Background Studieshowed thaDelta-like ligand 4 (Dll4) participatein the deveopmenof retinal celland angiogenesis.The Dll4-Notch pathway and vasculaendothelial growth facto(VEGF) are thoughto be critical mediatorof neovascularization undehypoxiconditions.The relationship between Dll4 and VEGF inovery cleaand furtheresearch ineeded.Objective Thistudy wato observe the inhibition of Dll4 on experimental retinal neovascularization and VEGF expression.MethodThe retinal neovascularization animal model wainduced by oxygen-induced retinopathy (OIR) in 5-day-old SPF SD ratby rearing the new postnatal ratwith the motherattogethein closed box with oxygen level a(80±2) ％ till 12-day-old.The ratwere then raised in normal aifo5 days.Aftethat,2.5μl (0.5 μg) of Dll4 monoclonal antibody wainjected into the mid-vitreoucavity in the righeye(Dll4 injected group) and PBwaused in the same way in the fellow eye(PBcontrol group) in the 12-day-old rats.Retinawere isolated in the 17-day-old rats,and retinal vasculamorphology waexamined by adenosine diphosphatease (ADPase) staining of retinal flatmounts,and the endotheliocyte nuclei above the internal limiting membrane were counted in the retinal tissue-slices.Reverse transcription PC(RT-PCR) waused to detecthe mRNexpression level of Dll4,VEGF,VEGF receptor-1 (VEGFR-1),VEGFR-2 and neuropilin-1 mRNin the retinas.Statistical analysiwaperformed by the paired t-test.The care and use of the animalcomplied with the Guidance Suggestion issued by the Ministry of Science and Technology of Chinin 2006.ResultThe Dll4 mRNexpression in the retin(Dll4 mRNA/β-actin mRNA) wa0.22± 0.06 and 0.98 ± 0.13 in the Dll4 injected group and the PBcontrol group,respectively,with statistically significandifference (=21.839,P =0.000).No significandifferencewere found in the expression of the VEGF mRNA,VEGFR-1 mRNand VEGFR-2 mRNin the retinabetween the two group(t=0.463,P=0.649;=1.687,P=0.109;=-1.674,P=0.111).Compared with the PBcontrol group,the expression of neuropilin-1 mRNwasignificantly elevated in the Dll4-injected group (0.73±0.08 vs.0.64±0.07) (t=-2.677,P=0.015).ADPase staining showed thathere were much more new blood vesselin the Dll4 injected group than those of the PBcontrol group.The numbeof nuclei structurally adjacento the vitreal side of the internal limiting membrane wa(63.6± 11.6)/slide in the Dll4 injected group,which wamore than thaof the PBcontrol group a(35.1±5.2)/slide (=-7.879,P =0.000).ConclusionDll4 playan essential role in the procesof pathological angiogenesiin the retina.Dll4 ithoughto be feedback regulatoof VEGFR,which participatein the procesof restraining pathological vasculogenesis.

