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Qiang Zhang

Publications and source records attributed to Qiang Zhang.

At least 55 records · Page 3Linked to original sources
PubMed2006

Molecular relaxation dynamics of self-assembled monolayers.

Dielectric relaxation spectroscopy is used to quantify molecular motion in alkylsilane SAMs coated on porous glass over a broad temperature range, -30 to -150 degrees C. Systematic measurements using SAMs with variable coating densities allow us to determine the effect of monolayer disorder on molecular mobility in thin molecular films. A relaxation process with an activation energy of approximately 25 kJ/mol is found to dominate dynamics of SAM-chain segments near the substrate. By introducing polar CN groups at the ends of the chain, we show that the relaxation process in the monolayer canopy can be isolated and studied. This approach can be generalized to other substituent polar groups to probe localized relaxation dynamics in surface-grafted monolayer films.

Journal Article↗
PubMed2006

Scaffold hopping through virtual screening using 2D and 3D similarity descriptors: ranking, voting, and consensus scoring.

The ability to find novel bioactive scaffolds in compound similarity-based virtual screening experiments has been studied comparing Tanimoto-based, ranking-based, voting, and consensus scoring protocols. Ligand sets for seven well-known drug targets (CDK2, COX2, estrogen receptor, neuraminidase, HIV-1 protease, p38 MAP kinase, thrombin) have been assembled such that each ligand represents its own unique chemotype, thus ensuring that each similarity recognition event between ligands constitutes a scaffold hopping event. In a series of virtual screening studies involving 9969 MDDR compounds as negative controls it has been found that atom pair descriptors and 3D pharmacophore fingerprints combined with ranking, voting, and consensus scoring strategies perform well in finding novel bioactive scaffolds. In addition, often superior performance has been observed for similarity-based virtual screening compared to structure-based methods. This finding suggests that information about a target obtained from known bioactive ligands is as valuable as knowledge of the target structures for identifying novel bioactive scaffolds through virtual screening.

Cyclin-Dependent Kinase 2↗
PubMed2006

A novel stealth liposomal topotecan with amlodipine: apoptotic effect is associated with deletion of intracellular Ca2+ by amlodipine thus leading to an enhanced antitumor activity in leukemia.

The objectives of the present study were to define whether amlodipine induces apoptosis and what mechanism is involved in the process in human resistant and non-resistant leukemia cells following co-administration of stealth liposomal topotecan with amlodipine, a novel antiresistant liposomes developed by our institution. In three leukemias, K562, HL-60, and multidrug resistant (MDR) HL-60, cytotoxicity of topotecan was potentiated by amlodipine, while topotecan alone was resistant to MDR HL-60 cells. In two selected K562 or MDR HL-60 cells, the apoptotic effects were increased by addition of amlodipine, showing a dose-dependent manner. The activities of caspase 3 and 7 (marked as caspase 3/7), and caspase 8 were significantly activated by topotecan with amlodipine co-treated as the stealth liposomes. The deletions of intracellular Ca2+ stores induced by amlodipine correlated with the activated activities of caspase 3/7, or 8, respectively. In xenograft model with MDR HL-60 in nude mice, antitumor activity of stealth liposomal topotecan with amlodipine was significantly enhanced as compared to that of stealth liposomal topotecan or topotecan alone. In conclusion, apoptotic effect is associated with deletion of intracellular Ca2+ by amlodipine through activation of caspase 8 and then 3/7 activities. The enhanced antitumor activities by stealth liposomal topotecan with amlodipine are mainly due to the potentiating apoptotic effect and reversing the resistance by amlodipine. Stealth liposomal encapsulation of anticancer agent with a modulator may provide a novel strategy for improving the chemotherapeutic effects.

Amlodipine↗
PubMed2006

Infiltration of tumor-reactive transforming growth factor-beta insensitive CD8+ T cells into the tumor parenchyma is associated with apoptosis and rejection of tumor cells.

