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Biomedical subjects

Yong Sun

Publications and source records attributed to Yong Sun.

At least 19 recordsLinked to original sources
PubMed2006

[Detection of Yersinia enterocolitica in diarrhea stool by real-time PCR].

OBJECTIVE: To establish a quick and accurate molecular biological method to detect the Yersinia enterocolitica in diarrhea stool as an alterative to the tedious and time-consuming culture methods. METHODS: Real-time PCR, using the primer-probe specific for the yst gene, was applied to detect the pathogenic (7 serotypes) and nonpathogenic (5 serotypes) Yersinia enterocolitica, other species of Yersinia (8 types), and other enteric bacteria (8 types). Additionally, 200 samples of diarrhea stool were examined by culture method too so as to test the consistency of these two methods. RESULTS: Real-time PCR was 100 percent specific for the virulent Yersinia enterocolitica with the detection limits of 10(2) CFU/ml and 10(3) CFU/g for the pure culture and stool sample respectively. Of the 200 samples for comparison, 18 positive samples were successfully examined by both real-time PCR and culture method with a consistency of 100 percent. CONCLUSION: Highly specific for virulent Yersinia enterocolitica without cross reaction to other bacteria, convenient to operate, and rapid to get the result, real-time PCR can be used as a quick method to detect Yersinia enterocolitica from diarrhea stool.

Diarrhea↗
PubMed2006

Protective effects of EUK4010 on beta-amyloid(1-42) induced degeneration of neuronal cells.

EUK4010 has been identified to exhibit an inhibitory effect on beta-amyloid (Abeta)(1-42)-induced loss of neuronal cell viability. Further studies demonstrated that EUK4010 attenuated the Abeta(1-42)-induced degeneration in both cultured rat hippocampal neurons and human neuroblastoma cells, as demonstrated by typical morphological changes, cell viability and the chip-based flow cytometric assay. Gene expression analysis using DNA microarray showed that the senescence marker calcium-binding protein, regucalcin (Rgn), GABA-A receptor pi subunit (Gabrp), the huntingtin binding protein, optineurin (Optn) and a semaphorin family plexin A3 similar protein (Plex-similar) changed their expression levels significantly in cultured neurons after Abeta(1-42) treatment. In this report, we have undertaken a chemical genetic approach to study the molecular basis of Abeta(1-42) effects on the neuronal degeneration. Our results demonstrate that EUK4010 completely blocked the Abeta(1-42)-induced up-regulation of GABA-A receptor pi subunit and the semaphorin family plexin A3 similar protein, and partially attenuated the down-regulation of senescence marker calcium-binding protein, regucalcin. These observations suggest that EUK4010 may prevent or reduce the Abeta toxicity by regulating the expression of genes involved in the Abeta induced neuronal degeneration. These genes may represent a promising target for the therapeutic drug development for Alzheimer's disease (AD) and other neurological disorders. Furthermore, EUK4010 and its analogues could potentially be developed as neuronal protective agents for the treatment of these diseases.

Amyloid beta-Peptides↗
PubMed2006

[A prospective, randomized, controlled trial of autologous mesenchymal stem cells transplantation for dilated cardiomyopathy].

