Dynamic Changes and Differences of B-cell Responses between Severe Dengue Disease and Mild Dengue Fever / 中山大学学报(医学科学版)

@#【Objective】 To find out the possible marker for early warning or therapeutic target of severe dengue disease ，we studied B cell responses during natural dengue virus（DENV）infection and their association with disease severity.【Methods】Sixty-two cases and their blood samples were collected from the patients hospitalized during September to December in 2014 and three groups were designated as mild dengue（DF，n=33），severe dengue（SD，n=29）and control group（Control ，n=6）. Multicolor flow cytometrywas used to analyze the dynamic changes of B cells and plasmablasts in the peripheral blood of patients during the acute phase and the critical phase. The plasmablasts in a succession of samplesfrom the same infected patients （including 3 mild and 3 severe cases） were further analyzed. We also observed the changes of B cells and their subsets ，including naive B cells ，memory B cells and plasmablasts，during primary and secondary infections. 【Results】 The expansion of B cells in the severe group was significantly higher than that in the mild group（P=0.013），especially on day 5 and day 6 after the symptom onset（P = 0.017 and 0.002，respectively）. Compared with those in the control group，the plasmablasts in the mild and severe groups showed significant proliferation（P=0.011 and 0.032，respectively），but no statistical difference was observed between these two groups. The analysis of the serial blood samples showed that the plasmablasts，in mild cases，peaked on day 7 and 8 and returned to baseline on day 10，whereas in the severe group，peaked on day 7 to 9，and still existed at a certain rate after day 10. In mild dengue group，more proliferative B cells，less naive B cells and memory B cells were found in secondary infection than in primary infection（P = 0.028，0.010 and 0.037，respectively），but plasmablasts revealed no difference. In severe dengue group， only naïve B cells significantly decreased in secondary infection （P = 0.018）. 【Conclusion】 B cell responses between mild and severe dengue after DENV- 1 infection present different trends. The significant proliferation of B cells in the early stage of the disease and the persistent existence of plasmablasts may be related to the severity of the dengue disease.

Effect of transcatheter embolization by autologous fat particles in the treatment of coronary artery perforation during percutaneous coronary intervention / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Coronary artery perforation (CAP) is a rare but severe complication of percutaneous coronary intervention (PCI). The aim of our study was to evaluate the effect and safety of transcatheter embolization by autologous fat particles in the treatment of CAP.</p><p><b>METHODS</b>Once the CAP was confirmed, a little autologous subcutaneous fatty tissue was obtained from the groin of the patient and then was made into 1 mm × 1 mm fat particles. The perforated vessel was embolized by fat particles via a micro-catheter. There were eight patients undergoing transcatheter embolization by autologous fat particles in the treatment of CAP during PCI in Peking University Third Hospital from February 2009 to June 2014, and the clinical data of these patients were collected and analyzed retrospectively.</p><p><b>RESULTS</b>The lesion morphology of the patients was classified based on the American College of Cardiology/American Heart Association Task Force classification, there were one patient with Class B2 lesion and seven patients with Class C lesions (there were five patients with chronic total occlusion lesions). According to the Ellis classification of CAP, there were six patients with Class II perforations and two patients with Class III perforations. The causes of perforation included that seven patients induced by guide wire and one patient by balloon predilation. Three patients had pericardial effusion. All of the eight patients with CAP underwent transcatheter embolization by autologous fat particles. Coronary angiography confirmed that all of them were embolized successfully. There was no severe complication after the procedure. The coronary angiography of one patient at 1 week and another patient at 2 years after the embolization showed that the embolized arteries had recanalized. The median follow-up time was 20.3 months (8.8-50.2 months), the event-free survival rate was 100%.</p><p><b>CONCLUSIONS</b>Transcatheter embolization by autologous fat particles was an effective, safe, cheap, and easy way to treat the perforation of small vessels during PCI.</p>

