Objective To investigate the effect of taking medical students as standardized patients(SSP) on problem based leaming(PBL) teaching in clerkship.Methods Totally 161 students (grade 2008) selected from clinical medical department was divided into PBL group(n=81) and lecture-based learning(LBL) group(n=80).SSP was introduced into PBL teaching and LBL group was taught by LBL.After the clerkship,theory test was conducted in two groups and questionnaire was given to LBL group.Statistical analyses were conducted by SPSS 13.0,measurement data were analyzed by t test and enumeration data were described by frequency and constituent ratio.Results Theory test results showed that the average score of medical record analysis was (37.35 ± 5.95) in PBL group,much higher than (33.25 ± 4.89) in LBL group(P=0.001) ;the total score was (71.20 ± 8.67) in PBL group,much higher than that of (67.79 ± 9.87) in LBL group(P=0.018) as well.The average scores of choice question in 2 groups were (33.85 ± 5.05) and (34.24 ± 6.87),without significant differences(P=0.658).The constituent ratio of answer ‘OK' regarding 10 entries in questionnaire was more than 75％.The constituent ratio of answer ‘OK' regarding 3 entries(SSP matching degree,SSP without implied language or action,stimulating the learning interest) was more than 90％.Conclusions Introducing SSP PBL teaching can improve students' ability of clinical analysis and problem solving but not so effective for the basic theoretical knowledge grasp.SSP could replace standardized patients in PBL teaching.

OBJECTIVE: To determine the clinical value of arterial blood lactic acid monitoring in patients after cardiac surgery. METHODS: Relationship between dynamic blood lactic acid level and the prognosis of 200 patients (9 patients in the dead group, and 191 patients in the healing group) was analyzed after cardiac operation. RESULTS: The level of blood lactic acid was (1.2+/-0.3) mmol/L in the healing group,and (5.6+/-0.9) mmol/L in the death group. The level of blood lactic acid in the healing group descended to normal in 24 hours, while that in the death group rose persistently. The dynamic change of lactic acid indicated more sensitively the prognosis of the disease than pH and BE. CONCLUSION The higher the arterial blood level of lactic acid, the longer the duration, the more critical the condition, the higher the mortality rate. Blood lactic acid level can be used as an excellent prognosis index for patients after cardiac surgery.
Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Female ; Heart Defects, Congenital ; blood ; surgery ; Humans ; Infant ; Lactic Acid ; blood ; Male ; Middle Aged ; Monitoring, Physiologic ; methods ; Postoperative Period ; Prognosis ; Radial Artery ; Rheumatic Heart Disease ; blood ; surgery ; Thoracic Surgery ; Young Adult

Objective:To explore the feasibility and clinical efficacy of gelatin sponge packing in reducing bone cement leakage in percutaneous kyphoplasty (PKP).Methods:A retrospective case-control study was conducted in data of 171 patients (171 vertebrae) with monosegmental lumbar osteoporosis compressive fracture treated by PKP from January 2015 to December 2018 in Sichuan Orthopedic Hospital. There were 66 males and 105 females, with the age of (67.9±6.7)years (range, 60-87 years). There were 22 patients with T 10 fracture, 28 with T 11 fracture, 37 with T 12 fracture, 34 with L 1 fracture, 32 with L 2 fracture and 18 with L 3 fracture. A total of 80 patients were pre-filled with gelatin sponge before injection (Group A), and 91 patients were not filled with gelatin sponge before injection (Group B). The operation time, amount of bone cement, and rate of bone cement leakage were recorded. The change of anterior vertebral height, Cobb angle, visual simulation score (VAS) and Oswestry disability index (ODI) were compared before operation and at postoperative 1 day, 3 months, 6 months, 12 months. Results:All patients were followed up for 1-12 months [(12.8±0.6)months]. The operation time in Group A and B was (48.3±1.2)minutes and (42.3±1.3)minutes ( P<0.05). The amount of bone cement in Group A and B was (5.4±0.8)ml and (5.6±0.7)ml ( P>0.05). The incidence of bone cement leakage in Group A and B was 11% (9/80) and 26% (24/91) ( P<0.05). There was no significant difference between the two groups in the anterior height of injured vertebrae, change of Cobb angle, VAS and ODI before and after operation ( P>0.05). Conclusion:Gelatin sponge can reduce the rate of bone cement leakage in PKP for the treatment of thoracolumbar osteoporosis compressive fracture, and has similar effect with PKP in correcting kyphosis, alleviating pain and improving life quality.

