Environmental drivers of increased ecosystem respiration in a warming tundra.

Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5-7. This hampers the accuracy of global land carbon-climate feedback projections7,8. Here we synthesize 136 datasets from 56 open-top chamber in situ warming experiments located at 28 arctic and alpine tundra sites which have been running for less than 1 year up to 25 years. We show that a mean rise of 1.4 °C [confidence interval (CI) 0.9-2.0 °C] in air and 0.4 °C [CI 0.2-0.7 °C] in soil temperature results in an increase in growing season ecosystem respiration by 30% [CI 22-38%] (n = 136). Our findings indicate that the stimulation of ecosystem respiration was due to increases in both plant-related and microbial respiration (n = 9) and continued for at least 25 years (n = 136). The magnitude of the warming effects on respiration was driven by variation in warming-induced changes in local soil conditions, that is, changes in total nitrogen concentration and pH and by context-dependent spatial variation in these conditions, in particular total nitrogen concentration and the carbon:nitrogen ratio. Tundra sites with stronger nitrogen limitations and sites in which warming had stimulated plant and microbial nutrient turnover seemed particularly sensitive in their respiration response to warming. The results highlight the importance of local soil conditions and warming-induced changes therein for future climatic impacts on respiration.

[Transcriptomic analysis of the ΔPaLoc mutant of Clostridioides difficile and verification of its toxicity].

Objective: Comparative analyses of wild-type Clostridioides difficile 630 (Cd630) strain and pathogenicity locus (PaLoc) knockout mutant (ΔPaLoc) by using RNA-seq technology. Analysis of differential expression of Cd630 wild-type strain and ΔPaLoc mutant strain and measurement of its cellular virulence changes. Lay the foundation for the construction of an toxin-attenuated vaccine strain against Clostridioides difficile. Methods: Analysis of Cd630 and ΔPaLoc mutant strains using high-throughput sequencing (RNA-seq). Clustering differentially expressed genes and screening differentially expressed genes by DESeq software. Further analysis of differential genes using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Finally, cytotoxicity assays of ΔPaLoc and Cd630 strains were performed in the African monkey kidney epithelial cell (Vero) and the human colonic cell (Caco-2) lines. Results: The transcriptome data showed that the ΔPaLoc mutant toxin genes tcdA and tcdB were not transcribed. Compared to the wild-type strain, CD630_36010, CD630_020910,CD630_02080 and cel genes upregulated 17.92,11.40,8.93 and 7.55 fold, respectively. Whereas the hom2 (high serine dehydrogenase), the CD630_15810 (spore-forming protein), CD630_23230 (zinc-binding dehydrogenase) and CD630_23240 (galactitol 1-phosphate 5-dehydrogenase) genes were down-regulated by 0.06, 0.075, 0.133 and 0.183 fold, respectively. The GO and KEGG enrichment analyses showed that the differentially transcribed genes in ΔPaLoc were enriched in the density-sensing system, ABC transport system, two-component system, phosphotransferase (PTS) system, and sugar metabolism pathway, as well as vancomycin resistance-related pathways. Cytotoxicity assays showed that the ΔPaLoc mutant strain lost its virulence to Vero and Caco-2 cells compared to the wild-type Cd630 strain. Conclusion: Transcriptional sequencing analysis of the Cd630 and ΔPaLoc mutant strains showed that the toxin genes were not transcribed. Those other differential genes could provide a reference for further studies on the physiological and biochemical properties of the ΔPaLoc mutant strain. Cytotoxicity assays confirmed that the ΔPaLoc mutant lost virulence to Vero and Caco-2 cells, thus laying the foundation for constructing an toxin-attenuated vaccine strain against C. difficile.

[The prediction of disease progression by 18Fluorodeoxyglucose-positron emission computed tomography/CT in patients with dermatomyositis and interstitial lung disease].