Usefulness of lumen area parameters determined by intravascular ultrasound to predict functional significance of intermediate coronary artery stenosis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Coronary artery disease is the leading cause of death in China. Percutaneous coronary intervention is a recent milestone technology for treatment coronary artery disease. However, clinical decision making for patients with intermediate coronary stenosis is still controversial. We designed this study to assess the optimal intravascular ultrasound (IVUS) criteria for predicting functional significance of intermediate coronary lesions.</p><p><b>METHODS</b>We enrolled 141 patients with 165 intermediate coronary lesions located in vessels with a diameter ≥ 2.50 mm. IVUS of intermediate coronary lesions were performed before intervention. Pressure-derived fractional flow reserve (FFR) was measured at maximal hyperemia induced by adenosine infusion. An FFR < 0.80 was considered as abnormal functional significance.</p><p><b>RESULTS</b>For the overall 165 lesions, the mean FFR value was 0.84 ± 0.09. The diameter of the stenosis by visual estimation on angiogram was (59.63 ± 11.29)%. Minimum lumen diameter (MLD), minimum lumen area (MLA) and plaque burden (PB) were (2.00 ± 0.36) mm, (3.88 ± 1.34) mm(2), (67.28 ± 9.89)% respectively by IVUS measurements. An FFR < 0.80 was seen in 43 lesions (30.5%). There was a moderate correlation between IVUS parameters and FFR, including MLD (r = 0.372, P < 0.001), MLA (r = 0.442, P < 0.001) and PB (r = -0.172, P < 0.05). MLA was a predictor for FFR as a continuous variable independent of possible confounding variables (P < 0.05), and MLA and PB, were predictors for FFR < 0.80 as binary variables (P < 0.05). The best cutoff value of MLA to predict FFR < 0.80 was < 3.15 mm(2), with a 73.6% diagnostic accuracy; sensitivity 71.4%, specificity 67.0%, AUC = 0.709, and P < 0.001. The cutoff value of the PB to predict FFR < 0.80 was 65.45%; sensitivity 82.6%, specificity 41.2%, AUC = 0.644, and P < 0.01. If both MLA and PB were taken into account, the negative predictive value and the positive predictive value were 88.7% and 64.8% respectively.</p><p><b>CONCLUSIONS</b>Anatomic measurements of intermediate coronary lesions obtained by IVUS showed a moderate correlation to FFR values. IVUS-derived MLA ≥ 3.15 mm(2) may be useful to exclude FFR < 0.80, but poor specificity limits its applicability for physiological assessment of lesions < 3.15 mm(2). MLA was one of many factors affecting coronary flow hemodynamics. Both MLA and PB should be taken into account when determining functional ischemia.</p>

Association between fractional flow reserve and quantitative coronary angiography parameters in intermediate coronary artery stenosis / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the relationship between quantitative coronary angiography (QCA) parameters and fractional flow reserve (FFR) for identifying ideal angiographic parameters predictive of myocardial ischemia.</p><p><b>METHODS</b>The study included 121 lesions with QCA and FFR data from 106 patients [mean age: (63 ± 10) years]. The lesions were grouped into FFR > 0.75 group and FFR ≤ 0.75 group. Assessed parameters by QCA included percentage diameter stenosis, minimum luminal diameter (MLD), percentage area stenosis, minimum luminal area (MLA), reference vessel diameter (RVD) and lesion length (LL). Correlation analysis was used to identify the relationship between QCA parameters and FFR value, and receiver operating characteristic (ROC) curve was used to determine parameters predictive of FFR ≤ 0.75.</p><p><b>RESULTS</b>LL was significantly higher [(14.8 ± 7.9) mm vs. (10.7 ± 5.4) mm, P = 0.024] while MLD [(1.47 ± 0.31) mm vs. (1.82 ± 0.51) mm, P = 0.028], RVD [(2.30 ± 0.50) mm vs. (2.81 ± 0.64) mm, P = 0.036], and MLA [(2.30 ± 1.50) mm(2) vs. (3.60 ± 2.30) mm(2), P = 0.038] were significantly lower in FFR ≤ 0.75 group than in FFR > 0.75 group. LL (r = -0.209, P = 0.040) was negatively correlated with FFR, and MLD (r = 0.414, P = 0.040), RVD (r = 0.303, P = 0.000) and MLA (r = 0.315, P = 0.002) were positively correlated with FFR. ROC analysis showed that MLD ≥ 1.6 mm was the best cut-off value to predict FFR > 0.75 with sensitivity 63%, specificity 82%, and positive predictive value 96%.</p><p><b>CONCLUSIONS</b>QCA derived anatomic parameters of intermediate coronary lesions correlate to FFR value in some extent. MLD ≥ 1.6 mm is the best cut-off value to predict FFR > 0.75 in patients with intermediate coronary lesions.</p>