Objective To study the influences of Yang-warming, Blood-activating, and Toxin-removing Recipe(YBTR)-containing serum sampled under different conditions on the proliferation of human umbilical vein endothelial cells(HUVECs). Methods HUVECs were cultured in vitro for the experiment. Pharmacological serum for the experiment was prepared as follows: Thirty-two SD rats (male in half) were randomly divided into 4 groups, namely normal saline group and low-, middle-, and high-dose YBTR groups (at the intragastric dosage of 10.35, 31.05, 93.15 g·kg-1 respectively, twice a day). The pharmacological serum was taken from one female rat and one male rat in various groups at 4 time points, i.e. at hour 1, 2 after first intragastric administration on the fourth feeding day, and at hour 1, 2 after first intragastric administration on the sixth feeding day(abbreviated as D3H1, D3H2, D5H1, D5H2 respectively). The effects of YBTR-containing serum on the proliferation of HUVECs were observed by CCK-8 assay method. Results The difference of proliferation-inhibition rate of HUVECs was statistically significant after treated with YBTR-containing serum prepared from rats of different genders at different time(Pgender=0.000<0.01, Ptime=0.000<0.01). The difference of interaction of time and gender was also significant (Ptime × gender=0.001<0.01), and the effect at D3H1 and D5H1 varied with the gender (PD3H2×gender = 0.000 < 0.01, PD5H1×gender = 0.002 < 0.01). The inhibitory action of YBTR-containing serum became stronger with the increase of the dosage of serum of female rat at D3H2, and the inter-group difference was statistically significant (P < 0.05), the effect showing concentration-dependent tendency. The inhibition of HUVECs proliferation reached the peak after treated by various doses of YBTR-containing serum from the female rat at D3H2, while the inhibition arrived to the peak after treated by low- and middle-dose YBTR-containing serum from the male rat at D5H1, and the inhibition arrived to the peak in the group of high-dose YBTR-containing serum from the male rat at D3H1. Conclusion The inhibitory action of YBTR-containing serum on the proliferation of HUVECs was stronger when the serum was taken from the female rat at D3H2.

Objective:To investigate the feasibility of establishing a canine model of lumbar intervertebral disc degeneration through the application of cumulative axial load and a six-phase combined motion on the vertical sitting dog's lumbar spine.Methods:Twenty adult female grass dogs, each weighing 10.0±0.5 kg, were randomly divided into two groups, with 10 dogs in each group. In the model group, dogs were secured to an exercise machine in a vertical position, and six phases of lumbar spine movement (flexion and extension, left and right lateral flexion, left and right rotation, 45° each) were combined with a specific number of cycles under continuous axial load (245 N). In the control group, dogs were secured to the exercise machine in a vertical position without any intervention. Radiographic examinations were performed before and after 20,000, 50,000, 100,000, and 150,000 compound exercises in the model group. The disc height index (DHI) was measured through lateral X-ray, and MRI T2-mapping was used for quantitative analysis of intervertebral disc degeneration. When intervertebral disc degeneration was evident on MRI T2-weighted imaging (modified Pfirrmann system > Grade V), the combined motion was halted. Micro-CT quantitative analysis of bone mineral density (BMD) in the upper and lower endplates, trabecular bone structure, and histological staining (HE staining, "O" staining, Sirius red staining) were employed to verify and assess the degree of intervertebral disc degeneration.Results:After 50,000 compound exercises, mild degeneration of the intervertebral discs at L 6-7 and L 7S 1 was observed on T2-weighted imaging. With the accumulation of exercise load, the degree of degeneration progressively increased, reaching a moderate degree of degeneration after 100,000 composite exercises, and DHI began to decrease. Mild degeneration was also observed in the upper L 5-6 intervertebral disc. When the cumulative exercise volume reached 150,000 repetitions, the height of intervertebral spaces in the L 5-6, L 6-7, and L 7S 1 segments further decreased, and the intervertebral discs exhibited severe degeneration (improved Pfirrmann grading system Grades IV-VI). The upper L 4-5 intervertebral discs also displayed mild degeneration. Histological scores were as follows: L 5-6 (8.2±0.8), L 6-7 (9.5±0.7), and L 7S 1 (10.3±0.5), indicating a degree of degeneration in the order of L 5-6

OBJECTIVETo evaluate the effects of arginine modified chitosan or hexadecylated modified chitosan as gene carriers on the cellular uptake by vascular smooth muscle cells and its in vitro cytotoxicity. METHODS Plasmid DNA was labeled with alpha-32P-dATP and complexed with the modified chitosans or unmodified chitosan to form nanoparticle complexes by complex coacervation method. Uptake of all kinds of chitosan/ DNA nanoparticle complexes (CNC) by A10 cells was measured by beta-liquid scintillation counting. The in vitro cytotoxicity of the CNC was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay.