BACKGROUND: TGF-beta is a potent immunosuppressant. High levels of TGF-beta produced by cancer cells have a negative inhibition effect on surrounding host immune cells and leads to evasion of the host immune surveillance and tumor progression. In the present study, we report a distinct ability of tumor reactive, TGF-beta-insensitive CD8+ T cells to infiltrate into established tumors, secrete relevant cytokines, and induce apoptosis of tumor cells. METHODS: CD8+ T cells were isolated from the spleens of C57BL/6 mice, which were primed with irradiated mouse prostate cancer cells, the TRAMP-C2 cells. After ex vivo expansion, these tumor reactive CD8+ cells were rendered TGF-beta-insensitive by infection with a retroviral (MSCV)-mediated dominant negative TGF-beta type II receptor (TbetaRIIDN). Control CD8+ cells consist of those transfected with the GFP-only empty vector and naïve CD8+ T cells. Recipient mice were challenged with a single injection of TRAMP-C2 cells 21 days before adoptive transfer of CD8+ T cells was performed. Forty days after the adoptive transfer, all animals were sacrificed. The presence of pulmonary metastases was evaluated pathologically. Serial slides of malignant tissues were used for immunofluorescent staining for different kinds of immune cell infiltration, cytokines, and apoptosis analysis. RESULTS: Pulmonary metastases were either eliminated or significantly reduced in the group receiving adoptive transfer of tumor-reactive TGF-beta-insensitive CD8+ T cells (3 out of 12) when compared to GFP controls (9 out of 12), and naïve CD8+ T cells (12 out of 12). Results of immunofluorescent studies demonstrated that only tumor-reactive TGF-beta-insensitive CD8+ T cells were able to infiltrate into the tumor and mediate apoptosis when compared to CD4+ T cells, NK cells, and B cells. A large amount of cytokines such as perforin, nitric oxide, IFN-gamma, IL-2, TNF-alpha were secreted in tumor tissue treated with tumor-reactive TGF-beta-insensitive CD8+ T cells. No immune cells infiltration and cytokine secretion were detected in tumor tissues treated with naïve T cells and GFP controls. CONCLUSIONS: Our results demonstrate the mechanism of anti-tumor effect of tumor-reactive TGF-beta-insensitive CD8+ T cells that adoptive transfer of these CD8+ T cells resulted in infiltration of these immune cells into the tumor parenchyma, secretion of relevant cytokines, and induction of apoptosis in tumor cells. These results support the concept that tumor-reactive TGF-beta-insensitive CD8+ T cells may prove beneficial in the treatment of advanced cancer patients.

Animals↗
PubMed2006

[Inhibition of nuclear factor kappa B attenuates multiple organ injury following ruptured abdominal aortic aneurysm: an experiment with rats].

