Biomedical subjects

Jian Wu

Publications and source records attributed to Jian Wu.

At least 37 records · Page 2Linked to original sources

PubMed2006

Double-deformable-mirror adaptive optics system for phase compensation.

Two kinds of algorithm for an adaptive optics (AO) system that uses two deformable mirrors (DMs), one with large stroke and the other with high spatial frequency, to correct different aberrations are described. The algorithms are based on modal method and direction-gradient method, respectively. Numerical simulations for the algorithms have been made. The simulation results indicate that the two DMs in the AO system can correct different aberrations with different characteristics, and the closed-loop performance of a double-DM AO system will be almost the same as that of an AO system that uses a single DM with an ideal stroke.

Journal Article↗

PubMed2006

Expression of hiwi gene in human gastric cancer was associated with proliferation of cancer cells.

Stem cell genetics research may be critical to our understanding of carcinogenesis, as both stem cells and cancer cells possess the ability to self-renew. Recent discoveries have indicated that the piwi family of genes plays an essential role in stem cell self-renewal in diverse organisms. The hiwi gene, the human homolog of the piwi family, participates in germ cell proliferation and its overexpression may cause the development of germ cell malignancy, but its expression and function in epithelial solid cancers have not been explored. In the present study, we investigated whether there was an association between hiwi expression and human gastric cancer and its potential mechanism. RT-PCR findings demonstrated that hiwi was expressed in different gastric cancer cell lines. To identify the HIWI protein in gastric cancer, we developed a specific monoclonal antibody against HIWI and immunohistochemistry was performed on various gastric tissues. We found that the expression ratio of hiwi in normal gastric tissues, atrophic gastritis, intestinal metaplasia and gastric cancers was 10% (5/50), 36% (18/50), 36% (18/50) and 76% (38/50), respectively, which was consistent with precancerous development. Notably, the expression pattern of hiwi in gastric cancer tissues was similar to that of Ki67, which was used as a marker of proliferation. Moreover, the suppression of hiwi by antisense or RNAi inhibited the growth of gastric cancer cells and induced cell cycle arrest in G2/M phase. These results suggest that hiwi may be involved in the development of gastric cancer and is a potential target for cancer therapy.

Antibodies, Monoclonal↗

PubMed2006

Complete elimination of colorectal tumor xenograft by combined manganese superoxide dismutase with tumor necrosis factor-related apoptosis-inducing ligand gene virotherapy.

Manganese superoxide dismutase (MnSOD) is a latent tumor suppressor gene. To investigate the therapeutic effect of MnSOD and its mechanisms, a replication-competent recombinant adenovirus with E1B 55-kDa gene deletion (ZD55) was constructed, and human MnSOD and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) genes were inserted to form ZD55-MnSOD and ZD55-TRAIL. ZD55-MnSOD exhibited an inhibition in tumor cell growth approximately 1,000-fold greater than Ad-MnSOD. ZD55-TRAIL was shown to induce the MnSOD expression in SW620 cells. Accordingly, by the combined use of ZD55-MnSOD with ZD55-TRAIL (i.e., "dual gene virotherapy"), all established colorectal tumor xenografts were completely eliminated in nude mice. The evidence exists that the MnSOD overexpression led to a slower tumor cell growth both in vitro and in vivo as a result of apoptosis caused by MnSOD and TRAIL overexpression after adenoviral transduction. Our results showed that the production of hydrogen peroxide derived from MnSOD dismutation activated caspase-8, which might down-regulate Bcl-2 expression and induce Bax translocation to mitochondria. Subsequently, Bax translocation enhanced the release of apoptosis-initiating factor and cytochrome c. Cytochrome c finally triggered apoptosis by activating caspase-9 and caspase-3 in apoptotic cascade. Bax-mediated apoptosis seems to be dependent on caspase-8 activation because the inhibition of caspase-8 prevented Bid processing and Bax translocation. In conclusion, our dual gene virotherapy completely eliminated colorectal tumor xenografts via enhanced apoptosis, and this novel strategy points toward a new direction of cancer treatment.

