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Biomedical subjects

Jian Sun

Publications and source records attributed to Jian Sun.

At least 91 records · Page 5Linked to original sources
PubMed2005

[Transpositional anastomosis of C7 posterior root and spinal accessory nerve to reconstruct the trapezius muscle function].

OBJECTIVE: To introduce a new approach of neurotization to treatment of the shoulder syndrome after the radical neck dissection by using transpositional anastomosis of C7 posterior root and the spinal accessory nerve to reconstruct the function of trapezius muscle. METHODS: From March 1999 to February 2001, 10 patients underwent the neurotization during the radical neck dissection. In the operation, the apo-cranial part of spinal accessory nerve was preserved from the trapezius muscle (> 3. 0 cm in length) and anastomosed to C7 posterior root. Objective physical examinations and electromyography were conducted before and after operation. One, 6 and 12 months after operation the trapezius muscle function after the transpositional anastomosis was evaluated. RESULTS: One, 6 and 12 months after operation, the recovery rates of each part were as follows: 9.8%, 68.9% and 73.5% in upper part; 4.7%, 73.6% and 69.4% in middle part; and 6.2%, 70.5% and 70.3% in lower part. The range of abduction motion of upper arm in 7 cases (70%) exceeded 90 degrees. The mean maximal abduction angle was more than 95 degrees. Evaluation of the shoulder function showed that myoatrophy was mild and the disability of abduction was classified as grade II in 7 cases and grade II in 3 cases. CONCLUSION: Transpositional anastomosis of the C7 posterior root to the spinal accessory nerve after radical neck dissection can well reconstruct the function of trapezius muscle. This approach provides a wide indication in comparison with the functional neck dissection without impairment of arm function after the cutting of C7.

Accessory Nerve↗
PubMed2005

[Effects of tumor necrosis factor alpha on expression of phospholamban and intracellular calcium in cardiomyocytes].

OBJECTIVE: To explore the effects of tumor necrosis factor alpha (TNFalpha) on the expression of phospholamban (PLB) and sarco (endo) plasmic reticulum Ca(2+)-ATPase (SERCA2a) and concentration of intracellular free calcium in myocardiocytes. METHODS: The neonatal rat myocardiocytes were randomly divided into 6 groups: treatment with different concentrations of TNFalpha (1,10,30,50,and 70 microg/L, respectively) and without TNFalpha (control). The mRNA and protein expression of PLB and SERCA2a were detected with one-step reverse transcription-polymerase chain reaction and Western blotting. The changes of intracellular free calcium concentration ([Ca2+]i) in cultured single neonatal rat cardiomyocyte were determined with Fluo-3/AM loading by laser scanning confocal microscopy. RESULTS TNFalpha significantly increased the expression of PLB mRNA and protein in a dose-dependent fashion. The ratio of PLB/beta-actin mRNA in myocardiocytes incubated with 10,30,50, and 70 microg/L TNFalpha significantly increased by 66%, 106%, 141%, and 189% compared with control (P < 0.05), and protein levels significantly increased by 30%, 48%, 73%, and 114% respectively compared with control (P < 0.001), but there was no significant difference in PLB mRNA expression between the group treated with 1 microg/L TNFalpha and control group. TNFalpha had no effect on the expression of mRNA and protein of SERCA2a. TNFalpha (50 microg/L) incubated with cell for 24 hours diminished delta[Ca2+]i of single neonatal rat cardiomyocyte about 33% stimulated by isoproterenol (P < 0.01), but had no effect on delta [Ca2+]i of cardiomyocyte without isoproterenol stimulation. CONCLUSION: TNFalpha can increase the expression of PLB and decrease delta[Ca2+]i in cardiomyocytes, which may be related with its negative inotropic effects on cardiomyocytes.

Animals↗
PubMed2004

A novel hepatitis B virus genotyping system by using restriction fragment length polymorphism patterns of S gene amplicons.