Predictive value of postprocedural leukocyte count on myocardial perfusion, left ventricular function and clinical outcomes in ST-elevated myocardial infarction after percutaneous coronary intervention / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Baseline white blood cell (WBC) count was correlated with ischemic events occurrence in patients with ST-elevated myocardial infarction (STEMI). However, circulating WBC count is altered after percutaneous coronary intervention (PCI). The aim of this study was to assess the relationship between postprocedural WBC count and clinical outcomes in STEMI patients who underwent PCI.</p><p><b>METHODS</b>A total of 242 consecutive acute STEMI patients who underwent successful primary PCI were enrolled and followed up for two years. WBC counts were measured within 12 hours after PCI. ST-segment resolution (ST-R) and myocardial blush grades (MBG) were evaluated immediately after PCI. Left ventricular ejection fraction (LVEF) was obtained at baseline and 12 - 18 months after PCI.</p><p><b>RESULTS</b>Postprocedural WBC count was an independent inverse predictor of ST-R (OR 0.80, P < 0.0001) and MBG 3 (OR 0.82, P < 0.0001). It was negatively correlated with LVEF (baseline r = -0.22, P = 0.001; 12 - 18 months r = -0.29, P < 0.0001). The best cutoff value of WBC for predicting death was determined to be 13.0 × 10(9)/L. The patients with a postprocedural WBC count above 13.0 × 10(9)/L showed a significantly lower cumulative survival rate (30 days, 82.4% vs. 99.0%, P < 0.0001 and 2 years 75.0% vs. 96.4%, P < 0.0001). Multivariate Cox regression analysis showed that a postprocedural WBC count was a strong independent predictor of 30-day mortality (HR 8.48, P = 0.019) and 2-year mortality (HR 4.93, P = 0.009).</p><p><b>CONCLUSIONS</b>Increased postprocedural WBC count is correlated with myocardial malperfusion and left ventricular dysfunction, and is an independent predictor of poor clinical outcomes in STEMI patients who underwent PCI.</p>

A rare case of arterial thrombosis due to heparin-induced thrombocytopenia / 中华医学杂志(英文版)

A 78-year-old man presented with an eight-hour history of chest distress. Electrocardiograph and serum cardiac enzymes were suggestive of acute inferior myocardial infarction with right ventricular infarction. The patient, who underwent emergency percutaneous coronary intervention, suffered from thrombocytopenia presenting with cerebral infarction and myocadial reinfarction during haparin exposure. The laboratory test for heparin-induced thrombocytopenia (HIT) specific antibodies (heparin-platelet factor, PF4) was positive. The case was diagnosed as arteries thrombosis due to heparin-induced thrombocytopenia; the patient died after cessation of heparin.

Analysis of hepatitis C virus (HCV) subtypes in HIV/HCV co-infected and HCV mono-infected individuals in Guangdong province / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the transmission routes, genotypes/subtypes distribution and genetic character of HCV in HIV/HCV co-infected and HCV mono-infected individuals in Guangdong Province.</p><p><b>METHODS</b>Reverse transcription (RT) nested PCR was performed to amplify the HCV NS5B gene region from 95 HIV/HCV co-infected and 99 HCV mono-infected individuals lived in Guangdong province. The PCR products were then sequenced for HCV subtyping. Genetic analysis was done by MEGA4 software.</p><p><b>RESULTS</b>(1) HIV/HCV co-infected individuals infected HCV mostly through injection drug use (IDU, 78.9%), the HCV subtypes were identified as 6a (53.7%), 3a (17.9%), 1b (15.8%), 3b (11.6%) and 1a (1.0%) respectively, the genetic distance within subtype 1b was longer than those within other subtypes, the predominant HCV subtype in HIV/HCV co-infected individuals infected through IDU was 6a (60.0%). (2) HCV mono-infected individuals infected HCV mostly through blood or blood products transfusions (80.8%), the HCV subtypes were identified as 1b (67.7%), 6a (17.2%), 3a (6.1%), 2a (5.0%), 3b (2.0%), 4a (1.0%) and 5a (1.0%) respectively, the genetic distance within subtype 1b was also longer than those within other subtypes, the predominant HCV subtype in HCV mono-infected individuals infected through blood or blood products transfusions was 1b (76.2%).</p><p><b>CONCLUSION</b>The diversity of HCV subtypes in HIV/HCV co-infected and HCV mono-infected individuals in Guangdong Province was high, both the major transmission route and HCV subtype between HIV/HCV co-infected individuals and HCV mono-infected individuals were different.</p>