Adenoviridae↗

PubMed2006

Nanofibrous poly(acrylonitrile-co-maleic acid) membranes functionalized with gelatin and chitosan for lipase immobilization.

Nanofibrous membranes with an average diameter of 100 and 180 nm were fabricated from poly(acrylonitrile-co-maleic acid) (PANCMA) by the electrospinning process. These nanofibrous membranes contain reactive groups which can be used to covalently immobilize biomacromolecules. Two natural macromolecules, chitosan and gelatin, were tethered on these nanofibrous membranes to fabricate dual-layer biomimetic supports for enzyme immobilization in the presence of 1-ethyl-3-(dimethyl-aminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxyl succinimide (NHS). Lipase from Candida rugosa was then immobilized on these dual-layer biomimetic supports using glutaraldehyde (GA), and on the nascent PANCMA fibrous membrane using EDC/NHS as coupling agent, respectively. The properties of the immobilized lipases were assayed. It was found that there is an increase of the activity retention of the immobilized lipase on the chitosan-modified nanofibrous membrane (45.6+/-1.8%) and on the gelatin-modified one (49.7+/-1.8%), compared to that on the nascent one (37.6+/-1.8%). The kinetic parameters of the free and immobilized lipases, K(m) and V(max), were also assayed. In comparison with the immobilized lipase on the nascent nanofibrous membrane, there is an increase of the V(max) value for the immobilized lipases on the chitosan- and gelatin-modified nanofibrous membranes. Results also indicate that the pH and thermal stabilities of lipases increase upon immobilization. The residual activities of the immobilized lipases are 55% on the chitosan-modified nanofibrous membrane and 60% on the gelatin-modified one, after 10 uses.

Acrylic Resins↗

PubMed2006

Generation and weak beam control of two-dimensional multicolored arrays in a quadratic nonlinear medium.

We report on the first experimental observation of 2D multicolored transverse arrays in a quadratic nonlinear medium under the pump of two crossly overlapped femtosecond beams. The 2D reproducible patterns are caused by cascaded noncollinear quadratic nonlinear couplings between the input pulses and quadratic spatial solitons originated from spatial breakup of one of the input beams with spatial ellipticity. A seed supercontinuum pulse is then diffracted and amplified with phase preservation, resulting in the formation of up-converted multicolor 2D transverse arrays. By seeding with weak second harmonic pulses, the 2D multicolored transverse patterns are suppressed due to weak beam control of the induced quadratic spatial solitons.

Journal Article↗

PubMed2006

Molecular therapy for hepatic injury and fibrosis: where are we?

Hepatic fibrosis is a wound healing response, involving pathways of inflammation and fibrogenesis. In response to various insults, such as alcohol, ischemia, viral agents, and medications or hepatotoxins, hepatocyte damage will cause the release of cytokines and other soluble factors by Kupffer cells and other cell types in the liver. These factors lead to activation of hepatic stellate cells, which synthesize large amounts of extracellular matrix components. With chronic injury and fibrosis, liver architecture and metabolism are disrupted, eventually manifesting as cirrhosis and its complications. In addition to eliminating etiology, such as antiviral therapy and pharmacological intervention, it is encouraging that novel strategies are being developed to directly address hepatic injury and fibrosis at the subcellular and molecular levels. With improvement in understanding these mechanisms and pathways, key steps in injury, signaling, activation, and gene expression are being targeted by molecular modalities and other molecular or gene therapy approaches. This article intends to provide an update in terms of the current status of molecular therapy for hepatic injury and fibrosis and how far we are from clinical utilization of these new therapeutic modalities.

Animals↗

PubMed2006

An amplified mass piezoelectric immunosensor for Schistosoma japonicum.

