Background Dacryocystitis is one of the most common infectious eye diseases.The gold standard for the identification of bacteria causing dacryocystitis is bacterial culture.The combination of regular culture method with molecular biology techeniques will generate more reliable results.However,very few research data are available in ophthalmological studies in this area.Objective This study was to identify the genera and species of the dacryocystitis-causing bacteria by PCR amplification of the 16S rRNA sequences.Methods Ten cases of qualified standardized bacteria samples were taken,and the nucleic acids were released in the heating process of the PCR procedure.The 16S rRNA genes were amplified and sequenced,and the genera and species were identified using BLAST from GenBank,and the results were used to compare with the results from biochemical identification to test the reliability of this method.The cultured bacterial species from the lacrimal sac secretions from 30 cases of dacryocystitis patients were identified with the above method.Results The outcome of the PCR identification for the 10 cases of quality control standard bacterial specimens was consistent with the results from the biochemical identification.The identification of the 30 cases of dacryocystitis through sequencing the 16S rRNA revealed there were 13 cases of Staphylococcus epidermidis infection,2 cases of Staphylococcus warneri infection,1 case of Staphylococcus hominis infection,5 cases of Corynebacterium macginleyi infection,3 cases of Streptococcus pneumonia infection,2 cases of Bacillus cereus infection,1 case of Micrococcus luteus infection,1 case of Moraxella catarrhalis infection,1 case of Moraxella osloensis infection and 1 case of Pseudomonas aeruginosa infection.Conclusions Sequencing the 16S rRNA is an accurate and specific way for the identification of the genera and species of bacteria that cause dacryocystitis in patients.This sequencing method is feasible in monitoring a variety of dacryocystitis-causing pathogens.More information and epidemiological statistics about dacryocystitis can be obtained from 16S rRNA sequencing.

【Objective】 To establish a new method for the determination of fibrinogen content in cryoprecipitated antihemophilic factor. 【Methods】 Fibrinogen (Fib) could bind with sheep anti-human fibrinogen (anti-Fib) specifically and further form antigen-antibody complex. When the Fib was present in the solution, the fluorescence of fluorescein isothiocyanate (FITC) labeled on the anti-Fib (FITC-anti-Fib) was quenched due to the formation of immune complex. The fluorescence quenching degree of FITC-anti-Fib was positively correlated with Fib concentration (cFib) in a certain concentration range. 【Results】 The linear relationship between fluorescence quenching degree [(I0-I)/I0] of FITC-anti-Fib and ln(cFib) was (I0-I)/I0=15.53ln(cFib)+ 80.79 (R²=0.99) when the cFib was in the range of (0.007 8-0.560 0) g/L. The recovery of Fib was (96.77-102.43) %. When the method was applied to determine Fib at high, medium, and low concentrations, the obtained intra-day variation coefficients were 0.31%, 0.56%, and 0.49%, respectively, and the inter-day variation coefficients were 3.81%, 3.06%, and 4.13%, respectively. There was no significant difference between the results measured by fluorescence quenching method and coagulation method (t=-0.075, P>0.05). 【Conclusion】 In this work, a new fluorescence method for the determination of Fib in cryoprecipitated antihemophilic factor was successfully established based on the specific combination of fib and FITC-anti-Fib. The method is simple and rapid. The obtained results were accurate and reliable by using this method to determine Fib.

【Objective】 To determine the volume range of suspended erythrocyte and establish its internal control standard. 【Methods】 The theoretical value of suspended erythrocyte volume was calculated according to the screening criteria of healthy blood donors and Quality Requirements for Whole Blood and Blood Components. A total of 2 410 bags of 1 U and 2 U suspended erythrocyte were randomly selected and weighed, and the volume range were formulated by ±2S and ±10% respectively and then compared to determine the volume range in line with the actual situation of our center. 【Results】 The theoretical volume range of 1 U and 2 U suspended erythrocyte were 117-160 mL vs 234-320 mL, and the actual volume range were 142-180 mL vs 276-393 mL. The volume range of 1 U and 2 U suspended erythrocyte formulated by ±2S were 145-181 mL vs 298-358 mL, and by ±10% were 147-179 mL vs 295-361 mL. The hematocrit and hemoglobin content of suspended erythrocyte within the actual volume range met the quality requirements. There were fluctuations in the volume of suspended erythrocyte from different regions. 【Conclusion】 Based on the actual situation of our center and the sampling results of suspended erythrocytes in recent two years, 163 mL±10% and 328 mL±10% were determined as the internal control standards of 1 U and 2 U suspended erythrocyte, respectively. Blood centers should establish accurate and feasible standard of suspended erythrocyte according to the actual situation.