Dose of glucocorticosteroids in the treatment of severe acute respiratory syndrome / 南方医科大学学报

<p><b>OBJECTIVE</b>To survey the dose of glucocorticosteroids administered in patients with severe acute respiratory syndrome (SARS) and assess the effect of glucocorticosteroid doses in improving the patients' lung function.</p><p><b>METHODS</b>A retrospective analysis was conducted among 225 SARS patients treated in our in 2003. Oxygenation index was used as the effectness index, and the criteria for effectiveness was defiend as increase of the value of OI by 20% or above.</p><p><b>RESULTS</b>Glococoticostecoids were used in 59.56% of the SARS cases. The average value of OI before intravenous use of glucocorticosteroids was 237.08 mmHg, and that after the administration was 335.08 mmHg. The glucocorticosteroid doses that produce better effects were 1-3 mg/kg and 160-240 mg daily, with the total accumulative dose of 1000-2000 mg. The optimal duration of glucocorticosteroid use was 8-14 days.</p><p><b>CONCLUSIONS</b>For SARS treatment, Glucocorticosteroids can effectively ameliorate the SARS patients' lung symptoms and improve the lung function. The appropriate daily dose of glucocorticosteroids is 1-3 mg/kg or 160-240 mg/d for a duration of 8-14 d; the accumulative dose should be controlled around 1500 mg.</p>

Increased postprocedural neutrophil count is an independent predictive factor of poor prognosis in acute ST elevation myocardial infarction patients treated with percutaneous coronary intervention / 中华心血管病杂志

<p><b>OBJECTIVE</b>The aim of the study was to evaluate the prognostic value of the postprocedural neutrophil count in patients with first acute ST elevation myocardial infarction (STEMI) treated with successful primary percutaneous coronary intervention (PCI).</p><p><b>METHODS</b>A total of 226 consecutive STEMI patients underwent successful primary PCI were enrolled. Electrocardiograms were recorded before PCI and 2 hours after PCI. Neutrophil counts were measured within 12 hours after PCI. All patients were followed up for 2 years. Logistic regression analysis was used to evaluate predictive values of postprocedural neutrophil for ST-segment resolution (STR) after PCI and for death, non-fatal myocardial infarction and heart failure at 30 days and 2 years post PCI. Time-to-event analyses were performed using the Kaplan-Meier survival curves in patients with various ranges of postprocedural neutrophil counts.</p><p><b>RESULTS</b>Postprocedural neutrophil count ranged from 2.83x10(9)/L to 18.74x10(9)/L, first quartile, median and fourth quartile were 5.66x10(9)/L, 7.38x10(9)/L and 9.34x10(9)/L respectively. Multivariable logistic analysis showed that when postprocedural neutrophil count increased 1x10(9)/L, the risk of non-STR increased 2.28 fold (OR: 2.28, P=0.009), the risk of death (OR: 1.63, P=0.010) and heart failure (OR: 1.16, P=0.035) at 30 days increased 1.63 and 1.16 folds respectively, and the risk of death (OR: 1.29, P=0.003) and heart failure (OR: 1.20, P=0.007) at 2 years increased 1.29 and 1.20 folds respectively, but the risk of non-fatal myocardial infarction was not affected by postprocedural neutrophil count. Furthermore, the patients with postprocedural neutrophil count>or=9.34x10(9)/L had significant lower 30-day (89.1% vs. 99.1% vs. 98.2%, P=0.010) and 2-year (82.4% vs. 96.1% vs. 96.3%, P=0.003) survival rates compared with the patients with postprocedural neutrophil count from 5.66x10(9)/L to 9.33x10(9)/L and the patients with postprocedural neutrophil count<5.66x10(9)/L (all P<0.05).</p><p><b>CONCLUSION</b>Postprocedural neutrophil count is an independent predictor of short- and long-term death and heart failure in first acute STEMI patients treated with successful primary PCI.</p>

Molecular and functional comparisons of the vacuolar Na+/H+ exchangers originated from glycophytic and halophytic species / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

