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Biomedical subjects

Wei Wang

Publications and source records attributed to Wei Wang.

At least 253 records · Page 14Linked to original sources
PubMed2006

Kinetic distribution of paeoniflorin in cortex of normal and cerebral ischemia-reperfusion rats after intravenous administration of Paeoniae Radix extract.

The time course of paeoniflorin in the cortex of normal and cerebral ischemia-reperfusion rats, following intravenous administration of Paeoniae Radix extract at a dose of 60 mg/kg of paeoniflorin, was determined using high-performance liquid chromatographic (HPLC) assay. The results showed that paeoniflorin could penetrate through the blood-brain barrier to reach the cortex, and that the injuries of ischemia-reperfusion could play an important role in pharmacokinetic process of paeoniflorin in the cortex after intravenous administration of Paeoniae Radix extract. The cortex concentrations of paeoniflorin in cerebral ischemia-reperfusion rats were lower 5 min after dosing and declined more slowly than that in normal control.

Animals↗
PubMed2006

A universal and rapid protocol for protein extraction from recalcitrant plant tissues for proteomic analysis.

A simple and universally applicable protocol for extracting high-quality proteins from recalcitrant plant tissues is described. We have used the protocol with no modification, for a wide range of leaves and fruits. In all cases, this protocol allows to obtain good electrophoretic separation of proteins. As the protocol is rapid, universal, and compatible with silver staining, it could be used for routine protein extraction from recalcitrant plant tissues for proteomic analysis.

Electrophoresis, Gel, Two-Dimensional↗
PubMed2006

EOF measurement by detection of a sampling zone with end-channel amperometry in microchip CE.

A simple method for EOF measurement by detection of sampling zones with end-channel amperometry in microchip CE is developed. This method is based on the principle of the Kohlrausch regulating function (KRF). A dilute electroactive ionic species is added to the BGE as a continuously eluting electrophore which is used as a probe. When a BGE-like sample at a different concentration is injected, a peak of sampling zone appears and the migration time is related to EOF. In a microchip CE with hybrid PDMS/glass channel, a cathodic EOF of the hybrid glass/PDMS microchip was measured by end-channel amperometry; the effects of sample concentration and different probes on EOF rate were discussed. The present method was applied to monitor EOF rates in glass and in PDMS microchips. There was no significant difference between the values of EOF rates measured by the present method and the current-monitoring method. Detection of nonelectroactive analytes K(+), Na(+), and Li(+) can also be accomplished by the indirect amperometric method. Hence, the effective mobility of analyte can be accurately obtained.

Conductometry↗
PubMed2006

A new method for fabrication of an integrated indium tin oxide electrode on electrophoresis microchips with amperometric detection and its application for determination of synephrine and hesperidin in pericarpium citri reticulatae.

A new, simple, and fast method to integrate indium tin oxide electrode in an amperometric detection (AD) microchip is introduced. Without the help of photoresist and complicated apparatus, the microchip could be fabricated in most laboratories in a very short time by this method. The experiment indicated that the microchip was stable and had good reproducibility. On this microchip, a new method was established to separate and determine synephrine and hesperidin, which are the main electroactively bioactive ingredients of pericarpium citri reticulatae, by AD. Under the optimal conditions, the two compounds could be completely separated within 5.5 min and the detection limits were 0.13 and 0.57 microg/mL, respectively. The proposed method has been successfully used to determine synephrine and hesperidin in real pericarpium citri reticulatae sample, and the results show that the proposed method is sensitive, reliable, fast, and economical.

Citrus↗
PubMed2006

Quantitative analysis of fibrosis formation on the microcapsule surface with the use of picro-sirius red staining, polarized light microscopy, and digital image analysis.

