Biomedical subjects

Qun Zhao

Publications and source records attributed to Qun Zhao.

15 recordsLinked to original sources

PubMed2006

SmartPhantom--an fMRI simulator.

Many informatics tools have emerged to process the voluminous and complex data generated by functional magnetic resonance imaging (fMRI). The interpretation of fMRI exams is largely determined by these tools. However, their performance is hard to evaluate because there is no independent means of calibration. A novel fMRI calibration system called SmartPhantom has been developed to simulate functional blood oxygen level dependent (BOLD) imaging. SmartPhantom contains a quadrature radio frequency coil, comprising two perpendicular planar loops that can be externally activated or deactivated. The system is able to produce reasonably uniform signal enhancements in a calibration sample surrounded by the two loops during an MRI scan. The enhancement is controlled well in both magnitude and predefined timing and produces BOLD-like signals. Characteristics of SmartPhantom are discussed in detail, followed by a comparison of fMRI informatics tools. Two fMRI data sets are acquired with the SmartPhantom. One with high signal-to-noise ratio provides the calibration. Another with lower SNR is input into three software packages (BrainVoyager, FSL and Statistical Parametric Mapping 2) for data preprocessing and statistical analysis. Results from the three packages are compared in both sensitivity of detecting the activation and correlation between the predicted activation and calibration.

Calibration↗

PubMed2006

Determination of telmisartan in rat tissues by in-tube solid-phase microextraction coupled to high performance liquid chromatography.

A poly(methacrylic acid-ethylene glycol dimethacrylate, MAA-EGDMA) monolithic capillary was used for the direct and on-line extraction of telmisartan from Sprague-Dawley rat tissue (heart, kidney, and liver) homogenates. Under optimized conditions, the tissue homogenates were simply diluted with a mixture of phosphate buffer (pH 2)/ACN (90:8 v/v), and then injected for extraction only after centrifugation and filtration. Coupled to HPLC with fluorescence detection, the method was linear over the range of 1.25-1500 ng/g for telmisartan in heart and kidney, 12.5-15 000 ng/g in liver with correlation coefficients over 0.9992. The detection limits were found to be in the range from 0.24 to 1.8 ng/g. RSDs for intra- and inter-day ranged from 1.2 to 8.1%. The determination of telmisartan in treated rat tissues was achieved by using the proposed method.

Angiotensin II Type 1 Receptor Blockers↗

PubMed2006

[Effects of BMP-2 gene therapy on vascularization in repairing bone defects].

OBJECTIVE: To study the effects of BMP-2 gene therapy on vascularization in repairing bone defects. METHODS: The isolated rabbit mesenchymal stem cells (rBMSC), after being transfected by adenovirus carrying BMP-2 gene (Ad-BMP-2) and seeded on xenogeneic bone scaffolds, were used to repair 1.5 cm-long radius bone defects. Five methods were in use in the experiments: Ad-BMP-2 infected rBMSC plus antigen-free bovine cancellous bone (BCB, Group A), rBMSC-BCB plus reconstructed hBMP-2 (Group B1), Ad-LacZ infected rBMSC-BCB (Group C), rBMSC-BCB (Group D) and only BCB scaffolds (Group E). After 4, 8, and 12 weeks of the operations, capillary vessel ink infusion, vascular endothelial growth factor ( VEGF) immunohistochemical staining and histological examination were conducted. RESULTS: After 4 weeks of the operations, usually in Group A one newly formed artery was found in every pore between the trabeculae of the BCB. The density of these intraosseous vessels was high in the periphery and decreasing towards the center of the grafts; by transmission electron microscopy, osteoblasts were always next to vascular endothelial cells and gradually developed into osteocytes with the increase of capillary vessel; VEGF expression were apparently enhanced in mesenchymocytes. CONCLUSIONS: BMP-2 gene therapy, by up-regulating VEGF expression, indirectly induces vascularization of grafts and is of great value to the treatment of bone in union and bone defects.

Animals↗

PubMed2006

[Assessment of therapeutic results for simple bone cyst with percutaneous injection of autogenous bone marrow].