To investigate the predictive value of [18F]fluorodeoxyglucose-positron emission computed tomography(PET)/CT for disease progression in patients with dermatomyositis (DM) and interstitial lung diseases (ILD). Sixty-seven DM patients who underwent [18F] FDG-PET/CT imaging were retrospectively analyzed from January 2012 to September 2017 at PLA General Hospital. Their clinical manifestations and imaging characteristics were recorded. Compared with those chronically progressed (C-ILD), patients with rapid progression (RP-ILD) had significantly higher erythrocyte sedimentation rate (ESR) and standardized uptake value (SUV) in lungs (P<0.05). In patients with RP-ILD, SUV in lungs was positively correlated with age, disease course, and ESR. Receiver operating characteristic curve analysis suggested that when lung SUV cut off value was 2.25, the sensitivity and specificity to predict disease progression was 77.8% and 72.8%, respectively. Old age, longer disease course, low creatine kinase level, higher ESR, and high SUV are prognostic factors for DM-associated ILD.

[Impact of health literacy on patient experience of outpatients in China and its mechanism].

OBJECTIVE: To understand the relationship between health literacy and patient experience of outpatients in China, and to explore its mechanism. METHODS: The conceptual framework was developed based on Andersen's behavioral model of health services use and health literacy skills framework. An online cross-sectional survey was conducted with snowball sampling method, while the health literacy was measured by self-designed patient health literacy scale, and the patient experience was measured by the Chinese patient experience questionnaire for ambulatory care developed by Peking Union Medical College. And a structural equation model was built to explore the relationship between them and test the mechanism of health literacy influencing patient experience. RESULTS: A total of 2 773 subjects were investigated. The average score of health literacy was (90.72±12.90) points, accounting for 78.89% of the full score, and the dimension of seeking social support had the lowest score. The average score of overall rating of patient experience was (3.71±0.74) points, and the scores of each dimension of patient experience were between 3.56 and 3.80. The model fit indices of structural equation model for overall rating of patient experience among the outpatients were χ2/df=9.29 (χ2=4 107.27, df=442), root mean square error of approximation (RMSEA)=0.055 (< 0.06), comparative fit index (CFI)=0.926 (>0.90), Tucker-Lewis index (TLI)=0.918 (>0.90), standardized root mean square residual (SRMR)=0.061 (< 0.08), the model was acceptable. The variance in patient experience explained by the model was 0.108. The structural equation model analysis results showed that the overall rating of outpatient experience was directly affected by health literacy (ß=0.263, P < 0.001), also indirectly affected by health literacy (ß=0.012, P < 0.001). In other words, the overall rating increased by 0.275 units for each standard deviation increase of health literacy. Self-evaluated health status mediated the relationship between health literacy and the overall rating of outpatient experience. In terms of diffe-rent dimensions of patient experience, the standardized path coefficient of the total effect of health literacy on patient experience was as follows: Information guidance 0.337, humanistic care 0.319, communication with doctors 0.294, service efficiency 0.240, and hospital environment 0.173. CONCLUSION: The patients with higher level of health literacy were more likely to have a better outpatient experience in China, and the information guidance experience and humanistic care experience were most affected by health literacy. And the communication and information utilization ability had the greatest influence on patient experience.

First-principles investigation of nonmetal doped single-layer BiOBr as a potential photocatalyst with a low recombination rate.

Nonmetal doping is an effective approach to modify the electronic band structure and enhance the photocatalytic performance of bismuth oxyhalides. Using density functional theory, we systematically examine the fundamental properties of single-layer BiOBr doped with boron (B) and phosphorus (P) atoms. The stability of the doped models is investigated based on the formation energies, where the substitutional doping is found to be energetically more stable under O-rich conditions than under Bi-rich ones. The results showed that substitutional doping of P atoms reduced the bandgap of pristine BiOBr to a greater extent than that of boron substitution. The calculation of the effective masses reveals that B doping can render the electrons and holes of pristine BiOBr lighter and heavier, respectively, resulting in a slower recombination rate of photoexcited electron-hole pairs. Based on the results of HOMO-LUMO calculations, the introduction of B atoms tends to increase the number of photocatalytically active sites. The top of the valence band and the conduction band bottom of the B doped BiOBr monolayer match well with the water redox potentials in an acidic environment. The absorption spectra propose that B(P) doping causes a red-shift. Overall, the results predict that nonmetal-doped BiOBr monolayers have a reduced bandgap, a slow recombination rate, more catalytically active sites, enhanced optical absorption edges, and reduced work functions, which will contribute to superior photocatalytic performance.