AIM: Traditional hepatitis B virus (HBV) genotyping methods using restriction fragment length polymorphism (RFLP) can reliably identify genotypes A to F. As HBV genotypes G and H have been recently identified, this study was to establish an accurate and simple genotyping method for all eight HBV genotypes (A to H). METHODS: Two hundred and forty HBV small S sequences obtained from GeneBank were analysed for restriction enzyme sites that would be genotype-specific. Restriction patterns following digestion with restriction enzymes BsrI, StyI, DpnI, HpaII, and EaeI, were determined to identify all eight HBV genotypes. Mixed genotype infections were confirmed by cloning and further RFLP analysis. RESULTS: The new genotyping method could identify HBV genotypes A to H. Genotypes B and C could be determined by a single step digestion with BsrI and StyI in parallel. This was particularly useful in the Far East where genotypes B and C are predominant. Serum samples from 187 Chinese HBV carriers were analysed with this genotyping system, and the genotype distribution was 1.1% (2), 51.9% (97), 40.6% (76) and 4.8% (9) for genotypes A, B, C, and D, respectively. Mixed genotypes were found in only 3 patients (1.6%). Sequence data analysis confirmed the validity of this new method. CONCLUSION: This HBV genotyping system can identify all eight HBV genotypes. It is accurate and simple, and can be widely used for studies on HBV genotyping.

Adult↗
PubMed2004

Proteomic characterization of isolated retinal pigment epithelium microvilli.

Polarized epithelial cells are characterized by displaying compartmentalized functions associated with differential distribution of transporters, structural proteins, and signaling molecules on their apical and basolateral surfaces. Their apical surfaces frequently elaborate microvilli, which vary in structure according to the specific type and function of each epithelium. The molecular basis of this heterogeneity is poorly understood. However, differences in function will undoubtedly be reflected in the specific molecular composition of the apical surface in each epithelial subtype. We have exploited a method for isolating microvilli from the mouse eye using wheat germ agglutinin (WGA)-agarose beads to begin to understand the specific molecular composition of apical microvilli of the retinal pigment epithelium (RPE) and expand our knowledge of the potential function of this interface. Initially, apical RPE plasma membranes bound to WGA beads were processed for morphological analysis using known apical and basolateral surface markers. The protein composition of the apical microvilli was then established using proteomic analysis. Over 200 proteins were identified, including a number of proteins previously known to be localized to RPE microvilli, as well as others not known to be present at this surface. Localization of novel proteins identified with proteomics was confirmed by immunohistochemistry in both mouse and rat eye tissue. The data generated provides new information on the protein composition of the RPE apical microvilli. The isolation technique used should be amenable for isolating microvilli in other epithelia as well, allowing new insights into additional functions of this important epithelial compartment.

Animals↗
PubMed2004

Support for a proposed retinoid-processing protein complex in apical retinal pigment epithelium.

The interaction of cellular retinaldehyde-binding protein (CRALBP) with ERM (ezrin, radixin, moesin)-binding phosphoprotein 50 (EBP50) in retinal pigment epithelium (RPE) microsomes has led to the hypothesis that a retinoid-processing protein complex exists in apical RPE. Mouse RPE apical processes were isolated on wheat germ agglutinin-coated agarose beads. Proteomic analyses of the isolated apical RPE demonstrated the presence of CRALBP, EBP50, 11-cis-retinol dehydrogenase, cellular retinol-binding protein 1, and interphotoreceptor retinoid-binding protein. The results support the hypothesis that a visual cycle protein complex may serve in the localization and release of 11-cis-retinoid in the apical RPE.

Alcohol Oxidoreductases↗
PubMed2004

Comparing directly measured standard gamble scores to HUI2 and HUI3 utility scores: group- and individual-level comparisons.

