Evolution of ferromagnetic cluster in perovskite La0.88Sr0.12MnO3 nanocrystalline detected by EPR spectrum.

Electron paramagnetic resonance (EPR) studies were performed on La0.88Sr0.12MnO3 (LSMO) nanocrystalline together with the measurement of its magnetization. Various spectrum parameters including line width, effective g-value and double-integrated intensities have been analyzed in detail. We found nonlinear behavior occurred in the inverse susceptibility far above the Curie temperature TC, indicating short-range ferromagnetic (FM) clusters and Griffiths-like phase behavior in the paramagnetic (PM) phase. Based on the variation of EPR spectra, except for a typical PM resonance peak, an extra resonance signal was observed in the lower field region and developed as temperature decreased from 320 K to 110 K, which gave a direct evidence of the existence of FM cluster in the PM region of LSMO nanocrystalline. We proposed that the appearance of the Griffiths phase was due to the short FM correlation in the PM regime enhanced by surface spin ordering.

Enzymatic Preparation and Processing Properties of DPP-IV Inhibitory Peptides Derived from Wheat Gluten: Effects of Pretreatment Methods and Protease Types.

The choice of appropriate proteases and pretreatment methods significantly influences the preparation of bioactive peptides. This study aimed to investigate the effects of different pretreatment methods on the hydrolytic performance of diverse proteases during the production of dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides derived from wheat and their foaming and emulsion properties. Dry heating, aqueous heating, and ultrasound treatment were employed as pretreatments for the protein prior to the enzymatic hydrolysis of wheat gluten. FTIR analysis results indicated that all pretreatment methods altered the secondary structure of the protein; however, the effects of dry heating treatment on the secondary structure content were opposite to those of aqueous heating and ultrasound treatment. Nevertheless, all three methods enhanced the protein solubility and surface hydrophobicity. By using pretreated proteins as substrates, five different types of proteases were employed for DPP-IV inhibitory peptide production. The analysis of the DPP-IV inhibitory activity, degree of hydrolysis, and TCA-soluble peptide content revealed that the specific pretreatments had a promoting or inhibiting effect on DPP-IV inhibitory peptide production depending on the protease used. Furthermore, the pretreatment method and the selected type of protease collectively influenced the foaming and emulsifying properties of the prepared peptides.

A paper-based sensor for rapid and ultrasensitive detection of ibuprofen in water and herbal tea.

As the use of non-steroidal anti-inflammatory drugs (NSAIDS) increases, their side effects have also attracted attention. Ibuprofen is one of the most widely-used NSAIDs. In this study, we screened the highly-sensitive and specific antibody 6E10, with an IC50 of 1.92 ng mL-1, and a linear range of 0.53-6.97 ng mL-1. In this study, we developed a rapid lateral flow immunochromatographic assay (ICA) strip method to detect ibuprofen in water or herbal tea. The cut-off limit of the strip is 10 ng mL-1 in water, and concentrations as low as 1 ng mL-1 can be detected in herbal tea samples, with the results obtained by the naked eye within 6 min. All the data were confirmed by high performance liquid chromatography-quadrupole time of flight-mass spectrometry (HPLC-QTOF-MS). This lateral-flow ICA strip is thus a rapid tool for on-site detection and screening of ibuprofen in water and herbal tea.

Development of a lateral-flow ICA strip for the detection of colchicine.

Colchicine (COL), which is extracted from colchicine and papaya, is widely used in medicine. However, COL poisoning causes serious adverse complications including death. Therefore, there is a need to develop a sensitive COL detection method. In this study, we developed a highly sensitive monoclonal antibody 1E4 with a half-maximal inhibitory concentration and linear range of 0.43 ng mL-1 and 0.09-2.16 ng mL-1, respectively. Using 1E4, we developed a lateral-flow immunochromatographic assay (ICA) strip for COL detection. Based on the results, the detection interval was 1-25 ng mL-1 in milk, 2.5-50 ng mL-1 in beef, 1-25 ng mL-1 in edible lily and 2.5-25 ng mL-1 in daylily. The lateral-flow ICA strip can be used as an effective tool for COL detection in food samples on site.