The importance of proper and prompt treatment of ocular syphilis: a lesson from permanent vision loss in 52 eyes.

BACKGROUND: Ocular involvement can occur at any stage of syphilis. Prompt diagnosis and proper treatment of ocular syphilis are vital to avoid long-term consequences. OBJECTIVES: To describe the risk factors for ocular syphilis and clinical features of blindness caused by syphilis. METHODS: We report risk factors for ocular syphilis amongst patients seen at the Shanghai Skin Disease Hospital between October 2009 and October 2017. We identify patients with ocular syphilis resulting in blindness and report the clinical characteristics, laboratory findings and treatment outcomes of these patients. RESULTS: A total of 8310 new cases of syphilis were seen, of which 213 patients had ocular disease and 50 patients had blindness due to syphilis. Increasing age and higher RPR titres were associated with ocular involvement but there was no association with HIV status. Blindness in syphilis was restricted predominantly to patients with optic nerve involvement and not patients with isolated uveitis. Fifty patients (and a total of 67 eyes) met the WHO definition of blindness prior to treatment for syphilis. At the end of follow-up, vision had improved in 24 of 67 eyes (35.8%) after treatment. Successful treatment of uveitis was associated with the best improvement in visual acuity, whilst patient with underlying optic atrophy prior to treatment had the worst visual outcome. CONCLUSIONS: Ocular involvement is an important manifestation of syphilis which may result in blindness. Our data demonstrate outcomes for ocular syphilis are poor if detected late; early recognition and diagnosis is therefore vital to avoid permanent visual loss.

[Prevention and treatment of bearing dislocation of mobile-bearing unicompartmental knee arthroplasty].

Bearing dislocation is a special complication of mobile-bearing unicompartmental arthroplasty, caused by many factors, such as imbalance of the flexion and extension gap, malposition of components, impingement by the remaining osteophytes and cement, damage or delayed chronic laxity of medial collateral ligament, traumatic accident and habitual high knee flexion. It can be reduced by strictly controlling the operation indications before operation, osteotomy and implanting the prosthesis accurately while protecting the medial collateral ligament during operation, actively guiding the appropriate rehabilitation actions and activity intensity of patients after operation. Treatment should be individualized according to the causes and individual conditions of patients.

[Comparison of the early efficacy of unicompartmental and total knee arthroplasty in patients with medial compartmental osteoarthritis of the knee: a propensity score matching study].

Objective: To compare the short-term efficacy of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty(TKA) in the treatment of medial compartmental knee osteoarthritis. Methods: A retrospective analysis was performed on 197 patients with medial compartment osteoarthritis of the knee treated by the same group of doctors from January 2015 to December 2018.There were 86 males and 111 females, aged (67.7±10.5) years (range: 46 to 92 years), among which 101 cases received UKA and 96 cases received TKA.The UKA and TKA patients were matched by the propensity score matching method, and a total of 41 pairs of patients were successfully matched.The difference of short-term outcomes between the two groups were compared by t test, χ(2) test or Fisher exact probability methods. Results: Compared with TKA group, the postoperative reduction of hemogloblin in the UKA group was lower ((15.3±6.4) g/L vs. (20.1±7.5) g/L, t=-3.117, P<0.01), opioid dosage was lower ((160.5±29.3) mg vs. (186.1±46.8) mg, t=-2.969, P<0.01), and the length of hospital stay was shorter ((7.0±2.0)d vs. (10.0±2.5)d, t=-6.000, P<0.01). Forgotten joint score of UKA group was higher ( (65.1±7.6) vs. (58.3±13.9) , t=2.732, P<0.01), the incidence of knee clunk or crepitus was lower (P=0.03) . There was no significant difference in the time of surgical tourniquet, range of motion, American knee society clinical score and incidence of deep vein thrombosis in lower extremities between the two groups.No complications such as surgical site infection, prosthesis loosening and dislocation occurred in the two groups. Conclusion: The early effect of UKA is similar to that of TKA, and it is better than TKA in the aspects of knee clunk or crepitus, forgotten joint score, blood loss, opioid dosage and postoperative hospital stay.

