolated mitochondria, cells bearing full-length HCV replicons, and liver mitochondria derived from HCV transgenic mice. In addition to these direct effects on mitochondria, core protein has been shown to causes a state of ER stress and an increase in the efficiency of ER to mitochondria Ca(2+) transfer. The resulting oxidized redox state has a number of potential consequences for liver function. It interferes with the antiviral innate immune responses and potentiates fibrosis and carcinogenesis. Alcohol exacerbates these effects by increasing core-induced ROS production, further oxidizing the mitochondrial glutathione pool. The resulting mitochondrial effects may contribute to liver injury and oxidative stress seen in chronic hepatitis C.

Alcohols↗
PubMed2006

Development and pharmacokinetics of nimodipine-loaded liposomes.

In order to improve the water solubility of nimodipine and prolong the time of the drug in the circulation, nimodipine-loaded liposomes with a small size and high entrapment efficiency were prepared by a method that was easy to scale up (the modified ethanol injection method). The nimodipine liposome dispersions were characterized with respect to particle size distribution, zeta potential and entrapment efficiency. Liposomal nimodipine and nimodipine solution were intravenously administered to mice as a single dose of 4 mg kg-1. The pharmacokinetic parameters of nimodipine changed significantly when encapsulated in liposomes. The clearance of nimodipine encapsulated in liposomes was reduced and the elimination half-life was prolonged. The ratios of the area under the curve values of nimodipine liposomes to nimodipine solution were 1.78 and 1.90 in plasma and cerebral tissue, respectively. The drug concentration in cerebral tissue and in plasma showed a good linear correlation, which showed that liposomes could efficiently deliver nimodipine into brain tissue. These findings suggest that intravenous administration of liposomal nimodipine produces higher and more stable plasma and cerebral drug concentrations compared with nimodipine solution. In conclusion, liposomal nimodipine is a promising alternative to the solution preparation.

Animals↗
PubMed2006

[Study on Volt-ampere (V-A) characteristics of human acupoints].

OBJECTIVE: To study on basic Volt-ampere (V-A) characteristics of human acupoints and the changes with physiologic and pathologic changes, and probe their biophysical basis. METHODS: The research works of this research group about V-A characteristics of acupoints in recent 10 years were systematized and analyzed. RESULTS: V-A characteristic curve of human acupoints is of the both characteristics of non-linear and inertia. Compared with controlled point, the lower electric resistance characteristic of acupoints is not popular and the lower inertia is popular. V-A area of acupoints has no obvious circadian rhythms and the inertia area of a large part of acupoints has obvious circadian rhythms, with the phase of peak value corresponding to the phase of valley value of body temperature rhythms. V-A characteristics of acupoints in the patients of heart disease or stomach diseases changes obviously, and these changes have a certain specificities of acupoints. After remission of the lesion, the V-A characteristics of acupoints restore normal. The V-A area and the inertia area of acupoints in the corpse are obviously smaller than the normal person, with disappearance of the characteristics of both the non-linear and inertia of the normal person. CONCLUSION: Human acupoints have characteristics of non-linear and inertia, and the non-linear characteristic reflects complexity of physiology and behavior, while the inertia characteristic is related with energy metabolism of acupoints. The inertia area can more sensitively reflect human physiologic and pathological changes as compared with the V-A area, so it is an important index for the studies on electric characteristics of acupoints in the future.

Acupuncture Points↗
PubMed2006

[The resistance of acupoint and its measurement].

We have analysed the significance of acupoint resistance and some probable problems in its measurement according to biophysics theories and we believe that the skin resistance plays an important role in acupoint resistance. The Volt-ampere curve should be used to describe acupoint resistance, and only when the measurements are under the same condition should the results be compared, because acupoint resistance is nonlinear. The acupoint resistance could be detected only in vivo. In this paper is presented a simple and easy method with which we can connect acupoint into electric circle. Also reported here is how to control the circumstance condition while measurements are taken.

Acupuncture Points↗
PubMed2006

[Adaptability of Moina affinis (Crustacea: Cladocera: Moinidae) to seawater salinity].