Directly measured standard gamble (SG) utility scores reflect the respondent's assessment and valuation of their own health status. Scores from the health utilities index (HUI) are based on self-assessed health status but valued using community preferences obtained using the SG. Our objectives were to find if mean directly measured utility scores agree with mean HUI mark 2 (HUI2) and mean HUI mark 3 (HUI3) scores. Also, if individual directly measured utility scores agree with HUI2 and HUI3 scores, and whether HUI2 and HUI3 scores agree. Questionnaires based on the HUI2 and HUI3 health-status classification systems were administered by interviewers to 140 teenage survivors of extremely low birthweight (ELBW) and 124 control group teens. Respondents were asked to think about their own usual health states using six dimensions from HUI2 and value that state using the SG. Mean SG scores are compared with mean HUI2 and mean HUI3 scores using paired sample t-tests. Mean HUI2 scores are compared with mean HUI3 scores. Agreement among scores is assessed using intra-class correlation coefficient (ICC). The effect of severity of health-state morbidity on agreement was assessed using three approaches. ELBW cohort mean (standard deviation) SG, HUI2, and HUI3 scores were 0.90 (0.20), 0.89 (0.14), and 0.80 (0.22). Results for controls were 0.93 (0.11), 0.95 (0.09), and 0.89 (0.13). Mean SG and HUI2 scores did not differ; mean SG and HUI3 did differ; mean HUI2 and HUI3 also differed. At the individual level for ELBW, the ICCs between SG and HUI2, SG and HUI3, and HUI2 and HUI3 scores were 0.13, 0.28, and 0.64. For controls the ICCs were 0.14, 0.24, and 0.56. HUI2 scores appear to match directly measured utility scores reasonably well at the group level. HUI2 and HUI3 scores differ systematically. At the individual level, however, HUI2 and HUI3 scores are poor substitutes for directly measured scores.

Adolescent↗
PubMed2004

Superoxide, Hydrogen Peroxide and Hydroxyl Radical in D1/D2/cytochrome b-559 Photosystem II Reaction Center Complex.

Spin-trapping electron spin resonance (ESR) was used to monitor the formation of superoxide and hydroxyl radicals in D1/D2/cytochrome b-559 Photosystem II reaction center (PS II RC) Complex. When the PS II RC complex was strongly illuminated, superoxide was detected in the presence of ubiquinone. SOD activity was detected in the PS II RC complex. A primary product of superoxide, hydrogen peroxide, resulted in the production of the most destructive reactive oxygen species, *OH, in illuminated PS II RC complex. The contributions of ubiquinone, SOD and H(2)O(2) to the photobleaching of pigments and protein photodamage in the PS II RC complex were further studied. Ubiquinone protected the PS II RC complex from photodamage and, interestingly, extrinsic SOD promoted this damage. All these results suggest that PS II RC is an active site for the generation of superoxide and its derivatives, and this process protects organisms during strong illumination, probably by inhibiting more harmful ROS, such as singlet oxygen.

Journal Article↗
PubMed2004

Effects of Ginkgo biloba extract on number and activity of endothelial progenitor cells from peripheral blood.

The aim of this study is to investigate whether Ginkgo biloba extract can augment endothelial progenitor cells numbers, and promote the cells' proliferative, migratory, adhesive, and in vitro vasculogenesis capacity. Total mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After 7 days culture, attached cells were stimulated with Ginkgo biloba extract (to make a series of final concentrations: 10 mg/L, 25 mg/L, and 50 mg/L) or vehicle control for the respective time points (6 hours, 12 hours, 24 hours, and 48 h). Endothelial progenitor cells were characterized as adherent cells double positive for DiLDL-uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. They were further documented by demonstrating the expression of KDR, VEGFR-2, and AC133 with flow cytometry. Endothelial progenitor cells proliferation, migration, and in vitro vasculogenesis activity were assayed with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, modified Boyden chamber assay, and in vitro vasculogenesis kit, respectively. Endothelial progenitor cells adhesion assay was performed by replating those on fibronectin-coated dishes, and then counting adherent cells. Incubation of isolated human mononuclear cells with Ginkgo biloba extract dose- and time-dependently increased the number of endothelial progenitor cells, maximum at 25 mg/L, 24 hours (approximately 1-fold increase, P < 0.01). In addition, Ginkgo biloba extract also dose- and time-dependently promoted endothelial progenitor cells proliferative, migratory, adhesive, and in vitro vasculogenesis capacity. The results of the present study defined a novel functional effect of Ginkgo biloba extract: the augmentation of endothelial progenitor cells with enhanced functional activity.

Blood↗
PubMed2004

[Stress analysis of the mandible by 3D FEA in normal human being under three loading conditions].