Functional expression of the Spodoptera exigua chitinase to examine the virtually screened inhibitor candidates.

Chitinase is responsible for insect chitin hydrolyzation, which is a key process in insect molting and pupation. However, little is known about the chitinase of Spodoptera exigua (SeChi). In this study, based on the SeChi gene (ADI24346) identified in our laboratory, we constructed the recombinant baculovirus P-Chi for the expression of recombinant SeChi (rSeChi) in Hi5 cells. The rSeChi was purified by chelate affinity chromatography, and the purified protein showed activity comparable with that of a commercial SgChi, suggesting that we harvested active SeChi for the first time. The purified protein was subsequently tested for enzymatic properties and revealed to exhibit its highest activity at pH 8 and 40 C. Using homology modeling and molecular docking techniques, the three-dimensional model of SeChi was constructed and screened for inhibitors. In two rounds of screening, twenty compounds were selected. With the purified rSeChi, we tested each of the twenty compounds for inhibitor activity against rSeChi, and seven compounds showed obvious activity. This study provided new information for the chitinase of beet armyworm and for chitinase inhibitor development.

ZB transposon and chicken vasa homologue (Cvh) promoter interact to increase transfection efficiency of primordial germ cells in vivo.

1. In order to increase the efficiency of generating transgenic chicken, this trial focused on two points: primordial germ cells (PGCs）transfection in vivo and a germline-specific promoter.2. In order to transfect PGCs in vivo, two plasmids (pZB-CAG-GFP, pCMV-ZB）were co-injected into chicken embryos via the subgerminal cavity at Hamburger and Hamilton (HH) stage 2-3 or via blood vessel at HH stage 13-14. Results showed that the percentage of GFP+ embryos, viability and hatching rate of embryos injected at HH stage 13-14 were significantly higher than that at HH stage 2-3.3. Two plasmid transposon systems were used for chicken embryo micro-injections. The donor plasmid, with a green fluorescent protein (GFP) reporter gene, was mediated by the ZB transposon. The helper plasmid was a transposase expression vector driven by the promoter of the chicken vasa homologue (Cvh) gene or Human cytomegalovirus (CMV) promoter. Results showed that 60.98% of gonads in Cvh group expressed GFP, which was 52.50% higher than seen in the CMV group. Only gonad tissue from the Cvh group showed any GFP signal, whereas both gonads and other tissues in the CMV group showed green fluorescence.4. The data suggested that ZB transposon-mediated gene transfer was efficient for transfecting PGCs in vivo; the Cvh promoter drove the transposase gene specifically in the germline and increased the efficiency of germline transmission. Blood vessels injection at HH stage 13-14 may be a more efficient route for PGCs transfection in vivo.

Oxidative stress induced necroptosis activation is involved in the pathogenesis of hyperoxic acute lung injury.