OBJECTIVE: Recent experimental and clinical observations have suggested that cell transplantation could be of therapeutic value for the treatment of heart failure. This study was performed to explore the efficacy and safety of intracoronary autologous mesenchymal stem cells (MSCs) transplantation for treating patients with idiopathic dilated cardiomyopathy. METHOD: Twenty-four consecutive patients with idiopathic dilated cardiomyopathy received standard drug therapy were randomly divided into intracoronary injection of autologous mesenchymal stem cells (treated, n = 12) or saline (control, n = 12) groups. Serum IL-6, TNF-alpha and CRP, plasma brain natriuretic peptides (BNP) were determined and echocardiography, Holter electrocardiogram monitoring and six minutes walk test were performed at baseline, 3 and 6 months post injection. RESULTS: IL-6, TNF-alpha and CRP remained unchanged after MSCs transplantation. Plasma BNP levels at 3 months and 6 months post MSCs injection were significantly higher than that of pre-injection (378.10 +/- 147.47, 420.40 +/- 148.50 vs. 292.40 +/- 148.54 ng/L, respectively, P < 0.05) but were significantly lower than that in control group at comparable time points (3 months: 378.10 +/- 147.47 vs. 473.10 +/- 106.31 ng/L; 6 months: 420.40 +/- 148.50 vs. 544.60 +/- 93.11 ng/L, P < 0.05). Six-minute-walking distance significantly increased at 6 months after MSCs injection compared with pre-injection level and which is also higher than that in control patients (519.00 +/- 43.28 vs. 396.33 +/- 42.19 and 464.00 +/- 76.5 m, respectively, P < 0.05). Left ventricular ejection fraction and LVEDd remained unchanged post MSCs injection. No malignant arrhythmias and severe side effects could be observed around transplantation and during six months follow-up. Survival was similar between the two groups during six months follow-up. CONCLUSION: Percutaneous coronary autologous mesenchymal stem cells transplantation can attenuate the increase of plasma BNP, increase six-minute-walking capacity in patients with idiopathic dilated cardiomyopathy.

Aged↗
PubMed2006

[Study on spectroscopic properties of rare earth complexes with poly (N-vinylacetamide)].

Terbium-lanthanum (or gadolinium)-poly(N-vinylacetamide) complexes were synthesized and characterized by UV-Vis absorption spectroscopy, FTIR, XPS and fluorescence spectroscopy. The results of UV-Vis, FTIR and XPS suggested that terbium and lanthanum (or gadolinium) ions were bonded to amide group of PNVA polymer. Fluorescence experiment indicated that the characteristic emission intensity of terbium ion was greatly increased and possibly sensitized by lanthanum ion (or gadolinium). Moreover, the wavelengths of terbium characteristic emissions were changed slightly. Also the characteristic emission intensity of terbium ion doped with lanthanum ion was better than that with gadolinium ion.

English Abstract↗
PubMed2006

[Effects of glutamine given through different avenues on intestine mucosal barrier function in burned rats].

OBJECTIVE: To observe the effect of glutamine given through different avenues on intestine mucosal barrier damage induced by severe burn injury. METHODS: One hundred and sixty Wistar rats were randomly divided into four groups: namely normal control (C group), burned control (B group), parenteral nutrition with glutamine (PN+GLN group) and enteral nutrition with glutamine (EN+GLN group). Rats in B group, PN+GLN group, and EN+GLN group were subjected to 30% total body surface area (TBSA) full-thickness burn injury. In the latter three groups, nutritional intake was isonitrogenous and isocaloric. In PN+GLN group and EN+GLN group the nutrition were supplemented with glutamine 1.0 g.kg(-1).d(-1), and in B group tyrosine 1.0 g.kg(-1).d(-1). Indexes relevant to injury to the intestine were determined on postburn day (PBD) 1, 3, 5, 7 and 10. RESULTS: After burn injury, the index of intestinal mucosal injury, intestine mucosal permeability and the activity of plasma diamine oxidase (DAO) were significant increased compared with C group (all P<0.01). On the other hand, the intestine mucosal blood flow (IMBF), mucosa thickness, villous height, crypt depth and intestinal epithelial proliferation index were significantly decreased (P<0.05 or P<0.01). Compared with B group, the extent of changes in these indices were lowered in PN+GLN group and EN+GLN group (P<0.05 or P<0.01), and the effects were more marked in EN+GLN group than those in PN+GLN group. CONCLUSION: GLN is beneficial in minimizing intestinal injury, promoting intestinal mucosal repair. Enteral supplementation of GLN is a better way of administration.

Animals↗
PubMed2005

Theoretical study of the effect of water in the process of proton transfer of glycinamide.