Objective To explore the effect of calcium dobesilate on the apoptosis of retinal cells in diabetic rats .Methods Thirty-six Wistar rats were randomly into three groups:normal group ( n =12 ) , model group(n=12), test group(n=12).The rat in model and test groups of diabetes was given with high fat diet for 8 weeks, and then was made by intraperitoneal injection of streptozotocin ( STZ ) .After successfully es-tablished the diatetes animal model , the rats in test group was lavaged with 150 mg? kg -1? d-1 calcium dobesilate continuous 8 weeks, the rats in normal and model group were given same amount of normal saline . Neuronal apoptosis in retina was detected by TdT -mediated dUTP nick end labeling ( TUNEL ) . The expression of B -cell lymphoma -2 ( Bcl-2 ) , Bcl -2 assaciated X protein ( Bax ) and p53 protein and mRNA were assayed by Western blot and reverse transcription -polymer-ase chain reaction.The activity of cysteinyl aspartate specific proteinase 3 ( Caspase 3) was measured by spectrophotometry .Results Compared with normal group , apoptotic index of retina , the expression of Bax , p53 protein and mRNA , the activity of Caspase 3 was increased ( P<0.01 ) , the expression of Bcl -2 protein and mRNA was decreased in model group ( P<0.01 ) . The expression of Bax , Bcl -2 and p53 mRNA was ( 0.20 ±0.03 ) vs ( 1.00 ±0.09 ) , ( 1.39 ±0.10 ) vs (0.21 ±0.02);(0.28 ±0.05) vs (0.88 ±0.08), in normal group and model group, respectively.Compared with model group,apoptotic index of retina (12.40 ±1.24), the expression of Bax (0.57 ±0.05) and p53 (0.35 ±0.03) protein, the expression of Bax ( 0.56 ±0.05 ) and p53 ( 0.36 ±0.04 ) mRNA, the activity of Caspase 3 (1.72 ±0.17) in test group were all decreased.While the expression of Bcl -2 protein (0.63 ±0.06) and mRNA (0.74 ±0.04 ) were increased in test group ( all P<0.01 ) .Conclusion The calcium dobesilate inhibit neuronal apoptosis by regulation expression of cell apoptotic related protein .

AlM: To measure the retinal electrical activities in patients with diabetic retinopathy ( DR ) by applying multifocal electroretinogram ( mf-ERG) and evaluate the degree of visual damage at different stages of DR
METHODS:Thirty cases ( 30 eyes ) aged 50 ~70 years old, excluding other diseases, were as normal group, and 99 cases ( 99 eyes ) diagnosed with type 2 diabetes were as experiment group. The cases received mf-ERG examination in the standard state, respectively. The results were statistically analyzed
RESULTS: For DR patients with early and background stage, the reaction density of mf - ERG P1 wave decreased as the disease worsened, significantly reduced in non - proliferating stage and decreased more significantly in the background of the stage Ⅲ. This showed that in the macula, electrical activity had weakened before the retina without visual or morphological changes, and with the development of the disease, the electrical activity decreased more obviously.
CONCLUSlON:mf-ERG can evaluate the severity of DR, especially suit in the early and background period of DR.

OBJECTIVETo investigate the protective effect of exogenous inhibitor of matrix metalloproteinases-9 (MMP-9), batimastat, in the lung injury induced by cardiopulmonary bypass (CPB) in dogs.

METHODSThirty healthy mongrel puppies were randomly divided into 3 groups: control group, low-dose group [batimastat 10 mg/(kg.d) for 3 days before operation] and high-dose group [batimastat 30 mg/(kg.d) for 3 days before operation]. The off-pump puppies' model of acute lung injury was established, and hemodynamic and respiratory parameters were monitored. The preoperative and postoperative alveolar-arterial oxygen difference (A-aDO(2)) and respiratory index (RI) were calculated. From the beginning of surgery, blood samples were taken at the time 0, 60, 120, and 270 min. Plasma concentrations of MMP-9 were measured by ELISA, and blood MMP-9 mRNA expressions were determined by RT-PCR. The myeloperoxidase (MPO) activity of centrifugal bronchoalveolar lavage fluid were measured by Colorimetry. And MMP-9 activity was determined by Gelatin zymography. Light and electronic microscope were used to observe the morphological changes of lung tissue. A small piece of left lung tissue was taken, weighed and baked to calculate the wet weight (W/D) index.

RESULTSAfter cardiopulmonary bypass, the concentrations of MMP-9 and mRNA expressions of the control group were increased significantly, and lung injury was apparent. At 270 min, the MMP-9 plasma concentration of high-dose group (17.36 +/- 1.18) microg/L was significant reducing than control group (30.47 +/- 2.22) microg/L (P < 0.05). After operation, A-aDO(2) and RI of high-dose group were significantly improved than control group (P < 0.05). The W/D index of the high-dose group (2.8 +/- 0.48) was significantly lower than that of control group (4.7 +/- 0.6) (P < 0.05). And the pathological changes of lung tissue were significantly improved in the high-dose group. However, there was no significant difference in the MMP-9 mRNA expression in three groups.