Adult ; Asthenopia ; epidemiology ; prevention & control ; Automobile Driving ; Color Perception ; Humans ; Middle Aged

Objective:The recombinant human retinal pigment epithelium-derived factor(PEDF)protein to be obtained and the angiogenesis of the rPEDF to be identified.Methods: PEDF gene gene was amplified by PCR and cloned into pET32a,rPEDF protein was expressed in E.coli BL21 and confirmed by SDS-PAGE and Western blot.The rPEDF was purified by Ni-NTA on denature condition.The concentration of the rPEDF was determined by Bradford method.The angiogenesis of the rPEDF was determined by chick chorioallantoic membrane(CAM) method.Results: The expression plasmid pET32a-PEDF was constructed successfully.The rPEDF was expressed with stable efficiency in E.coli BL21.The results of the CAM experiment showed that the rPEDF had notable angiogenesis effect in the concentration 0.4、0.04 ng/ml,but had no effect in 4 ng/ml.Conclusion:The PEDF gene was cloned and expressed efficiently,the angiogenesis of the rPEDF to be identified and the activity was worked in certain range.The results can facilitate studying its function and spreading its application.

Background Allograft rejection is a main cause of failure of penetrating keratoplasty,especially in the patient with high risk of rejection condition.Previous study on allograft rejection mechanism focused on limbal and corneal neovascularization,but these factors did not explain all the phenomena of allograft rejection.Research found that immune cells appeared in iris and ciliary body when rejection occurred,but the relationship between these immune cells and allograft rejection is unclear Objective This study was to evaluate the relationship between diversity of vascular permeability in the iris and ciliary body and allograft rejection after penetrating keratoplasty.Methods Seventy clean eight-week-old BALB/c mice were divided into allogeneic corneal transplantation group (60 mice) and blank control group (10 mice).Allogeneic corneal transplantation was performed with the same age of C57BL/6 mice as donor and BALB/c mice as the recipients.The grafts were examined under the slit lamp microscope and scored based on the criteria of Hegde.The mice were sacrificed and iris and ciliary tissue were obtained 5,10 days and rejection after surgery.Immunohistochemistry and reverse transcription PCR (RT-PCR) was used respectively to detect the expression diversities of occludin,zonula occludens protein-1 (ZO-1),matrix metalloproteinase-9(MMP-9),major histocompatibility complex-Ⅱ (MHC-Ⅱ),and CCR5,CCR7 and their mRNA in iris and ciliary body.Image-J image analysis software was used to calculate the quantity of positive cells on iris wholemount,and absorbance of target genes (A values).The use and care of the experimental animals complied the ARVO Resolution on the Use of Animals in Research.Results The mean survival time of corneal gratts was (17±3) days after operation.The mean score was 0.6 in 5 days and 0.5 in 10 days,and 3.3 in 18 days after operation.Expression of ZO-1 reduced significantly,and that of MMP-9 increased obviously at the time of rejection.MHC Ⅱ + cells were scattered in iris and ciliary body in normal mice,and the number of the positive cells (cells/field) was increased after operation with a peak value when rejection occurred.A significant difference was seen between normal mice and rejection mice (1559.67±350.29 vs.4021.83±495.18) (P=0.000).The expressions of occludin mRNA and ZO-1 mRNA in the iris and ciliary body decreased obviously in the rejection mice.Compared with normal mice,theA value of ZO-1 and occluding were 36.74±3.13 vs.110.11±11.88 and 57.54±3.41 vs.59.90±3.50respectively,with significant differences between them (all P＜0.05).The expressions of MMP-9 mRNA,CCR5 mRNA and CCR7 mRNA in the iris and ciliary body increased gradually with the time lapse after operation and peaked when the rejection appeared.The A value of MMP-9 mRNA,CCR5 mRNA and CCR7 mRNA were significantly higher than those of normal mice (20.29±1.19 vs.2.77±0.85 for MMP-9 mRNA; 35.43±2.56 vs.9.11±0.29 for CCR5 mRNA,and 60.83±0.87 vs.0.89 ±0.95 for CCR7 mRNA) respectively (all P＜0.05).Conclusions The permeability of vascules in the iris and ciliary body increase during the allograft rejection after penetrating keratoplasty.Increased antigen presenting cells were also detected.

【Objective】 To establish a simple, economical and rapid method for the determination of methylene blue (MB) release in virus inactivation bag. 【Methods】 Based on the fluorescence energy transfer between MB and BSA-stabilized gold nanoclusters (BSA-AuNCs), the standard curve of MB determination was established by measuring the fluorescence quenching degree of MB to BSA-AuNCs in different concentrations to conduct the determination of MB release in virus inactivation bag. 【Results】 There was a good linear relationship between the MB concentration (cMB) and the fluorescence quenching degree of BSA-AuNCs[ (I0-I)/I0=0.018cMB+ 0.021(r=0.996)] when the fluorescence emission wavelength was about 620 nm and the cMB was in the range of (0.9-36) μmoL/L. The recovery of MB was 98.00% -101.95 % when applied to determine MB at high, medium, and low concentrations, the obtained intra-day variation coefficients were 0.73%, 0.81% and 0.77% respectively, and the obtained inter-day variation coefficients were 3.92%, 3.81%, and 4.73% respectively. There was no significant difference between the results measured by this method and those measured by combination of solid-phase extraction and spectrophotometry(P>0.05). 【Conclusion】 The fluorescence energy transfer method could achieve simple and rapid determination of MB release in virus inactivation bag with accurate and reliable results.

