Effects of parenting style on depressive symptoms, anxiety symptoms, and their comorbidity during the COVID-19 pandemic lockdown among 3117 Chinese junior high school students.

INTRODUCTION: Depressive symptoms, anxiety symptoms, and comorbidity increased in junior high school students due to the outbreak of COVID-19. The objective of this study was to measure the impacts of parenting style on depressive symptoms, anxiety symptoms, and their comorbidity in Chinese junior high school students during the COVID-19 pandemic lockdown period. METHODS: An online survey was conducted in June 2020 among 3117 junior high school students from Shandong Province, China. The Egna Minnen av Barndoms Uppfostran scale was used to measure parenting styles. The 9-item Patient Health Questionnaire scale and the 7-item Generalized Anxiety Disorder scale were used to measure depressive symptoms and anxiety symptoms, respectively. Multinomial logistic regression was conducted with SPSS 25.0 Version. RESULTS: 3117 junior school students enrolled in this study. The prevalence of depressive symptoms only, anxiety symptoms only, and comorbidity among junior high school students was 11.55 %, 5.29 %, and 22.97 %. Paternal over-protection was a risk factor not only for depressive symptoms only (OR = 1.075, 95 % CI = 1.020-1.134) but for anxiety symptoms only (OR = 1.090, 95 % CI = 1.016-1.170) and comorbidity (OR = 1.098, 95 % CI = 1.050-1.148). Paternal over-interference was a protective factor for depressive symptoms only (OR = 0.947, 95 % CI = 0.908-0.987) and comorbidity (OR = 0.953, 95 % CI = 0.921-0.986). However, maternal over-interference and over-protection were risk factors for depressive symptoms only (OR = 1.039, 95 % CI = 1.011-1.068). LIMITATIONS: This was a cross-sectional study and the causal inferences could not be conducted. CONCLUSIONS: Junior high school students with poorer family environmental factors were more likely to suffer from the comorbidity of anxiety symptoms and depressive symptoms during the COVID-19 pandemic lockdown. Decision-makers from the government, educational, and healthcare institutions should pay more attention to junior high school students at higher risk of mental disorders due to poor parenting styles. We should discuss family interventions in the future to prevent mental disorders in junior high school students.

A sentiment analysis approach for travel-related Chinese online review content.

Using technology for sentiment analysis in the travel industry can extract valuable insights from customer reviews. It can assist businesses in gaining a deeper understanding of their consumers' emotional tendencies and enhance their services' caliber. However, travel-related online reviews are rife with colloquialisms, sparse feature dimensions, metaphors, and sarcasm. As a result, traditional semantic representations of word vectors are inaccurate, and single neural network models do not take into account multiple associative features. To address the above issues, we introduce a dual-channel algorithm that integrates convolutional neural networks (CNN) and bi-directional long and short-term memory (BiLSTM) with an attention mechanism (DC-CBLA). First, the model utilizes the pre-trained BERT, a transformer-based model, to extract a dynamic vector representation for each word that corresponds to the current contextual representation. This process enhances the accuracy of the vector semantic representation. Then, BiLSTM is used to capture the global contextual sequence features of the travel text, while CNN is used to capture the richer local semantic information. A hybrid feature network combining CNN and BiLSTM can improve the model's representation ability. Additionally, the BiLSTM output is feature-weighted using the attention mechanism to enhance the learning of its fundamental features and lessen the influence of noise features on the outcomes. Finally, the Softmax function is used to classify the dual-channel fused features. We conducted an experimental evaluation of two data sets: tourist attractions and tourist hotels. The accuracy of the DC-CBLA model is 95.23% and 89.46%, and that of the F1-score is 97.05% and 93.86%, respectively. The experimental results demonstrate that our proposed DC-CBLA model outperforms other baseline models.

Function of Long Noncoding RNAs in Glioma Progression and Treatment Based on the Wnt/ß-Catenin and PI3K/AKT Signaling Pathways.

