Biomedical subjects

Ge Wang

Publications and source records attributed to Ge Wang.

79 records · Page 5Linked to original sources

PubMed2002

[Rapid induction of mRNAs for liver regeneration genes by hepatopoietin and partial hepatectomy].

OBJECTIVE: To investigate the effect of recombinant human hepatopoietin (rhHPO) and partial hepatectomy on rapidly induced expression of immediate early gene. METHODS: We investigated the different gene expression within 1 hour after 2/3 partial hepatectomy by representational difference analysis and in primary cultured hepatocytes system. RESULTS: In the expressed sequence tag (EST) library, we identified that most of these genes were immediate early gene, and found one new gene PC3 that might be associated to liver regeneration in the EST library. Moreover, PC3 gene was rapidly induced after 2/3 partial hepatectomy and the expressing peak was within 1~2 hours after operation. HPO can rapidly induce the expression of these genes (c-fos, LRF-1, and PC3, etc.) in primarily cultured rat hepatocyte, which might be one of HPO molecular mechanism on stimulating hepatocyte proliferation. CONCLUSIONS: rhHPO and partial hepatectomy can rapidly induce the expression of immediate early gene. PC3 gene is immediate early gene related to liver regeneration.

Animals↗

PubMed2002

[Preparation of thin hydroxyapatite layers on cp titanium through anodic oxidation followed with hydrothermal treatment].

To study the method of anodic oxidation followed by hydrothermal treatment for cp titanium and to know bone response to thin hydroxyapatite layers in vivo, commercially pure titanium plates were anodized at 200 V-400 V with direct electric current density no more than 50 mA/cm2 for 15 minutes in the electrolytic trough. beta-glycerophosphate sodium(0.03-0.04 M) and calcium acetate(0.2-0.3 M) were used as electrolytes. Then, titanium plates were hydrothermal treated in the autoclave for 2 hours at 280 degrees C-300 degrees C. Polishing and grit-blasting surface was used as control to learn bone response to thin layers. Twelve rabbits were evenly divided into 3 groups, each group was implanted with 12 implants into the rabbits femoral bone. After 4, 8 and 16 weeks, implants were taken out and collected respectively and were made grinding slices. The bone-implant interface was observed with light microscope. And the bone-implant interface of polishing and layered implants after 8 weeks implantation was observed with scanning electron microscope. The element contents at the interface of polishing and layered implants before and after 8 weeks implantation were detected with EDAX. Results showed that there was hydroxyapatite(HA) precipitated on the titanium surfaceamellae bone in 8 weeks for thin HA coatings, and no HA debris were found at the interfacial zone. In addition, Ca and P content on the hydrothermal treated implant surface increased much more after implantation than that of polished implants. It was concluded that anodic oxidation followed by hydrothermal treatment could precipitate thin hydroxyapatie layer on the surface of cp titanium, which could improve early formation of woven bone and accelerate woven bone transferring to lamellae bone at the implanted site.

Animals↗

PubMed2001

Fast Algorithm for X-ray Cone-beam Microtomography.

Cone-beam X-ray microtomography attracts increasing attention due to its applications in biomedical sciences, material engineering, and industrial nondestructive evaluation. Rapid volumetric image reconstruction is highly desirable in all these areas for prompt visualization and analysis of complex structures of interest. In this article, we reformulate a generalized Feldkamp cone-beam image reconstruction algorithm, utilize curved voxels and mapping tables, improve the reconstruction efficiency by an order of magnitude relative to a direct implementation of the standard algorithm, and demonstrate the feasibility with numerical simulation and experiments using a prototype cone-beam X-ray microtomographic system. Our fast algorithm reconstructs a 256-voxel cube from 100 projections within 2 min on an Intel Pentium II(R) 233 MHz personal computer, produces satisfactory image quality, and can be further accelerated using special hardware and/or parallel processing techniques.

Journal Article↗

PubMed1999

Novel Helicobacter pylori alpha1,2-fucosyltransferase, a key enzyme in the synthesis of Lewis antigens.