By the methods of experimental ecology, this paper studied the effects of different salinity (0, 1, 2, 3, 4, 5) on the survival, growth, and reproduction of Moina affinis (Crustacea: Cladocera: Moinidae) at 25 degrees C +/- 0.5 degrees C under laboratory conditions, aimed to know the adaptability of freshwater cladocerans to seawater salinity. The results indicated that when the salinity increased from 0 to 5, the mean lifespan of M. affinis was 16.8 +/- 1.3, 17.8 +/- 3.5, 14.2 +/- 5.7, 13.0 +/- 1.6, 9.6 +/- 1.5 and 6.6 +/- 1.8 days, intrinsic increase rate (rm) was 0.91 +/- 0.01, 0.96 +/- 0.01, 0.86 +/- 0.10, 0.86 +/- 0.05, 0.49 +/- 0.18 and 0.24 +/- 0.06 d (-1) mean eggs production per clutch was 34.5 +/- 3.7, 34.2 +/- 3.9, 27.5 +/- 7.1, 34.6 +/- 3.9, 12.3 +/- 5.0 and 9.1 +/- 2.1 ind., and life fecundity was 410 +/- 32, 445 +/- 84, 250 +/- 106, 294 +/- 47, 59 +/- 38 and 24 +/- 6 ind., respectively. There was a significant difference in mean lifespan, intrinsic increase rate, and mean eggs production per clutch between treatments salinity 0, 1, 2 and 3 and treatments salinity 4 and 5, and in life fecundity between treatments salinity 0 and 1 and treatments salinity 2, 3, 4 and 5. The body length and daily growth rate was lower in control than in other treatments. It was suggested that salinity 5 was the maximum threshold salinity for the survival and reproduction of M. affinis, but after a short period of acclimatization in diluted seawater, the maximum threshold could reach 6. 5.

Acclimatization↗
PubMed2005

The behavior of SATB1, a MAR-binding protein, in response to apoptosis stimulation.

As a MAR-binding protein, SATB1 regulates genes by folding chromatin into a loop domain. Apoptosis is known to be accompanied by a collapse of nuclear architecture and cleavage of condensing chromatin into oligonucleosomal fragments. To further understand the functional role of MAR-binding proteins during apoptosis we investigated the relationship of the behavior of SATB1 and the collapse of nuclear architecture in Jurkat cells with immunostaining and Western blot analysis. We demonstrated that SATB1 formed special three-dimensional network distributions during early apoptosis. The distribution change of SATB1 was associated with cleavage of the protein and accompanied by the nuclear architecture collapse. Cleavage of SATB1 was mediated by caspase-3 and was apoptosis specific. Our observations further support the notion that early proteolysis of MAR-binding proteins might represent a universal mechanism that renders these DNA sites vulnerable to endonucleolysis.

Apoptosis↗
PubMed2005

Improved protein-adsorption-resistant property of PES/SPC blend membrane by adjustment of coagulation bath composition.

To improve surface protein-adsorption-resistant property of polyethersulfone (PES) membranes, soybean phosphatidylcholine (SPC) was added to PES casting solution. The blend membranes were prepared by a phase inversion method in a wet process. The surface of PES/SPC blend membranes was characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). XPS data revealed that the phosphorylcholine (PC) groups were concentrated at the surface by changing the composition of coagulation bath. Addition of N,N-dimethylformamide (DMF) in coagulation bath could prolong coagulation time and facilitate the migration of SPC from polymer bulk to membrane surface. The PES/SPC blend membranes dramatically reduced BSA and fibrinogen adsorption compared to PES control membrane due to effective immobilization of PC groups at the surface of PES/SPC blend membranes.

Adsorption↗
PubMed2005

Tcf- and Vent-binding sites regulate neural-specific geminin expression in the gastrula embryo.

Vertebrate neural development has been extensively investigated. However, it is unknown for any vertebrate gene how the onset of neural-specific expression in early gastrula embryos is transcriptionally regulated. geminin expression is among the earliest markers of dorsal, prospective neurectoderm at early gastrulation in Xenopus laevis. Here, we identified two 5' sequence domains that are necessary and sufficient to drive neural-specific expression during gastrulation in transgenic Xenopus embryos. Each domain contained putative binding sites for the transcription factor Tcf, which can mediate Wnt signaling and for Vent homeodomain proteins, transcriptional repressors that mediate BMP signaling. Results from embryos transgenic for constructs with mutated Tcf or Vent sites demonstrated that signaling through the Tcf sites was required for dorsal-specific expression at early gastrulation, while signaling through the Vent sites restricted geminin expression to the prospective neurectoderm at mid-gastrulation. Consistent with these results, geminin 5' regulatory sequences and endogenous Xgem responded positively to Wnt signaling and negatively to BMP signaling. The two 5' sequence domains were also conserved among geminin orthologs. Together, these results demonstrate that signaling through Tcf and Vent binding sites regulates transcription of geminin in prospective neurectoderm during gastrulation.

Animals↗