RESULTSThe diameters of the CNC ranged from 55.9-174.9 nm and the zeta potentials were from 10. 8 mV for the arginine modified chitosan/DNA nanoparticle complexes (ACNC) to 1.8 mV for the hexadecylated chitosan/DNA nanoparticle complexes (HCNC). The cellular uptake of the modified chitosan/ DNA nanoparticle complexes (MCNC) by A10 cells increased significantly when compared with the unmodified chitosan/DNA nanoparticle complexes (UCNC) (P < 0.05), with the HCNC at N/P ratio of 1:1 and the ACNC at ratio of 8:1 showing the highest cellular uptake (1.3 fold higher than UCNC, P < 0.05). MCNC were much less cytotoxic when compared with Lipofectamine 2000-DNA nanoparticles.

CONCLUSIONDNA nanoparticle complexes prepared with either arginine or hexadecylated modified chitosan can improve the cellular uptake of the DNA, while the in vitro cytotoxicity of both of the modified chitosan is much less than that of Lipofectamine 2000.

Animals ; Antigen-Antibody Complex ; Arginine ; pharmacology ; Chitosan ; chemistry ; pharmacology ; Citric Acid ; analogs & derivatives ; pharmacology ; Cytotoxicity, Immunologic ; DNA ; pharmacology ; Genetic Vectors ; Nanoparticles ; Rats

BACKGROUNDCardiovascular complications of Kawasaki disease (KD) are a common cause of heart disease in pediatric populations. Previous studies have suggested a role for endothelial progenitor cells (EPCs) in coronary artery lesions associated with KD. However, long-term observations of EPCs during the natural progression of this disorder are lacking. Using an experimental model of KD, we aimed to determine whether the coronary artery lesions are associated with down-regulation of EPCs.

METHODSTo induce KD, C57BL/6 mice were administered an intraperitoneal injection of Lactobacillus casei cell wall extract (LCWE; phosphate buffered saline used as control vehicle). Study groups included: group A (14 days following LCWE injection), group B (56 days following LCWE injection) and group C (controls). Numbers of circulating EPCs (positively staining for both CD34 and Flk-1 while staining negative for CD45) were evaluated using flow cytometry. Bone marrow mononuclear cells were cultured in vitro to expand EPCs for functional analysis. In vitro EPC proliferation, adhesion and migration were assessed.

RESULTSThe model was shown to exhibit similar coronary artery lesions to KD patients with coronary aneurysms. Numbers of circulating EPCs decreased significantly in the KD models (groups A and B) compared to controls ((0.017 ± 0.008)% vs. (0.028 ± 0.007)%, P < 0.05 and (0.016 ± 0.007)% vs. (0.028 ± 0.007)%, P < 0.05). Proliferative, adhesive and migratory properties of EPCs were markedly impaired in groups A and B.

CONCLUSIONCoronary artery lesions in KD occur as a consequence of impaired vascular injury repair, resulting from excess consumption of EPCs together with a functional impairment of bone marrow EPCs and their precursors.

Animals ; Cell Adhesion ; physiology ; Cell Movement ; physiology ; Cell Proliferation ; Cells, Cultured ; Endothelial Cells ; cytology ; Flow Cytometry ; Male ; Mice ; Mice, Inbred C57BL ; Mucocutaneous Lymph Node Syndrome ; pathology ; Stem Cells ; cytology

OBJECTIVETo investigate the cytotoxic effect of multi-walled carbon nanotubes (MWCNTs) on human liver L02 cells and its relevant mechanism.

METHODSMWCNTs, carboxyl modification MWCNTs (MWCNTs-COOH), and hydroxyl modification MWCNTs (MWCNTs-OH) were characterized by transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. The carbon nanotubes at concentrations of 12.5, 25, 50, 100, and 200 μg/ml were incubated with human liver L02 cells for 24, 48 and 72 hours, respectively. The cell viability was evaluated by water soluble tetrazolium salts assay and the intercellular reactive oxygen species induced by the carbon nanotubes were detected by 2', 7'-dichlorodihydrofluorescein diacetate method.

RESULTSTransmission electron microscope showed that the average outside diameters (10 to 20 nm) and the average length (10 to 30 μm) of the three MWCNTs were similar. Scanning electron microscope indicated that the three MWCNTs had a similar surface topography. X-ray photoelectron spectroscopy demonstrated that the MWCNTs-COOH and MWCNTs-OH had relatively high peak areas at 289 and 286ev, respectively,indicating that they have been modified by carboxyl and hydroxyl groups,respectively. Water soluble tetrazolium salts assay showed that the MWCNTs-COOH was less cytotoxic when compared to MWCNTs which demonstrated to be slightly more cytotoxic than MWCNTs-OH. The capability to induce increase in intracellular reactive oxygen species was in the following order: MWCNTs > MWCNTs-COOH > MWCNTs-OH.