OBJECTIVE: To investigate the effect of inhibition of nuclear factor kappa B on multiple organ injury following ruptured abdominal aortic aneurysm. METHODS: Forty-five Wistar rats underwent catheterization to observe the intestinal microcirculation blood flow, and were randomly divided into 3 equal groups. Rats of the ruptured abdominal aortic aneurysm (RAAA) group underwent laparotomy and extraction of blood to cause hemorrhage shock for 1 h (hemorrhagic shock phase), by the end of this phase normal saline at the dose of 50 ml/kg was injected intravenously, after that the abdominal aorta and bilateral common iliac arteries were blocked with artery clamps for 45 min so as to cause lower torso ischemia, and then the extracted blood was reperfused. The lungs, small intestine were taken out to undergo histological examination, and examination of lung polymorphonuclear neutrophilic leukocyte (PMN) sequestration, lung wet tissues/dry (W/D) tissues ratio, and myeloperoxidase (MPO) activity. The rats of pyrrolidine dithiocarbamate (PDTC) group were perfused with PDTC, a specific inhibitor of nuclear factor kappa B (NF-kappaB), by the end of the hemorrhagic shock phase. And the rats of the sham operation group were perfused of normal saline. RT-PCR was used to detect the mRNA expression of NF-kappaB p65 and intercellular adhesion molecule (ICAM). Western blotting was used to detect the protein expression of NF-kappaB p65 and ICAM-1. Immunohistochemistry was used to detect the expression of NF-kappaB p65 and ICAM-1 in the lung and small intestine tissues. RESULTS: Histological examination showed that severe damage could be found in the lung and small intestine of the RAAA group, and damages were significantly mild in the PDTC group. Lung PMN sequestration, W/D ratio, MPO activity were significantly increased in the RAAA group and these changes were relatively mild in the PDTC group (all P < 0.01). The intestinal microcirculation blood flow was 0.25 +/- 0.04 mlxmin(-1)xg(-1) in the RAAA group, significantly less than that of the sham operation group (0.71 +/- 0.11 mlxmin(-1)xg(-1), P < 0.01), and was 0.64 +/- 0.06 mlxmin(-1)xg(-1) in the PDTC group, significantly higher than that of the RAAA group (P < 0.01). The mRNA expression of NF-kappaB p65 in the lung of the RAAA group was 0.68 +/- 0.22, significantly higher than that of the sham operation group (0.11 +/- 0.02, P < 0.01) and that of the PDTC group (0.23 +/- 0.07, P < 0.01). The mRNA expression of NF-kappaB p65 in the intestine of the RAAA group was 0.48 +/- 0.10, significantly higher than that of the sham operation group (< 0.20 +/- 0.05, P < 0.01) and that of the PDTC group (0.27 +/- 0.06, P < 0.01). The mRNA expression of ICAM-1 in the lung of the RAAA group was 0.92 +/- 0.31, significantly higher than that of the sham operation group (0.07 +/- 0.02, P < 0.01) and that of the PDTC group (0.21 +/- 0.04, P < 0.01). The mRNA expression of ICAM-1 in the intestine of the RAAA group was 0.74 +/- 0.15, significantly higher than that of the sham operation group (0.14 +/- 0.05, P < 0.01) and that of the PDTC group (0.25 +/- 0.08, P < 0.01). The protein expression of NF-kappaB p65 in the lung of the RAAA group was 1.04 +/- 0.26, significantly higher than that of the PDTC group (0.52 +/- 0.13, P < 0.01). The protein expression of NF-kappaB p65 in the intestine of the RAAA group was 1.20 +/- 0.30, significantly higher than that of the PDTC group (0.64 +/- 0.21, P < 0.01). The protein expression of ICAM-1 in the lung of the RAAA group was 0.40 +/- 0.12, significantly higher than that of the PDTC group (0.18 +/- 0.06, P < 0.01). The protein expression of ICAM-1 in the intestine of the RAAA group was 0.46 +/- 0.15, significantly higher than that of the PDTC group (0.22 +/- 0.05, P < 0.01). Immunohistochemistry showed that NF-kappaB p65 and ICAM-1 positive cells were widely distributed in the lungs and intestine of the RAAA group and were rarely distributed in the sham operation group. CONCLUSION: PDTC attenuates the multi-organ injury by inhibiting the expression of NF-kappaB p65, thus reducing the mRNA and protein expression of its downstream gene ICAM-1 gene.

Animals↗
PubMed2006

Study of peptide conformation in terms of the ABEEM/MM method.

The ABEEM/MM model (atom-bond electronegativity equalization method fused into molecular mechanics) is applied to study of the polypeptide conformations. The Lennard-Jones and torsional parameters were optimized to be consistent with the ABEEM/MM fluctuating charge electrostatic potential. The hydrogen bond was specially treated with an electrostatic fitting function. Molecular dipole moments, dimerization energies, and hydrogen bond lengths of complexes are reasonably achieved by our model, compared to ab initio results. The ABEEM/MM fluctuating charge model reproduces both the peptide conformational energies and structures with satisfactory accuracy with low computer cost. The transferability is tested by applying the parameters of our model to the tetrapeptide of alanine and another four dipeptides. The overall RMS deviations in conformational energies and key dihedral angles for four di- or tetrapeptide, is 0.39 kcal/mol and 7.7 degrees . The current results agree well with those by the accurate ab initio method, and are comparable to those from the best existing force fields. The results make us believe that our fluctuating charge model can obtain more promising results in protein and macromolecular modeling with good accuracy but less computer cost.

