Biomedical subjects

Wei Yao

Publications and source records attributed to Wei Yao.

At least 19 recordsLinked to original sources

PubMed2006

Sequential treatment of ovariectomized mice with bFGF and risedronate restored trabecular bone microarchitecture and mineralization.

Basic fibroblast growth factor (bFGF), a potent mitogen, has been found to restore trabecular bone mass and connectivity in osteopenic rats. The purpose of this study was to determine how sequential treatment of ovariectomized (OVXed) mice with bFGF followed by risedronate would restore trabecular microarchitecture and improve bone strength through alterations in bone mineralization. Six-month old female Swiss-Webster mice were OVXed or sham-operated and left untreated for 4 weeks to develop osteopenia. At week 5, a group of Sham and OVXed mice were treated with vehicle, and 3 other groups of OVXed mice were treated with bFGF (1 mg/kg daily, s.c., 5x/week) for 3 weeks. At week 8, one group of bFGF-treated mice was sacrificed and the other two bFGF-treated groups were treated with vehicle or risedronate (Ris, 5 microg/kg, s.c., 3x/week) for an additional 6 weeks. Study endpoints included trabecular microarchitecture by microCT, histomorphometry, bone turnover, degree of bone mineralization (DBM), and whole bone strength for the lumbar vertebral body. Compared to sham-operated animals, OVXed mice had significant reductions in trabecular bone volume, connectivity density, DBM, and bone biomechanical properties (P < 0.05). Treatment with bFGF resulted in higher trabecular bone structure and bone strength compared to pre-treatment sham control (P < 0.05). Treatment of OVXed mice with bFGF for 3 weeks followed by 6 weeks Ris maintained the trabecular microarchitecture gained by bFGF treatment, and DBM and bone strength were restored to baseline control levels. Also compared to Sham-operated animals, serum TGF-beta1 was transiently increased after OVX, increased an additional 100% after bFGF withdrawal, and decreased by 30% with risedronate. In addition, DBM was the strongest predictor for bone biomechanical properties (R2 > 0.7, P < 0.001). Serum TGF-beta1 correlated with bone turnover (DPD/Cr, osteocalcin) and was negatively correlated to DBM. Thus, in osteopenic mice, sequential treatment with bFGF followed by risedronate increased trabecular bone microarchitecture, DBM, and bone strength. In addition, suppression of the serum TGF-beta1 with risedronate was associated with increased DBM. Therefore, sequential treatment with bFGF and Ris restores trabecular architecture and allows mineralization of bone to increase, which appears to be beneficial to bone strength.

Animals↗

PubMed2006

Mannose selection system used for cucumber transformation.

The selectable marker system, which utilizes the pmi gene encoding for phosphomannose-isomerase that converts mannose-6-phosphate to fructose-6-phosphate, was adapted for Agrobacterium-mediated transformation of cucumber (Cucumis sativus L.). Only transformed cells were capable of utilizing mannose as a carbon source. The highest transformation frequency of 23% was obtained with 10 g/l mannose and 10 g/l sucrose in the medium. Molecular, genetic analysis, and PMI activity assay showed that the regenerated shoots contained the pmi gene and the gene was transmitted to the progeny in a Mendelian fashion. The results indicated that the mannose selection system, which is devoid of the disadvantages of antibiotic or herbicide selection, could be used for cucumber Agrobacterium-mediated transformation.

Cucumis sativus↗

PubMed2006

Effects of codon modification on human BMP2 gene expression in tobacco plants.

Bone morphogenetic protein 2 (BMP2) has great potential in therapeutic applications. We are working on generating transgenic plants as a bioreactor to produce BMP2. We have studied the effects of codon optimization on the expression of human BMP2 (hBMP2) in tobacco plants. Three modified hBMP2 genes were transformed into tobacco under the control of either cauliflower mosaic virus 35S (CaMV35S) promoter or double-CaMV35S promoter plus alfalfa mosaic virus (AMV) enhancer. The fused beta-glucuronidase (GUS) reporter gene was used to facilitate the assay of protein expression. The results indicated that codon optimization could increase the protein expression level obviously under CaMV35S promoter. However, under relatively stronger initiation condition (double-CaMV35S promoter plus AMV enhancer), only the gene with the lowest degree of codon optimization could increase the protein expression level. Our findings suggest that the action of codon optimization may be influenced by the factors of promoter strength and A+T content in tobacco plants.