lncRNA MALAT1 promotes cell proliferation and invasion by regulating the miR-101/EZH2 axis in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral cavity. Emerging evidence indicates that long non-coding (lnc)RNAs play a key role in the cellular processes of tumor cells, including glycolysis, growth and movement. Here, the purpose of this study was to explore the biological functions and potential mechanism of lncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in OSCC. OSCC tissues and adjacent matched paraneoplastic normal tissues were collected from 20 OSCC patients. The expression of MALAT1 and miR-101 in OSCC tissues and cell lines (HSC3, SCC9, SCC15 and SCC25) were determined by real-time-polymerase chain reaction (qPCR). Caspase-3, xaspase-8 and EZH2 protein levels were determined by western blot analysis. MALAT1-mediated miRNAs were verified by bioinformatics analysis of StarBase and Luciferase reporter assay. Cell Counting Kit-8 (CCK-8) and Transwell assays were used for investigating MALAT1 effect on cell proliferation and invasion in the OSCC cells. qPCR analysis indicated that MALAT1 expression was obviously increased, and miR-101 was decreased in the OSCC tissues and cell lines. Functional studies revealed that overexpression of MALAT1 promoted OSCC cell proliferation and invasion. Further experiments revealed that miR-101 was a target of MALAT1 and that the miR-101 inhibitor abolished the effect of MALAT1 on OSCC cell proliferation and invasion. Enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) acted as a downstream effecter of MALAT1 in the OSCC cells. Collectively, these findings revealed that upregulation of MALAT1 facilitated OSCC proliferation and invasion by targeting the miR-101/EZH2 axis.

Transformation of roxarsone in the anoxic-oxic process when treating the livestock wastewater.

In order to evaluate the influence of roxarsone (ROX) on the livestock wastewater treatment, a lab-scale pilot employing an anoxic-oxic (A-O) process was investigated by adding different concentrations of ROX at different periods. The mass balance of arsenic (As) in the A-O system was established through the analysis of As speciation and As migration in the gas, liquid and solid phases. The results showed that around 80% of total ROX (initial concentration was 50mgROXL-1) was eliminated in the anoxic reactor (R1) in which at least about 11% of total ROX was transformed to inorganic Asv (iAsv) due to the direct breaking of the C-As bond of ROX. Inorganic AsIII (iAsIII) and arsine (AsH3) were produced in R1, while the generated iAsIII in the effluent of R1 was almost completely oxidized to iAsV in the aerobic reactor (R2). However, the concentration of ROX in the effluent of R2 was almost the same as that in the effluent of R1. After 85days operation, iAsV and residual ROX as the main forms of As were observed after the A-O process. Furthermore, the mass balance of As at steady state revealed that around 0.08%, 3.91% and 96.01% of total As was transformed into gas (biogas), solid (excess sludge) and liquid (effluent). Additionally, the 16S rRNA analysis demonstrated that the existence of ROX in livestock wastewater may play a crucial role in the diversity of bacterial community in the A-O system.

Biochemical properties and application of a novel ß-1,3-1,4-glucanase from Paenibacillus barengoltzii.

A novel endo-ß-1,3-1,4-glucanase gene (PbBglu16A) was cloned from Paenibacillus barengoltzii and heterogeneously expressed in Escherichia coli. The recombinant ß-1,3-1,4-glucanase (PbBglu16A) was purified to homogeneity with a recovery yield of 78.6% and a specific activity of 431.8Umg-1. The molecular mass of PbBglu16A was estimated to be 44.0kDa by SDS-PAGE. The optimal pH and temperature of PbBglu16A were 6.0 and 55°C, respectively. The enzyme was stable within pH 3.5-9.0 and up to 55°C. PbBglu16A exhibited high substrate specificity towards barley ß-glucan, oat ß-glucan and lichenin. PbBglu16A showed an endo-type cleavage pattern and hydrolyzed endogenous enzyme-deactivated oat bran into ß-gluco-oligosaccharides with a yield of 7.0%, which mainly consisted of trioligosaccharide and tetraoligosaccharide. Further, PbBglu16A could promote mashing with a reduced filtration time (14.0%) and viscosity (3.4%). Thus, PbBglu16A might be a promising candidate for the production of ß-gluco-oligosaccharides and in brewing industry.

Epitaxial patterning of nanometer-thick Y3Fe5O12 films with low magnetic damping.