CONCLUSIONSBatimastat plays a role in the protection of the lung injury of CBP by reducing the concentration and activity of MMP-9, the degradation of the cell membrane and pulmonary neutrophil infiltration and reduction of pulmonary edema.

Acute Lung Injury ; etiology ; prevention & control ; Animals ; Cardiopulmonary Bypass ; Disease Models, Animal ; Dogs ; Lung ; pathology ; Matrix Metalloproteinase 9 ; metabolism ; Matrix Metalloproteinase Inhibitors ; Phenylalanine ; analogs & derivatives ; pharmacology ; Postoperative Complications ; prevention & control ; Thiophenes ; pharmacology

OBJECTIVETo evaluate the effects of rapamycin (RPM)-loaded poly (lactic-co- glycolic) acid (PLGA) nanoparticles (NPs) on the proliferation, distribution of cell cycle, and expression of p27 protein in human umbilical arterial vascular smooth muscle cell (HUASMC) in vitro.

METHODSThe primarily culture model of HUASMC was successfully established by explant-attached method in vitro. The cells were administrated with different doses of RPM, and RPM-PLGA NPs were observed as treat groups compared with PLGA NPs and M231-SMGs medium cultured group. The effect of RPM-PLGA NPs on proliferation of HUASMC was assessed using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) colorimetry method. The influences of RPM-PLGA NPs on the cell cycle and cellular growth kinetics of HUASMCs were tested by flow cytometry. The effect of RPM-PLGA NPs on the expression of p27 protein of HUASMCs was assessed through an immunohistochemical method.

RESULTSCompared with the control group, the proliferation of HUASMCs was inhibited by 50 microg/L and higher concentration of RPM-PLGA NPs in a dose-dependent manner (P < 0.05). The numbers of cells entering cell cycle of S/G2/M phases were significantly lower in RPM-PLGA NPs and RPM treated groups. Histologically, the expression of p27 were up-regulated in 500 microg/L RPM-PLGA NPs and 100 microg/L RPM treated group (all P < 0.01 ) when compared with the control group.

CONCLUSIONSRPM-PLGA NPs has a similar effects as RPM in inhibiting the growth of in vitro cultured HUASMC. It can remarkably suppress the expression of in vitro cultured HUASMC p27 protein, arrest its cell cycle at G1/S phase, and inhibit its proliferation.

Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Drug Carriers ; Humans ; Lactic Acid ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; metabolism ; Nanoparticles ; Polyglycolic Acid ; Sirolimus ; administration & dosage ; pharmacology ; Umbilical Arteries ; cytology

The growth of three plague phages from Qinghai Plateau in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,PTB5,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were detected through a micromethod based on the OmniLogTM microbial identification system and by the drop method,to provide a scientific basis for future ecological studies and classification based on the host range.For plague vaccine strains EV76 and 614F,successful phage infection and subsequent phage growth were observed in the host bacte-rium.Diminished bacterial growth and respiration and a concomitant decrease in color were observed with the OmniLogTM mi-crobial identification system at 33 ℃ for 48 h.Yersinia pseudotuberculosis PTB5 was sensitive to Yersinia pestis phage 476,but Yersinia pseudotuberculosis PST5 was insensitive to phage 087 and 072204.Three strains of non-Yersinia pestis(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were insensitive to Yersinia pestis pha-ges 087,072204,and 476 showed similar growth curves.The growth of phages 476 and 087,as determined with the drop method,in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersin-ia enterocolitica 52302-2)showed the same results at 37 ℃,on the basis of comparisons with the OmniLogTM microbial i-dentification system;in contrast,phages 072204 did not show plaques on solid medium at 37 ℃ with plague vaccine strains EV76 and 614F.Determination based on the OmniLogTM detection system can be used as an alternative to the traditional determination of the host range,thus providing favorable application val-ue for determining the interaction between the phage and host bacteria.