Base Sequence↗

PubMed2006

Expression of human BMP-2 gene in different tissues of tobacco plants.

The bone morphogenetic proteins (BMPs) are a family of growth factors that regulate the development of bone. BMP-2 is the most effective in the induction of bone tissue. A large amount of BMP-2 is needed for both bone tissue engineering research and clinical application. Thus, an effective way is necessary to produce sufficient BMP-2 protein. With the advance in plant biotechnology, transgenic plants have been targeted as a bioreactor to produce desired recombinant proteins. Here, the expression of recombinant human bmp-2 gene (rhbmp-2) was studied in tobacco plants using gus as a reporter gene. The difference of expression levels in root, stem and leaf tissues was analyzed by GUS activity assay, semi-quantitive RT-PCR and western blotting.The results indicated that the expression levels of fusion protein in root and stem tissues were significantly higher than those in leaf tissue. For the protein compositions in root and stem tissues were simpler than those in leaf tissue,this suggested that the purification process with root and stem tissues would potentially be easier.

Blotting, Western↗

PubMed2006

Ca2+ sparks and Ca2+ glows in superior cervical ganglion neurons.

AIM: Ca2+ release from the endoplasmic reticulum (ER) is an integral component of neuronal Ca2+ signaling. The present study is to investigate properties of local Ca2+ release events in superior cervical ganglion (SCG) neurons. METHODS: Primary cultured SCG neurons were prepared from neonatal rats (P3-P7). Low concentration of caffeine was used to induce Ca2+ release from the ER Ca2+ store, and intracellular Ca2+ was recorded by high-resolution line scan confocal imaging and the Ca2+ indicator Fluo-4. RESULTS: Two populations of local Ca2+ release events with distinct temporal characteristics were evoked by 1.5 mmol/L caffeine near the surface membrane in the soma and the neurites of SCG neurons. Brief events similar to classic Ca2+ sparks lasted a few hundreds of milliseconds, whereas long-lasting events displayed duration up to tens of seconds. Typical somatic and neurite sparks were of 0.3- and 0.52-fold increase in local Fluo-4 fluorescence, respectively. Typical Ca2+ glows were brighter (deltaF/F0 approximately 0.6), but were highly confined in space. The half maximum of full duration of neurite sparks was much longer than those in the soma (685 vs 381 ms). CONCLUSION: Co-existence of Ca2+ sparks and Ca2+ glows in SCG neurons indicates distinctive local regulation of Ca2+ release kinetics. The local Ca2+ signals of variable, site-specific temporal length may bear important implications in encoding a 'memory' of the trigger signal.

Animals↗

PubMed2006

Immunological properties of recombinant Mycobacterium bovis bacillus Calmette-Guérin strain expressing fusion protein IL-2-ESAT-6.

The live vaccine Mycobacterium bovis bacillus Calmette-Guérin (BCG) provides variable efficacy against adult pulmonary tuberculosis (TB). Recombinant BCG, expressing either immunodominant antigens or Th1 cytokines, is a promising strategy for developing a new TB vaccine. However, not much is known about whether the introduction of cytokine and specific antigen genes concurrently into the BCG strain could improve the immunogenicity of BCG. In this study, a recombinant BCG strain (rBCG) expressing the fusion protein human interleukin (IL)-2 and ESAT-6 (early secreted antigenic target-6 kDa) antigen of Mycobacterium tuberculosis was constructed. Six weeks after BALB/c mice (H-2d) were immunized with 106 colony forming units (CFUs) BCG or rBCG, splenocyte proliferation was determined with MTT [3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide] assay, IL-4 and interferon (IFN)-gamma produced by splenocytes were tested by enzyme linked immunosorbent assay (ELISA,) and the cytotoxicity of splenocytes from immunized mice to P815 cells (H-2d) expressing ESAT-6 protein was measured using CytoTox 96 Non-Radioactive Cytotoxicity Assay. Compared with native BCG-vaccinated mice, rBCG induced stronger Th1 responses that were confirmed by high lymphoproliferative responses and IFN-gamma production to culture filtrate protein (CFP) or ESAT-6 protein. Moreover, rBCG induced significant enhanced CTL responses against P815-ESAT-6 cells. Results from rBCG-immunized mice demonstrated that introducing the il-2 and esat-6 genes into BCG could enhance Th1 type immune responses to ESAT-6. Further investigation is needed by introducing other Th1 cytokines and antigens into BCG to optimize the protective efficacy against TB.