For the purpose of investigating the tautomerism from glycinamide (G) to glycinamidic acid (G*) induced by proton transfer, we carried out a study of structural interconversion of the two tautomers and the relative stabilizing influences of water during the tautomerization process. Throughout the study, we used density functional theory (DFT) calculations at the B3LYP/6-311++G** level of theory, also considering the correction functions, that is, the effect of basis set superposition error (BSSE). Totally, 42 geometries, including fourteen important transition states, were optimized, and their geometric parameters have also been discussed in detail. Water molecules were gradually put in three different regions in the vicinity of G and its tautomer G*. The calculation results indicate that water in two of these regions can protect G from tautomerizing to G*, while in another region, water can assist in the tautomerism; this reveals that water molecules have stabilization and mutagenicity effects for G simultaneously.

Computer Simulation↗
PubMed2005

Assay of CCNU in tumor by RP-HPLC.

This paper reports a RP-HPLC method for the determination of Lomustine (CCNU) in mouse tumor tissue. CCNU was separated and determined on a reverse-phase C18 5 microm column with a mobile phase of H2O-acetonitrile (54:46), detected at 254 nm and no internal standard. The calibration curve was linear (r = 0.9999) within the range of 0.98-15.68 microg/ml for CCNU. The recovery ratio of CCNU was 68.64% (n = 5). The relative standard deviation (RSD) was 0.32%. This method is simple and accurate.

Animals↗
PubMed2005

Human bone marrow-derived mesenchymal stem cells transplanted into damaged rabbit heart to improve heart function.

OBJECTIVE: The present study was designed to test whether transplantation of human bone marrow-derived mesenchymal stem cells (hMSCs) in New Zealand rabbits with myocardial infarction can improve heart function; and whether engrafted donor cells can survive and transdifferentiated into cardiomyocytes. METHODS: Twenty milliliters bone marrow was obtained from healthy men by bone biopsy. A gradient centrifugation method was used to separate bone marrow cells (BMCs) and red blood cells. BMCs were incubated for 48 h and then washed with phosphate-buffered saline (PBS). The culture medium was changed twice a week for 28 d. Finally, hematopoietic cells were washed away to leave only MSCs. Human MSCs (hMSCs) were premarked by BrdU 72 h before the transplantation. Thirty-four New Zealand rabbits were randomly divided into myocardial infarction (MI) control group and cell treated group, which received hMSCs (MI+MSCs) through intramyocardial injection, while the control group received the same volume of PBS. Myocardial infarction was induced by ligation of the left coronary artery. Cell treated rabbits were treated with 5 x 10(6) MSCs transplanted into the infarcted region after ligation of the coronary artery for 1 h, and the control group received the same volume of PBS. Cyclosporin A (oral solution; 10 mg/kg) was provided alone, 24 h before surgery and once a day after MI for 4 weeks. Echocardiography was measured in each group before the surgery and 4 weeks after the surgery to test heart function change. The hearts were harvested for HE staining and immunohistochemical studies after MI and cell transplantation for 4 weeks. RESULTS: Our data showed that cardiac function was significantly improved by hMSC transplantation in rabbit infarcted hearts 4 weeks after MI (ejection fraction: 0.695+/-0.038 in the cell treated group (n=12) versus 0.554+/-0.065 in the control group (n=13) (P<0.05). Surviving hMSCs were identified by BrdU positive spots in infarcted region and transdifferentiated into cardiomyocytes characterized with a positive cardiac phenotype: troponin I. CONCLUSION: Transplantation of hMSCs could transdifferentiate into cardiomyocytes and regenerate vascular structures, contributing to functional improvement.

Animals↗
PubMed2005

Segmental radiofrequency ablation of pulmonary vein ostia for patients with refractory paroxysmal atrial fibrillation using multi-slice spiral computed tomography guidance.