An ultrasensitive piezoelectric immunosensor using an amplification path based on an insoluble biocatalyzed precipitation product has proposed for Schistosoma japonicum. A mercapto Schistosoma japonicum antigen was self-assembled onto the quartz crystal surface via an Au nanoparticle mediator monolayer to sense the Schistosoma japonicum antibody (SjAb). And the horseradish peroxidase labeled protein A conjugate which was bounded to the SjAb by a "sandwich" format was used as a biocatalyst for the oxidative precipitation of 4-chloro-1-naphthol by H(2)O(2) to yield the insoluble product benzo-4-chlorohexadienone, resulting in an amplified mass sensing of antigen-antibody interaction. The amount of the precipitate accumulated on the quartz crystal is controlled by the antibody concentration. The SjAb can be linearly determined in the range of 10-200 ngml(-1) and the detection limit reaches as low as 5 ngml(-1).

Animals↗

PubMed2006

Phagocytosis of apoptotic bodies by hepatic stellate cells induces NADPH oxidase and is associated with liver fibrosis in vivo.

Hepatic stellate cell activation is a main feature of liver fibrogenesis. We have previously shown that phagocytosis of apoptotic bodies by stellate cells induces procollagen alpha1 (I) and transforming growth factor beta (TGF-beta) expression in vitro. Here we have further investigated the downstream effects of phagocytosis by studying NADPH oxidase activation and its link to procollagen alpha1 (I) and TGF-beta1 expression in an immortalized human stellate cell line and in several models of liver fibrosis. Phagocytosis of apoptotic bodies in LX-1 cells significantly increased superoxide production both in the extracellular and intracellular milieus. By confocal microscopy of LX-1 cells, increased intracellular reactive oxygen species (ROS) were detected in the cells with intracellular apoptotic bodies, and immunohistochemistry documented translocation of the NADPH oxidase p47phox subunit to the membrane. NADPH oxidase activation resulted in upregulation of procollagen alpha1 (I); in contrast, TGF-beta1 expression was independent of NADPH oxidase activation. This was also confirmed by using siRNA to inhibit TGF-beta1 production. In addition, with EM studies we showed that phagocytosis of apoptotic bodies by stellate cells occurs in vivo. In conclusion, these data provide a mechanistic link between phagocytosis of apoptotic bodies, production of oxidative radicals, and the activation of hepatic stellate cells.

Animals↗

PubMed2006

Delivery of antioxidative enzyme genes protects against ischemia/reperfusion-induced liver injury in mice.

Hepatic ischemia/reperfusion (I/R) injury is characterized by the generation of reactive oxygen species (ROS), such as superoxide anions and hydrogen peroxide. The aim of this study is to investigate whether antioxidative gene delivery by our polylipid nanoparticles (PLNP) is an effective approach for prevention of the injury. Polyplexes of extracellular superoxide dismutase (EC-SOD) and/or catalase genes were injected via the portal vein 1 day prior to a warm I/R procedure in mice. The effects of the gene delivery were determined 6 hours after starting reperfusion. PLNP-mediated antioxidative gene delivery led to a marked increase in human EC-SOD and catalase gene expression in the liver. Liver superoxide dismutase (SOD) and catalase activity both increased approximately 10-fold. Increased liver superoxide anion levels caused by the I/R procedure were reduced to normal levels by EC-SOD gene delivery. The overexpression of these 2 antioxidative genes significantly suppressed the I/R-induced elevation of serum alanine aminotransferase (ALT) levels, decreased liver malondialdehyde content, restored glutathione reserve, and improved liver histology. In conclusion, EC-SOD or catalase gene delivery by PLNP resulted in high levels of the transgene activity in the liver, and markedly attenuated hepatic I/R injury. The protection is directly associated with elevated antioxidative enzyme activity as the result of the gene delivery. This novel approach may become a potential therapy to improve graft function and survival after liver transplantation.

Animals↗

PubMed2006

Effect of astragalus injection on serious abdominal traumatic patients' cellular immunity.