Gliomas are a deadly primary malignant tumor of the central nervous system, with glioblastoma (GBM) representing the most aggressive type. The clinical prognosis of GBM patients remains bleak despite the availability of multiple options for therapy, which has needed us to explore new therapeutic methods to face the rapid progression, short survival, and therapy resistance of glioblastomas. As the Human Genome Project advances, long noncoding RNAs (lncRNAs) have attracted the attention of researchers and clinicians in cancer research. Numerous studies have found aberrant expression of signaling pathways in glioma cells. For example, lncRNAs not only play an integral role in the drug resistance process by regulating the Wnt/ß-catenin or PI3K/Akt signaling but are also involved in a variety of malignant biological behaviors such as glioma proliferation, migration, invasion, and tumor apoptosis. Therefore, the present review systematically assesses the existing research evidence on the malignant progression and drug resistance of glioma, focusing on the critical role and potential function of lncRNAs in the Wnt/ß-catenin and PI3K/Akt classical pathways to promote and encourage further research in this field.

circTOP2A functions as a ceRNA to promote glioma progression by upregulating RPN2.

Competing endogenous RNA (ceRNA)-mediated signaling pathway dysregulation provides great insight into comprehensively understanding the molecular mechanism and combined targeted therapy for glioblastoma. circRNA is characterized by high stability, tissue/developmental stage-specific expression and abundance in brain and plays significant roles in the initiation and progression of cancer. Our previous published data have demonstrated that RPN2 was significantly upregulated in glioma and promoted tumor progression via the activation of the Wnt/ß-catenin pathway. Furthermore, we proved that miR-422a regulated the Wnt/ß-catenin signaling pathway by directly targeting RPN2. In this study, based on the glioblastoma microarray profiles, we identified the upstream circTOP2A, which completely bound to miR-422a and was co-expressed with the RPN2. circTOP2A was significantly overexpressed in glioma and conferred a poor prognosis. circTOP2A could regulate RPN2 expression by sponging miR-422a, verified by western blot, dual-luciferase reporter gene assay, and RNA pull-down assay. Functional assays including CCK8, transwell and FITC-annexin V were performed to explore the RPN2-mediated role of the circTOP2A effect on the glioma malignant phenotype. Additionally, TOP/FOP and immunofluorescence analysis were used to confirm that sh-circTOP2A could suppress the Wnt/ß-catenin pathway partly through RPN2. Finally, a tumor xenograft model was applied to validate the biological function of circTOP2A in vivo. Taken together, our findings reveal the critical role of circTOP2A in promoting glioma proliferation and invasion via a ceRNA mechanism and provide an exploitable biomarker and therapeutic target for glioma patients.

Influence of PCDH9 (rs9540720) and narcissistic personality traits on the incidence of major depressive disorder in Chinese first-year university students: findings from a 2-year cohort study.

Objective: The objective of this study was to explore the influence of the polymorphism of the protocadherin 9 (PCDH9) gene and the narcissistic personality trait (NPT) on the risk of major depressive disorder (MDD) in Chinese first-year university students. Methods: A 2-year cohort study was conducted among Chinese first-year university students who were enrolled in 2018 from two universities in Shandong Province, China. The snapshot technique was used to detect the genotypes of PCDH9 (rs9540720). The Chinese version of the Composite International Diagnostic Interview was used for the MDD assessment. The NPTs were measured by 11 items based on DSM-IV. Patient Health Questionnaire-9 and the Beck Anxiety Inventory were used to assess depressive and anxiety symptoms, respectively. Logistic regression modeling was carried out to examine the relationship between rs9540720, NPTs, and the incidence of MDD. Results: A total of 5,327 students participated in the baseline and follow-up studies and provided their blood samples. PCDH9 (rs9540720) (ORGG+GA = 2.33, 95% CI: 1.35-4.02) and NPTs (OR5-9 = 2.26, 95% CI: 1.40-3.64) increased the risk of MDD onset. There was no multiplicative interaction between NPTs and Rs9540720 (OR = 1.51, 95% CI: 0.30-7.63). Furthermore, there was no additive interaction between them (RERI = 2.40, 95% CI: -0.82-5.62; AP = 0.47, 95% CI: -0.04-0.97; and S = 2.37, 95% CI: 0.54-10.33). Conclusion: PCDH9 (rs9540720) and more NPTs are the risk factors for the incidence of MDD in Chinese first-year university students.