OBJECTIVE: To evaluate the safety and clinical efficacy of segmental radiofrequency ablation of pulmonary vein (PV) ostia for patients with refractory paroxysmal atrial fibrillation (AF) under multi-slice spiral computed tomography (MSCT) guidance before the procedure. METHODS: A series of 58 consecutive patients with refractory paroxysmal AF were enrolled to undergo segmental radiofrequency ablation of PV ostia. The 36 male and 22 female patients with mean age of (57.4+/-9.5) (32-79) years and no obvious organic heart disease. Before ablation, patients received MSCT to generate 3-dimensional image of the left atrium (LA) and proximal PVs. Patients then underwent segmental radiofrequency ablation of PV ostia using PV circular mapping catheter manipulated several times to ensure complete isolation between PVs and LA. RESULTS: No complications occurred during the procedure. One patient developed delayed cardiac tamponade, which was drained percutaneously. The mean follow-up time was (17.1+/-9.3) months. Forty-one patients (95%) experienced improved quality of life one month after the procedure. Thirty-six patients (83%) showed stable sinus rhythm, while 10 patients (23%) required additional anti-arrhythmic drugs. AF returned> or =1 time in 6 (14%) patients who underwent anti-arrhythmic drug therapy, but the number of episodes was less than that before the procedure. However, one patient experienced recurrent episodes of atrial flutter. CONCLUSION: It is safe and effective to perform segmental radiofrequency ablation of PV ostia for patients with refractory paroxysmal AF using MSCT guidance mappening.

Adult↗
PubMed2005

[Assembly of apoptin gene using oligodeoxyribonucleotides in vitro].

OBJECTIVE: To explore the method for in vitro gene assembly of apoptin-encoding DNA sequence, for instance, using a large number of oligodeoxyribonucleotides (oligos). METHODS: Based on the encoding sequence of apoptin gene (GeneBank accession number AY171617), a number of oligos were designed to assembly apoptin gene in pfu mix reaction system, and each oligo was 40 nucleotides (nt) in length, in which synonymous codon substitution was used to eliminate the restriction enzyme sites of Bgl II ( position 172, agatct-agatcc) and Hind III (position 306, aagctt-aatcct). The assembly mixture was further diluted and amplified with two end oligos. The targeting sequence was gel-purified, amplified for one more time, followed by the addition of T to the 3' end in the presence of Taq polymerase and dATP before cloning into pGEM-T easy vector. The positive clones were confirmed by restriction enzyme digestion and sequence analysis. RESULTS: The synthetic mixture presented obvious "tails" in the first PCR for assembly. After dilution of the mixture and amplification with two end oligos, clear DNA ladder bands with a clear targeted band were yielded. After PCR, the targeted gene was cloned into pGEM-T easy vector, and the positive clones were confirmed by sequence analysis with be identical to the designed coding sequence of apoptin gene. CONCLUSION: Gene assembly is a rapid and cost-effective approach for synthesis of genes or vectors, which allows simultaneous mutagenesis of several genes in vitro.

Base Sequence↗
PubMed2005

[Endophthalmitis after phacoemucification surgery].

OBJECTIVE: To study the infective endophthalmitis after phacoemulsification and to discuss the methods for prevention and treatment of this complication. METHODS: A retrospective analysis was performed on phacoemulsification with implantation of artificial lens underwent in 10 MaiGe Ophthalmological Centers during past 10 years (from 1993 to 2003). RESULTS: Among 63,372 cases (84,497 eyes) underwent the phacoemulsification, 14 cases suffered infective endophthalmitis with the incidence of 0.02%. In these 14 cases, 11 cases occurred before 1999 (78.6%). There were 5 cases of ruptured posterior lens capsule in these 14 cases (35.7%). Microbiological examination was performed in 11 cases (aqueous or vitreous sample), 7 cases showed positive results (63.6%), including 3 cases of staphylococcus epidermidis (42.8%), 1 case of pseudomonas aeruginosa (16.7%), 1 case of bacilli (16.7%) and 2 cases (33.4%) of fungus (yeast and candida albicans). After the treatment, the vision of 5 patients was recovered to 2.0 or more, 4 cases recovered to hand movement and light perception, enucleation was performed in 3 cases and atrophy of eyeballs occurred in 2 cases. CONCLUSIONS: The attack rate of endophthalmitis after phacoemucification surgery is 0.02%. The main pathogen is staphylococcus epidermidis. Rupture of posterior lens capsule is one of the main risk factors of endophthalmitis. Observing the operative routine strictly pre-, during and post-operatively can reduce the occurrence of infective endophthalmitis.