Magnetic insulators such as yttrium iron garnet, Y3Fe5O12, with extremely low magnetic damping have opened the door for low power spin-orbitronics due to their low energy dissipation and efficient spin current generation and transmission. We demonstrate here reliable and efficient epitaxial growth and nanopatterning of Y3Fe5O12 thin-film based nanostructures on insulating Gd3Ga5O12 substrates. In particular, our fabrication process is compatible with conventional sputtering and lift-off, and does not require aggressive ion milling which may be detrimental to the oxide thin films. Their structural and magnetic properties indicate good qualities, in particular low magnetic damping of both films and patterned structures. The dynamic magnetic properties of the nanostructures are systematically investigated as a function of the lateral dimension. By comparing with ferromagnetic nanowire structures, a distinct edge mode in addition to the main mode is identified by both experiments and simulations, which also exhibit cross-over with the main mode upon varying the width of the wires. The non-linear evolution of dynamic modes over nanostructural dimensions highlights the important role of size confinement to their material properties in magnetic devices where Y3Fe5O12 nanostructures serve as the key functional component.

Large and fast single-crystal resistive humidity sensitivity of metal pnictide halides containing van der Waals host-guest interactions.

Two new metal pnictide halides, (Hg(9.75)As(5.5))(GaCl4)3 and (Hg13Sb8)(ZnBr4)4, have been prepared by solid-state reactions. Their structures feature 3D cationic host frameworks built of mercury pnictide polyhedra and form 1D tunnels filled with discrete guest halide polyanions; the guests and hosts are assembled by van der Waals interactions. Both complexes exhibit good single-crystal humidity sensitivity, with a humidity sensitivity factor as big as three orders of magnitude, a quick resistance response, fast recovery, and good reproducibility. This study provide a new way to design promising resistive humidity detectors by introducing van der Waals host-guest interactions into their structures.

[Determination of bitter components in citrus juice by high performance liquid chromatography].

Bitterness in citrus juice is primarily due to the presence of both limonin and naringin, and determination of them is a standard in controlling the quality of juice. A high performance liquid chromatographic (HPLC) method was developed for the rapid determination of bitter components in citrus juice. The HPLC conditions were as follows: ODS column with acetonitrile-tetrahydrofuran-water (17.5: 17.5: 65, v/v) as mobile phase, flow rate at 1 mL/min, 207 nm as detection wavelength for limonin, and methanol-100% acetic acid-water (40:1:59, v/v) as mobile phase, flow rate at 1 mL/min, 283 nm as detection wavelength for naringin. As results showed, for limonin and naringin, the linearity was good within the ranges of 1.00 - 50.00 mg/L (r = 0.9992) and 20.00 - 160.00 mg/L (r = 0.9988) respectively, and the detection limits were 0.07 microg and 0.14 microg, then the average recoveries were 98.69% and 100.13% with relative standard deviations of 2.5% and 1.5%, respectively. The method is simple, rapid and accurate for determining limonin and naringin in juice.

Experimental studies of melanin associated antigen and its relationship with sympathetic ophthalmia and Vogt-Kayanagi-Harada syndrome.

PURPOSE: To discuss the relationship of Bovine Melanin-Associated Antigen (BMAA) to Sympathetic Ophthalmia (SO) and Vogt-Kayanagi-Harada (VKH) syndrome. METHODS: BMAA was isolated and purified from bovine iris and ciliary body and MTT method was used to measure the peripheral lymphocyte reactions of SO and VKH syndrome patients to BMAA. 15 cases of SO were included in the SO group with 11 males and 4 females. The average age was 37.5, ranging from 23 to 56 years; 15 patients with VKH syndrome were included in the VHK group with 7 males and 8 females. Their average age was 37.2 years, ranging from 24 to 69 years; 20 normal individuals without ocular and systemic autoimmune diseases were included in the control group. These included 9 males and 11 females, aging from 14 to 28 with an average of 23.8 years. RESULTS: The OD values of each group were as follows: SO controls 0.327 +/- 0.032; SO + BMAA 0.490 +/- 0.758; SO + PHA 0.5310 +/- 0.918; VKH controls 0.328 +/- 0.503; VKH + BMAA 0.430 +/- 0.530; VKH + PHA 0.328 +/- 0.484; Normal controls 0.304 +/- 0.267; Normal + BMAA 0.343 +/- 0.326; Normal + PHA 0.477 +/- 0.598. The average OD values of peripheral lymphocytes to BMAA stimulation in SO patients and normal controls were 0.490 and 0.343 respectively. The difference was statistically significant, P < 0.001; The average OD values of peripheral lymphocytes to BMAA stimulation in SO and VKH syndrome patients were 0.470 and 0.430 respectively. The difference was not statistically significant, P > 0.05. CONCLUSIONS: BMAA effectively stimulate the proliferative reaction of peripheral lymphocytes in SO patients and BMAA may act as an antigen and contribute in the pathological process of SO. No difference in proliferative reaction of peripheral lymphocytes was found between SO and VKH syndrome patients after BMAA stimulations and BMAA may be involved in the development of both SO and VKH syndrome.