Necroptosis has been found to be involved in the pathogenesis of some lung diseases, but its role in hyperoxic acute lung injury (HALI) is still unclear. This study aimed to investigate contribution of necroptosis to the pathogenesis of HALI induced by hyperbaric hyperoxia exposure in a rat model. Rats were divided into control group, HALI group, Nec-1 (necroptosis inhibitor) group and edaravone group. Rats were exposed to pure oxygen at 250 kPa for 6 h to induce HALI. At 30 min before hyperoxia exposure, rats were intraperitoneally injected with Nec-1 or edaravone, and sacrificed at 24 h after hyperoxia exposure. Lung injury was evaluated by histology, lung water to dry ratio (W/D) and bronchoalveolar lavage fluid (BALF) biochemistry; the serum and plasma oxidative stress, expression of RIP1, RIP3 and MLKL, and interaction between RIP1 and RIP3 were determined. Results showed hyperoxia exposure significantly caused damage to lung and increased necroptotic cells and the expression of RIP1, RIP3 and MLKL. Edaravone pre-treatment not only inhibited the oxidative stress in HALI, but also reduced necroptotic cells, decreased the expression of RIP1, RIP3 and MLKL and improved lung pathology. Nec-1 pretreatment inhibited necroptosis and improved lung pathology, but had little influence on oxidative stress. This study suggests hyperoxia exposure induces oxidative stress may activate necroptosis, involving in the pathology of HALI, and strategies targeting necroptosis may become promising treatments for HALI.

Comparison of Eversion Carotid Endarterectomy and Patch Carotid Endarterectomy: A Retrospective Study of 6 Years of Experience.

BACKGROUND The aim of this study was to compare early and long-term results of eversion carotid endarterectomy (e-CEA) and patch carotid endarterectomy (p-CEA). MATERIAL AND METHODS In a retrospective study, we collected data on 441 patients who underwent CEA (e-CEA=211 vs. p-CEA=230) between October 2009 and October 2015 at our institute. Economic costs, postoperative hospital days, use of shunts and antibiotics, early (30-day) complications, long-term restenosis, and mortality rates were compared between groups during 4 to 76 months of follow-up. RESULTS Patients in the p-CEA group had a significantly higher percentage of antibiotic use (58.3% vs. 27%, respectively; P0.05). Long-term complication, including stroke or heart attack, recurrent stenosis rate, and mortality rate, showed no difference between the 2 groups (all P>0.05). Kaplan-Meier analysis shows that the recurrent stenosis-free and survival rates were not significantly different between the 2 groups (P=0.867, P=0.177, respectively). CONCLUSIONS The adverse event rates of perioperative and long-term follow-up showed no significant difference between the e-CEA and p-CEA groups. Both e-CEA and p-CEA are effective for carotid artery stenosis.

Production of lactobionic acid from lactose using the cellobiose dehydrogenase-3-HAA-laccase system from Pycnoporus sp. SYBC-L10.

The aim of this study was to produce lactobionic acid from lactose by a new Pycnoporus sp. SYBC-L10 strain. Recently, studies on enzymatic production of lactobionic acid mostly focus on cellobiose dehydrogenase from Sclerotium rolfsii CBS 191·62 and laccase from Trametes pubescens MB 89 oxidize lactose to lactobionic acid with redox mediators. In this study, we converted lactose to lactobionic acid by shaking flask fermentation without exogenous mediator in the reaction mixture. In this bioconversion process, lactose is efficiently converted into lactobionic acid with a specific productivity of up to 3·1 g l-1  h-1 and 96% yield. 3-Hydroxyanthranilic acid added externally to the reaction mixture can obviously accelerate the conversion of lactose to lactobionic acid. The results showed that 3-hydroxyanthranilic acid produced by the fungus itself is an important influencing factor in this bioconversion process. This study presents the first attempt to efficiently produce lactobionic acid by white-rot fungi, suggesting definite potential for Pycnoporus to produce lactobionic acid. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobionic acid has been applied to a wide range of applications in pharmaceutical, food, nanotechnology and chemical industries. Here, an attempt was done to produce lactobionic acid from lactose using the cellobiose dehydrogenase-3-HAA-laccase system in a fermentation system. After a survey of other methods to produce lactobionic acid by cellobiose dehydrogenase, this study explores a new and significant perspective for the production of lactobionic acid.

[Retinal image quality in northern rural Chinese adult population].