Aged↗
PubMed2005

[Tissue Doppler imaging evaluate the effect of optimal biventricular resynchronization for congestive heart disease in left ventricular synchrony and function].

OBJECTIVE: To evaluate the immediate change of left ventricular systolic performance and asynchronization between simultaneous biventricular pacing and sequential biventricular pacing by tissue synchronization imaging (TSI) and tissue velocity imaging (TVI) in patients with congestive heart failure. The effect of sequential biventricular resynchronization therapy was also observed. METHODS: Ten patients with dilated cardiomyopathy who received sequential biventricular resynchronization were enrolled. The TVI and TSI imagings were performed by GE vivid7 with M3S probe. The left ventricular ejection fraction (LVEF), stroke volume (SV), aortic velocity time integral (VTI), left ventricular end diastolic diameter (LVEDd), the standard deviation of the electro-mechanical delay (EMD-SD) of 6 segments and TSI index were measured before implanting of InSync 8042 and 1 month, 3 months, 6 months after implanting respectively. RESULTS: After 6 months of implanting, the LVEF, SV and VTI were obviously increased from (22.0 +/- 8.8)% to (38.0 +/- 9.9)%; (36.0 +/- 14.9) ml to (57.0 +/- 15.7) ml; (20.22 +/- 5.72) cm to (26.20 +/- 5.98) cm, P < 0.05, respectively, compared with the before of implanting. The LVEDd was decreased from (6.6 +/- 0.6) cm, to (6.0 +/- 0.9) cm, P < 0.05. The EMD-SD and TSI-index were declined gradually after implanting, which was more evident in the 6 months after implanting, from (83.07 +/- 46.99) ms to (22.37 +/- 16.38) ms; (2.20 +/- 0.36) to (1.50 +/- 0.43), P < 0.05, respectively, but the immediate EMD-SD did not change obviously between simultaneous biventricular pacing and sequential biventricular pacing, whereas, the TSI index and VTI were significantly improved from (1.87 +/- 0.31) to (1.71 +/- 0.29); (22.44 +/- 5.43) cm to (25.44 +/- 5.36) cm, P < 0.05, respectively, in the sequential biventricular pacing. CONCLUSION: Sequential biventricular resynchronization could improve the left ventricular systolic function and synchronism of wall motion in the patients with congestive heart failure, which is more effective than simultaneous biventricular pacing after implanting immediately.

Aged↗
PubMed2004

The toxicological study of CCNU controlled release film in vivo.

We planted the Lomustine (CCNU) controlled release films into normal mice, and after a period of time observed the effects of the films on the blood cells and the brain nerve cells of the mice. Compared with the traditional administration (PO), the results indicated that the planted CCNU controlled release film had less effects on the blood cells, and caused less harm to the brain nerve cells. So the conclusion was that the planted CCNU controlled release film had no significant acute arrest of bone marrow and neural toxicity.

Animals↗
PubMed2004

Allograftic bone marrow-derived mesenchymal stem cells transplanted into heart infarcted model of rabbit to renovate infarcted heart.