OBJECTIVE: To evaluate the therapeutic results of percutaneous injection of autogenous bone marrow for simple bone cyst and to analyze the prognostic factors of the treatment. METHODS: From March 2000 to June 2005, 31 patients with simple bone cysts were treated by percutaneous injection of autogenous bone marrow. Of 31 patients, there were 18 males and 13 females, aged 5 years and 7 months to 15 years. The locations were proximal humerus in 18 cases, proximal femur in 7 cases and other sites in 6 cases. Two cases were treated with repeated injections. The operative process included percutaneous aspiration of fluid in the bone cysts and injection of autogenous bone marrow aspirated from posterior superior iliac spine. The mean volume of marrow injected was 40 ml (30-70 ml). RESULTS: No complications were noted during treatment. Thirty patients were followed for an average of 2.2 years (1-5 years) with 2 cases out of follow-up. After one injection of bone marrow, 9 cysts (29.0%) were healed up completely, 7 cysts (22.6%) basically healed up, 13 cysts (41.9%) healed up partially and 2 (6.5%) had no response. The satisfactory and effective rates were 67.7% and 93.5% respectively. There was significant difference between active stage group and resting stage group(P<0.05). There were no statistically significant difference in therapeutic results between groups of different ages, lesion sites or bone marrow hyperplasia(P>0.05). CONCLUSION: Percutaneous injection of autogenous bone marrow is a safe and effective method to treat simple bone cyst, but repeated injections is necessary for some patients. The therapeutic results are better in cysts at resting stage than those at active stage.

Adolescent↗

PubMed2005

MAP kinase phosphatase 1 controls innate immune responses and suppresses endotoxic shock.

Septic shock is a leading cause of morbidity and mortality. However, genetic factors predisposing to septic shock are not fully understood. Excessive production of proinflammatory cytokines, particularly tumor necrosis factor (TNF)-alpha, and the resultant severe hypotension play a central role in the pathophysiological process. Mitogen-activated protein (MAP) kinase cascades are crucial in the biosynthesis of proinflammatory cytokines. MAP kinase phosphatase (MKP)-1 is an archetypal member of the dual specificity protein phosphatase family that dephosphorylates MAP kinase. Thus, we hypothesize that knockout of the Mkp-1 gene results in prolonged MAP kinase activation, augmented cytokine production, and increased susceptibility to endotoxic shock. Here, we show that knockout of Mkp-1 substantially sensitizes mice to endotoxic shock induced by lipopolysaccharide (LPS) challenge. We demonstrate that upon LPS challenge, Mkp-1-/- cells exhibit prolonged p38 and c-Jun NH2-terminal kinase activation as well as enhanced TNF-alpha and interleukin (IL)-6 production compared with wild-type cells. After LPS challenge, Mkp-1 knockout mice produce dramatically more TNF-alpha, IL-6, and IL-10 than do wild-type mice. Consequently, Mkp-1 knockout mice develop severe hypotension and multiple organ failure, and exhibit a remarkable increase in mortality. Our studies demonstrate that MKP-1 is a pivotal feedback control regulator of the innate immune responses and plays a critical role in suppressing endotoxin shock.

Animals↗

PubMed2005

Monitoring of five sulfonamide antibacterial residues in milk by in-tube solid-phase microextraction coupled to high-performance liquid chromatography.

A simple, rapid, and sensitive method for the quantitative monitoring of five sulfonamide antibacterial residues in milk was developed by coupling in-tube solid-phase microextraction (SPME) to high-performance liquid chromatography with an ultraviolet detector. A poly(methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary column was selected as the extraction medium for this on-line technique. To obtain optimum extraction efficiency, several parameters relating to in-tube SPME were investigated. By simple extraction with ethanol, dilution with phosphate buffer solution, and centrifugation, the sample solution then could be directly injected into the device for extraction. The calculated detection limits for sulfadiazine, sulfamethazine, sulfamethoxazole, sulfamonomethoxine sodium, and sulfacetamide sodium were 2.0, 2.8, 1.7, 2.5, and 22 ng/mL, respectively. The method was linear over the range of 20-5000 ng/mL (100-5000 ng/mL for sulfacetamide sodium) with a correlation coefficient R (2) value >0.9980. Excellent method reproducibility was found by intra- and interbatch precisions, yielding the relative standard deviations of <10.0 and <9.94%, respectively. The proposed method was proved to be robust in monitoring sulfadiazine, sulfamethazine, sulfamethoxazole, sulfamonomethoxine sodium, and sulfacetamide sodium residues in milk.