A novel vacuolar Na+/H+ exchanger, CgNHX1, was cloned from a halophytic species Chenopodium glaucum by using reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) technique. Sequence alignment and phylogenetic analysis of 22 NHX genes from GenBank as well as the new CgNHX1 gene indicate that NHX genes shared a great degree of similarity, regardless of their glycophytic or halophytic origin. Expression of the CgNHX1 gene was induced by NaCl and peaked at 400 mmol/L NaCl. Overexpression of NHX1 genes in rice enhanced their tolerance to salt stress. However, there is no significant difference in salt tolerance among the transgenic rice plants overexpressing the NHX1 genes from either glycophytic or halophytic species. The Na+ content of both the wild type (WT) and transgenic plants increased when exposed to 50 and 100 mmol/L NaCl, and the Na+ concentration in transgenic plants was marginally higher than that of WT. Our data demonstrate that the overexpression of the NHX1 gene from either glycophytic or halophytic species resulted in the enhanced tolerance to salt stress at a similar level, suggesting that NHX gene per se might not be the reason accounting for the difference in salt tolerance between glycophytes and halophytes.

Preparation of plasmid nanoemulsion and its character determination by anion exchange chromatography method / 生物工程学报

Nanoemulsion-encapsulated lzp3 DNA vaccine (pCDNA3-Aat-COMP-lzp3-C3d3, lzp3) was prepared, and its quality was evaluated. The interfacial emulsification method was employed to make the nanoemulsion-encapsulated plasmid, and its sizes and distribution were detected by electron microscope. Anion exchange chromatography was used to separate the nanoemulsion from the plasmid based on the charge characteristics of plasmid. The determination method for encapsulation efficiency of the plasmid nanoemulsion was established by anion exchange chromatography. The results indicated that the average size of the plasmid nanoemulsion is (23 +/- 10) nm, and the encapsulation efficiency is 80.5%. The separation and determination conditions of nanoemulsion-encapsulated plasmid was as follows: eluent buffer was 0.05 mol/L Tris-HCl solution at a flow rate of 0.7 mL/min, while detection wavelength for plasmid was 260 nm, the temperature of column was maintained at 30 degrees C, and injection volume was 2mL. On this condition, nanoemulsion and plasmid can be separated on the column of anion exchange chromatography significantly. This method is simple, sensitive and reproducible with respect to good linearity in the range of 0.05-0.80 mg/mL (r = 0.9983), which can be applied to determine the entrapment efficiency of nanoemulsion-encapsulated plasmid.

Clinical characteristics of the patients with dengue fever seen from 2002 to 2006 in Guangzhou / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the clinical characteristics of the patients with dengue fever (DF) seen from 2002 to 2006 in Guangzhou in order to prevent and treat dengue fever better.</p><p><b>METHODS</b>Clinical data from 1342 inpatients with DF seen from 2002 to 2006 were retrospectively analyzed. The dengue virus was isolated by C6/36 cell culture and genotyped by reverse transcriptase-polymerase chain reaction and gene sequence analysis.</p><p><b>RESULTS</b>The average age of the patients was 34.4 years, without sex difference in distribution. Most of the patients had obvious toxemic symptoms including fever (100 percent), headache (85.9 percent), myalgia (64.5 percent), bone soreness (46.6 percent) and skin rash (65.9 percent). Leukopenia, thrombocytopenia, elevated alanine aminotransferase, elevated aspartate aminotransferase and hypokalemia were found in 66.0 percent, 61.3 percent, 69.0 percent , 85.7 percent and 28.4 percent of patients, respectively. DF-IgM could be detected in 90 percent of patients. The virus was identified as dengue virus type-I.</p><p><b>CONCLUSIONS</b>The epidemic of DF was caused by dengue virus- I from 2002 to 2006 in Guangzhou. Most of the patients had classic DF clinical manifestation with high percentage of hepatic injury. Few patients progressed to dengue hemorrhagic fever.</p>

