ObjectiveTo investigate the role of iNOS in the middle and late stage of pulmonary hypertension (PH) and the effect of L-Arginine(L-Arg) on these stage.MethodsThirty healthy male SD rats were randomly divided into five groups.All rats except those in control group were injected intraperitoneally (ip) with a single dose (50 mg/kg) of MCT to induce PH.Then the L3 and L5 groups were injected ip with 500 mg/kg L-Arg daily for 3 weeks and 5weeks respectively,the M3 and M5groups received a daily ip injection of the same amount of saline as L-Arg for 3 weeks and 5 weeks respectively; the same amount of saline was injected ip daily in control group for 5 weeks.Right ventricular systolic pressure(RVSP) was measured before lungs were excised for immunohistochemistry at the end of experiments. ResultsThe expressions of iNOS and elastin in M3 and M5 were higher compared to the control group,but L-Arg partly reduced the expressions of iNOS and elastin both at 3weeks and 5 weeks post-MCT.The reduction of eNOS expression in L3 and L5 groups were lower compared to M3 and M5 groups,but the eNOS expression in L3 and L5 groups were still lower than control group.ConclusionDuring the middle and late stage of PH,the expression of eNOS was decreased.The expression of iNOS was induced,which would produce numerous NO.However,these NO had no benefit on the development of PH.L-Arg could restore the balance of eNOS and iNOS,and could inhibit the development of PH,which may provide a new clues to explore the pathogenesis and treatment of PH.

AIMTo investigate the effect of interleukin-8 (IL-8) on the differentiation and clonal expansion of 3T3-L1 preadipocyte during the differentiation period.

METHODSThe morphological changes of 3T3-L1 cells during differentiation after the treatment of IL-8 was observed by Oil-Red O staining. Glycerol-3-phosphate dehydrogenase (GPDH) activity was measured by a spectrophotometric method. MTT method and 3H-TdR incorporation were applied to examine the changes of cell proliferation and DNA synthesis in clonal expansion of 3T3-L1 cells. Cell cycle analysis was taken by flow cytometry.

RESULTSIL-8 could inhibit the differentiation and GDPH activity in a dose dependent manner. IL-8 decreased the cell proliferation and DNA synthesis in clonal expansion after induction. Also, the proportion of cells in G1 phase was increased and that of cells in S and G2 phase was declined after the treatment of IL-8.

CONCLUSIONIL-8 inhibits the differentiation of 3T3-L1 preadipocytes by decreasing the clonal expansion of the cells.

3T3-L1 Cells ; Adipocytes ; cytology ; metabolism ; Animals ; Cell Cycle ; Cell Differentiation ; Cell Proliferation ; drug effects ; Interleukin-8 ; pharmacology ; Mice

Objective To investigate the efficacy of the bioactive artificial vertebrae of a nano- hydroapatite crystals and polyamide 66 composite(n-HA/PA66)to restore the height and architecture of thoracolumbar burst fracture.Methods From December 2003 to February 2006,38 patients(29 males and 9 females)with a mean age of 35.6 years(17-63 years)were treated surgically through anterior ap- proach for decompression and implanted with the bioactive artificial vertebrae of n-HA/PA66 composite to reconstruct the structure of the thoracolumbar burst fractured vertebra.Results All the patients were successfuly followed-up for an average of 8 months,ranging from 6 to 21 months.The bioaetive artificial vertebrac of n-HA/PA66 composite were fused with the receptor bone 3-4 months after operation.The neu- rological function of the patients was restored partially or completely.The thoracolumbar spine was stable during physical examination and the height of thoraeolumbar burst fractured vertebrae that had been restored did not changa during the follow-up.Conclusions Our results show the bioaetive artificial vertebrae of n-HA/PA66 can restore the height and structure of thoracolumbar burst fractured vertebrae and reconstruct the structure of the tboraeolumbar vertebrae effectively,indicating that the bioaetive artificial vertebrae of n- HA/PA66 can be used extensively in clinical spinal surgery.