PURPOSE: The condition and character of stress distribution in the mandibular in normal human being during centric, protrusive, laterotrusive occlusion were analysed. METHODS: The three-dimensional finite element model of the mandibular was developed by helica CT scanning and CAD/CAM software, and three-dimensional finite element stress analysis was done by ANSYS software. RESULT: Three-dimensional finite element model of the mandibular was generated. Under these three occlusal conditions, the stress of various regions in the mandible were distributed unequally, and the stress feature was different;while the stress of corresponding region in bilateral mandibular was in symmetric distribution. The stress value of condyle neck, the posterior surface of coronoid process and mandibular angle were high. CONCLUSION: The material properties of mandible were closely correlated to the value of stress. Stress distribution were similar according to the three different loading patterns, but had different effects on TMJ joint. The concentrated areas of stress were in the condyle neck, the posterior surface of coronoid process and mandibular angle.

Finite Element Analysis↗
PubMed2004

[Research and development for the CAD system of maxillofacial prosthesis].

OBJECTIVE: To establish a CAD system of maxillofacial prostheses. METHODS: The maxillofacial prosthesis CAD system, which included mirror technique, boolean operation and use of FreeForm software, was introduced in detail by use of two clinical cases of auricular and orbital prostheses. RESULTS: The CAD system of maxillofacial prosthesis was successfully established. The 3-D digital images of defected sides of two cases were quickly and conveniently obtained, which were symmetrical and harmoniously match to the deficient sides. CONCLUSION: The established CAD technique is a useful system in maxillofacial area. It may be applied in clinic in future.

Computer-Aided Design↗
PubMed2004

[Effects of hypercholesterolemia on the number and activity of endothelial progenitor cells in peripheral blood].

OBJECTIVE: To investigate whether hypercholesterolemia has influences on the number and activity of endothelial progenitor cells (EPCs). METHODS: Mononuclear cells were isolated from patients with hypercholesterolemia (n = 20) and age-matched control subjects (n = 20). EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. EPCs proliferation and migration were assayed by MTT assay and modified Boyden chamber assay, respectively. EPCs adhesion assay was performed by replating cells on fibronectin-coated dishes, then counting the adherent cells. RESULTS: The number of EPCs was significantly reduced in patients with hypercholesterolemia as compared with that in control subjects [(41.8 +/- 8.7 vs 64.5 +/- 16.6) EPCs/x 200 fields; P < 0.05] and it was inversely correlated with total cholesterol levels (r = -0.659, P < 0.001) and LDL cholesterol levels (r = -0.611, P < 0.001). In addition, EPCs proliferative, migratory and adhesive capacity were also impaired. CONCLUSION: It is suggested that a novel pathophysiological mechanism of hypercholesterolemia may be defined i.e. reduction of EPCs with decreased functional activity.

Aged↗
PubMed2004

[Clinical observation and treatment of failing flaps in oral and maxillofacial surgery: a report of 44 cases].

PURPOSE: For the purpose of enhancing the successful transplanting rate of free flaps and reviewing the clinical characters, a retrospective study was undertaken to analyze the causes as well as clinical characters of the failing flap in oral and maxillofacial regions. METHODS: A total of 832 free revascularized flaps were performed in our department from August 1997 to April 2003. The data including the time to occurence, causes, clinical characters and the managements of flap crises were reviewed and then analyzed. RESULTS: Forty-four flaps developed vascular crisis (5.29%), most of them were caused by venous occlusion (38/44). Thirty-eight in forty-four flaps crises occurred within 72 hours (86.36%). 32 flaps crises were explored with 21 flaps successfully salvaged; the success rate was as high as 65.63%. CONCLUSIONS: For the highest successful transplanting rate of free flaps, the management of the local factors plays an important role. Most of the failing flaps happened within three days after operation. The surgical exploration should be done as soon as possible, if the crises flap happened within six hours.

Adolescent↗
PubMed2004

Effects of puerarin on number and activity of endothelial progenitor cells from peripheral blood.