Folic acid attenuates homocysteine induced human monocytes chemokine secretion via reducing NADPH oxidase activity / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effect of folic acid on homocysteine (Hcy)-induced chemokine secretion and NADPH oxidase activity in human monocytes.</p><p><b>METHODS</b>Human monocytes from healthy volunteers were incubated with Hcy (100 micromol/L) with or without folic acid (5 micromol/L) for 24 h; MCP-1 and IL-8 were assessed by ELISA. DCFH-DA was added to monitor intracellular ROS production on confocal microscopy. A cytochrome c reduction assay was used to measure NADPH oxidase activity.</p><p><b>RESULTS</b>The Hcy-induced secretion of MCP-1 and IL-8 was significantly reduced by folic acid [(1.88 +/- 0.51) ng/ml vs. (4.36 +/- 0.72) ng/ml vs. (2.40 +/- 0.60) ng/ml and (4.9 +/- 1.9) ng/ml vs. (12.7 +/- 1.5) ng/ml vs. (7.2 +/- 1.9) ng/ml, all P < 0.05]. The Hcy-induced production of ROS was also significantly attenuated by folic acid. Moreover, the Hcy-induced NADPH oxidase activity increase was significantly inhibited by cotreatment with folic acid.</p><p><b>CONCLUSION</b>Folic acid may attenuate oxidative stress induced by Hcy by reducing NADPH oxidase activity in monocytes.</p>

Molecular analysis on the S gene of three Crimean-Congo hemorrhagic fever virus strains in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To compare the molecular characteristics of 3 Crimean-Congo hemorrhagic fever viruses(CCHFV) isolated in Xinjiang province.</p><p><b>METHODS</b>YL05035, YT05099 and LT05146 were isolated in 2005 from Hyalomma ticks and viral RNA was extracted from suckling mouse brains infected with these three strains respectively. The polymerase chain reaction(PCR) products of S segments from the 3 strains of CCHFV were directly sequenced.</p><p><b>RESULTS</b>The full-length'S RNA from the 3 strains of CCHFV all comprised 1673 nucleotides with ORF of them including 1449 nucleotides and encoding a protein which comprised 482 amino acids in a viral complementary sense. The sequences indicated that the three strains of CCHFV isolated from ticks in Xinjiang province were highly homologenic. Data from the phylogenetic analysis showed that the obtained sequences were identical. The homology between 3 strains of CCHFV was 99.5%. Their homologies compared with that of the other strains isolated from other region of Xinjiang were also high at nucleotide levels (92.7%-99.8%). The three strains which were clustered together with 7001 strain and 79121 strain (isolated from patient and rat in Xinjiang respectively) was only different by 2%-3%. The genetic difference from the prototype CCHFV Nigerian strain IBAR10200 was 13%. In comparison, the Nigerian CCHFV tick isolate was more divergent when compared with the reference China strains 66019 and with the three variants mentioned above.</p><p><b>CONCLUSION</b>The CCHFV isolated from China comprised a group of genetically high conserved strains.</p>

Selecting the RNAi efficiency target sites of lZP3 gene by mouse in vivo / 生物工程学报

As the combining target with sperms, ZP3 undergoes an important role in the fertilization of oocytes and therefore it has been the focus in studying the mechanism of mammalian. According to the sequence of the zona pellucida 3 gene of Lagurus lagurus (lZP3), three RNA interference recombinant vectors were constructed with pGenesil-1 aiming at lZP3 mRNA by synthesizing oligonucleotides. And then co-transfected into the Hela cells by Lipofectamine2000 and co-injected into the mice by hydrodynamics-based transfection method with the expression vector pCDNA3-lZP3. In order to select the efficient target sites of lZP3 for RNAi, the mRNA expression level of lZP3 gene in Hela cells and the mouse liver was detected by semi-quantative RT-PCR and real-time PCR. Results show that there are 2 interference vectors can interfere of the expression of lZP3 mRNA, and the mRNAs of the exogenous genes expressed in the mouse liver are coincident with those of in Hela cells after co-transfected with the interference vectors and expression vector. It also suggests that the mice can be the experimental materials for selecting the efficiency target sites of the RNA interference.