Objective: To assess the retinal image quality of the normal northern rural Chinese adult population. Methods: A normal population-based, cross-sectional study. From Oct, 2012 to Jan 2013, a clustered, random sampling procedure was used to select normal population who visual acuity≤ 0(LogMAR) and 30-69 years old from 2 villages. All eligible subjects were invited to undergo a comprehensive eye examination, and the retinal image quality related index were examined with pupil 4 mm using objective optical quality analysis systemⅡ(OQAS Ⅱ, Visiometrics, Spain), including MTFcutoff, VA20, VA9, PSF50, PSF10, OSI, SR. And describe the retinal image quality of different age group, including 30-39y, 40-49y, 50-59y, 60-69y. Results: Among 1 108 participants (61.9%) that completed examinations in our center, 681 participants (1 362 eyes) were recruited. There were 146, 586, 440 and 190 eyes in each group. The spherical equivalent refraction of each group was (-0.35±0.84), (-0.19±0.50), (-0.03±0.54) and (0.20±0.71) D. The best corrected vision acuity of each group was -0.02±0.04, -0.01±0.03, -0.01±0.02 and -0.00±0.01. The MTFcutoff of each group was (37.06±9.31), (36.69±8.93), (36.52±9.05) and (32.61±10.08) c/deg. Retinal imaging parameters were significantly different(MTFcutoff: MD=4.45, SR:MD=0.03, PSF50: MD=-0.45, PSF10: MD=-2.87, VA20:MD=0.13, A9:MD=0.09, OSI:MD=-0.41, P<0.001)between aged 30-39 group and aged 60-69 group. Objective scattering index (OSI) were significantly different(MD=-0.13, P=0.004)between aged 30-39 group and aged 50-59 group. Retinal imaging parameters were significantly different(MTFcutoff:MD=4.45, SR:MD=0.03, PSF50:MD=-0.45, PSF10:MD=-2.87, VA20:MD=0.13, VA9: MD=0.09, OSI: MD=-0.41, P<0.001)between aged 40-49 group and aged 60-69 group. Retinal imageing parameters were significantly different(MTFcutoff: MD=4.45, SR: MD=0.03, PSF50: MD=-0.45, PSF10: MD=-2.87, VA20:MD=0.13, VA9:MD=0.09, OSI:MD=-0.41,P<0.001)between aged 50-59 group and aged 60-69 group. Conclusion: Retinal image quality was gradually worse over time in the northern rural Chinese adult population. (Chin J Ophthalmol, 2018, 54:593-598).

A rating scale for the severity of Guillain-Barré syndrome.

INTRODUCTION: The objective of this study was to develop a rating scale to assess the severity of Guillain-Barré syndrome (GBS). METHODS: The preliminary rating scale, which contained 11 items, was developed by the Delphi method, and data of 258 patients were collected to evaluate it. Item analysis was accomplished by 100 patients; the additional 158 patients were used to evaluate the reliability, validity, and discriminative ability of the rating scale. The structure of the rating scale was testified by the confirmatory factor analysis and also made a further evaluation by the correlation analysis. RESULTS: The rating scale contained 10 items. The three factors mainly generalized the motor function, cranial nerve function and autonomic function. The results of reliability and validity showed that the structure of the rating scale was good (χ2 =68.25, df=32, χ2 /df=2.13, normed fit index (NFI)=0.919, non-normed fit index (NNFI)=0.936, comparative fit index (CFI)=0.96, a root mean square error of approximation (RMSEA)=0.085), and the Cronbach's α coefficient for the scale was .852, with the three dimensions ranging from .585 to .752. CONCLUSION: Reliability and validity of the rating scale are all satisfied. The scale contained the main clinical presentations of GBS, and it is suitable to evaluate the severity of GBS.

Astaxanthin increases radiosensitivity in esophageal squamous cell carcinoma through inducing apoptosis and G2/M arrest.

