Objective To investigate the feature of pathogen distribution and antibiotic resistance of venti-lator associated pneumonia from Jan.to Dec,2007 in our ICU in order to provide a reference data guiding the appro-priate use of clinical antibiotics.Methods The 148 VAP cases of pathogen and drug sensitive tests were retrospec-tively analyzed.Results The incidence rate of VAP was 70.81%.Klebsiella pneumoniae,Pseudomonas aeruginosa,Escherichia coli,Acinetobacter sp were the top pathogen of Gram negative bacillus.Staphylococcus aureus (MBSA)was the major pathogen of Gram positive coccus.The resistance rates of Klebsiella pneumonia and Pseudomonas aeruginosa were very high.The effect rates of frequently used antibiotics were not satisfactory.The fungus infection rate was 6.76% among all the cases.Conclusion MRSA,Klebsiella pneumoniae and Pseudomonas aerugmosa are the major pathogens of VAP in our ICU with a high drug resistance rate.Gram negative bacillus is the major Pathogen of VAP with a faidy high drug resistance rate.

Objective Researches showed that matrix metalloproteinase-2 (MMP-2) has a critical role in the neovascularization of tumor,and vascular endothelial growth factor(VEGF)is a promoting factor of new blood vessel formation.There still is little literature about the effect of MMP-2 in retinal neovascularization up to now.This study tried to explore the expression and significance of MMP-2 and VEGF in retinal neovascularization.MethodsA retinal neovascularization model was established in 30 7-day-old cleaning C57BL/6J mice exposed to an environment of high concentration of oxygen for 5 days,and 30 matched mice were raised in normal air environment.Fifteen mice from hyperoxic group and control group were sacrificed in 10 days after treatment and the eyeballs were enucleated to make retinal stretched preparation.Adenosine diphosphate-ase (ADPase) stained retina flat-mounts was performed to assess the retinal vascular profiles,and H&E staining was applied to count the number of new vascular cell nuclei.The expression of MMP-2 and VEGF was detected using immunohistochemistry by calculating the intergrated value of positive cells.ResultsThe retinal stretched preparation presented more neovascularization in mice from the hyperoxic group compared with control group.The number of nuclei from the vascular endothelial cells in the new vessels breaking through the internal limiting membrane in the hyperoxic group was 33.51±2.55,indicating a significant increase in comparison with control group (7.27±0.20)(t=9.345,P＜0.05).There were stronger expression of MMP-2 protein and the VEGF protein in the ganglion cell layer,inner plexiform layer and inner nuclear layer,and neovascularization breaking through the internal limiting membrane in the hyperoxic group compared with control group (t=4.25,P＜0.05;t=6.38,P＜0.05).Expression of MMP-2 showed the positive correlation with the expression of VEGF(r=0.825,P＜0.05).ConclusionBoth MMP-2 and VEGF promote retinal neovascularization.The overexpression of MMP-2 and VEGF play a synergistic role during the formation of neovascularization.

AIM: To study the inhibitory effect of captopril on retinal neovascularization (RNV).METHODS: Sixty seven-day-old mice were randomly divided into treated group and control group with thirty mice in each group. These mice were exposed to 750 50mL/L oxygen for 5 days and then to room air.The treated group had been injected captopril (2.7mL/kg), while control group had been injected 9g/L sodium chloride (2.7mL/kg) by intravitreal for 5 days.The mice were sacrificed at the 17th day after birth and the eyes were enucleated. Adenosine diphosphate-ase(ADPase) stained retina flat-mounts was performed to assess the retinal vascular profiles, Hematoxylin Eosin (HE)staining method was applied to count the number of new vascular cell nuclei and the expression of matrix metalloproteinase-2(MMP-2)and pigment epithelium derived factor (PEDF)was detected by immunohistochemical method.RESULTS: Comparing with control group,regular distributions and good branch and reduced density of RNV were observed in the treated group. The number of nucleus of new vessels vascular endothelial cells breaking through the internal limiting membrane was less in the treated group than in the control group (P<0.05). Stain of retinal MMP-2 was weaker in the treated group than in the control group and stain of retinal PEDF was stronger in the treated group than in the control group.CONCLUSION: Intravitreal injection of captopril (2.7mL/kg) may block the RNV in the oxygen-induced mouse model and may provide an effective method for prevent-ing RNV.