OBJECTIVE: To study the feasibility, safety, effectiveness of linear ablation and circumferential isolation of pulmonary veins for atrial fibrillation (AF) guided by 3-dimensional mapping system. METHODS: Twenty-eight consecutive patients with drug refractory paroxysmal and persistent AF were included in this study. Real-time 3-dimensional left atrial (LA) and pulmonary veins (PVs) maps were constructed through 3-dimensional mapping system (Ensite NavX) in all patients. Pulmonary vein isolation was performed by encircling the left and right sides of PVs at 1 to 2 cm away from the ostium of PVs. The endpoint of ablation included: All circum PVs ablation lines finished; all PVs were isolated; and non-inducibility of AF was observed. RESULTS: All 28 patients reached the endpoint of ablation completely. The mean procedure time and fluoroscopy time was (161.3+/-23.2) min and (38.0+/-6.8) min, respectively. During the 6 approximately 17 month follow-up, 20 patients (71%) were free of AF without any antiarrhythmic drugs. Recurrence of AF was found in the other 8 patients (29%): Two were treated with amiodarone and 6 repeated ablation. After the second ablation, 4 were free of AF and 2 recurrence were treated with amiodarone. No complications occurred during the procedure and the follow-up. CONCLUSION Linear ablation and circumferential isolation of pulmonary veins for atrial fibrillation (AF) guided by 3-dimensional mapping system is effective and safe. But the long-term outcome remains to be investigated.
Adult ; Aged ; Atrial Fibrillation ; surgery ; Catheter Ablation ; methods ; Female ; Humans ; Imaging, Three-Dimensional ; Male ; Middle Aged ; Pulmonary Veins ; surgery ; Treatment Outcome

OBJECTIVETo study the changes in expression and activity of protein phosphatases type 2A (PP2A ) during differentiation of NB4 and NB4-MR2 cells induced by all-trans retinoic acid (ATRA), and evaluate the role of PP2A in MR2 resistance to ATRA.

METHODSATRA, okadaic acid (OKA) and ATRA + OKA at the same dosage were incubated with NB4 and MR2 cells respectively. Wright's staining and NBT reduction test were employed to evaluate the change in the cells. The CD11b expression was measured by flow cytometry. The activity of PP2A was evaluated by serine/threonine phosphatase assay system, and the level of PP2A subunits was detected by Western blot.

RESULTS1) Wright's staining, NBT reduction test and flow cytometry results showed OKA could augment the differentiation of NB4 induced by ATRA, and OKA + ATRA induced slight differentiation of MR2 cells. 2) Phosphatase assay showed a decrease in PP2A phosphatase activity [(534 +/- 43) pmol x min(-1) x microg protein(-1)] in NB4 after ATRA treatment, accompanied with that activity [(959 +/- 83) pmol x min(-1) x microg protein(-1)] in untreated NB4 cells. OKA enhanced the inhibitory effect of ATRA on the activity in NB4. When OKA + ATRA was incubated with MR2, PP2A in the cells was significantly decreased [(229 +/- 23) pmol x min(-1) x microg protein(-1)]. 3) Western blot analysis showed that the level of PP2A catalytic subunit (PP2A/C) was decreased during the course of ATRA-induced NB4 cell differentiation, whereas expressions of every subunits of PP2A in MR2 cells were somewhat unaltered.

CONCLUSIONExpression of PP2A/C and activity of PP2A is decreased during differentiation of NB4 induced by ATRA, and no repression of the PP2 activity maybe related to MR2 resistance to ATRA.

Cell Differentiation ; drug effects ; Cell Line, Tumor ; Humans ; Leukemia, Promyelocytic, Acute ; metabolism ; pathology ; Okadaic Acid ; pharmacology ; Phosphoprotein Phosphatases ; metabolism ; Protein Phosphatase 2 ; antagonists & inhibitors ; metabolism ; Tretinoin ; pharmacology

OBJECTIVETo observe the protective effect of metformin on the endothelial function and the mechanisms in rats with low-density lipoprotein (LDL) injection.