Hydrogen Bonding↗
PubMed2006

Memantine protects neurons from shrinkage in the lateral geniculate nucleus in experimental glaucoma.

OBJECTIVE: To determine whether memantine as a treatment for glaucoma prevents neuron shrinkage in the lateral geniculate nucleus, the major target for retinal ganglion cells. METHODS: Sixteen monkeys with right-eye unilateral experimental glaucoma for 14 months were studied and treated with memantine (n = 9) or vehicle only (n = 7). Left lateral geniculate nucleus relay neurons (layers 1, 4, and 6) were examined following parvalbumin immunolabeling. Cell body cross-sectional areas and neuron numbers were assessed using unbiased methods. Memantine- and vehicle-treated glaucoma groups were compared using t tests and analysis of covariance. RESULTS: Compared with vehicle-treated animals, memantine-treated animals showed significantly less mean +/- SD neuron shrinkage in layers 1 (-4.0% +/- 13.9% vs 28.2% +/- 17.4%; P = .001) and 4 (24.9% +/- 10.0% vs 37.2% +/- 12.3%; P = .04). For layer 6, the difference was not statistically significant (34.2% +/- 10.1% vs 45.3% +/- 14.5%; P = .10). Analysis of covariance results showed significantly less neuron shrinkage in the memantine-treated group for layers 1, 4, and 6 (P < .001; P < .02; and P < .04, respectively). This difference was greatest in layer 1. In each of these layers, neuron numbers did not differ significantly between groups. CONCLUSION: Monkeys with glaucoma that were treated with memantine showed significantly less neuron shrinkage in the lateral geniculate nucleus than the vehicle-treated glaucoma group. CLINICAL RELEVANCE: The finding that memantine protects adult visual neurons from transsynaptic atrophy in experimental glaucoma could have therapeutic value. Currently, memantine is being tested in an ongoing clinical trial as a treatment for glaucoma.

Animals↗
PubMed2006

Therapeutic and toxicological evaluations of cyclosporine a microspheres as a treatment vehicle for uveitis in rabbits.

AIM: This study was undertaken to investigate the therapeutic efficacy and the toxicity of the intravitreal biodegradable poly(dl-lactide-co-glycolide)co-polymer microspheres containing cyclosporin A (CsA-PLGA-MS) on experimental uveitis in rabbits. METHODS: CsA-PLGA-MS that had been prepared by a solvent evaporation approach were characterized for morphology, particle size, entrapment efficiency, and in vitro release profile of CsA-PLGA-MS. Therapeutic efficacy of the CsA-PLGA-MS was evaluated by scoring of the inflammation, aqueous leukocyte counting, aqueous protein determination, and histological examination in the experimental rabbits with artificial uveitis induced by the injection of lipopolysaccharide. The toxicity was investigated by slit-lamp examination, indirect ophthalmoscopy, and electroretinography (ERG) in the noninflamed rabbit eye. RESULTS: The CsA-PLGA-MS were spherical in shape, with an average particle size of nearly 50 microm and an entrapment efficiency of more than 80%. The compositions of the formulation that was most effective in the in vivo studies included CsA, PLGA, and 3% Pluronic F68. In vitro released cyclosporine A from the optimized microspheres was approximately 25% during the 60-day incubation at 37 degrees C. It was demonstrated that the intravitreal injection of the optimized CsA-PLGA-MS decreased significantly the severity of the inflammatory signs, cellular infiltrate, aqueous leukocyte counts, and protein levels in the eyes of experimental rabbits with uveitis, compared to other formulations. Also, the preparation did not cause obvious toxicity in the noninflamed eyes of rabbits, except that the ERG b-wave amplitude for the test eyes was reversibly depressed, compared to those of the control eyes at 2 weeks, which almost recovered at the end of 6 weeks. CONCLUSIONS: The CsA-PLGA-MS preparation might be useful in the treatment of patients with severe chronic posterior uveitis who cannot tolerate systemic or periocular therapy.