Animals↗

PubMed2006

PM-20, a novel inhibitor of Cdc25A, induces extracellular signal-regulated kinase 1/2 phosphorylation and inhibits hepatocellular carcinoma growth in vitro and in vivo.

We have synthesized several new phenyl maleimide compounds, which are potent growth inhibitors of several human tumor cell lines. Among these, PM-20 was the most potent with an IC50 of 700 nmol/L for Hep3B human hepatoma cell growth. Two other derivatives, PM-26 and PM-38, did not inhibit Hep3B cell growth even at 100 micromol/L. Interestingly, under identical experimental conditions, PM-20 inhibited DNA synthesis of primary cultures of normal hepatocytes at a 10-fold higher concentration than that needed to inhibit the DNA synthesis of the Hep3B hepatoma cells. PM-20 affected two cellular signaling pathways in Hep3B cells: Cdc25 phosphatase and extracellular signal-regulated kinase (ERK) 1/2. It competitively inhibited the activity of Cdc25 (preferentially Cdc25A) by binding to the active site, likely through the catalytic cysteine, but did not inhibit PTP1B, CD45, or MKP-1 phosphatases. As a result of its action, tyrosine phosphorylation of the cellular Cdc25A substrates Cdk2 and Cdk4 was induced. It also induced strong and persistent phosphorylation of the Cdc25A substrate ERK1/2. Hep3B cell lysates were found to contain ERK2 phosphatase(s) activity, which was inhibited by the actions of PM-20. However, activity of exogenous dual-specificity ERK2 phosphatase MKP1 was not inhibited. Induction of ERK1/2 phosphorylation correlated with the potency of growth inhibition in tumor cell lines and inhibition of ERK1/2 phosphorylation by the mitogen-activated protein kinase (MAPK)/ERK kinase 1/2 inhibitor U0126 or overexpression of the cdc25A gene in Hep3B cells antagonized the growth inhibitory actions of PM-20. Growth of transplantable rat hepatoma cells in vivo was also inhibited by PM-20 action with a concomitant induction of pERK in the tumors. The mechanism(s) of growth inhibition of Hep3B hepatoma cells by the phenyl maleimide PM-20 involves prolonged ERK1/2 phosphorylation, likely resulting from inhibition of the ERK phosphatase Cdc25A. PM-20 thus represents a novel class of tumor growth inhibitor that inhibits mainly Cdc25A, is dependent on ERK activation, and has a considerable margin of selectivity for tumor cells compared with normal cells.

Animals↗

PubMed2006

[Biomechanical study of restorations of medial-occlusal cavities of endodontically treated premolars].

OBJECTIVE: To compare the different restorations of endodontically treated premolars, and to choose the best method. METHODS: 10 pairs of symmetry maxillary first premolars were collected from 10 patients, and randomly divided into 2 groups. Every pair received different treatment accordingly. The test group was set up the medial-occlusal cavities model under the same standard. The 10 pairs teeth were test by instron 4302 universal test machine in speed of 1.00 mm/min until broken up and the top load was recorded. The load angle was 45 degree to the long axis of the teeth, as the load was pointed to the middle of the lingual surface on the buccal cusp. The records were analyzed by paired samples t test. RESULTS: Based on the medial-occlusal cavities, the fracture strength of the full crowned teeth was lower than the full natural teeth, and the fracture strength of the post-crowned teeth was higher than the full natural teeth. CONCLUSION: From the point of biomechanics, the different trauma of the endodontically treated teeth fits to different restorations. The medial-occlusion cavities fit the post-crown restoration mostly.

Bicuspid↗

PubMed2006

[Observation on the characters of infrared radiation spectrum of acupoints in normal humans and CHD patients].