METHODSA single dose (4 mg/kg) of natural LDL was injected through the sublingual vein of rats to induce vascular endothelial dysfunction. Blood samples were then collected from the rats to detect the concentrations of malondialdehyde (MDA) and nitric oxide (NO), activity of superoxide dismutase (SOD) and serum lipid levels. The thoracic aorta of rats was obtained to assay acetylcholine (ACh)-induced endothelium-dependent relaxation (EDR) and sodium nitroprusside (SNP)-induced endothelium-independent relaxation. The effects of metformin pretreatment on the endothelial functions in the rats were investigated.

RESULTSA single-dose LDL significantly inhibited ACh-induced EDR without affecting SNP-induced endothelial-independent relaxation. The injection decreased serum NO and elevated serum MDA level, but had no effect on serum lipid level. Metformin markedly attenuated LDL-induced inhibition of EDR, serum MDA elevation, and serum NO reduction without affecting the serum lipid levels.

CONCLUSIONMetformin provides protection against vascular endothelial dysfunction induced by LDL in rats, the mechanism of which is probably associated with protection of endothelium-dependent relaxation factor and inhibition of the oxidative stress.

Animals ; Endothelium, Vascular ; drug effects ; physiopathology ; Endothelium-Dependent Relaxing Factors ; metabolism ; Lipoproteins, LDL ; administration & dosage ; Male ; Malondialdehyde ; blood ; Metformin ; pharmacology ; Nitric Oxide ; blood ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; Vasodilation ; drug effects ; physiology

OBJECTIVETo study long-term behavioral and ultrastructural alterations in a hypoxic-ischemic brain damage (HIBD) model of neonatal rats.

METHODSSixty seven-day-old Sprague-Dawley rats were randomly subjected to unilateral carotid artery ligation followed by hypoxic exposure (HIBD group) or sham operation (n=30 each). A battery of behavioral tests, including Morris water maze test and sensorimotor tests, were performed at a postnatal age of 5 weeks. Nissl staining was used for counting neurons. Transmission electron microscopy was used for observing synapse structures and measuring the thickness of the postsynaptic density area and the length of the postsynaptic active area. The correlations of histological changes with the results of behavioral tests were evaluated.

RESULTSThe HIBD group showed a significantly longer escape latency (P<0.05) and a lower frequency of original platform crossing (P<0.05) in the Morris water maze test compared with the sham operation group. The sensorimotor function test showed that the sensorimotor function in the HIBD group was worse than in the sham operation group. Nissl staining showed that the number of neurons in the HIBD group was significantly reduced (P<0.01) compared with the sham operation group. Transmission electron microscopy showed that synapses were significantly reduced in number, and that the thickness of the postsynaptic density area and the length of the postsynaptic active area were reduced in the HIBD group. The thickness of the postsynaptic density area was negatively correlated with escape latency in the Morris water maze test (r=-0.861, P<0.01), and also negatively correlated with the total score of sensorimotor function tests (r=-0.758, P<0.05) in the HIBD group.

CONCLUSIONSHypoxia ischemia can lead to neuron loss and ultrastructure damage, resulting in long-term deficit of behavioral functions in neonatal rats.

Animals ; Animals, Newborn ; Brain ; pathology ; ultrastructure ; Female ; Hypoxia-Ischemia, Brain ; pathology ; psychology ; Male ; Maze Learning ; Microscopy, Electron, Transmission ; Rats ; Rats, Sprague-Dawley ; Reaction Time

OBJECTIVETo elucidate the role of let-7a-mediated gene regulation in the pathogenesis of lung cancer.

METHODSTwo template DNA sequences were designed based on hsa-let-7a sequence in miRBase database. The let-7a expression construct and a control plasmid, namely pGenesil-let-7a and pGenesil-control, respectively, were generated by cloning the annealed oligonucleotides into pGenesil-1 and then transfected into A549 cells, which were selected by G418 to establish the lung cancer cell lines stably expressing let-7a-GFP and control-GFP. The living cells were counted by MTT assay and cell growth curves were drawn to analyze the cell proliferation. The k-Ras mRNA level was assessed by semi-quantitative RT-PCR, and the expression of k-Ras protein was determined by Western blotting and immunocytochemistry.