Dynamics of Microbial Community during the Co-Composting of Swine and Poultry Manure with Spent Mushroom Substrates at an Industrial Scale.

Spent mushroom substrates (SMSs) can be developed as a biofertilizer through composting. Here, we investigated the dynamics of bacterial and fungal communities during commercial composting and the effect of swine and poultry manure on their communities through MiSeq pyrosequencing. Weissella paramesenteroides and Lactobacillus helveticus were dominant bacterial species in the composts with soy waste (SMS-SW), whereas Thermotogaceae sp. and Ureibacillus sp. were dominant in the composts with swine and poultry manure (SMS-PM). For the fungal community, Flammulina velutipes was dominant in SMS-SW, whereas Trichosporon asahii, Candida catenulate, Aspergillus fumigatus, and Candida tropicalis were dominant in SMS-PM. The addition of manure affected the bacterial community significantly. Redundancy analysis indicated that bacterial communities were affected by temperature, potassium, and potassium oxide and fungal communities by temperature, Kjeldahl nitrogen, organic matter, and ammonium nitrogen. Our findings can guide future research on composting microbiology.

Effects of Cinnamomum camphora Leaves Extracts-Flocculants Composite Algaecide on Microcystis aeruginosa Growth and Microcystins Release.

In this study, a composite algaecide containing flocculants and Cinnamomum. camphora leaves extracts (CCCLE) were synthesized. The inhibition and flocculation effects on Microcystis aeruginosa (M. aeruginosa) were investigated, and the release of microcystin-LR (MC-LR) was determined. Results showed that the CCLEC composite algaecide was effective for the inhibition and flocculation of M. aeruginosa, and the optimal dose of CCLEC composite algaecide was 1.8%, which resulted in an algae inhibition ratio of 98.00% and a flocculation efficiency of 99.44% within 5 days of M. aeruginosa culturing. Besides, the total amount of MC-LR decreased by 80.04% on day 20 compared with the control group, while the concentration of intracellular MC-LR on day 5 was 36.69 µg L-1, which was related to a portion of cells underwent apoptosis-like cell death under CCLEC composite algaecide stress. The results of this study may improve our understanding of the M. aeruginosa control by CCCLE composite algaecide.

Implication of single year seasonal sampling to genetic diversity fluctuation that coordinates with oceanographic dynamics in torpedo scads near Taiwan.

Many fisheries management and conservation plans are based on the genetic structure of organisms in pelagic ecosystems; however, these structures tend to vary over time, particularly in cyclic ocean currents. We performed genetic analyses on the populations of the pelagic fish, Megalaspis cordyla (Osteichthyes: Carangidae) in the area surrounding Taiwan during 2000-2001. Genotyping was performed on M. cordyla collected seasonally around Taiwan as well as specimens collected from Singapore (Malacca strait) and Indonesia (Banda Sea). Gonadosomatic indices (GSI) revealed that M. cordyla does not spawn near Taiwan. Data related to the mitochondrial control region revealed that the samples from Singapore and Indonesia represented two distinct genetic cohorts. Genotyping revealed that during the summer (June-August 2000), the Indonesian variant was dominant in eastern Taiwan (presumably following the Kuroshio Current) and in the Penghu region (following the Kuroshio Branch Current). During the same period, the Singapore genotype was dominant along the western coast of Taiwan (presumably following the South China Sea Current); however, the number dropped during the winter (December-February 2001) under the effects of the China Coast Current. Divergence time estimates indicate that the two genetic cohorts split during the last glacial maximum. Despite the fact that these results are based on sampling from a single year, they demonstrate the importance of seasonal sampling in unravelling the genetic diversity in pelagic ecosystems.

Bayesian inference of nonylphenol exposure for assessing human dietary risk.