Objective To evaluate the visual outcomes,depth of focus and safety after implantation of the Acrysof ReSTOR and the Acrysof Natural.Design Nonrandomized clinical trial.Participant 53 patients with age-related cataract(61 eyes)were divided into two groups:Acrysof ReSTOR group(MIOL)included 28 patients(31 eyes),and reference group-Acrysof Natural group(SIOL)included 25 patients(30 eyes).Method All patients underwent phacoemulsification and IOL implantation.At 1 week,1 month and 3 months postoperatively,distant and near visual acuities were observed,and depth of focus was measured 3 months postoperatively.Main Outcome Measure Uncorrected distant visual acuity(UCDVA),uncorrected near visual acuity(UCNVA),best corrected distant visual acuity(BCDVA),best corrected near visual acuity(BCNVA),distant corrected near visual acuity(DCNVA),depth of focus.Result At 3 months postoperatively,in MIOL group:UCDVA was 0.90?0.15,UCNVA was 0.70?0.19,DCNVA was 0.73?0.21 and depth of focus was 5.5D(+1.5～-4.0D),while in SIOL group:UCDVA was 0.84?0.14,UCNVA was 0.36?0.10,DCNVA was 0.26?0.08 and depth of focus was 2.5D(+1.0～-1.5D).In MIOL group,UCDVA and UCNVA at 1 month were markedly better than those at 1 week. Conclusion Acrysof ReSTOR can provide excellent outcomes both in distants and near visions and it may reduce the dependence on spectacles in near vision.(Ophthalmol CHN,2006,15:344-347)

Along with the transgenic plant planting more and more popular in the world,the influence of transgenic plants on ecological environment was widely given attention and the comprehensive research had been done on effect of transgenic plants in soil ecosystems.The latent risks of transgenic plants to the soil ecosystem were reviewed.Also,the study on decomposition of transgenic plants in soil,the vertical and horizontal transfer possibility of recombinant DNA by transformation,as well as the influence of the exogenous gene and its expression product on soil animals,soil microbes as well as soil physical and chemical properties were also discussed,all of which would provide useful information for utilization of transgenic plants more safely in future.

Chitosan, deacetylated derivative of chitin, is a kind of natural polysaccharide polymer. It has advantages of rich source, good biocompatibility and biodegradation. Chitosan can be processed into porous scaffolds used for cell transplantation and tissue regeneration in bone tissue engineering, control-released carrier of growth factors and delivery vector of exogenous genes. Meanwhile, it can also be processed into injectable scaffolds used in bone tissue engineering in the form of microspheres or hydrogel. Chitosan and its derivatives will have broad application prospects in the research field of bone tissue engineering. However, chitosan composite scaffold has poor mechanical function, difficult accuracy control of In vivo degradation, and low efficiency for genetic carrier, chitosan research stays in in vitro tests and in vivo animal experiments. With the development of materials science and life science, chitosan will be widely used for clinical application of bone tissue defect.