Transplantation of microencapsulated cells shows potential to treat a variety of diseases. To improve the quality of microcapsules, efficient methods need to be established and standardized for the evaluation of biocompatibility of microcapsules. To this end, a microscopical method was developed to analyze quantitatively the degree of fibrotic overgrowth (FO), which serves as the index of biocompatibility. In this method, sections were stained with picro-sirius red and illuminated with a polarized light microscope. The images were digitized with the use of a computer-video system in which collagenous content was depicted by gray levels 1 to 255. Both the area of collagen and the thickness of FO were examined. The ratio of Type I/Type III collagen and the thickness were used as indexes of the degree of FO. The data showed that the ratio of Type I/Type III collagen and the thickness increased with time, and FO was not significant 4 weeks after transplantation. In comparison, this new method is more efficient to evaluate FO.

Animals↗
PubMed2006

Silicon inhibition effects on the polymerase chain reaction: a real-time detection approach.

In the miniaturization of biochemical analysis systems, biocompatibility of the microfabricated material is a key feature to be considered. A clear insight into interactions between biological reagents and microchip materials will help to build more robust functional bio-microelectromechanical systems (BioMEMS). In the present work, a real-time polymerase chain reaction (PCR) assay was used to study the inhibition effects of silicon and native silicon oxide particles on Hepatitis B Virus (HBV) DNA PCR amplification. Silicon nanoparticles with different surface oxides were added into the PCR mixture to activate possible interactions between the silicon-related materials and the PCR reagents. Ratios of silicon nanoparticle surface area to PCR mixture volume (surface to volume ratio) varied from 4.7 to 235.5 mm2/microL. Using high speed centrifugation, the nanoparticles were pelleted to tube inner surfaces. Supernatant extracts were then used in subsequent PCR experiments. To test whether silicon materials participated in amplifications directly, in some cases, entire PCR mixture containing silicon nanoparticles were used in amplification. Fluorescence histories of PCR amplifications indicated that with the increase in surface to volume ratio, amplification efficiency decreased considerably, and within the studied ranges, the higher the particle surface oxidation, the stronger the silicon inhibition effects on PCR. Adsorption of Taq polymerase (not nucleic acid) on the silicon-related material surface was the primary cause of the inhibition phenomena and silicon did not participate in the amplification process directly.

Hepatitis B virus↗
PubMed2006

Improved temporal clustering analysis method for detecting multiple response peaks in fMRI.

PURPOSE: To develop an improved temporal clustering analysis (TCA) method for detecting multiple active peaks by running the method once. MATERIALS AND METHODS: Two cases of simulation data and a set of actual fMRI data from nine subjects were used to compare the traditional TCA method with the new method, termed extremum TCA (ETCA). The first case of simulation data simulated event-related activation and block activation in one cerebral area, and the second case simulated event-related activation and block activation in two cerebral areas. An in vivo visual stimulating experiment was performed on a 1.5T MR scanner. All imaging data were processed using both traditional TCA and the new method. RESULTS: The results of both the simulated and actual fMRI data show that the new method is more sensitive and exact than traditional TCA in detecting multiple response peaks. CONCLUSION: The new method is effective in detecting multiple activations even when the timing and location of the brain activation are completely unknown.

Brain Mapping↗
PubMed2006

Suppression of astroglial scar formation and enhanced axonal regeneration associated with functional recovery in a spinal cord injury rat model by the cell cycle inhibitor olomoucine.

It is well established that axons of the adult mammalian CNS are capable of regrowing only a limited amount after injury. Astrocytes are believed to play a crucial role in the failure to regenerate, producing multiple inhibitory proteoglycans, such as chondroitin sulphate proteoglycans (CSPGs). After spinal cord injury (SCI), astrocytes become hypertrophic and proliferative and form a dense network of astroglial processes at the site of lesion constituting a physical and biochemical barrier. Down-regulations of astroglial proliferation and inhibitory CSPG production might facilitate axonal regeneration. Recent reports indicated that aberrant activation of cell cycle machinery contributed to overproliferation and apoptosis of cells in various insults. In the present study, we sought to determine whether a cell cycle inhibitior, olomoucine, would decrease neuronal cell death, limit astroglial proliferation and production of inhibitory CSPGs, and eventually enhance the functional compensation after SCI in rats. Our results showed that up-regulations of cell cycle components were closely associated with neuronal cell death and astroglial proliferation as well as the production of CSPGs after SCI. Meanwhile, administration of olomoucine, a selective cell cycle kinase (CDK) inhibitor, has remarkably reduced the up-regulated cell cycle proteins and then decreased neuronal cell death, astroglial proliferation, and accumulation of CSPGs. More importantly, the treatment with olomoucine has also increased expression of growth-associated proteins-43, reduced cavity formation, and improved functional deficits. We consider that suppressing astroglial cell cycle in acute SCIs is beneficial to axonal growth. In the future, therapeutic strategies can be designed to achieve efficient axonal regeneration and functional compensation after traumatic CNS injury.