Nonylphenols (NPs) are endocrine-disrupting compounds commonly found in the environment and a number of food products. In this study, we constructed a probabilistic risk framework incorporating a Bayesian inference of exposure level in foodstuffs in conjunction with effect analysis of reproduction and renal disease. Our objective was to contrast the risk of dietary exposure to NPs among individuals in various age groups, with a particular focus on fertile females. In this study, seafood presented relatively high NP concentrations; however, seafood accounts for only a small proportion of the total food intake of most individuals. Rice was shown to make the largest contribution to NP daily intake among males and females in most age groups. Chicken made the largest contribution in the 12-16 and 16-18 year age groups. The mean average daily dose of NPs tended to decrease with age, regardless of gender. The estimated distribution of hazard quotients of <1 in all groups means that the risk of reproductive or renal abnormalities due to dietary exposure to NPs is negligible within most of the Taiwanese population. Nonetheless, preschoolers (3-6-year-olds) appear to be more vulnerable to NPs than do individuals in other age groups. There has been growing concern among researchers concerning the neurotoxic effects of NPs on offspring via maternal exposure. We recommend conducting a comprehensive assessment of exposure to NPs via multiple exposure routes, particularly among fertile women and preschoolers.

Safety investigation of Pulsatilla chinensis saponins from chronic metabonomic study of serum biomedical changes in oral treated rat.

ETHNOPHARMACOLOGICAL RELEVANCE: Pulsatilla chinensis (Bunge) Regel is a valuable traditional Chinese medicine (TCM) which is widely used for the treatment of schistosomiasis, inflammatory, bacterial infections. In recent years, P chinensis has been reported to exhibit antitumor activities. However, the mechanisms underlying its toxic effects remain largely unresolved. This paper is designed to investigate the damage of long-term oral P. chinensis saponins (PRS) and to explore its potential damage mechanisms by serum metabonomics approach. MATERIALS AND METHODS: The serum samples from control and PRS treated rats were analyzed by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) in positive ionization mode and negative ionization mode. Liver function index of ALT, AST and ALP, blood biochemistry and biomarkers were examined to identify specific changes of injury. Acquired data were subjected to principal component analysis (PCA) for differentiating the control and PRS treated groups. Then, serum metabolic profiling was analyzed and pathway analysis performed on the biomarkers reversed after PRS treated and further integration of metabolic networks. RESULTS: The results suggested that serum liver function indexes of ALT had significantly changed and stage increased. AST, ALP detection content show volatility changes. Changes in the 15 biomarkers found in the serum, such as acetaminophen glucuronide, 9 E, 11 E-linoleic acid, chenodeoxycholic acid, monoacylglycerides, sphingomyelin (SM), 7-ketodeoxycholic acid and 12-keto-deoxycholic acid, which were closely related to changes in liver injury. It could be seen clearly that with the change of the dosing time, the biomarkers in the serum have undergone obvious, regular and progressive changes through the score plot and corresponding loading plot. The underlying regulations of PRS-perturbed metabolic pathways were discussed according to the identified metabolites. CONCLUSION: The present study proves the potential of UPLC-QTOF-MS based metabonomics in mapping metabolic response. Long-term oral administration of P. chinensis saponins can cause chronic liver injury, and its safety needs further attention. It is of great significance in safeguarding human health to explore the damage mechanism of Pulsatilla chinensis saponins on liver by serum metabolomics.

Fetal growth velocity: the NICHD fetal growth studies.