[Changes of lens capsule after phacoemulsification].

OBJECTIVE: To observe the changes in the lens capsule after phacoemulsification and its effects on the position of intraocular lens (IOL) and to demonstrate the best position of IOL in relation to the anterior capsule. METHODS: The present series comprised 141 eyes in 127 patients underwent phacoemulsification and foldable lens implantation with 5 mm continuous curvilinear capsulorhexis. The changes in the lens capsule and the position of IOL with dilated pupil were observed using slit lamp microscope 3 months after the operation. RESULTS: Capsular bag shrinkage and white Soemmering ring along the margin of capsulorhexis were observed in all cases. Three different kinds of relationship between anterior capsule opening and the IOL optic surface were found, including the non-capture (68 eyes), partial-capture (52 eyes) and total-capture (21 eyes) relationships. The incidence of central posterior capsule opacification (PCO) was significantly higher in the total-capture group (47.6%) than that in the non-capture (11.7%) and partial-capture (21.2%) groups (P < 0.01). IOL in well centered position was significantly higher in the non-capture (91.2%) and total-capture (81.0%) groups than that in the partial-capture group (42.3%) (P < 0.01). CONCLUSION: In the present study, various changes in the lens capsule were observed after phacoemulsification and foldable lens implantation. It is suggested that keeping the IOL in a non-capture position is a key point to avoid the occurrence of PCO and IOL decentration.

[Effects of exogenous p21 gene on cells cycle of human lens epithelial cells].

OBJECTIVE: To investigate the effects of transfected exogenous p21 gene on the cells cycle of HLE-B3 cells line. The feasibility of prevention of secondary cataract by gene therapy was evaluated. METHODS: Total length of human p21 gene cDNA was cloned on the parent's plasmid pcDNA3 to construct the recombinant plasmids of pcDNA3/p21, a large amount of pcDNA3/p21 plasmid DNA was prepared by QIAGEN endofree maxi kit. After harvest of the plasmid DNA, the HLE-B3 cells line was transfected. The cell growth was observed and the cells cycle was analyzed by flow cytometry. The expression of p21 mRNA was detected by RT-PCR and the expression of p21 protein was detected by immunohistochemistry and western blot analysis. RESULTS: Forty eight hours after transfection, the growth of transfected cells became slower, some cells floated and died; the control cells and blank plasmid (blank pcDNA3) transfected cells grew normally. Flow cytometry analysis revealed that the number of cells in G(1) phase increased markedly in transfected cells. The RT-PCR showed that the product of p21 in the transfected cells (dead or alive cells) was obviously higher than that of the controls. Immunohistochemical studies showed few positive cells in the controls, and very high positive signal was detected after transfection. Western blot showed a positive band at the level of 21 000 in transfected cells, no positive band could be found in the controls. CONCLUSION: Exogenous p21 gene can transfect the HLE-B3 cells and can be expressed. The transfection can affect the cells cycle by G(1) arrest and induces cells death through the apoptosis process. This result suggests that it is possible to prevent the occurrence of secondary cataract by gene therapy.

[The characteristic of vernier acuity on retrobulbar neuritis patients].

PURPOSE: To investigate the clinical characteristic of vernier acuity in retrobulbar neuritis patients. METHODS: The vernier acuity test soft wear system was developed to detect the 15 cases (25 eyes) with retrobulbar neuritis patients. There were 8 eyes of 6 cases with acute retrobulbar neuritis and 17 eyes of 9 cases with chronic retrobulbar neuritis. Subjects' age ranged from 11 to 58 (mean = 25.87). There were 14 eyes of 7 cases male and 11 eyes of 8 cases female. The best visual acuity ranged from 0.05 to 0.7. Two fixed targets and a movable target are shown on the computer screen. The examine was asked to adjust the position of the central target and the relationship between it and align them by using a track-ball. The computer automatically records the deviations of distances between the movable target and the specific one, and computes the average threshold and its variance. RESULTS: There was significant statistical difference in the vernier threshold and its variance between the normal subjects and patients with retrobulbar neuritis in acute stage or convalescence. The correlation coefficient between visual acuity and vernier acuity threshold was -0.88 in the patients with retrobulbar neuritis in acute stage of neuritis (P < 0.01). The correlation coefficient between visual acuity and threshold variance was -0.46(P < 0.05). In convalescence, with an improvement of the disease and the increase of visual acuity, the vernier acuity threshold decreased and the threshold variance reduced. The difference of threshold and its variance between acute stage and convalescence had statistical signification (P < 0.01). The correlation coefficients between visual acuity and vernier acuity threshold was -0.93 in convalescence (P < 0.01). The correlation coefficients between visual acuity and vernier threshold variance was -0.84(P < 0.01) in convalescence. No significant statistical difference was found in the correlation between the vernier threshold in acute stage and in convalescence (P = 0.261). No significant statistical difference was found in the correlation between visual acuity in acute stage and in convalescence (P = 0.11). The correlation coefficients between vernier threshold variance in acute stage and in convalescence was -0.67 (P < 0.01). There was statistical difference among the difference of threshold, visual acuity and standard deviation between acute stage and convalescence respectively (t-test, P < 0.01). CONCLUSIONS: It is suggested that vernier acuity, which changed with the state of the disease, was one of the indexes to evaluate the visual function of patients with retrobulbar neuritis. It could be use as an observation index of supervising the change of patients' visual function and the reaction to medication and guiding medication.