Animals↗

PubMed2005

Production of active recombinant mitogen-activated protein kinases through transient transfection of 293T cells.

Mitogen-activated protein (MAP) kinases are a family of serine/threonine protein kinases that play an important role in a myriad of cellular processes, including cell proliferation, differentiation, and apoptosis. Abnormal activation of MAP kinases has been shown to participate in a variety of human diseases which include cancer, septic shock, rheumatoid arthritis, diabetes, and cardiovascular diseases. Active MAP kinase enzymes are not only valuable for basic biomedical research but are also critical for the development of pharmacological inhibitors as therapeutic drugs in the treatment of relevant human diseases. MAP kinases produced in a bacterial system are poorly active due to a lack of proper phosphorylation at their characteristic threonine and tyrosine residues. To overcome these limitations, we have developed a mammalian expression system for high level expression and one-step purification of enzymatically MAP kinases. We cloned JNK1, p38, and p38-regulated MAP kinase-activated protein kinase-2 into the mammalian expression vector pEBG, and expressed these protein kinases as glutathione S-transferase fusion proteins in human embryonic kidney 293T cells through transient transfection. The protein kinases were activated in vivo through treating the transfected cells with sodium arsenite and affinity-purified using glutathione-Sepharose beads. The enzymatic activities of these protein kinases were demonstrated by Western blot analysis and in vitro kinase assays. Our results indicate that this system is an extremely powerful tool for generating valuable reagents, and could be very valuable for proteomic studies.

Apoptosis↗

PubMed2005

[Detecting bone marrow micrometastasis of gastric cancer by magnetic activated cell sorting combined with fluorescent activated cell sorting].

BACKGROUND & OBJECTIVE: Several methods are used to detect bone marrow micrometastasis of gastric cancer with different accuracies. In breast cancer, tumor cells in blood can be detected sensitively and specifically by magnetic activated cell sorting (MACS) and fluorescent activated cell sorting (FACS). This study was to investigate the clinical value of this method in detecting bone marrow micrometastasis of gastric cancer. METHODS: Thirty-five patients, who received operation for gastric cancer from Dec. 2002 to Jun. 2003, were selected. Mononuclear cells were separated from their bone marrows. After marked by MACS minibeads conjugated with cytokeratin (CK) 7/8 antibodies, anti-CK-fluorescein isothiocyanate (FITC), and anti-CD45-perdinin chlorophyll protein (PerCP), tumor cells were enriched twice by MS+/RS+ positive separation column. FACS analysis was conducted on these samples before and after MACS enrichment. The results were compared with clinicopathologic parameters. RESULTS: Disseminated tumor cells were detected in bone marrow of 3 samples(8.6%) before MACS enrichment, and 25 samples (71.4%) after enrichment. The frequencies of tumor cells were 1.4 x 10(-8)-2.4 x 10(-5), 2.2 x 10(-7) -3.7 x 10(-5), and 4.0 x 10-(6)-8.6 x 10(-5) in patients with moderately differentiated, poorly differentiated, and undifferentiated carcinoma, respectively, with significant differences (P = 0.026). Bone marrow micrometastasis positively correlated with tumor TNM stage (P = 0.008), while had no correlation with tumor size, depth of wall invasion, and other clinicopathologic parameters. CONCLUSIONS: MACS combined with FACS may improve detection rate of bone marrow micrometastasis of gastric cancer. The patients with poor differentiation and in advanced TNM stage have more disseminated tumor cells in bone marrow.

Adenocarcinoma↗

PubMed2005

[Effect of shenqi fuzheng injection on pre/post-operational change of argyrophilic-nucleolar organizer regions in peripheral T-lymphocyte in patients with gastric carcinoma].