In this experiment the data of the infrared radiation spectrum of acupoints in human body were obtained through an ingenious device. In thirty-one healthy volunteer subjects and thirty-one patients suffering from coronary heart disease, we detected the infrared radiation spectra from some acupoints and compared them with those of the healthy subjects. The curves of patients showed more differences. After analyzing the data, we noted statistically significant differences in some fields between the healthy subjects and the patients. And after reducing the data, we observed significant differences in larger fields. So utilization of reduced data from patients for analysis is our choice.

Acupuncture Points↗

PubMed2006

[The effects of remain of residual tooth on retention of post-core crown system].

This study was aimed to assess the effects of remain of residual tooth on the retention of postpost-core was made,casted and cemented. The post-core was tested at the speed of 10 mm/min on the Instron4302, and the retention force was recorded. Other samples were made and subjected to the test for cohesion of polymethylmethacrylate and metal. The result showed that retention significantly increased with the adding of the residual tooth. When the length of post was longer than 8 mm and 1 mm was added to tooth remain, the difference in retention between the two groups was statistically significant. It was noted that there existed relationships of retention to length of post and tooth remain, of cohesion to length of post and tooth remain, and of frictiion resistence to length of post and tooth remain; moreover, the relevant linear regression equations were obtained. So during the tooth preparation of post-core system, the tooth tissue should be reserved as much as possible.

Crowns↗

PubMed2006

Low dose pirfenidone suppresses transforming growth factor beta-1 and tissue inhibitor of metalloproteinase-1, and protects rats from lung fibrosis induced by bleomycina.

OBJECTIVE: To investigate the optimal dosage of pirfenidone for the treatment of pulmonary fibrosis induced by bleomycin in Wistar rats, and the alteration of expressions of transforming growth factor beta-1 (TGF-beta 1), tissue inhibitor of metalloproteinase-1 (TIMP-1), and matrix metalloproteinase-13 (MMP-13) in lung tissue. METHODS: Male Wistar rats were endotracheally instilled with bleomycin or normal saline. Pirfenidone (25-800 mg x kg(-1) x d(-1)), dexamethasone (3 mg/kg), or 1% carboxymethylcellulose sodium were given daily by feed 2 days before instillation of bleomycin. Groups T7 and T14 were fed pirfenidone 50 mg x kg(-1) x d(-1) at 7 days or 14 days after bleomycin instillation. Lungs were harvested at 28 days after bleomycin instillation. Patholological changes in lung tissues were evaluated with HE staining. Lung collagen was stained by sirius red and measured by content of hydroxyproline. Expression of proteins of TGF-beta 1, TIMP-1, and MMP-13 were detected by Western blotting. RESULTS: At doses of 25, 50, and 100 mg x kg(-1) x d(-1), pirfenidone had significant anti-fibrotic effects for bleomycin-induced rat pulmonary fibrosis, and these effects were most significantly attenuated at the dosage of 50 mg x kg(-1) x d(-1) (HE: P < 0.01, P < 0.01, and P = 0.064; sirius red: P < 0.05, P < 0.01, and P < 0.05; hydroxyproline: P = 0.595, P < 0.01, and P = 0.976). Pirfenidone at a dosage of 50 mg x kg(-1) x d(-1) inhibited protein expression of TGF-beta1 and TIMP-1 in lung tissue in the early phase (0.79 and 0.75 times of control group), but had no effect on expression of MMP-13. CONCLUSION: Low dose pirfenidone, especially at dosage of 50 mg x kg(-1) x d(-1), has significant anti-fibrotic effects on bleomycin-induced rat pulmonary fibrosis. Pirfenidone partially inhibits the enhancement of the expression of TGF-beta 1 and TIMP-1 in lung tissue.

Animals↗

PubMed2005

Glucocorticoid-treated mice have localized changes in trabecular bone material properties and osteocyte lacunar size that are not observed in placebo-treated or estrogen-deficient mice.