Objective To investigate he intervention effect of knockdown of activating transcription factor 4(ATF-4)on fructose-induced lipid accumulation in liver cells. Methods HepG2 cells were divided into the control group(C),high fructose group(F),high-fructose+negative control group(F+NC)and high-fructose+ATF-4 siRNA group(F+ATF-4-). The mRNA level of gens of the upstream transcriptional factors and ERS markers was detected. The protein level of ACC,FAS and SCD-1 was also detected. Results Compared with group C,the mRNA expression of SREBP-1c,ChREBP,GRP78 and CHOP was increased(P < 0.01),while ATF-4 knock-down decreased the expression of the above genes(P < 0.01 ,respectively). Compared with group C ,the protein expression of ACC,FAS and SCD-1 was increased in group F(P<0.01,respectively). While ATF-4 knockdown decreased the protein expression of ACC ,FAS and SCD-1. Conclusions ATF-4 knockdown can improve the lipid steatosis induced by fructose through down-regulating lipid lipogenesis ,indicating ATF-4 possesses a regulatory effect on lipogenesis.

【Objective】 To detect the anti-SARS-CoV-2 neutralizing antibody levels in convalescent plasma (CP) and to evaluate whether it has specific anti-SARS-CoV-2 S antigen effect, so as to provide laboratory data support for clinical use of CP. 【Methods】 Nine CP donors who have recovered from COVID-19 were studied, and 4 volunteers who completed the vaccination and 3 asymptomatic infected blood donors were compared. Anti-SARS-CoV-2 antibodies including total antibody, IgM and IgG were measured by chemiluminescence microparticle immunoassays (CMIA) test in three groups. The VSV pseudovirus-based neutralization assay for evaluating neutralizing antibodies against SARS-CoV-2 was carried out in all samples. 【Results】 All samples were tested positive by the total antibody and IgG CMIA in COVID-19 CP donors and recipients of inactivated COVID-19 vaccine. High titers of IgG were observed in CP donors and vaccine recipients compared with asymptomatic blood donors. All vaccine recipients and 8 of 9 CP donors tested positive by SARS-CoV-2 pseudovirus-based neutralization test, whereas all asymptomatic blood donors tested negative. 【Conclusion】 The levels and characteristics of neutralizing antibodies among COVID-19 CP donors, vaccine recipients and asymptomatic blood donors were different. When unable to implement the pseudovirus assay to measure neutralizing antibodies, the detection of total antibody can be considered instead.

A novel type of carbon nanotube-coated Au nanoparticle and [bmim]BF4 composite modified glassy carbon electrode was fabricated by a layer-by-layer self-assembly technique. The electrochemical performance of acetaminophen (ACOP) on the modified electrode was investigated by cyclic voltammetry. The Nafion/GNPs/RTIL/MWNTs/GC electrode showed an excellent electrocatalytic activity for the oxidation of ACOP and accelerated electron transfer between the electrode and ACOP. For ACOP, the reversible electrochemical process was observed on the Nafion/GNPs/RTIL/MWNTs/GC electrode, while irreversible electrochemical process occurred on the GC electrode. For the Nafion/GNPs/RTIL/MWNTs/GC electrode, the anodic peak potential of ACOP was moved from 0.562 V to 0.413 V, with a potential drop of 149 mV. At the same time, the reduction peak potential was 0.384 V, and the potential difference was only 29 mV. It was shown that the modified electrode possessed higher electrocatalytic activity and more sensitive effect for the detection of ACOP than both MWNTs/GC electrode and GC electrode. The effects of the different experimental conditions on the electrochemical behaviors of ACOP were explored. Under the optimum conditions of preparation and experimental, the linear calibration curves of ACOP were obtained in a wide range of 2 x 10(-1) to 4.0 x 10(-4) mol x L(-1) with a correlation coefficient 0.999 2 and a detection limit of 2.6 x 10(-8) mol x L(-1) (the ratio of signal to noise, 3:1). The recovery rate was 97.9%-100.8%. This method can be used to determine ACOP in paracetamol tablets with satisfactory results.
Acetaminophen ; analysis ; Analgesics, Non-Narcotic ; analysis ; Antipyretics ; analysis ; Electrochemical Techniques ; methods ; Electrochemistry ; methods ; Electrodes ; Electron Transport ; Gold ; chemistry ; Nanotubes, Carbon ; chemistry ; Oxidation-Reduction ; Reproducibility of Results