Animals↗
PubMed2006

The leader sequence triggers and enhances several functions of clusterin and is instrumental in the progression of human prostate cancer in vivo and in vitro.

OBJECTIVE: To investigate the role of the leader sequence (which during clusterin biosynthesis facilitates its proper post-translational processing and secretion) in the functional activities of clusterin, a ubiquitous secretory glycoprotein with many biological functions, reported to be pro-apoptotic and anti-apoptotic in target cells, but for which the dual mechanism remains unclear. MATERIALS AND METHODS: We designed an expression vector starting from the second in-frame ATG on the full-length human clusterin cDNA that was capable of driving the expression of both the full-length and the truncated isoforms of clusterin. We established stable expression clones of the androgen-dependent prostate cancer line LNCaP expressing clusterin with and without the leader sequence. This induced expression provided an opportunity to evaluate both the in vivo and in vitro actions of clusterin expression. RESULTS: The LNCaP cells expressing clusterin with the leader sequence resisted apoptosis induced by tumour necrosis factor (TNF)-alpha, but clones with no leader sequence were highly susceptible to TNF-alpha-induced apoptosis. Furthermore, in the absence of the leader sequence, the expressed clusterin had a molecular weight consistent with that of the predicted holoprotein (40 kDa), suggesting a compromised post-translational processing with diffuse distribution throughout the cytoplasm. However, cells transfected with the full-length vector expressed clusterin of 60 and 35 kDa variants, and located exclusively in the Golgi apparatus. In vivo, only the overexpression of the full-length clusterin is anti-apoptotic and stimulates the proliferation of tumour. CONCLUSION: The leader sequence is important in determining the functions of clusterin, which include anti-apoptotic and anti-necrotic properties. The lack of the leader sequence allowed the incompletely processed clusterin to induce apoptosis in target cells; without the leader sequence, clusterin functions differently. Thus, the leader sequence is a trigger for many functions of clusterin in the progression of human prostate cancer cells.

Apoptosis↗
PubMed2006

Blockade of transforming growth factor-{beta} signaling in tumor-reactive CD8(+) T cells activates the antitumor immune response cycle.

Transforming growth factor-beta (TGF-beta) is a potent immunosuppressant. Overproduction of TGF-beta by tumor cells leads to evasion of host immune surveillance and tumor progression. Results of our early studies showed that adoptive transfer of tumor-reactive, TGF-beta-insensitive CD8(+) T cells into immunocompetent mice was able to eradicate lung metastasis of mouse prostate cancer. The present study was conducted with three objectives. (a) We tested if this technology could be applied to the treatment of solid xenograft tumors in allogeneic immunodeficient hosts. (b) We determined relevant variables in the tumor microenvironment with the treatment. (c) We tested if immune cells other than CD8(+) T cells were required for the antitumor effect. Mouse prostate cancer cells, TRAMP-C2 of the C57BL/6 strain, grown in immunodeficient allogeneic hosts of BALB/c strain, were used as a xenograft model. Tumor-reactive CD8(+) T cells from C57BL/6 mice were isolated, expanded ex vivo, and rendered insensitive to TGF-beta by introducing a dominant-negative TGF-beta type II receptor vector. Seven days following s.c. injection of TRAMP-C2 cells (5 x 10(5)) into the flank of male BALB/c-Rag1(-/-) mice, tumor-reactive, TGF-beta-insensitive CD8(+) T cells (1.5 x 10(7)) were transferred with and without the cotransfer of an equal number of CD8-depleted splenocytes from C57BL/6 donors. Naive CD8(+) T cells or green fluorescent protein-empty vector-transfected tumor-reactive CD8(+) T cells were transferred as controls. Forty days following the transfer, the average tumor weight in animals that received cotransfer of tumor-reactive, TGF-beta-insensitive CD8(+) T cells and CD8-depleted splenocytes was at least 50% less than that in animals of all other groups (P < 0.05). Tumors in animals of the former group showed a massive infiltration of CD8(+) T cells. This was associated with secretion of relevant cytokines, decreased tumor proliferation, reduced angiogenesis, and increased tumor apoptosis. Based on these results, we postulated a concept of antitumor immune response cycle in tumor immunology.