CONCLUSIONSModification of MWCNTs with carboxyl group and hydroxyl group improves the biocompatibility of MWCNTs to some extents. MWCNTs-COOH has better compatibility than MWCNTs at the low concentration,and MWCNTs-OH showed better compatibility than MWCNTs after 48 hours. Different mechanisms may be involved in the interaction between cells and the MWCNTs with different chemical surfaces.

Cell Survival ; drug effects ; Cells, Cultured ; Hepatocytes ; drug effects ; metabolism ; Humans ; Nanotubes, Carbon ; chemistry ; toxicity ; Reactive Oxygen Species ; metabolism

BACKGROUNDCoronary artery damage from Kawasaki disease (KD) is closely linked to the dysfunction of endothelial progenitor cells (EPCs). The aim of the present study was to evaluate the therapeutic effect of EPCs transplantation in KD model.

METHODSLactobacillus casei cell wall extract (LCWE)-induced KD model in C57BL/6 mice was established. The model mice were injected intravenously with bone marrow-derived in vitro expanded EPCs. Histological evaluation, number of circulating EPCs and the function of bone marrow EPCs were examined at day 56.

RESULTSInflammation was found around the coronary artery of the model mice after 14 days, Elastin breakdown was observed after 56 days. CM-Dil labeled EPCs incorporated into vessel repairing foci was found. At day 56, the number of peripheral EPCs in the KD model group was lower than in EPCs transplanted and control group. The functional index of bone marrow EPCs from the KD model group decreased in proliferation, adhesion and migration. Increased number of circulating EPCs and improved function were observed on the EPCs transplanted group compared with model group.

CONCLUSIONExogenously administered EPCs, which represent a novel strategy could prevent the dysfunction of EPCs, accelerate the repair of coronary artery endothelium lesion and decrease the occurrence of aneurysm.

Animals ; Cell Adhesion ; physiology ; Cell Proliferation ; Disease Models, Animal ; Elastin ; metabolism ; Endothelial Cells ; cytology ; Male ; Mice ; Mucocutaneous Lymph Node Syndrome ; metabolism ; therapy ; Stem Cell Transplantation ; psychology ; Stem Cells ; cytology ; physiology

OBJECTIVETo investigate the anti-inflammatory effect of bone marrow stromal cells (MSCs) transfected with recombinant adenovirus-mediated ciliary neurotrophic factor (CNTF) gene in C57BL/6 mice with experimental allergic encephalomyelitis (EAE).

METHODSAn adenovirus vector containing CNTF gene Ad-CNTF-IRES-GFP was constructed and transfected in the MSCs (MSC-CNTF). After examination of CNTF expression, the transfected cells were transplanted in C57BL/6 mice with MOG 35-55-induced EAE, which were monitored for the changes in the symptoms scores. The levels of tumor necrosis factor-alpha (TNF-alpha), inteferon-gamma (IFN-gamma), interleukin-12P35 (IL-12P35), and IL-10 in the peripheral blood of the mice were detected, and the number of MSC-CNTF cells in the spleen and spinal cord was counted. CD3+ T cell infiltration and TNF-alpha and IFN-gamma expressions in the lesions were also observed after the cell transplantation.

RESULTSCNTF gene transfection resulted in significantly increased CNTF expression in the MSCs. The mice receiving MSC-CNTF transplantation exhibited significantly improved symptoms with shortened disease course and lessened disease severity. The cell transplantation also resulted in significantly decreased peripheral blood TNF-alpha levels, ameliorated CD3+T cell infiltrations and lowered TNF-alpha expression in the lesions, while the levels of IFN-gamma underwent no significant changes.

CONCLUSIONTransplantation of CNTF gene-transfected MSCs results in decreased peripheral blood TNF-alpha and IFN-gamma levels and reduced inflammatory cells, CD3-positive cells and TNF-alpha expression in the lesion of EAE, therefore providing better effect than MSCs in relieving the symptoms of EAE in mice.

Adenoviridae ; genetics ; metabolism ; Animals ; Bone Marrow Cells ; metabolism ; Ciliary Neurotrophic Factor ; biosynthesis ; genetics ; therapeutic use ; Encephalomyelitis, Autoimmune, Experimental ; therapy ; Female ; Genetic Therapy ; Interferon-gamma ; blood ; Mice ; Mice, Inbred C57BL ; Random Allocation ; Stromal Cells ; metabolism ; T-Lymphocytes ; immunology ; Transfection ; Tumor Necrosis Factor-alpha ; blood