Helicobacter pylori lipopolysaccharides (LPS) contain complex carbohydrates known as Lewis antigens which may contribute to the pathogenesis and adaptation of the bacterium. Involved in the biosynthesis of Lewis antigens is an alpha1,2-fucosyltransferase (FucT) that adds fucose to the terminal betaGal unit of the O-chain of LPS. Recently, the H. pylori (Hp) alpha1,2-FucT-encoding gene (fucT2) was cloned and analysed in detail. However, due to the low level of expression and instability of the protein, its enzymic activity was not demonstrated. In this study, the Hp fucT2 gene was successfully overexpressed in Escherichia coli. Sufficient amounts of the protein were obtained which revealed alpha1,2-fucosyltransferase activity to be associated with the protein. A series of substrates were chosen to examine the acceptor specificity of Hp alpha1,2-FucT, and the enzyme reaction products were identified by capillary electrophoresis. In contrast to the normal mammalian alpha,2-FucT (H or Se enzyme), Hp alpha1,2-FucT prefers to use Lewis X [betaGal1-4(alphaFuc1-3)betaGlcNAc] rather than LacNAc [betaGal1-4betaGIcNAc] as a substrate, suggesting that H. pylori uses a novel pathway (via Lewis X) to synthesize Lewis Y. Hp alpha1,2-FucT also acts on type 1 acceptor [betaGal1-3betaGlcNAc] and Lewis a [betaGal1-3(alphaFuc1-4)betaGIcNAc], which provides H. pylori with the potential to synthesize H type 1 and Lewis b epitopes. The ability to transfer fucose to a monofucosylated substrate (Lewis X or Lewis a) makes Hp alpha1,2-FucT distinct from normal mammalian alpha1,2-FucT.

Antigens, Bacterial↗

PubMedDate not supplied

Projection-based bolus detection for computed tomographic angiography.

Computed tomographic (CT) angiography is important for imaging studies on cardiovascular structures, peripheral vessels, and solid organs. In practice, a CT angiography scan is triggered by the bolus arrival at a prespecified anatomical location, which is determined using CT fluoroscopy. In this article, we propose a projection-based method adapted from the Grangeat formula to detect the bolus arrival. Then, we evaluate our new method in numerical and animal studies. Our results indicate that this method allows significantly better temporal resolution and is computationally more efficient, as compared with the image-based methods.

Algorithms↗

PubMedDate not supplied

Boundary integral method for bioluminescence tomography.

Bioluminescence tomography (BLT) allows in vivo localization and quantification of bioluminescent sources inside a small animal to reveal various molecular and cellular activities. We develop a reconstruction method to identify such a bioluminescent source distribution using the boundary integral method. Based on the diffusion model of the photon propagation in the biological tissue, this method incorporates a priori knowledge to define the permissible source region, and establish a direct linear relationship between measured body surface data and an unknown bioluminescent source distribution to enhance numerical stability and efficiency. The feasibility of the proposed BLT algorithm is demonstrated in heterogeneous mouse chest phantom studies.

Algorithms↗

PubMedDate not supplied

A clinical evaluation of bleaching using whitening wraps and strips.

This study evaluated the degree of color change of teeth and the sensitivities of teeth and gums in an in vivo study. Ranir Whitening Wraps (WW2) and Crest Whitestrips Premium (WP2) were used twice a day and Ranir Whitening Wraps (WW1) were used once a day. Color evaluations occurred at baseline, after five and seven-day use of bleaching agent and 14 days post-bleaching. Color change was evaluated objectively and subjectively. Sensitivity evaluations were also accomplished. Seventy-six of the 78 subjects enrolled completed the study. All three products significantly lightened teeth. WW2 lightened more than WP2 and WW1 in L*, a*, b*, E and shade guide value. WP2 lightened more than WW1 in a*, b*, E and shade guide value. There was no difference in tooth sensitivity, but WW1 and WP2 caused less gingival sensitivity than WW2. The mean age of smokers was seven years younger than nonsmokers who qualified.

Adult↗