Chorioretinal disease has become a significant problem affecting human vision. Abnormal expression of vascular endothelial growth factor(VEGF)leads to increased fundus permeability and neovascularization. Vitreous injection of anti-VEGF agents can rapidly inhibit the level of VEGF in the eye and effectively control the development of the disease. At present, anti-VEGF agents are widely administered in ophthalmology. However, studies have shown that intravitreal anti-VEGF agents can reduce plasma VEGF concentration after entering the circulatory system, and the pointless off-target effects of drugs may lead to systemic adverse reactions. For elderly patients, patients with serious comorbidities, lactating women, premature infants and other special populations, attention should be paid to systemic VEGF inhibition after multiple injections. In this paper, in order to provide reference for clinical anti-VEGF therapy, the pharmacokinetics therapy, systemic adverse reactions, contralateral eye effects, and effects of anti-VEGF on breast milk and preterm infants were discussed, and the systemic effects of vitreous injection of anti-VEGF agents were reviewed.

Objective To investigate the Gram-positive coccus resistance in nationwide's tertiary hospitals and understand the trend of antimicrobial resistance.Methods All the clinical isolates were collected from 19 hospitals and the minimal inhibitory concentrations(MICs)were tested using agar/broth dilution method recommended.Results A total of 1 974 pathogenic Gram-positive coccus from 19 tertiary hospitals in 19 cities nationwide over the period from July 2021 to June 2022 were studied.Based on the MIC results,the prevalence of methicillin resistant Stapylococcus aureus(MRSA)and methicillin resistant Stapylococcus epidermidis(MRSE)were 36.4％and 79.9％respectively.No vancomycin insensitivity Staphylococcus was detected.Staphylococcus aureus were 100％susceptibility to linezolid and teicoplanin.Antibiotic resistance rate of Enterococcus faecalis and Enterococcus faecium to ampicillin were 3.1％and 92.9％.The detectation rate of vancomycin resistant Enterococcus(VRE)was 1.6％.Nonsusceptibility rate of Enterococcus faecalis to linezolid was 32.2％,two consecutive monitoring rises and nonsusceptibility rate of Enterococcus faecium(12.5％)was also significantly increased.The prevalence of penicillin non-susceptible Streptococcus pneumoniae(PNSSP)was 0.8％based on non-meningitis and parenteral administration criterion,decrease of nearly 30 percentage points from the previous surveillance.While for cases of oral penicillin,the rate was 71.8％,showing similar to last time.The results indicated that the number of strains with higher MIC value of penicillin(MIC ≥4 mg·L-1)decreased significantly.There were no significant differences of resistance rates of Stapylococcus aureus,Stapylococcus epidermidis,Enterococcus faecalis,Enterococcus faecium and Streptococcus pneumoniae among various groups such as different department,age,or specimen source.Conclusion VRE detection ratio stablized at a relatively low level.The number of Streptococcus pneumoniae with higher MIC value of penicillin decreased significantly compared with the previous monitoring.The increase of linezolidin-insensitive Enterococcus was noteworthy.