Analysis of Variance↗
PubMed2006

Effects of ischemia and anoxia on cell activation and cell cycle of cultured astrocytes in vitro.

To examine the effects of ischemia and anoxia on cell activation and cell cycle of astrocytes in vitro, the cell cycles and the proliferation of astrocytes in different time points after ischemia and anoxia were studied by flow cytometry and BrdU labeling and the expression of GFAP and cyclin D1 was detected by the fluorescence immunochemistry. After ischemia and anoxia in vitro, the astrocytes in S phase were significantly increased as compared with those in the normal group and the proliferating ability of the astrocytes was highest 6 h after the treatment as revealed by BrdU pulse labeling, but the astrocytes in S phase and proliferating ability were decreased after 6 h. At the early stages of ischemia and anoxia, the positive staining intensity of GFAP was increased, peaked at 6th h, while 12 h after the ischemia and anoxia, the positive staining intensity of GFAP became weak, and the expression of cyclin D1 was gradually increased after the ischemic and anoxic damage. It is concluded that astrocytes are activated to proliferate and enter new cycle events by ischemia and anoxia, and cyclin D1 is implicated in the proliferation and repair of astrocytes. The cell cycle events are closely associated with the proliferation and activation of astrocytes.

Animals↗
PubMed2006

Perihematoma damage at different time points in experimental intracerebral hemorrhage.

The damage degree of neurons in perilesion at different time points was observed in order to explore the optimal operation occasion. Piglet lobar hematomas were produced by pressure-controlled infusions of 2.5 mL autonomous blood into the right frontal hemispheric white matter over 15 min, and the metabolic changes were ambulatorily detected with MRS at 3rd, 12th, 24th and 48th h after hematoma induction. Brain tissues of perihematoma were also obtained at different time points. The transcription level of Bax gene was detected by in situ hybridization and apoptosis by TUNEL technique, and the pathologic change of neurons was observed under an electron microscope. The results showed that the number of Bax positive cells reached the peak at 24 h (79.00 +/- 4.243/5 fields). There was no significant difference in A values between 3 h and 6 h, 12 h (P > 0.05), but there significant difference between 24 h and 3 h, 6 h, 12 h (P < 0.05). The number of apoptotic cells reached the peak at 24 h (P < 0.001), and there was no significant difference between 3 h and 6 h (P = 0.999). The area of the apoptotic cells showed no significant difference between 3 h and 6 h or among 3 h, 6 h and 6 h (P > 0.05). Lac peak mainly occurred at 24 h and 48 h, while on the healthy side, no Lac peak was detectable. The ratio of NAA/Cr presented a descent tendency, but there was no significant difference among the groups before 12 h (P > 0.05), there was very significant difference between 3, 6 and 24, 48 h (P < 0.01). Under electronic microscopy, the neuronal damage surrounding hematoma in 3 to 6 h was milder than in 24 h to 48 h. It was concluded that the secondary apoptosis, damage and metabolic disturbance of the neurons surrounding hematoma was milder in 3-6 h in acute intracerebral hemorrhage, while obviously aggravated in 24-48 h. An effective intervention is needed to reduce secondary damage as soon as possible.