OBJECTIVE: To investigate the pre-post operational change of argyrophilic-nucleolar organizer regions (Ag-NORs) in peripheral T-lymphocyte of patients with gastric carcinoma (GC), and to explore the effect of shenqi fuzheng injection(SFI) on it. METHODS: Eighty five patients were divided into two groups according to the operation performed was radical or non-radical, and the two groups were subdivided into two by additional intravenous dripping of SFI was given to them or not. The content of Ag-NORs in peripheral T-lymphocyte in all patients before and after operation as well as in 12 healthy subjects was determined. RESULTS: Content of Ag-NORs in GC patients was significantly lower than that in the healthy subject (P < 0.01), which significantly increased after patients underwent radical operation (P < 0. 01 or P < 0.05), especially in those treated with SFI (P < 0.01). While in patients underwent non-radical operation but not treated with SFI, it showed insignificant change after operation, however it did significantly increase in those treated with SFI (P < 0.05). CONCLUSION: The immune function of T lymphocyte was low in patients with gastric carcinoma, post-operational adjuvant treatment of SFI can significantly improve the cellular immunity of patients.

Adjuvants, Immunologic↗

PubMed2004

The role of mitogen-activated protein kinase phosphatase-1 in the response of alveolar macrophages to lipopolysaccharide: attenuation of proinflammatory cytokine biosynthesis via feedback control of p38.

Mitogen-activated protein (MAP) kinases are critical mediators of innate immune responses. In response to lipopolysaccharide (LPS), MAP kinases are rapidly activated and play an important role in the production of proinflammatory cytokines. Although a number of MAP kinase phosphatases (MKPs) have been identified, their roles in the control of cytokine production have not been well defined. In the present report, we investigated the role of MKP-1 in alveolar macrophages stimulated with LPS. We found that LPS triggered transient activation of three MAP kinase subfamilies, ERK, JNK, and p38, in both immortalized and primary murine alveolar macrophages. MKP-1 was rapidly induced by LPS, and its induction correlated with the dephosphorylation of these MAP kinases. Blocking MKP-1 with triptolide prolonged the activities of both JNK and p38 in immortalized alveolar macrophages. Stimulation of primary alveolar macrophages isolated from MKP-1-deficient mice with LPS resulted in a prolonged p38 phosphorylation compared with wild type alveolar macrophages. Accordingly, these MKP-1-deficient alveolar macrophages also mounted a more robust and rapid tumor necrosis factor alpha production than their wild type counterparts. Adenovirus-mediated MKP-1 overexpression significantly attenuated tumor necrosis factor alpha production in immortalized alveolar macrophages. Finally, MKP-1 was induced by a group of corticosteroids frequently prescribed for the treatment of inflammatory lung diseases, and the anti-inflammatory potencies of these drugs closely correlated with their abilities to induce MKP-1. Our studies indicated that MKP-1 plays an important role in dampening the inflammatory responses of alveolar macrophages. We speculate that MKP-1 may represent a novel target for therapeutic intervention of inflammatory lung diseases.

Adenoviridae↗

PubMed2004

The function of mitogen-activated protein kinase phosphatase-1 in peptidoglycan-stimulated macrophages.

Mitogen-activated protein (MAP) kinases play a pivotal role in the macrophages in the production of proinflammatory cytokines triggered by lipopolysaccharides. However, their function in the responses of macrophages to Gram-positive bacteria is poorly understood. Even less is known about the attenuation of MAP kinase signaling in macrophages exposed to Gram-positive bacteria. In the present study, we have investigated the regulation of MAP kinases and the role of MAP kinase phosphatase (MKP)-1 in the production of pro-inflammatory cytokines using murine RAW264.7 and primary peritoneal macrophages after peptidoglycan stimulation. Treatment of macrophages with peptidoglycan resulted in a transient activation of JNK, p38, and extracellular signal-regulated kinase. Most interestingly, MKP-1 expression was potently induced by peptidoglycan, and this induction was concurrent with MAP kinase dephosphorylation. Triptolide, a diterpenoid triepoxide, potently blocked the induction of MKP-1 by peptidoglycan and prolonged the activation of JNK and p38. Overexpression of MKP-1 substantially attenuated the production of tumor necrosis factor (TNF)-alpha induced by peptidoglycan, whereas knockdown of MKP-1 by small interfering RNA substantially increased the production of both TNF-alpha and interleukin-1 beta. Finally, we found that in primary murine peritoneal macrophages, MKP-1 induction following peptidoglycan stimulation also coincided with inactivation of JNK and p38. Blockade of MKP-1 induction resulted in a sustained activation of both JNK and p38 in primary macrophages. Our results reveal that MKP-1 critically regulates the expression of TNF-alpha and interleukin-1 beta in RAW264.7 cells and further suggest a central role for this phosphatase in controlling the inflammatory responses of primary macrophages to Gram-positive bacterial infection.