Objective To investigate the Gram-negative bacteria resistance in nationwide's tertiary hospitals and understand the trend of antimicrobial resistance.Method All the clinical isolates were collected from 19 hospitals and the minimal inhibitory concentrations(MICs)were tested using agar/broth dilution method recommended.Results A total of 4 066 pathogenic isolates from 19 tertiary hospitals in 19 cities nationwide over the period from July 2021 to June 2022 were studied.Based on the MIC results,Escherichia coli and Klebsiella pneumoniae showed extended spectrum β-lactamase(ESBLs)phenotype rates of 55.0％and 21.0％,respectively,ESBLs phenotype rate of Klebsiella pneumoniae keep going down.The ratios of carbapenems resistance Klebsiella pneumoniae increased by 5 percentage points compared with the previous monitoring.Carbapenems,moxalactam,sitafloxacin,β-lactam combination agents,fosfomycin trometamol,and amikacin displayed desirable antibacterial activity against Enterbacterales,susceptibal rates were above 75％.In addition,tigacycline,omacycline,colistin and fluoxefin maintained good antibacterial activity against their respective effective bacteria/species,and the bacterial sensitivity rates by more than 80％.Resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannnii to imipenem were 26.3％and 72.1％and multidrug-resistant(MDR)detection rates were 41.1％and 77.3％,extensively drug-resistant(XDR)were 12.0％and 71.8％,respectively.Comparison of drug resistance rates from different wards,ages and specimen sources indicated that the proportion of resistance in Klebsiella pneumoniae and Acinetobacter baumannii isolated from intensive care unit(ICU)were significantly higher than non-ICU.Carbapenem resistance rates of Klebsiella pneumoniae isolated from ICU were more than 35％.Resistance rates of Haemophilus influenzae isolated in children to β-lactam,macrolide,clindamycin and ESBLs detection rate in Klebsiella pneumoniae isolated from children were more than those from adults and the old people,so bacterial resistance in children is an important problem in China.Conclusion ESBLs detection rate of Escherichia coli increased slightly after years of continuous decline.The proportion of carbapenem resistant Pseudomonas aeruginosa was stable,but the resistance rate of Klebsiella pneumoniae and Acinetobacter baumannii to carbapenems was still increased,which should be paid more attention.

OBJECTIVETo investgate the effects of rapamycin(RPM)and RPM-loaded poly(lactic-co-glycolic)acid(PLGA)nanoparticles(NPs)on the apoptosis of human umbilical arterial vascular smooth muscle cells(HUASMCs)in vitro and expression of bcl-2 and p27(kip1) protein.

METHODSHUASMCs were cultured in vitro and divided to RPM and RPM-PLGA-NPs groups treated at 3 different concentration by 12 and 24 hours,with M231-smooth muscle growth supplements medium and null-PLGA-NPs treated groups as controlled. The apoptosis of HUASMCs was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling staining and flow cytometry. The expressions of bcl-2 and p27(kip1) were detected by streptacidin/peroxidase immunohistochemical method. The effect on cellular proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidecolorimetry.

RESULTSThe proliferation of HUASMCs was inhibited by RPM and RPM-PLGA-NPs in a dose-dependent manner. DNA electrophoresis showed DNA ladder in RPM and RPM-PLGA-NPs groups and classical scalar strips in control groups. The apoptotic indexes of RPM 100 ng/ml group and RPM-PLGA-NPs 500 ng/ml group detected by flow cytometry were(45.45<2.36)% and(35.04<5.64)%,respectively,which were significantly higher than that of M231-smooth muscle growth supplements control group [(2.60<0.95)%,all P<0.01]. The apoptotic indexes of groups incubated with RPM and RPM-PLGA-NPs for 24 hours were significantly higher than those of groups which incubated for 12 hours(P<0.05,P<0.01). The positive expression indexes(PEI)of p27(kip1) and bcl-2 protein were higher in RPM and RPM-PLGA-NPs groups than that of control groups. The Spearman's rank correlation coefficient test showed that there was no significant correlation between the PEI of p27(kip1) and the apoptotic indexes in the RPM group and RPM-PLGA-NPs group(P>0.05).

CONCLUSIONSRapamycin-loaded PLGA nanoparticles and rapamycin have similar effects in inhibiting proliferation and inducing apoptosis;meanwhile,they upregulate the expression of p27(kip1) protein without downregulating the expression of bcl-2 protein in HUASMCs in vitro. RPM-PLGA-NPs has more potent pro-apoptotic effect than equivalent dose of RPM but is not linearly correlated with the p27(kip1) expression level.

Apoptosis ; Cell Proliferation ; Cells, Cultured ; Cyclin-Dependent Kinase Inhibitor p27 ; Humans ; In Situ Nick-End Labeling ; Lactic Acid ; Muscle, Smooth, Vascular ; Myocytes, Smooth Muscle ; Nanoparticles ; Polyglycolic Acid ; Sirolimus ; Umbilical Arteries