Animals↗
PubMed2006

Effect of coriaria lactone-activated astrocyte-conditioned medium on the cerebral TNF-alpha of normal rats.

To explore the effect of coriaria lactone (CL)-activated astrocyte-conditioned medium on the cerebral TNF-alpha of normal rats, the CL-activated astrocyte-conditioned medium (ACM) was injected into the lateral ventricle of SD rats. The rats were observed for behavioral changes, and the changes of the expression of TNF-alpha in the cerebral cortex and hippocampus were immunohistochemically examined by employing SP method. TNF-alpha level was assessed by means of radioimmunoassay in homogenate of cerebral cortex and hippocampus as well as cerebrospinal fluid. Seizure episodes were observed in ACM group 30 min after the ACM injection, but they were not observed in the control group. Immunohistochemical detection showed that the immunoreaction of TNF-alpha in hippocampus and cerebral cortex of rats were stronger than that of the control group 4 h after the ACM injection (P<0. 05). In this group, the concentrations of TNF-alpha in homogenate of cerebral cortex and hippocampus and cerebrospinal fluid were higher than those of the control group (P<0.05). It is suggested that the ACM activated by CL can enhance the expression of TNF-alpha in normal rats, and is related to epileptogenesis.

Animals↗
PubMed2006

Parthenolide-induced apoptosis in multiple myeloma cells involves reactive oxygen species generation and cell sensitivity depends on catalase activity.

The sesquiterpene lactone, parthenolide (PTL), possesses strong anticancer activity against various cancer cells. We report that PTL strongly induced apoptosis in 4 multiple myeloma (MM) cell lines and primary MM cells (CD38(+) high), but barely induced death in normal lymphocytes (CD38(-/+)low). PTL-mediated apoptosis correlated well with ROS generation and was almost completely inhibited by L-N-acetylcysteine (L-NAC), indicating the crucial role of oxidative stress in the mechanism. Among 4 MM cell lines, there is considerable difference in susceptibility to PTL. KMM-1 and MM1S cells sensitive to PTL possess less catalase activity than the less sensitive KMS-5 and NCI-H929 cells as well as normal lymphocytes. A catalase inhibitor 3-amino-1,2,4-triazole enhanced their PTL-mediated ROS generation and cell death. The siRNA-mediated knockdown of catalase in KMS-5 cells decreased its activity and sensitized them to PTL. Our findings indicate that PTL induced apoptosis in MM cells depends on increased ROS and intracellular catalase activity is a crucial determinant of their sensitivity to PTL.

Acetylcysteine↗
PubMed2006

A novel hydrogel crosslinked hyaluronan with glycol chitosan.

A novel hydrogel was prepared by crosslinking hyaluronan with glycol chitosan in aqueous solution using water soluble carbodiimide at nearly neutral pH and room temperature. The products can be easily formulated into injectable gels, various films, membranes and sponges for soft tissue augmentation, viscosupplementation, drug delivery, preventing adhesion of post operation, wound dressing and tissue engineering scaffolds. The said hydrogel has high water adsorption property and biostability. Rheololgical results of the gel showed a soft and viscoelastic structure. FTIR further confirmed the formation of amide bonds between carboxyl groups of hyaluronan and amine groups of glycol chitosan and no N-acylurea and other derivatives were identified.

Biocompatible Materials↗
PubMed2006

Cloning, expression and function of phosphate transporter encoded gene in Oryza sativa L.

OsPT6:1, a phosphate transporter encoding gene from the leaf samples of Oryza sativa, was identified through PCR with specifically designed primers. The phylogenetic analysis and the conserved amino acid residue site detection suggested OsPT6:1 a possible high-affinity phosphate transporter encoding gene. In situ hybridization and RT-PCR demonstrated the expression of OsPT6:1 in both roots and leaves. The peak expression signal was observed in mesophyll cells under low phosphorus (P) induction. A homologous recombination study indicated that OsPT6:1 can enhance the Pi uptake efficiency of Pichia pastoris. At the meantime, the introduction of OsPT6:1 was able to complement the Pi uptake function of yeast cells with high-affinity phosphate transporters deficient. Those results substantiated our contention that OsPT6:1 encoded a high-affinity phosphate transporter of Oryza sativa.