Adoptive Transfer↗
PubMed2006

Cyclosporine-loaded microspheres for treatment of uveitis: in vitro characterization and in vivo pharmacokinetic study.

PURPOSE: A sustained intraocular level of immunosuppressive drug is desirable for the treatment of uveitis and other intraocular immune disorders. The objective of the present investigation was to assess the suitability of cyclosporine-loaded poly(lactic-co-glycolic acid) microspheres (CyS-PLGA-MS) to achieve this goal. METHODS: A solvent-evaporation method was used in the preparation of CyS-PLGA-MS. These microspheres were characterized for drug loading, entrapment efficiency, and in vitro release by high-performance liquid chromatography, particle size by phase-contrast light microscopy and surface morphology by scanning electron microscopy. The 3H-CyS-PLGA-MS suspension was injected into the vitreous body of healthy rabbits, and the concentration of cyclosporine in various ocular tissues and blood at predetermined intervals was measured by a scintillation counting technique and the pharmacokinetic parameters were calculated. Intravitreous administration of 3H-CyS solution was conducted as the control. RESULTS: The CyS-PLGA-MS was produced, with drug-loading ranging from 11% to 16% and a high entrapment efficiency from 86% to 98%. Microspheres were discrete, spherical particles with a diameter of approximately 50 microm. The CyS was constantly and slowly released from microspheres in the in vitro release experiment. Compared with CyS solution, microspheres prolonged the release of CyS and maintained therapeutic CyS concentrations for at least 65 days in disease-related tissues such as the choroid-retina and iris-ciliary body. The percentage of CyS released in vitro correlated well with the CyS distribution rate in vivo. CONCLUSIONS: CyS-PLGA-MS, displaying sustained intraocular release of CyS and showing advantages over CyS solution, may meet clinical needs more efficiently.

Animals↗
PubMed2006

Pharmacokinetics and anti-asthmatic potential of non-parenterally administered recombinant human interleukin-1 receptor antagonist in animal models.

The objectives of this study were to define the pharmacokinetics of recombinant human interleukin-1 receptor antagonist (rhIL-1ra) and its effects on allergic asthma, cell adhesion molecules, and upper respiratory tract following non-parenteral administration in animals. Pharmacokinetics and immunomodulating effects of rhIL-1ra were investigated in Sprague-Dawley rats and asthmatic guinea pigs, respectively. Effects on the upper respiratory tract following the applications of rhIL-1ra were investigated on the ex vivo nasal mucosa of Sprague-Dawley rats and in situ in the upper palate of Chinese toads. Absolute bioavailabilities after intratracheal and intranasal administrations of rhIL-1ra were 94.3% and 24.8%, respectively. After administration of rhIL-1ra solution as ultrasonic spraying, the asthmatic symptom in guinea pigs was obviously attenuated. The plasma soluble intercellular cell adhesion molecule (sICAM-1) and P-selectin levels in asthmatic guinea pigs were each dose-dependently reduced with the increase of rhIL-1ra dose. The rhIL-1ra solution after administration via the airway seemed to have no impact on the integrity of nasal mucosa and mucocilia clearance in the upper respiratory tract. The present study provides evidence that rhIL-1ra effectively suppresses allergen-induced asthmatic symptoms through spraying, which corresponds to nasal and pulmonary absorption or both, and the efficacy is associated with downregulation of sICAM-1 and P-selectin expressions.

Administration, Intranasal↗
PubMed2006

[The ubiquitin-proteasome proteolytic pathway and tumorigenesis].

The ubiquitin-proteasome proteolytic pathway, a major pathway for protein degradation in cells, plays a critical role in the protein metabolism. So abnormality of the ubiquitin-proteasome proteolytic pathway is closely related to many diseases, especially cancer. In this paper, we reviewed the study of the significant role of the ubiquitin-proteasome proteolytic pathways during the cell cycle, DNA repair and apoptosis, especially the relationship between these pathways and tumorigenesis.