OBJECTIVE: To explore the change of serious abdominal traumatic patients' cellular immunity and the effect of Astragalus Injection (AI) on it. METHODS: Sixty-three serious abdominal traumatic patients were randomly assigned into two groups, the conventional group and the treated group, patients in the conventional group were given conventional treatment, while others in the treated group were given conventional treatment as the basis, with AI 20 ml was added into 250 ml of 5% glucose solution given through intravenous dripping, and then on the first day and 14th day, their T cell activated antigens as well as that of 10 healthy subjects were monitored. RESULTS: On the first day, in the conventional group and treated group, the levels of CD(3)(+), CD(4)(+), CD(4)(+)/CD(8)(+), CD(16)(+), CD(69)(+) and CD(3)(+)/homologous leucocytic antigen-DR (HLA-DR(+)) were apparently lower than those in the healthy group (P < 0.05), while the CD(8)(+) was significantly higher than that in the healthy group (P < 0.05), and there was no significant difference between the conventional group and the treated group (P > 0.05); on the 14th days, the levels of CD(3)(+), CD(4)(+), CD(4)(+)/CD(8)(+), CD(16)(+), CD(69)(+) and CD(3)(+)/HLA-DR(+) of the treated group got closed to healthy subject value, and got even higher than those of conventional group (P < 0.05); CD(8)(+) got close to that of healthy subjects, while obviously lower than that of conventional group (P < 0.05). CONCLUSION: After serious abdominal trauma, cellular immunity lowered, auxiliary use of AI was beneficial to the restoration of cellular immunity.

Abdominal Injuries↗

PubMed2006

Soybean isoflavones preserve bone mass in hindlimb-unloaded mice.

It is well known that skeletal unloading induces bone loss. It has been shown that soybean isoflavones are effective in preventing bone loss in osteoporotic animals. We investigated the ability of isoflavones to protect bone loss induced by hindlimb unloading by using a tail-suspension mouse model. Eight-week-old female mice were divided into five groups: (1) normal housed group (Normal), (2) sham unloaded group fed a control diet (Sham-UL), (3) hindlimb unloaded group fed a control diet (UL-C), (4) hindlimb unloaded group fed a 0.25% isoflavone conjugates diet (UL-ISO 0.25), and (5) hindlimb unloaded group fed a 0.5% isoflavone conjugates diet (UL-ISO 0.5). After 3 weeks, bone mineral density (BMD) of the femur was significantly decreased in UL-C, and this bone loss was prevented by isoflavone treatment. Histomorphometric analysis revealed a decrease in the cancellous bone of the distal femur in the UL-C group, and isoflavone prevented this change. Serum corticosterone increased in the UL-C group, and isoflavones inhibited the elevation. These results suggest that isoflavones might be promising food components that provide protection from bone loss and normalize stress-induced serum corticosterone during skeletal unloading.

Animals↗

PubMed2006

Cooperative effects of isoflavones and exercise on bone and lipid metabolism in postmenopausal Japanese women: a randomized placebo-controlled trial.

Cooperative effects of isoflavones and exercise on bone and lipid metabolism have been exhibited in estrogen-deficient animals; however, results from clinical trials have not been published. In this study, we determined the effects of isoflavone intake and walking and their interaction on bone and lipid metabolism in postmenopausal women over 24 weeks. The bioavailability and metabolism of isoflavones (daidzein in particular) were also examined to clarify the mechanism of their bone-protective effects in humans. One hundred twenty-eight subjects were randomly assigned to 4 groups: placebo; placebo combined with walking (3 times per week); isoflavone intake (75 mg of isoflavones conjugates per day); and isoflavone combined with walking. The subjects were classified by equol status (producers or nonproducers) as identified using production of equol from daidzein in fecal culture. Bone mineral density (BMD), body composition, and serum concentrations of isoflavones were assessed. Serum high-density lipoprotein cholesterol concentration significantly increased (6.1%, P = .03), and fat mass in the whole body significantly decreased (-4.3%, P = .0003) from the baseline in the combined intervention group. There were no significant differences in BMD between baseline and postintervention in any of the treatment groups. However, the percent changes in BMD in equol producers were -0.53% and +0.13% in the sub-whole body and total hip, respectively. This was significantly different compared with -1.35 and -1.77 for the sub-whole body and total hip, respectively, in nonproducers in the isoflavone group (P = .049 and .040, respectively). The mean serum equol concentration was significantly higher in equol producers than in nonproducers in the isoflavone groups, but not in the placebo group. The combination of isoflavones and exercise exhibited favorable effects on serum lipid and body composition of postmenopausal women. The findings of this study suggest that the preventive effects of isoflavones on bone loss depend on the individual's intestinal flora for equol production.