Cloning, Molecular↗
PubMed2006

Vaccination with a recombinant chicken FGFR-1 bypasses immunological tolerance against self-FGFR-1 in mice.

The possibility that a recombinant protein vaccine based on xenogeneic homologous FGFR-1 of chicken induces production of autoantibodies against self-FGFR-1 in BALB/c mice was examined by using ELISA, Western blot analysis and ELISPOT assay respectively. Autoantibodies against mouse FGFR-1 were identified by Western blot analysis and ELISA. Compared with the two control groups, the number of APBCs, which were detected by ELISPOT assay, was significantly increased in the spleens of mice immunized with cFR1 (P < 0.05). IgG1 and IgG2b, which were detected by ELISA, were the major subclasses and were substantially increased in response to chicken FGFR-1 when compared with control group. The recombinant chicken FGFR-1 protein used as a vaccine can induce autoantibodies against self-FGFR-1 in mice and provide a basis for the active immunotherapy of tumor angiogenesis.

Animals↗
PubMed2006

A climatologic investigation of the SARS-CoV outbreak in Beijing, China.

The first cases of severe acute respiratory syndrome (SARS) were identified in November 2002, in Guangdong Province, China. The epidemic spread rapidly within China and internationally, with 8454 recorded infections and 792 deaths by June 15, 2003. Temperature, relative humidity, and wind velocity were the three key meteorological determinants affecting the transmission of SARS. The peak spread of SARS occurred at a mean temperature of 16.9 degrees C (95% CI, 10.7 degrees C to 23.1 degrees C), with a mean relative humidity of 52.2% (95% CI, 33.0% to 71.4%) and wind speed of 2.8 ms(-1) (95% CI, 2.0 to 3.6 ms(-1)). In northern China, these conditions are most likely to occur in the spring and suggest that SARS has a seasonal nature akin to viruses such as influenza and the common cold. A regression equation (Y=218.692-0.698X(t)-2.043X(h)+2.282X(w)) was derived to represent the optimal climatic conditions for the 2003 SARS epidemic. Further investigations in other regions are necessary to verify these results.

China↗
PubMed2006

Multivariable analysis of factors associated with hospital readmission after intestinal surgery.

BACKGROUND: Readmission rates after major abdominal surgery have a significant impact on hospital costs and quality of care. Identification of risk factors for readmission may improve postoperative care and discharge plans. METHODS: One hundred fifty consecutive patients readmitted within 30 days of discharge after intestinal surgery (RD) were compared with matched nonreadmitted patients. Patient-related (demographic, comorbidity, medications), disease-related (diagnosis, type of surgery), and perioperative course variables were collected for logistic regression analysis. RESULTS: RD was associated with chronic obstructive pulmonary disease (odds ratio [OR] 7.12 and 95% confidence interval [CI] 1.4-37.6), worse functional capacity class (OR 2.02 and CI 1.15-3.56), previous anticoagulant therapy (OR 4.85 and CI 1.2-19.7), steroid treatment, and discharge to a facility other than home (OR 4.35 and CI 0.97-20.0, P = .055). In patients with intestinal perforation, RD rate was decreased (OR 0.3 and CI 0.1-0.9), but this was associated with a longer primary hospital stay (median 8 vs. 6 days, P = .12). RD causes included surgical site septic complications (33%), ileus and/or small-bowel obstruction (23%), medical complications (24%), and others (20%). CONCLUSIONS: Functional capacity, chronic obstructive pulmonary disease, previous anticoagulant therapy, perioperative steroids, and discharge destination are independent predictors of RD. Disease-related factors have minor impact on RD rates. Improving functional status before surgery, decreasing the adverse impact of steroids, and/or stratifying perioperative anticoagulant use may decrease unexpected readmissions in this patient population.

Case-Control Studies↗