Effects of cecropin-XJ on growth and adherence of oral cariogenic bacteria in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cecropin-XJ belongs to cecropin-B, which is the most potent antibacterial peptide found naturally. The aim of this study was to investigate the effects of cecropin-XJ on growth and adherence of oral cariogenic bacteria.</p><p><b>METHODS</b>Four oral cariogenic bacteria (Streptococcus mutans, Lactobacillus acidophilus, Actinomyces viscosus and Actinomyces naeslundii) were chosen for this experiment. The minimal inhibitory concentrations (MICs) and reductive percent of bacterial growth were used to assay the antibacterial activity of cecropin-XJ. Mammalian cytotoxicity of cecropin-XJ was tested with human periodontal membrane fibroblasts by tetrazolium (MTT) colorimetric assay. The bacterial morphological changes induced by cecropin-XJ were examined on scanning electron microscope (SEM). The influence of cecropin-XJ on bacterial adhesion to saliva-coated hydroxyapatite (S-HA) was measured by scintillation counting.</p><p><b>RESULTS</b>The MICs of cecropin-XJ for inhibition of the growth of four bacteria ranged from 4.0 to 42.8 micromol/L with the highest susceptible to A. naeslundii and the lowest susceptible to L. acidophilus. At pH 6.8, 5.5 and 8.2, 1/2 MIC of cecropin-XJ reduced the number of viable bacteria by 40.9%, 67.8% and 32.8% for S. mutans and by 28.1%, 57.2% and 37.9% for L. acidophilus. The activities against S. mutans and L. acidophilus increased at pH 5.5 compared with pH 6.8 (P < 0.01, respectively). In present of 50% saliva, 1/2 MIC of the peptide decreased the direct count of viable cells by 29.2% and 14.4% for S. mutans and L. acidophilus, respectively (P < 0.01 and P > 0.05, respectively), whereas almost no reduction counts were detected in the presence of 20% serum for both bacteria (P > 0.05, respectively). Mammalian cytotoxicity of cecropin-XJ from 1.0 to 100 micromol/L exhibited no cytotoxicity against human periodontal membrane fibroblasts (P > 0.05). Bacterial morphological changes induced by MIC of cecropin-XJ examined on SEM showed cell surface disruption. Furthermore, the ability of A. naeslundii adhesion to S-HA decreased significantly with MIC of cecropin-XJ for 10 and 20 minutes (P = 0.001 and 0.000, respectively), and S. mutans, A. viscosus to S-HA decreased significantly with MIC of cecropin-XJ for 20 minutes (P = 0.000, respectively).</p><p><b>CONCLUSIONS</b>Cecropin-XJ exhibited bactericidal action against cariogenic pathogens, and the antibacterial activity enhanced in the acid environment. The results also demonstrate that cecropin-XJ prevents S. mutans and actinomyces adsorption to S-HA. These findings suggest that Cecropin-XJ may have potential to prevent caries.</p>

Analysis on clinical and epidemiological characteristics of 1032 patients with Dengue fever in Guangzhou / 中华流行病学杂志

<p><b>OBJECTIVE</b>To analyze the clinical and epidemiological characteristics of Dengue fever (DF) during the Dengue-1 epidemic in Guangzhou.</p><p><b>METHODS</b>Clinical and epidemiological data of 1032 patients with DF from May 2002 to November 2003 were retrospectively analyzed. Dengue virus were isolated by cell culture and typed by reverse transcriptase polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>Age of the patients ranged from 55 days to 91 years old (average 34.7 +/- 13.2 years) with sex ratio 1.03:1. Incubation period ranged from 2 to 12 days with mean periods of 5.3 +/- 2.4 days. Most (45.0%) cases appeared in September and the epidemic last from July to November. Dengue outbreak had involved 675 cases in 26 common places. The common manifestations were seen as fever (100%), headache (90.9%), myalgia (68.4%), bone soreness (48.8%), fatigue (79.3%), skin rash (60.1%), positive tourniquet test (45.3%), leukopenia (63.3%) and thrombocytopenia (60.8%), respectively. Dengue virus was isolated from serum of 19 out of 54 patients' and identified as Dengue virus type 1. DNA sequence analyzes on rates of nucleotide homology were 97%, 97% and 98% compared with those of Dengue virus type 1 strain of DF outbreak in Cambodia, in 1997 and 1999 in China.</p><p><b>CONCLUSION</b>The epidemic of DF in Guangzhou in 2002/2003 was caused by Dengue virus type-1 with most patients showing classic type of the disease. Date suggested that change can happen from non-endemic to hypoendemic regions in Guangdong province.</p>