Asian People↗

PubMed2006

Effects of spirulina, a blue-green alga, on bone metabolism in ovariectomized rats and hindlimb-unloaded mice.

The safety and effectiveness were examined of the spirulina alga on bone metabolism in ovariectomized estrogen-deficient rats and hindlimb-unloaded mice. The dosage range was from an amount equal to that recommended in so-called health foods for humans (0.08 g/kg BW/day) to a 100-fold higher dose. The bone mineral density (BMD) of the whole femur and tibia of ovariectomized rats in the any spirulina-treated groups was not significantly different from that of the ovariectomized group, although BMD of the distal femur and proximal tibia was significantly lower in the spirulina-treated groups than in the ovariectomized group after a 6 week-experimental period. BMD of the femur and tibia was not affected by treatment with any dose of spirulina in hindlimb-unloaded mice. These results suggest that the intake of spirulina decreased BMD in the trabecular bone of rodents under estrogen-deficient conditions.

Aging↗

PubMed2006

Effects of isoflavone and exercise on BMD and fat mass in postmenopausal Japanese women: a 1-year randomized placebo-controlled trial.

UNLABELLED: The combined intervention of isoflavone intake and walking exercise over 1 year in postmenopausal Japanese women exhibited a trend for a greater effect on prevention of bone loss at the total hip and Ward's triangle regions. INTRODUCTION: The additive effects of isoflavones and exercise on bone and lipid metabolism have been shown in estrogen-deficient animals. In this study, we determined the effects of isoflavone intake, walking exercise, and their interaction on bone, fat mass, and lipid metabolism over 1 year in postmenopausal Japanese women. MATERIALS AND METHODS: A total of 136 postmenopausal women at <5 years after the onset of menopause were randomly assigned to four groups: (1) placebo, (2) walking (45 minutes/day, 3 days/week) with placebo, (3) isoflavone intake (75 mg of isoflavone conjugates/day), and (4) combination of isoflavone plus walking. BMD, fat mass, serum lipid, and serum and urinary isoflavone concentrations were assessed. RESULTS: A significant main effect of isoflavone on the reduction in trunk fat mass was obtained at 12 months. Significant main effects of walking on the reduction in fat mass in the whole body and the trunk were observed at 3, 6, and 12 months and that in the legs and arms at 6 and 12 months. Serum high-density lipoprotein (HDL)-cholesterol concentration significantly increased by 12 months after the walking and the combined intervention. After 12 months, a significant main effect of isoflavone on BMD was observed only at Ward's triangle. Walking prevented bone loss at the total hip and the Ward's triangle to significant degrees. The effect of the combined intervention on BMD at total hip and Ward's triangle regions was greater than that of either alone. No significant interaction was observed between isoflavone and walking in any measurements recorded during the study. CONCLUSIONS: Our study suggest that combined intervention of 75 mg/day of isoflavone intake and walking exercise 3 times/week for 1 year showed a trend for a greater effect on BMD at total hip and Ward's triangle regions than either alone. Intervention with isoflavone in postmenopausal Japanese women showed a modest effect on BMD compared with those in Westerners. Further studies over longer treatment duration that include assessment of BMD at various regions are necessary to ascertain the clinical significance of the combined intervention of isoflavone plus walking in postmenopausal women.

Adiposity↗

PubMed2006

[The effect of aerobic and anaerobic endurance training on the regulating function of autonomic nervous system and its significance].