UNLABELLED: This study compares changes in bone microstructure in 6-month-old male GC-treated and female ovariectomized mice to their respective controls. In addition to a reduction in trabecular bone volume, GC treatment reduced bone mineral and elastic modulus of bone adjacent to osteocytes that was not observed in control mice nor estrogen-deficient mice. These microstructural changes in combination with the macrostructural changes could amplify the bone fragility in this metabolic bone disease. INTRODUCTION: Patients with glucocorticoid (GC)-induced secondary osteoporosis tend to fracture at higher bone mineral densities than patients with postmenopausal osteoporosis. This suggests that GCs may alter bone material properties in addition to BMD and bone macrostructure. MATERIALS AND METHODS: Changes in trabecular bone structure, elastic modulus, and mineral to matrix ratio of the fifth lumbar vertebrae was assessed in prednisolone-treated mice and placebo-treated controls for comparison with estrogen-deficient mice and sham-operated controls. Compression testing of the third lumbar vertebrae was performed to assess whole bone strength. RESULTS: Significant reductions in trabecular bone volume and whole bone strength occurred in both prednisolone-treated and estrogen-deficient mice compared with controls after 21 days (p < 0.05). The average elastic modulus over the entire surface of each trabecula was similar in all the experimental groups. However, localized changes within the trabeculae in areas surrounding the osteocyte lacunae were observed only in the prednisolone-treated mice. The size of the osteocyte lacunae was increased, reduced elastic modulus around the lacunae was observed, and a "halo" of hypomineralized bone surrounding the lacunae was observed. This was associated with reduced (nearly 40%) mineral to matrix ratio determined by Raman microspectroscopy. These localized changes in elastic modulus and bone mineral to matrix ratio were not observed in the other three experimental groups. CONCLUSIONS: Based on these results, it seems that GCs may have direct effects on osteocytes, resulting in a modification of their microenvironment. These changes, including an enlargement of their lacunar space and the generation of a surrounding sphere of hypomineralized bone, seem to produce highly localized changes in bone material properties that may influence fracture risk.

Animals↗

PubMed2005

Changes in serum fibroblast growth factor 2 in patients with glucocorticoid-induced osteoporosis treated with human parathyroid hormone (1-34).

Since the ability of parathyroid hormone (PTH) to increase osteoblast maturation and activity is associated with basic fibroblast growth factor (bFGF) we determined the changes in serum bFGF levels in patients treated with human parathyroid hormone (hPTH) (1-34) for 12 months and 12 months follow up. All studied subjects (n=51) had postmenopausal osteoporosis, had been receiving long-term treatment with glucocorticoid plus estrogen or estrogen/progesterone and were randomly allocated either to a group receiving hPTH, 400 U/day (n=28), or to a control group (n=23). Osteocalcin (OST), bone-specific alkaline phosphatase (BSAP) and bFGF were monitored at the baseline, every 3 months for 18 months, and at 24 months. In the hPTH group, OST increased by more than 150% above baseline at 3 months and was maintained at this level throughout the treatment period. BSAP had increased more than 80% over the baseline level at 3 months and was maintained at 90% above baseline for the next 9 months. bFGF levels had increased by 45% at 3 months, 60% at 6 to 9 months (P<0.05) and had increased more than 90% from baseline by 12 months (P<0.05). We found that daily hPTH injections increased bFGF levels. These results support the hypothesis that up-regulation of bFGF could play a role in the osteoblastic response to PTH.

Administration, Cutaneous↗

PubMed2005

Basic fibroblast growth factor improves trabecular bone connectivity and bone strength in the lumbar vertebral body of osteopenic rats.

Recently, basic fibroblast growth factor (bFGF) has been found to increase trabecular bone mass and connectivity in the proximal tibial metaphyses (PTM) in osteopenic rats. The purpose of this study was to determine the bone anabolic effects of bFGF in the lumbar vertebral body (LVB), a less loaded skeletal site with a lower rate of bone turnover than the PTM. Six-month old female Sprague-Dawley rats were ovariectomized (OVX) or sham-operated and untreated for 8 weeks to induce osteopenia. Then group 1 (sham) and group 2 (OVX) were treated subcutaneously (s.c.) with vehicle, and OVXed groups 3 and 4 were treated s.c. with PTH [hPTH (1-34) at 40 microg/kg, 5x/week] and bFGF (1 mg/kg, 5x/week), respectively, for 8 weeks. At sacrifice, the fifth LVB was removed, subjected to micro-CT for determination of trabecular bone structure and then processed for histomorphometry to assess bone turnover. The sixth LVB was used for mechanical compression testing (MTS, Bionix 858). The data were analyzed with the Kruskal-Wallis test followed by post-hoc testing as needed. After 16 weeks of estrogen deficiency, there were significant reductions in vertebral trabecular bone volume and trabecular thickness. Treatment with either bFGF or hPTH (1-34) increased BV/TV in OVX animals. Human PTH (1-34)-treated animals had significant increases in trabecular (48%) and cortical thickness (30%) and bone strength [maximum load (53%) and work to failure (175%)] compared to OVX + Vehicle animals. Treatment of osteopenic rats with bFGF increased bone volume (15%), trabecular thickness (13%), maximum load (45%) and work to failure (140%) compared to OVX + Vehicle animals (all P <0.05). Basic FGF increased trabecular bone volume in the lumbar vertebral body of osteopenic rats by restoring trabecular number, thickness and connectivity density. Also, bFGF improved bone mechanical properties (maximum force and work to failure) compared to the OVX + Vehicle group. Therefore, increasing the number, thickness and connections of the trabeculae contributes to increased bone strength in this small animal model of osteoporosis.