Apoptosis↗
PubMed2006

[The pharmacokinetics and pharmacodynamics of recombinant hirudin-2 nasal spray].

AIM: To investigate the pharmacokinetics and the anticoagulation action of recombinant hirudin-2 (rHV2) nasal spray after administration of the preparation. METHODS: rHV2 concentration in plasma was determined by chromogenic substrate method and the relative bioavailability was calculated. The anticoagulation action of rHV2 spray after intranasal administration in normal rats and DIC model rabbits after intranasal administration of rHV2 spary were studied. RESULTS: The in vivo course of rHV2 in rats fitted to the one-compartment model after intranasal administration of rHV2 spray and the relative bioavailability was 28.53%. Coagulating times of APTT and TT were significantly prolonged in normal rats, and APTT in DIC model rabbits was significantly shortened and was close to the normal values after administration of rHV2 nasal spray. CONCLUSION: rHV2 spray could be an effective nasal preparation of rHV2.

Administration, Intranasal↗
PubMed2006

Balloon kyphoplasty: an experience of 38 patients with painful osteoporotic vertebral compressive fractures.

OBJECTIVE: To evaluate the efficacy and safety of percutaneous balloon kyphoplasty as a new therapy for patients with painful osteoporotic vertebral compressive fractures of the lumbar and thoracic spine. METHODS: A retrospective analysis was conducted in 38 consecutive patients (28 females, 10 males), whose ages ranged from 56 to 82 years (mean age 72 years). The symptom- and sign-positive spinal segment was identified by MRI. The time between onset of symptoms and surgical intervention ranged from 2 days to 1 year. 62 segments (36 thoracic, 26 lumbar) were treated in this cohort. The pain score estimated by Visual Analog Scale and activity degree were assessed immediately after operation and at 1-, 6-, and 12-month postoperative follow-up. Preoperative and postoperative anterior, midline vertebral heights in fractured vertebrae were measured on lateral radiographs to evaluate the effect of the procedure. RESULTS: The method achieved a swift pain relief associated with an evidently increased weight-bearing ability. The pain score was reduced from 8.2 to 2.4 points. The anterior and midline vertebral heights in 62 fractured vertebral bodies increased up to 82.76%+/-26.84%, 88.82%+/-21.75% and the wedge decreased from 15 to 8 degrees. This effect persisted at least over a period of two years. The procedure did not induce narrowing of the spinal canal and no severe complications occurred. CONCLUSIONS: Balloon kyphoplasty can result in immediate clinical improvement of mobility and pain relief, increase vertebral body height, and quickly return patient's activity. The short-term results are approved excellent, and the long-term results need further judgment.

Aged↗
PubMed2006

[Continuously modeling research on the transfer and transform processes of phosphorus in Heihe River watershed].

Taking supply water source of Xi'an city as an example, by the help of Matlab software, using fill and yield model, the Inverse-Gauss flow concentration model, runoff-sediment relation model and Viney model, the transfer and transform processes of phosphorus from 1981 to 1990 were modeled continuously. Phosphorus pollution loads of Heihe River were also estimated. The result shows that the continuous modeling result accorded with the generic law of phosphorus loss. The relative error between modeling result and monitor interpolation result was not more than +/-30%. So the modeling method proposed in this paper could be used to model continuously the transfer and transform processes of phosphorus in Heihe river watershed. This study was only primary attempt to non-point source pollution continous model, therefore, the modeling method needed to be improved and perfected further.

China↗
PubMed2006

[Recent advances in liposomes and nanoparticles as drug carriers for drug delivery].

Liposomes and nanoparticles have been used as drug carriers to increase solubility, prolong drug duration in vivo, target drug delivery, reduce toxicity and combat multi-drug resistance. With major advances in the preparation techniques, preparation material, and surface modifiers in recent years, liposomes and nanoparticles delivery systems have achieved success in fields including cancer therapy, overcoming biological barriers, and biological drugs and vaccine carriage.

Drug Carriers↗