To evaluate the effect of aerobic and anaerobic endurance training the regulating the function of autonomic nervous system, in order to provide scientific basis for optimizing the project of physical fitness training. Fourty-one healthy young men were randomly divided into aerobic and anaerobic endurance training groups. The training period was 8 weeks. Pre-exercise, 4 weeks and 8 weeks after trained, HRV were measured compared with pre-exercise. The autonomic balance in aerobic endurance group had an increasing parasympathetic activity (HF, HFnu, RMSSD, PNN50, all P was < 0.05) and relatively decreasing sympathetic activity (LFnu). This group showed a parasympathetic predominance (LF/HF) and increase of HRV. While in the anaerobic group there was a relative stabilization with the function of autonomic nervous system. The present study shows that the effect of aerobic and anaerobic endurance training on the autonomic nervous system depends on its intensity. Proper intensity of anaerobic endurance training may be beneficial to improve the adaptability of human body for circumstances as aerobic endurance training.

Adolescent↗

PubMed2005

[Clinical evaluation of emergency liver transplantation for patients with benign end-stage liver diseases].

OBJECTIVE: To evaluate the efficacy of emergency liver transplantation in treating patients with benign end-stage liver diseases and explore the possible prognostic factors. METHOD: The clinic data of 46 cases of recipients who underwent ELT were retrospectively analyzed. clinicopathological variables (including age, gender, etiology, serum creatinine, PT, INR, albumin, total bilirubin) were compared between the survival group (n = 32) and the dead group (n = 14). And the prognostic values of CTP and MELD score were analyzed. RESULTS: Higher serum creatinine level, MELD score and CTP score were found in the dead group, as compared to those in survival group. The survival rates among CTP or MELD categories showed significant difference. Three-and six months and one year survival rates of total recipients were 73.9% , 71.7% and 69.6% respectively. CONCLUSION: Emergency liver transplantation is an effective treatment to salvage patients in end-stage. Serum creatinine is the important prognostic factor to the posttransplant survival. MELD score system is more sensitive than CTP classification in predicting the prognosis.

Adult↗

PubMed2005

Liquid-crystalline supramolecular polymers formed through complementary nucleobase-pair interactions.

We report how the placement of nucleobase units, thymine, or N6-(4-methoxybenzoyl)adenine, onto the ends of a mesogenic core, bis-4-alkoxy-substituted bis(phenylethynyl)benzene, affects the properties of these materials. We show that addition of these bulky polar groups significantly reduces the range of liquid-crystalline behavior of these compounds. However, mixing two complementary nucleobase-containing AA- and BB-type monomer units together does result in the formation of stable, thermotropic liquid-crystalline (LC) phases. Hydrogen bonding is shown to play an important role in the formation of these LC phases, consistent with the formation of oligomeric or polymeric hydrogen-bonded aggregates. X-ray analyses of these mixed materials are consistent with the formation of smectic C phases.

Adenine↗

PubMed2005

Influences of bracket bonding on mutans streptococcus in plaque detected by real time fluorescence-quantitative polymerase chain reaction.

BACKGROUND: Enamel demineralization occurs frequently during orthodontic treatment. In this study, we evaluated the changes of the density of mutans streptococcus (MS) in plaque after bracket bonding and using fluoride adhesive on maxillary incisors by real time fluorescence-quantitative polymerase chain reaction (RT-FQ PCR). METHODS: The study was designed as a self-paired test. Brackets were bonded with fluoride adhesive on the left side, while non-fluoride adhesive on the right side for each patient. Plaque samples were taken from the surfaces around the brackets of four maxillary incisors before brackets bonding and after the bonding 4 weeks later. The amount of MS was measured by RT-FQ PCR. The data obtained were analyzed statistically using the SPSS 11.5 version and the alpha level was set at 0.05 (2-tailed). RESULTS: The amount of MS in plaque increased significantly after bracket bonding (P < 0.01), whereas no significant differences were observed among four maxillary incisors both before and after brackets bonding (P > 0.05), and among the incisors using and not using fluoride adhesive (P > 0.05). CONCLUSIONS: The increase of the density of MS in plaque after bracket bonding is one of the etiological factors for enamel demineralization in orthodontic patients. The result of this study did not support what we observed clinically that the incidence of enamel demineralization for lateral incisors was higher than that for central incisors. Using fluoride adhesive for bonding did not affect the amount of MS in plaque in our study. Further study is needed.

Adhesives↗