Nowadays esophageal squamous cell carcinoma (ESCC) is primarily treated by a comprehensive approach combining surgical resection and neoadjuvant chemo- or radiotherapy. However, ESCC is resistant to radiation therapy, resulting in its invasion, infiltration, and metastasis. It usually has rapidly progressed and has a poor outcome clinically. The purpose of this study is to determine the potential radiosensitizing effect of astaxanthin (ATX) and explore the underlying mechanisms in ESCC cells in vitro. ESCC cell lines were exposure to irradiation, in the presence or absence of ATX treatment. Cell viability and radiosensitization were tested by CCK8 assay and clonogenic survival assay, respectively. Cell apoptosis and the changes of cell cycle distribution were observed by flow cytometry. The protein expression of Bcl2, Bax, CyclinB1, and Cdc2 was examined by western blot analysis. It was shown that ATX improved radiosensitivity of ESCC cells and induced apoptosis and G2/M arrest via inhibiting Bcl2, CyclinB1, Cdc2, and promoting Bax expression. In conclusion, ATX might function as a promising radiosensitizer in ESCC cells by leading to apoptosis and G2/M arrest.

[Unilateral patellar resurfacing in bilateral total knee arthroplasty: a randomized controlled study].

OBJECTIVE: To perform unilateral patellar resurfacing and contralateral patellar retention in bilateral total knee arthroplasty (TKA) randomly, and to compare the clinical effects of patellar retention with patellar resurfacing in TKA. METHODS: In the study, 14 bilateral knee osteoarthritis (OA) patients were randomized in the bilateral TKA to receive unilateral patellar resurfacing and contralateral patellar retention, including 28 knees, all were females, 53 to 78 years old, with average (66.9±7.8) years, and the BMI was (26.3±1.8) kg/m2. All subjects were followed up from 3 to 12 months. The clinical effects were evaluated based on measurements of American Knee Society score (KSS), range of motion (ROM), anterior knee pain, patellar clunk, and patellar tilt angle (PTA). RESULTS: All the wounds healed primarily without significant complications, such as infection, aseptic loosening, patellar fracture and so on. The preoperative KSS scores of patellar resurfacing group were 38.9±22.2, and the scores changed to be 92.4±6.7 after operation, which were added by 53.5±20.3. While in the patellar retention group, the KSS scores were 38.4 ± 20.5 preoperatively, and after operation, which were added to be 92.1±4.2, and improved by 53.7±21.4. The differences in the changed KSS scores between TKA with and without patellar resurfacing were not statistically significant (Independent t-test, P=0.98). The ROM was changed from 95.4°±13.5° preoperatively to 120.4°±8.9° postoperatively in the patellar resurfacing group and from 92.9°±19.1° preoperatively to 120.4±8.4° postoperatively in the patellar retention group. The ROM of the two group were increased by 25.0°±14.5° and 27.5°±19.4° respectively. However, no remarkable differences were observed between the 2 groups in the knee ROM (Independent t-test, P=0.70). At the end of the latest follow-up, 3 knees in the patellar resurfacing group and 2 knees in the patellar retention group had knee anterior pain, the incidences of anterior knee pain were 21.4% and 14.3% respectively. There was no obvious difference for the incidence of post-operative anterior knee pain (Chi-square test, P=0.62). The incidences of post-operative patellar clunk in the 2 groups were all with 3 knees (21.4%), which had no significant difference in the 2 groups (Chi-square test, P=1.00). The post-operative PTA were 2.6°±2.6° in the patellar resurfacing group and 3.6°±2.9° in the patellar retention group, respectively. There was also no statistical difference between the 2 groups (Chi-square test, P=0.36). CONCLUSION: For knee OA patients with mild or moderate patellar cartilage damage, performing patellar resurfacing or not didn't significantly affect anterior knee pain, patellar clunk, functional outcomes or patellar tracking after TKA. So we suggest retain patella in TKA for OA patients with mild or moderate patellar cartilage damage.

[Antagonism of lovastatin on oxidative stress and apoptosis in primary rat hippocampal neurons induced by ß-amyloid peptide].