AIM: To investigate whether puerarin can augment endothelial progenitor cells (EPCs) numbers, promote EPC proliferative, migratory, adhesive, and in vitro vasculogenesis capacity. METHODS: EPCs were characterized as adherent cells by double staining of DiLDL-uptake and lectin binding under a laser scanning confocal microscope. Expression of KDR, VEGFR-2, and AC133 was detected by flow cytometry. EPCs proliferation, migration and in vitro vasculogenesis were determined with MTT assay, modified Boyden chamber assay, and in vitro vasculogenesis kit, respectively. EPCs adhesive assay was performed by replating those on fibronectin-coated dishes, then adherent cells were counted. RESULTS: Incubation of isolated human MNCs with puerarin 0.1-3 mmol/L increased the number of EPCs, EPC proliferative, migratory, adhesive, and in vitro vasculogenesis capacity in a concentration- and time-dependent manner, which reached maximum at 3 mmol/L, 24 h (approximately 1-fold increase, P<0.01). CONCLUSION: Puerarin enhanced EPCs functional activity.

AC133 Antigen↗
PubMed2004

[Differentiation and increase of dendritic cells from umbilical cord blood in vitro].

The aims of this study were to analyze the composition of umbilical cord blood cells (UCBC), to examine the characteristics of dendritic cells (DC) before and after culture, to search the method of differentiation and increase of DC in vitro and to appraise surface antigen from UCBC. Twelve units of umbilical cord blood were collected from May 2002 to September 2002. Peripheral blood mononuclear cells of 9 cases were collected from healthy adult donors. The nature of UCBC was freshly determined and then UCBC were cultured for 1, 2, 3 and 4 weeks with granulocyte-monocyte colony-stimulating factor (GM-CSF), interleukin 3 (IL-3), recombinant human stem cell factor (SCF) and EPO. Method of flow cytometry was used to determine the number of DC and cell surface antigens before and after culture by using monoclonal antibodies. The monoclonal antibodies included CD4, CD8, CD19, CD34, CD38, CD83, CD1a, CD11c and CDw123. The results showed that amounts of CD34+ progenitors in peripheral blood cells were 0.02 x 10(5)/ml, and amounts of CD34+ progenitors in human UCBC were 0.22 x 10(5)/ml. UCBC cultured for 1, 2, 3 and 4 weeks with GM-CSF, IL-3, EPO and SCF were shown to differentiate into CD1a+ CD11c+ CD83+ CDw123+ DC. Numbers of DC from UCBC remarkably generated in 2-4 weeks and then decreased in number. By culture with cytokines DC increased up to (10.6 - 28.2) x 10(5)/ml in actual numbers. It is concluded that the mononuclear cells of UCB are able to differentiate into CD1a+, CD83+, CD11c+ and CDw123+ DC when UCBC are cultured with proper cytokines of GM-CSF, SCF, EPO and IL-3 for 2-4 weeks. These DCs as antigen presenting cells are possibly effective in cancer immunotherapy.

Antigens, CD1↗
PubMed2004

[Effects of puerarin on number and activity of endothelial progenitor cells from peripheral blood].

OBJECTIVE: To investigate whether puerarin can augment endothelial progenitor cells (EPCs) numbers, promote EPC proliferation, migration and adhesion. METHOD: Total mononuclear cells (MNCs) were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After 7 days culture, attached cells were stimulated with puerarin (to make a series of final concentrations: 0. 1, 0.5, 1, 3 mmol x L(-1)) or vehicle control for the respective time points (6, 12, 24, 48 h). EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. EPCs proliferation, migration and in vitro vasculogenesis activity were assayed with MT assay, modified Boyden chamber assay and in vitro vasculogenesis kit, respectively. EPCs adhesion assay was performed by replating those on fibronectin-coated dishes, then adherent cells were counted. RESULT: Incubation of isolated human MNCs with puerarin dose increased the number of EPCs, maximum at 3 mmol x L(-1), 24 hours (approximately 1-fold increase, P < 0.01). In addition, puerarin also promoted EPC proliferative, migratory, adhesive and in vitro vasculogenesis capacity. CONCLUSION: Puerarin can augment the number of EPCs with enhanced functional activity.

Cell Adhesion↗
PubMed2004

[Effects of Ginkgo biloba extract on number and activity of endothelial progenitor cells from peripheral blood].