[Quality of life assessment of cataract surgery in elderly population of Doumen County, Guangzhou Province].

OBJECTIVE: To evaluate the outcome of cataract surgery in elderly population in Doumen County, Guangdong Province by assessment of subjective visual function and quality of life. METHODS: All the cataract postoperative subjects were identified in the population-level. Visual Function and Quality of Life (VF/QOL) questionnaire developed by National Eye Institute, USA in developing countries was used as the instrument. This Questionnaire was administered by four trained-interviewers in all subjects with visual acuity less than 0.1 in either eye (treated as visual impairment cases), One in every 20 persons with visual acuity better than 0.3 (treated as normal control cases) in both eyes (un-operated group) and all cataract postoperative cases (operated group). RESULTS: In 5 342 cross-sectional examined persons, individuals who could be successfully interviewed included 99 (90.8%) cataract postoperative cases, 535 (85.5%) visual impairment cases and 119 normal control ones. On a 0 - 100 scale, medium total scores of VF and QOL diminished from 92 to 2 and from 100 to 19 respectively along with visual status from normal to severe blindness in the un-operated group. Similar findings on visual status and VF/QOL scores were found in the operated group. The overall scores of VF and QOL were 40 and 56 for operated one and 56 and 72 for un-operated one. After adjusted the confounding effect of visual status, age, sex and education by multivariate regression model, the difference of QOL scores between un-operated and operated group was significant (P = 0.015), while no significant difference (P = 0.199) was found in VF scores. CONCLUSIONS: The scores of VF and QOL are significantly correlated with the visual status. Subjective visual function and quality of life could not be significantly improved after cataract surgery in this target population. Concerns should be paid in postoperative follow-up, aphakic correction and social-psychological rehabilitation.

[Detection of cell cycle related gene expression in cultured immortalized human lens epithelial cell].

OBJECTIVE: To investigate the gene expression of cyclin E, cyclin-dependent-kinase 2 (CDK(2)) and CDK inhibitor (CKI) p21 during cell cycle of the human lens epithelial cell (HLEC) for elucidating the molecular mechanism of proliferation of HLEC and the formation of posterior capsular opacification (PCO). METHODS: HLE-B3 cell line was cultured in vitro under MEM medium with 15% fetal bovine serum. The cell cycle was analyzed by flow cytometry (FCM) system. The cell cycle was synchronized by double thymidine block method. The mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). The total RNA was separated from cells at different phases. Protein expression was detected with immunohistochemistry or western blotting method. The primary antibodies were rabbit anti-human cyclin E polyclonal antibody, mouse anti-human p21 and CDK(2) monoclonal antibody, respectively. RESULTS: FCM showed that G(1) phase was about 33.5%, S phase cells about 46.1%, and the G(2) phase about 20.4%, total cells in G(2) and S phase were over 60%. It was suggested that HLE- B3 cells have relatively more capacity of mitosis than normal LEC. The mRNA expression of CDK(2) was found at all phases of cell cycle during synchronization, but cyclin E mRNA only expressed during synchronized cells, and not expressed in non-synchronized cells. Only Sphase cells could express very low p21 mRNA. There was no any positive signal of cyclin E by immunohistochemistry or western blot. CDK(2) protein detected by Western blot expressed at all phases. The p21 protein was expressed in a few cells by immunohistochemistry, but p21 could not detected by western blotting. These results showed cyclin E and CDK(2) were higher expressed than p21 in transcriptional level and translational level. CONCLUSIONS: There is mRNA expression of cyclin E, CDK(2) and p21 during the cell cycle in HLE-B3 cell line, but it means the imbalance of the association of CDK and CKI. These results suggest that the imbalance expression of cyclin, CDK and p21 be the molecular mechanism of PCO.