Effect of homocysteine on plaque formation and oxidative stress in patients with acute coronary syndromes / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cardiovascular diseases, especially coronary artery disease (CAD), are major causes of death in industrialized countries. Elevated concentrations of plasma homocysteine (Hcy) have been associated with an increased risk of CAD. Increased plasma levels of chemokine, characterized by their ability to induce migration and activation of leukocytes, may contribute to the pathogenesis of CAD. This study was designed to investigate the changes of plasma Hcy, monocyte chemoattractant protein-1 (MCP-1) and oxidative stress markers in acute coronary syndrome patients.</p><p><b>METHODS</b>A total of 149 subjects were divided into four groups: 50 patients with unstable angina, 30 patients with acute myocardial infarction, 20 coronary restenosis patients after percutaneous coronary intervention and 49 healthy control subjects. Plasma levels of Hcy, MCP-1, malondialdehyde and superoxide dismutase were measured.</p><p><b>RESULTS</b>Plasma levels of Hcy and MCP-1 showed significant increases in unstable angina, acute myocardial infarction and restenosis patients compared with control subjects (P < 0.05, respectively). Plasma levels of malondialdehyde were significantly increased in unstable angina and acute myocardial infarction patients when compared with control subjects (P < 0.05, respectively). Plasma superoxide dismutase levels were significantly reduced in acute myocardial infarction patients when compared with control group (P < 0.01).</p><p><b>CONCLUSION</b>Hcy might act as an atherogenic factor through promoting chemokine, reactive oxygen species and oxidized low density lipoprotein production and thereby convert a stable plaque into an unstable potentially occlusive lesion.</p>

Using single primer PCR to amplify the orf25 gene fragment related to plant male-sterility in Salicornia europaea / 生物工程学报

The gene orf25 encodes functional protein that may play an important role in plant fertility control in nature. To clone the orf25 from Salicornia europaea Xinjiang into a T-vector, a single designed primer was used to amplify 1.7kb cDNA fragment with RT-PCR. Sequence analysis reveals that the cloned fragment contains entire orf25 coding region with 98%, 95%, 92% and 88% identity to that of orf25 from Beta vulgaris, Nicotiana, wheat and maize mitochondrion, respectively. This analysis suggests that orf25 gene is highly conserved in terms of evolution in plant; and it also suggests that wild plant Salicornia europaea contain a male-sterility gene similar to crops that is of great importance in improvement of the breed of crop.

Sequence analysis of bacterial transposon in NHX gene of Populus euphratica / 生物工程学报

The United Nations Environment Program estimates that approximately 20% of agricultural land and 50% of cropland in the world is salt-stressed. The gene NHX (Na+/H+ exchanger) encodes functional protein that catalyzes the countertransport of Na+ and H+ across membranes and may play an important role in plant salt tolerance. To clone the NHX from the wild plant Populus euphratica collected in Tarim basin and Xinjiang Wujiaqu district into a T-vector, designed primer was used to amplify 1kb NHX cDNA fragment with RT-PCR. Total RNA was extracted from Populus euphratica tissue (plant tissue was collected from Tarim basin and Xinjiang Wujiaqu district and stored in liquid nitrogen) according to the Plant RNA Mini Kits of Omega. First cDNAs were synthesized from 1 microg total RNA of Populus euphratica seedling. A pair of primers were used to perform RT-PCR. The amplified DNA fragment was purified and cloned into pMD18-T vector. However, 1kb and 2.3kb fragment were obtained from Tarim basin and Xinjiang Wujiaqu district and named as PtNHX and PwNHX, respectively. Sequence analysis reveals that the cloned PtNHX fragment of Populus euphratica contains partial NHX coding region with 98%, 86%, 84% and 80% identity comparing with Atriplex gemelini, Suaeda maritima, Arabidopsis thaliana and Oryza sativa, respectively. This analysis suggests that NHX gene would be highly conserved in terms of evolution in plant; and it also suggests that the NHX gene of Populus euphratica also would have the similarity with that of Arabidopsis. It may be of great importance in improvement of the plant salt tolerance and breed of crop. At the same time, sequence analysis shows that PwNHX gene includes a coding region about 1350bp with 99% identity comparing with transposon Tn10 IS10-left transposase of Shigella flexneri. On the one hand, the NHX gene may lose its function because it was inserted a fragment in coding region. On the other hand, its product may play a important role in salt tolerance. Populus grow in saline soil. It speculates that it may have other salt tolerance mechanism in Populus. The transposon can be used as transposon tagging to clone other genes and it will help us to understand farther the salt tolerance mechanism.