AIM: To investigate whether Ginkgo biloba extract can augment endothelial progenitor cell (EPC) number, and promote EPC proliferation, migration and adhesion. METHODS: Total mononuclear cells (MNCs) were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After 7 days of culture, attached cells were stimulated with Ginkgo biloba extract (10, 25 and 50 mg x L(-1)) or vehicle control for the respective time points (6, 12, 24 and 48 h). EPC were characterized as adherent cells double positive for DiLDL-uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. EPC were further documented by demonstrating the expression of CD34, VEGFR-2 and AC133 with flow cytometry. EPC proliferation, migration and in vitro vasculogenesis activity were assayed with MTT assay, modified Boyden chamber assay and in vitro vasculogenesis kit, respectively. EPCs adhesion assay was performed by replating MNCs on fibronectin-coated dishes, and then counting adherent cells. RESULTS: Incubation of isolated human MNCs with Ginkgo biloba extract increased the number of EPC, maximum at 25 mg x L(-1), 24 hours (approximately 1-fold increase, P < 0.01). In addition, Ginkgo biloba extract promotes EPC proliferative, migratory, adhesive and in vitro vasculogenesis capacity. CONCLUSION: Ginkgo biloba may promote EPC augmentation and enhance its functional activity.

Cell Adhesion↗
PubMed2004

[Constitutive expression and purification of Alcaligenes faecalis penicillin G acylase in Escherichia coli].

Considering Alcaligenes faecalis pencillin G acylase(AfPGA), which possesses the attractive characteristics for beta-lactam antibiotics conversions, the gene of PGA was cloned into an expressing vector pKKFPGA. The recombinant plasmid contained multicopy replicon(COLE 1), trc promoter, AfPGA gene, rrnB transcript terminator and ampicillin marker transformed Escherichia coli DH5alpha. As both the recombinant plasmid and the host DH5alpha had no laclq gene, the trc promoter was always active and the AfPGA could be constitutively expressed without IPTG induction in the host DH5alpha. In the shaking flask, the recombinant cell was inoculated into the fermentation medium (tryptone 10g/L, yeast extract 5g/L, MgSO4 x 7 H2O 1g, KH2 PO4 2g/L, K2HPO4 x 3H2O 5g/L, Na2HPO4 x 12H2O 7g/L, (NH4)2SO4 1.2g/L, NH4Cl 0.2 g/L, NaCl 0.1g/L, dextrin 30g/L) and cultured at 28 degrees C for 20h. The production of AfPGA reached 2,590u/L(NIPAB method), with a cell-density-specific activity of more than 300(u/L)/A600, this yield increased 432 fold higher than the native expression of Alcaligenes faecalis . Without ammonium sulphate fractionation and dialysis, the supernatant of crude extract was directly loaded on DEAE-Sepharose CL 6B column equilibrated by phosphate buffer (50mmol/L, pH7.8), and the enzyme fraction was not absorbed on the column but impurities were absorbed. Subsequently the effluent was added ammonium sulphate to 1mol/L and loaded on Butyl-Sepharose CL 4B column equilibrated by 50mmol/L phosphate buffer pH7.8-1mol/L ammonium sulphate. The enzyme was eluted as concentration of ammonium sulphate in phosphate buffer decreased to 0, PGA was eluted. After these two column chromatography, the enzyme was enriched 20 times with a 91% activity recovery. The purified enzyme had a specific activity of 68.6u/mg protein. However, the overproduction of PGA was often limited by translocation and/or periplasmic processing steps, subsequently resulted in intracellular accumulation of various types of PGA precursors and then formed inclusion bodies in the cytoplasm and/or periplasm. In this study, 5% PGA precursors formed as inclusion bodies in the cytoplasm while no inclusion bodies formed in the periplasm. It suggested most PGA precursors were transported to the periplasm and matured to active PGA and also explained why PGA gene was highly expressed in the host DH5alpha. On the other hand, inclusion bodies in the cytoplasm indicated that the maturation of PGA in the host DHSalpha was limited by the translocation step.

Alcaligenes faecalis↗