[Urea soluble fraction of bovine melanin associated antigen and experimental study on its uveitogenic activity].

OBJECTIVE: The purpose of this study was to investigate the uveitogenic activity of autoantigen in the bovine iris-ciliary body. METHODS: Urea soluble fraction of boveine melanin associated antigen (USF-BMAA) was isolated from the bovine iris-ciliary body biochemically and determined by SDS-PAGE as well as amino acid analysis. Lewis rats and F344 rats were immunized with USF-BMAA emulsified with equal volume complete Freud's adjuvant and Bordetella pertussis. RESULTS: A strongly stained protein band was observed in the USF-BMAA by SDS-PAGE whose molecular weight is approximate 64 000. Amino acid analysis of USF-BMAA showed that it contains 17 kinds of amino acids with high content of Glu, Leu and Asp. The experimental melanin associated antigen-induced uveitis (EMIU) was successfully incited in both eyes of the Lewis and F344 rats. The inflammation was mainly located in the anterior uvea, and spontaneously recovered. Mild focal choroiditis was present in the rats with severe lesion. However, the inflammation was not observed in the retina and pineal gland. CONCLUSIONS: USF-BMAA may be the major part of autoantigen of the uveal tract with uveitogenic activity. Unlike experimental autoimmune uveoretinitis (EAU) which is incited by the retinal soluble antigen (S-Ag) in the rats, no involvement of the retina and pineal gland is found in EMIU.

[Studies on prediction of visual function of vitreous opacity patients by Vernier hyperacuity tests].

PURPOSE: To evaluate the clinical value of visual function with vitreous opacity patients preoperatively. METHODS: The vernier acuity examining soft wear system was developed to detect the 14 cases (14 eyes) with vitreous opacity patients preoperatively. Two fixed targets and a movable target are shown on the computer screen. The examine was asked to adjust the position of the central target and the relationship between it and align them by using a track-ball. The computer automatically recorded the deviations of distances between the movable target and the specific one, and computed the average threshold of hyperacuity and its variance. Then the hyperacuity result and postoperative visual acuity were compared. RESULTS: Paired t-test showed that the difference between peroperative and postoperative vernier acuity thresholds was not significant (t = 0. 52, P = 0. 612). The coefficient of correlation was 0. 85 (P < 0. 01). Neither was the threshold variance (t = 0. 431, P = 0. 674). The correlation coefficient was 0.97 (P < 0.01). The correlation coefficient between preoperative hyperacuity threshold and postoperative visual acuity was -0.74 (P < 0.01), and that between preoperative threshold variance and postoperative visual acuity was -0.95 (P < 0.01). Based on the preoperative vernier acuity threshold and its variance, the function of linear regression was Y = 0.943 - 0.000116THv - 0.00193SDv. CONCLUSIONS: Vernier acuity remains good consistency after vitrectomy, and it is one of the sensitive parameter in predicting the postoperative visual function for vitreous opacities.

Pterygium in aged population in Doumen County, China.

PURPOSE: To estimate the prevalence of pterygium and its influence on visual acuity in aged population of Doumen County, southern China. METHODS: A population-based survey was conducted in Doumen County, the rural area of southern China. Twenty-seven sample units were selected by random sampling. The prevalence and severity of pterygium and it-related low visual acuity were analyzed. RESULTS: Of the total 4 762 individuals aged 50 years or over, 4 214 were examined. The prevalence of pterygium was 33.01% in subjects aged 50 years or above. There was a significantly higher prevalence in female (35.70%) than in male (29.70%, P = 0.025). The prevalence of pterygium in age groups of 50s, 60s, 70s and 80s years old is 33.98%, 36.40%, 30.73% and 25.40%, respectively. Most of the pterygia were located in the nasal side (93.31%) of cornea, and only 6.69% in the temporal side. 0.92% of the eyes had visual acuity less than 0.32, which were directly caused by pterygia. CONCLUSION: The current survey suggests that the pterygium is one of the most common diseases of external eye in the population aged 50 years and above. It is still leading to the impairment of visual acuity in the rural area.