Animals↗

PubMed2005

Excretion and detection of SARS coronavirus and its nucleic acid from digestive system.

AIM: To study whether severe acute respiratory syndrome coronavirus (SARS-CoV) could be excreted from digestive system. METHODS: Cell culture and semi-nested RT-PCR were used to detect SARS-CoV and its RNA from 21 stool and urine samples, and a kind of electropositive filter media particles was used to concentrate the virus in 10 sewage samples from two hospitals receiving SARS patients in Beijing in China. RESULTS: It was demonstrated that there was no live SARS-CoV in all samples collected, but the RNA of SARS-CoV could be detected in seven stool samples from SARS patients with any one of the symptoms of fever, malaise, cough, or dyspnea, in 10 sewage samples before disinfection and 3 samples after disinfection from the two hospitals. The RNA could not be detected in urine and stool samples from patients recovered from SARS. CONCLUSION: Nucleic acid of SARS-CoV can be excreted through the stool of patients into sewage system, and the possibility of SARS-CoV transmitting through digestive system cannot be excluded.

Digestive System↗

PubMed2005

Concentration and detection of SARS coronavirus in sewage from Xiao Tang Shan Hospital and the 309th Hospital.

The transmission of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is associated with close contact to SARS patients and droplet secretions of those patients. The finding of positive RT-PCR results from stools of SARS patients suggests that stools of SARS patients or sewage containing stools of patients could transmit SARS-CoV. We used a novel style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing. We also used cell culture, RT-PCR and gene sequencing to detect and identify the viruses from sewage. No infectious SARS-CoV contamination was found in any of the samples collected, but the nucleic acid of SARS-CoV could be detected in the sewage from the two hospitals before disinfection. While the RNA was only detected in three samples from the 309th Hospital, the others were negative after disinfection. These findings provide strong evidence that SARS-CoV can be excreted through the stool/urine of patients into sewage system, thus making the sewage system a possible route of transmission.

China↗

PubMed2005

[Studies on the chemical constituents in herb of Ranunculus sceleratus].

OBJECTIVE: To isolate and determine the chemical constituents from Ranunculus sceleratus. METHOD: Six compounds were isolated and purified by extraction and different kinds of column chromatography. The structures were determined on the basis of extensive spectral analysis such as EI-MS, 1H-NMR, 13C-NMR, DEPT and NOEDS. RESULT: The structures were elucidated as stigmasta-4-ene-3,6-dione I, stigmasterol II, isoscopoletin III, scoparone IV, protocatechuic aldehyde V and protocatechuic acid VI, respectively. CONCLUSION: Compound I, III, IV, V and VI were isolated from R. genus for the first time.

Benzaldehydes↗

PubMed2005

[A dynamics model describing edema and its physiological analysis].

Edema is a common pathological symptom, but its development mechanism is unknown. Based on the bearings of pressure upon interstitium structure and substantial exchange between plasma and interstitial fluid, a dymamics model describing the development of edema was set up. The model's theoretical results showed that the variations of interstitium pressure and structure due to imbalance of substantial exchange may lead to the development of edema, which is in accordance with recent clinical researches. Discussions on the dynamic mechanism of the development of edema proposed that the best way to prevent edema is instituting treatment before the interstitial structure being destroyed.

Edema↗