Objective: To investigate the effect of lovastatin on oxidative stress and apoptosis in neurons induced by ß-amyloid peptide (Aß). Methods: Primary culture of rat hippocampal neuron was treated with Aß oligomers alone or combined with lovastatin. The levels of OH(-), H(2)O(2), O(2)·(-), malondialdehyde, superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities were measured by biochemical methods and protein expression of caspase-3 and bcl-2 was detected by Western blot. Results: As compared with the control group, treatment of 0.5 µmol/L Aß oligomers for 48 h led to significant increase of OH(-), H(2)O(2), O(2)·(-) and malondialdehyde content, inhibition of SOD and GSH-PX activities, enhanced caspase-3 expression and decreased bcl-2 expression. Interestingly, these neurotoxic modifications on the levels of OH(-), H(2)O(2), O(2)·(-) and malondialdehyde content, SOD and GSH-PX activities, and the protein expression of cleaved caspase-3 and bcl-2 were significantly attenuated when the cells were pretreated with 0.1 µmol/L lovastatin for 24 h before exposure of Aß oligomers. Conclusion: Lovastatin may play an important role in antagonizing the neurotoxicity of Aß through a mechanism likely related to the inhibition of oxidative stress.

[A preliminary study on macular retinal and choroidal thickness and blood flow change after posterior scleral reinforcement by optical coherence tomography angiography].

Objective: To investigate macular retinal and choroidal thickness and blood flow change using optical coherence tomography angiography after posterior scleral reinforcement (PSR) surgery. Methods: Prospective study. Twenty eyes of 10 patients with high myopia were enrolled in this open-label, single-treatment group and prospective study. Radial lines and Angio retina (3 mm×3 mm) module were performed for 20 eyes using Angio-vue optical coherence tomography (Avanti, Optovue) without pupil dilation, and best corrected visual acuity, spherical equivalent and axial length were compared before and 60 days after surgery. Retinal and choroidal thickness was measured in the fovea, 1 mm superior, 1 mm inferior, 1 mm nasal and 1 mm temporal to the fovea. Flow area, flow density and flow index were recorded using self-provided software in the superficial retina layer, deep retina layer, outer retina layer and choroid capillary layer, respectively. Statistical analysis was performed using SPSS 16.0. Data that followed normal distribution were compared with paired two-sample t-test, while others were compared with Wilcoxon signed rank test. Results: Of the patients participating in this preliminary study, the mean age was (35.5±4.2) years, and 50% were female. No significant difference was found between before and 60 days after PSR surgery in best corrected visual acuity (t=0.99, P=0.33), spherical equivalent (t=-1.89, P=0.07) and axial length (t=0.2, P=0.08). The retinal thickness in the fovea was thinner (Z=-2.58, P=0.01), while there was no significant difference in the 1 mm superior (t=0.44, P=0.67) , 1 mm inferior (t=0.05, P=0.96) , 1 mm nasal (Z=0.87, P=0.64) and 1 mm temporal (Z=-0.78, P=0.99) to the fovea. No significant difference was found in choroidal thickness (t=-0.12, P=0.87; t=-0.25, P=0.81. t=0.53, P=0.61; t=-0.91, P=0.38. t=1.2, P=0.25) before and after surgery. The postoperative flow density in the superficial and deep retinal layers (48.18±4.56% and 31.47±5.11%) was significantly increased (t=2.66, P=0.02; t=3.16, P=0.01) compared with pre-operation (33.82±4.33% and 14.29±3.89%). The postoperative flow index in the superficial and deep retina layers (0.044±0.005 and 0.025±0.005) was significantly increased (t=2.59, P=0.02. t=2.95, P=0.01) compared with pre-operation (0.028±0.004 and 0.010±0.003). The other flow measurements showed no significant difference. Conclusion: Retinal thickness decreased, and flow density and index increased in the superficial and deep retinal layers after PSR surgery. This suggested blood flow improvement in the macular region after PSR surgery in high myopic eyes. (Chin J Ophthalmol, 2017, 53:39-45).