Objective To explore the efficacy of GM6001,tissue inhibitor expression and significance of matrix metalloproteinase?9(MMP?9)in mice model of oxygen?induced retinal neovascularization(RNV)and evaluate the inhibition effect of MMP?9 inhibitor(GM6001)on RNV. Meth?ods Mice were placed in oxygen boxes to establish oxygen?induced RNV animal models. The GM6001 treated or hyperxia control groups received an intravitreal injection of 1μL GM6001(100μmol/L)or PBS at day 11 after birth. The normal control and hyperxia group were not treated. HE staining was used to detect RNV in retinal whole mounts,the mRNA level and protein expression of MMP?9 were measured by RT?PCR,Western blot and immunohistochemistry,respectively. Results RNV in the GM6001 treated group was decreased significantly compared with the hyperxia group and hyperxia control group. Compared with the normal control group,higher protein and mRNA expression of MMP?9 were observed in the hy?perxia group and hyperxia control group. The expression of MMP?9 protein and mRNA were decreased in the GM6001 treated group compared with the hyperxia control group(P<0.05). Conclusion The abnormal expression of MMP?9 was closely correlated with RNV. The development of RNV can be markedly inhibited by MMP?9 inhibitor(GM6001),which,we believe,will provide new molecular targets and therapeutic strategy for retinopathy of prematurity treatment.

MicroRNAs (miRNAs) are a class of highly conserved small noncoding single stranded RNAs.They participate in the regulation of target genes through the degradation of mRNA and/or inhibition of translation.As the most abundant miRNAs in the central nervous system,miRNA-124 (miR-124) has been widely given attention in recent years.The recent research suggests that miR-124 is closely associated with ischemic cerebral injury,but its specific regulation mechanism remains unclear.This article reviews the roles of miR-124 in ischemic cerebral injury.

Objective To explore the inhibition effect of Cysteine-rich 61 (CCN1; Cyr61) specific siRNA expression vector on RNV in a mouse model of oxygen-induced retinopathy (OIR).Methods One hundred and twenty healthy C57BL/6J mice were chosen and randomly divided into the experimental group and control group,with 60 mice in each group.The experimental group was intravitreously injected with CCN1siRNA recombinant plasmids.The control group was injected with vector plasmids.Adenosine diphosphate-ase stained retina flat-mounts was performed to assess the retinal vascular profiles,retinal section with HE staining was applied to count the number of new vascular cell nuclei and the protein and mRNA expression of CCN1 and vascular endothelial growth factor (VEGF) were detected by immunohistochemistry,Western blot and Real-time RT-PCR.Results Compared with control group,regular distributions,good branches and reduced density of retinal neovascularization were observed in the experimental group.The number of nucleus of vascular endothelial cells breaking through the inner limiting membrane was obviously less in the experimental group than that in the control group (t=8.756,P＜ 0.05).The expression of CCN1 and VEGF were obviously decreased in the experimental group compared with the control group (all P＜0.05).Conclusion The development of RNV of ROP can be markedly inhibited by RNA interference targeting CCN1,and CCNlsiRNA may provide an effective method for preventing vascular proliferative retinopathy.

Objective: This work aimed to construct stable MCF-7 cell sublines from which staphylococcal nuclease domain con-taining 1 (SND1) expression was interfered to analyze the effect of SND1 silencing on the proliferation and metastasis of MCF-7 cells. Methods: The lentivirus that could mediate SND1 silencing was prepared. MCF-7 cells were infected with the lentiviruses to construct stable sub-cell lines. Quantitative real-time polymerase chain reaction and Western blot analysis were employed to determine SND1 ex-pression level. MTS, wound healing, and transwell assays were applied to analyze the effect of SND1 silencing on the proliferation, mi-gration, and invasion of MCF-7 cells. Results: A lentivirus expression vector that contains sequences encoding shRNAs targeting SND1 and an shRNA negative control were successfully established. The lentiviruses (LV-SH1, LV-SH2, LV-SH3, and 和 LV-NC) were then collected and packaged. Stabilized MCF-7 sublines were prepared through infection with lentiviruses. The most efficient MCF-7 stable cell subline, MCF-SH3, was selected for SND1 silencing. Compared with the control cell, the proliferation, migration, and inva-sion potential of MCF-SH3 were significantly decreased. Conclusion: SND1 could promote the proliferation, migration, and invasion of breast cancer cells. Thus, silencing SND1 expression will inhibit such proliferation, migration, and invasion. These results indicated that the unusual expression of SND1 is associated with breast cancer and may participate in cancer progression by affecting prolifera-tion, migration, and invasion.