OBJECTIVE: To investigate the directed transplantation of allograftic bone marrow-derived mesenchymal stem cells (MSCs) in myocardial infarcted (MI) model rabbits. MATERIALS AND METHODS: Rabbits were divided into 3 groups, heart infarcted model with MSCs transplanted treatment (MSCs group, n = 12), heart infarcted model with PBS injection (control group, n = 20), sham operation with PBS injection (sham group, n = 17). MSCs labelled by BrdUrd were injected into the MI area of the MSCs group. The same volume of PBS was injected into the MI area of the control group and sham group. The mortality, LVIDd, LVIDs and LVEF of the two groups were compared 4 weeks later. Tropomyosin inhibitory component (Tn I) and BrdUrd immunohistochemistry identified the engrafted cells 4 weeks after transplantation. RESULT: The mortality of the MSCs group was 16.7% (2/12), and remarkably lower than the control group's mortality [35% (7/20) (P < 0.05)]. Among the animals that survived for 4 weeks, the LVIDd and LVIDs of the MSCs group after operation were 1.17+/-0.21 cm and 0.74+/-0.13 cm, and remarkably lower than those of the model group, which were 1.64+/-0.14 cm and 1.19+/-0.12 cm (P < 0.05); the LVEF of the MSCs group after operation was 63+/-6%, and remarkably higher than that of the model group, which was 53+/-6% (P < 0.05). Among the 10 cases of animals that survived for 4 weeks in the MSCs group, in 8 cases (80%), the transplanted cells survived in the non MI, MI region and its periphery, and even farther away; part of them differentiated into cardiomyocytes; in 7 cases (70%), the transplanted cells participated in the formation of blood vessel tissue in the MI region. CONCLUSION: Transplanted allograftic MSCs can survive and differentiate into cardiomyocytes, form the blood vessels in the MI region. MSCs transplantation could improve the heart function after MI.

Animals↗
PubMed2004

[Effects of catalase on the mitochondria and apoptosis of SW480 cells].

OBJECTIVE: To investigate the effects of catalase on the mitochondria and apoptotic behavior of SW480 cells treated by lipopolysaccharide (LPS), and the changes in intracellular expression of nuclear factor kappaB (NF-kappaB). METHODS: LPS-stimulated SW480 cells were treated with catalase and the changes in their mitochondria and apoptotic behavior were observed by transmission electron microscopy. The expression of NF-kappaB was detected by immunohistochemical method. RESULTS: Mitochondria damages and apoptosis were slightly diminished in the LPS-stimulated cells with catalase pretreatment, and the NF-kappaB expression was also decreased. CONCLUSION: Catalase protect the mitochondria of SW480 cells from damages by LPS and inhibit the cell apoptosis, possibly due to the activation of NF-kappaB.

Apoptosis↗
PubMed2003

[Effects of embryonic neural stem cells and glial cell line-derived neurotrophic factor in the repair of spinal cord injury].

The ability of implanted embryonic neural stem cells (NSCs) to improve survival, migration, and functional recovery following a compression spinal cord injury (SCI) was tested in adult rats. NSCs were isolated from E14-16 rat cerebral cortex and SCI was produced by using an aneurysm clip applicator applied to the 8th thoracic spinal cord according to method of Dolan and Tator. Two weeks after the injury, NSCs (4 microl of 1 x 10(4) cells/microl) were injected into the lesion site. The grafted NSCs were noted to survive and integrate with the host spinal cord 1 month after transplantation, which was demonstrated by the presence of Hoechst 33342 (a nuclear dye) pre-labeled NSCs within and surrounding the lesion site. Some of these cells remained undifferentiated and were stained with nestin, a marker for NSCs. Transplanted NSCs migrated for at least 3 mm from the injury epicenter towards both the rostral and caudal directions. Significant reduction in the lesion area (P<0.05) and improvement in inclined plane (P<0.05) and BBB locomotor rating scale (P<0.05) were found in the cases that received implantation of NSCs, as compared with those that received vehicle injection. More importantly, when glial cell line-derived neurotrophic factor (GDNF; 1.5 microg/microl) was added to the transplants, further reduction in lesion area (P<0.01) and improvement in the function were observed in the combined treatment group as compared with the vehicle infused group. Our results suggest that intraspinal treatment with NSCs and GDNF synergistically reduced lesion size and improved functional outcome after a compressive SCI in adult rats.

Animals↗
PubMed2003

The controlled release study of Vincristine Sulfate.

We prepared microspheres of Vincristine Sulfate (VCR) through drying-from-oil method, then mixed the microspheres into 0.7% collagen swelling solution to prepare emulsion, spread the emulsion on plate to form film by frozen-dry method. The film was cross-linked and sterilized, then planted into the site of tumor and expected to release at steady speed. We measured the release of VCR in vivo and in vitro by HPLC. The results demonstrated that VCR controlled release films release at approximate steady speed in 15 days.

Antineoplastic Agents↗