Animals↗

PubMed2004

[Experimental study on peripheral nerve regeneration after artery sleeve anastomosis and end-to-side suture].

OBJECTIVE: To know the possibility of nerve regeneration after artery sleeve anastomosis and end-to-side suture. METHODS: Seventy-five SD rats were divided into 5 groups. First, the distal end of severed peroneal nerve was sutured end-to-side with artery sleeve anastomosis with normal nerve tibial trunk in groups A, B, C and D. Second, the tibial epineurium at the suture site was not removed in group A; the epineurium at the suture site was removed (windowing) in group B; the distal end of pre-injured peroneal nerve was sutured after 14 days and windowing was done in group C; and the neural growth factor was injected into artery sleeve and windowing was done in group D. While the distal end of severed peroneal nerve was sutured end to side directly with normal nerve tibial trunk and windowing was done in group E. The histological observation was made and the number of nerve fibers was recorded after 4, 8 and 12 weeks of operation. RESULTS: After 4 weeks, there existed the regeneration of axons and myeline sheaths in groups C, D, E, and no nerve fiber regeneration was seen in group A. After 8 weeks, the regenerating nerve fibers were significantly more in groups C, D and E than in group B and in group E than groups C and D (P<0.05). After 12 weeks, the regenerating nerve fibers were significantly more in groups C,D and E than in group B (P<0.05). CONCLUSION: End-to-side coaptation with artery sleeve anastomosis is a new valuable method in repair of peripheral nerve injuries.

Anastomosis, Surgical↗

PubMed2004

[Drug distribution in gastric cancer and adjacent tissues by preoperative intraperitoneal chemotherapy with Co-fluorouracil liposome].

OBJECTIVE: To examine the distribution of fluorouracil in gastric cancer (CA), lymph node (LN), normal gastric mucosa (NG), peritoneum (PE), greater omentum (GO) and lesser omentum (LO) by preoperative intraperitoneal chemotherapy with Co-fluorouracil liposome (Co 5-Fu), and offer an experimental basis for clinic practice. METHODS: Ninety-six gastric cancer patients were divided into four groups: Co 5-Fu i.v. injection group (Co 5-Fu i.v.), Co 5-Fu intraperitoneal perfusion group (Co 5-Fu i.p.), 5-Fu i.v. injection group (5-Fu i.v.) and intraperitoneal perfusion group (5-Fu i.p.) given on day-2, day-1 and 60 minutes before operation. Fluorouracil concentration in all tissues collected during operation were examined by high performance liquid chromatography (HPLC). RESULTS: The fluorouracil concentration in the tissues in Co 5-Fu i.p. group was significantly higher than that in Co 5-Fu i.v. or 5-Fu i.p. group (P < 0.05 or P < 0.01), and that in 5-Fu i.p. group was greatly higher than that at 5-Fu i.v. group (P < 0.01). In Co 5-Fu i.p. group, the concentration of drug in LN, CA, PE, NG, GO and LO decreased gradually with the former 3 tissues significantly higher than the latter 3 tissues (P < 0.01), and adjacent lymph node was the highest. In Co 5-Fu i.v. group, the ranking was LN, CA, NG, PE, GO and LO with the former 3 tissues significantly higher than the latter 3 tissues (P < 0.01) and showing tumor tissues higher than the other tissues (P < 0.01). In 5-Fu i.p. group, the ranking was PE, LN, CA, NG, GO and LO with the former 2 tissues significantly higher than the latter tissues (P < 0.01). CONCLUSION: Co 5-Fu possesses drug targeting, slow release and long effect in gastric cancer tissues and adjacent lymph nodes. Preoperative chemotherapy with Co 5-Fu i.p. is more advantageous than 5-Fu given i.v. or 5-Fu i.p.