RESULTSThe recombinant vectors were verified by sequencing. The cell growth curves indicated that the proliferation of the cells transfected with pGenesil- let-7a were inhibited significantly compared with that of cells transfected with pGenesil-control and A549 cells. Semi- quantitative RT-PCR analysis showed that the levels of k-Ras mRNA almost remained unchanged in cells with or without the treatments. Western blotting and immunocytochemistry demonstrated a significant decrease of k-Ras protein levels in cells transfected with pGenesil-let-7a, but not in cells transfected with pGenesil-control, when compared to A549 cells.

CONCLUSIONlet-7a over-expression represses the expression of k-Ras protein and significantly inhibits the growth of lung cancer cells.

Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Genetic Vectors ; Humans ; Lung Neoplasms ; metabolism ; pathology ; MicroRNAs ; genetics ; metabolism ; Plasmids ; Proto-Oncogene Proteins p21(ras) ; genetics ; metabolism ; RNA, Messenger ; genetics ; Transfection

Objective To establish a computer-aided diagnosis (CAD) model for the classification and diagnosis of systemic lupus erythematosus (SLE) complicated with renal involvement,and to provide a new method for the timely detection and diagnosis of the disease.Methods Simulated annealing(SA) algorithm was used to optimize the penalty coefficient C and kernel function parameter g of the support vector machines(SVM) algorithm before an SA-SVM classifier model was established and was applied to the intelligent assistant diagnosis of SLE.Results Unlike the single SVM classifier,this method never fell into local optimum,and improved the classification accuracy of a classifier.The classification accuracy for SLE with renal involvement was as high as 98.72％.Conclusion The experimental results show that this classification model is well applicable to the intelligent diagnosis of SLE with renal involvement.

OBJECTIVE: To observe the effects of immune complexes (IC) prepared from human oxidized density lipoprotein (oxLDL) antibodies and human oxLDL on the foam cell forming and the macrophage activation, and to further uncover the possible mechanisms of immune complexes contributing to the atherosclerosis occurrence. METHODS: The immune complexes of human oxLDL and purified human oxLDL antibodies were added to culture U937 cells by protocols: polyethylene glycol-precipitated insoluble IC (PEG-IC) and IC immobilized by absorption to red blood cells (RBC-IC). With oxLDL as controls and heat-aggregated gamma globulin as an inhibitor of Fc gamma receptor, we measured the cholesterol ester, total cholesterol of the cellular extracts, and quantified the secreted MMP-1 of supernatants from U937 cells. RESULTS: A significant increase of MMP-1 release [(0.769 +/- 0.030) ng/ml vs (0.513 +/- 0.034) ng/ml, P < 0.01] and a higher level of cholesterol ester accumulation [(20.271 +/- 1.668) microg/mg protein vs (17. 226 +/- 1.298 ) microg/mg protein, P < 0.05] in U937 cells incubated with RBC-IC were observed, compared with those incubated with RBC-oxLDL. However, the above quantative difference between the cholesterol ester accumulation induced by oxLDL and insoluble PEG-IC was even more striking, and cholesterol ester accumulation was dosage-dependent. Heat-aggregated gamma globulin (10 mg/ml) as an inhibitor of Fc gamma receptors competitively inhibited cholesterol ester accumulation and decreased PEG-IC stimulating MMP-1 secretion to 71%. CONCLUSION Immune complexe of ox-LDL can transform macrophages into foam cells and activted macrophages. The immunological function of oxLDL is involved in the process of atherosclerosis occurrence.
Antibodies ; pharmacology ; Atherosclerosis ; etiology ; metabolism ; Cholesterol Esters ; metabolism ; Foam Cells ; drug effects ; Humans ; Lipoproteins, LDL ; immunology ; pharmacology ; Macrophage Activation ; drug effects ; Matrix Metalloproteinase 1 ; biosynthesis ; U937 Cells