Aged↗

PubMed2003

[Expression of MUC1, CD44v6, nm23 in gastric carcinomas and regional lymph node tissues and their association with invasion, metastasis, and prognosis of the tumor].

BACKGROUND & OBJECTIVE: The invasion depth and lymph node metastasis result from the polygenes and their protein expression in gastric carcinoma. The key of the basic and clinical research of the gastric carcinoma is to find out the related molecular biology marker. This study was designed to investigate the relationship between the expression of MUC1, CD44v6, nm23 in gastric carcinomas and regional lymph node tissues and invasion, metastasis, and prognosis of the tumor. METHODS: The expression of MUC1, CD44v6, and nm23 in 110 advanced gastric carcinomas and 613 regional lymph node specimens were examined by immunohistochemical technique. The results was judged by the criterion of the positive or the negative expression. RESULTS: (1) The expression of MUC1 (84.6%, 88.1%, 87.3%, 91.7%, 94.4%, and 95.5%, respectively) and CD44v6 (79.5%, 74.6%, 79.4%, 81.7%, 87.0%, and 87.9%, respectively) in gastric carcinoma tissues in the groups of low differentiated adenocarcinoma, infiltrated type, T3+T4, lymph node metastasis, stage III-IV, and survival < 5 years were significantly higher than those in the groups of high-middle differentiated adenocarcinoma, limited type, T1+T2, no lymph node metastasis, stage I-II, and survival >or= 5 years (P< 0.01 or P< 0.05); while the expression of nm23 was contrary (P< 0.01 or P< 0.05) except for the groups of differentiation and Borrmann type. (2) The expression of MUC1 and CD44v6 in the lymph node metastasis group of the gastric carcinoma (94.7% and 89.4%, respectively)were remarkably higher than those in the no lymph node metastasis group (19.6% and 19.6%, respectively) (P< 0.01); while the expression of nm23 was contrary (16.8% versus 74.9%, P< 0.01). (3) The 5-year survival rates of the patients in MUC1 and CD44v6 positive expression group (13.0% and 15.4%, respectively) in the regional lymph nodes of gastric carcinoma were significantly lower than those in the negative expression group (100% and 62.1%) (P< 0.01); while the 5-year survival rate of the patients in nm23 positive expression group was contrary (70.0% versus 4.0%, P< 0.01). CONCLUSION: The high expression of MUC1, CD44v6 and low expression of nm23 were related to the invasion, metastasis, and prognosis of the gastric carcinoma. The detection of MUC1, CD44v6, and nm23 can be useful for the diagnosis and treatment of advanced gastric carcinoma.

Adult↗

PubMedDate not supplied

The therapeutic efficacy of angiostatin against weakly- and highly-immunogenic 3LL tumors.

BACKGROUND: Antiagiogenesis represents a promising approach to cancer therapy. We have previously demonstrated that the antitumor effects of endostatin, one of the most potent angiostatic agents, could be enhanced when combined with immunotherapy. Our current study evaluated whether anti-tumor immune response could also potentiate the therapuetic efficacy of another antiangiogenic drug, angiostatin. METHODS AND RESULTS: Using Matrigel assay, we showed that our preparation of recombinant angiostatin possessed potent anti-angiogenic activity in vivo. The antitumor effects of recombinant angiostatin were tested against weakly-immunogenic 3LL Lewis lung carcinoma versus its highly immunogenic variant 3LL-C75. We showed that angiostatin inhibited the growth of 3LL-C75 more potently than that of 3LL tumor, suggesting that the host's immune response potentiates the antitumor effects of angiostatin. This conclusion was further supported by the finding that the antitumor activity of angiostatin against 3LL-C75 tumor was lower in immunodeficient nude mice in comparison with immunocompetent mice. Immunization of C57BL/6 mice with 3LL-C75 cells stimulated the antitumor immunity and inhibited the growth of parental 3LL tumor. Angiostatin treatment of immunized mice further enhanced the antitumor effect of tumor vaccination. CONCLUSION: Antitumor immune response could complement the therapeutic efficacy of angiostatin.

Angiogenesis Inhibitors↗