BACKGROUND: Accurately identifying pregnancies with accelerated or diminished fetal growth is challenging and generally based on cross-sectional percentile estimates of fetal weight. Longitudinal growth velocity might improve identification of abnormally grown fetuses. OBJECTIVE: We sought to complement fetal size standards with fetal growth velocity, develop a model to compute fetal growth velocity percentiles for any given set of gestational week intervals, and determine association between fetal growth velocity and birthweight. STUDY DESIGN: This was a prospective cohort study with data collected at 12 US sites (2009 through 2013) from 1733 nonobese, low-risk pregnancies included in the singleton standard. Following a standardized sonogram at 10w0d-13w6d, each woman was randomized to 1 of 4 follow-up visit schedules with 5 additional study sonograms (targeted ranges: 16-22, 24-29, 30-33, 34-37, and 38-41 weeks). Study visits could occur ± 1 week from the targeted GA. Ultrasound biometric measurements included biparietal diameter, head circumference, abdominal circumference, and femur length, and estimated fetal weight was calculated. We used linear mixed models with cubic splines for the fixed effects and random effects to flexibly model ultrasound trajectories. We computed velocity percentiles in 2 ways: (1) difference between 2 consecutive weekly measurements (ie, weekly velocity), and (2) difference between any 2 ultrasounds at a clinically reasonable difference between 2 gestational ages (ie, velocity calculator). We compared correlation between fetal growth velocity percentiles and estimated fetal weight percentiles at 4-week intervals, with 32 (±1) weeks' gestation for illustration. Growth velocity was computed as estimated fetal growth rate (g/wk) between ultrasound at that gestational age and from prior visit [ie, for 28-32 weeks' gestational age: velocity = (estimated fetal weight 32-28)/(gestational age 32-28)]. We examined differences in birthweight by whether or not estimated fetal weight and estimated fetal weight velocity were <5th or ≥5th percentiles using χ2. RESULTS: Fetal growth velocity was nonmonotonic, with acceleration early in pregnancy, peaking at 13, 14, 15, and 16 weeks for biparietal diameter, head circumference, femur length, and abdominal circumference, respectively. Biparietal diameter, head circumference, and abdominal circumference had a second acceleration at 19-22, 19-21, and 27-31 weeks, respectively. Estimated fetal weight velocity peaked around 35 weeks. Fetal growth velocity varied slightly by race/ethnicity although comparisons reflected differences for parameters at various gestational ages. Estimated fetal weight velocity percentiles were not highly correlated with fetal size percentiles (Pearson r = 0.40-0.41, P < .001), suggesting that these measurements reflect different aspects of fetal growth and velocity may add additional information to a single measure of estimated fetal weight. At 32 (SD ± 1) weeks, if both estimated fetal weight velocity and size were <5th percentile, mean birthweight was 2550 g; however, even when size remained <5th percentile but velocity was ≥5th percentile, birthweight increased to 2867 g, reflecting the important contribution of higher growth velocities. For estimated fetal weight ≥5th percentile, but growth velocity <5th, birthweight was smaller (3208 vs 3357 g, respectively, P < .001). CONCLUSION: We provide fetal growth velocity data to complement our previous work on fetal growth size standards, and have developed a calculator to compute fetal growth velocity. Preliminary findings suggest that growth velocity adds additional information over knowing fetal size alone.

Fetal Growth Patterns in Pregnancies With First-Trimester Bleeding.

OBJECTIVE: To assess the relationship between first-trimester vaginal bleeding and fetal growth patterns. METHODS: We conducted a secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singletons, a prospective cohort study of low-risk, nonobese women with healthy lifestyles. Duration of bleeding was self-reported at enrollment (10 0/7 to 13 6/7 weeks of gestation) and categorized as 0, 1, or more than 1 day. Longitudinal measures of fetal biometrics were obtained in up to six study visits, and estimated fetal weight was computed. Growth trajectories were created for biometrics and estimated fetal weight. When global tests among groups was significant (P<.05), week-specific global and pairwise differences were tested. Birth weight and risk of a small-for-gestational-age (SGA) neonate were secondary outcomes. All analyses were adjusted for maternal age, weight, height, parity, and racial-ethnic group and neonatal sex in a sensitivity analysis. RESULTS: In 2,307 eligible women, 410 (17.8%) reported first-trimester bleeding, of whom 176 bled for 1 day and 234 bled for more than 1 day. Women with more than 1 day of bleeding demonstrated decreased fetal abdominal circumference from 34 to 39 weeks of gestation compared with women without bleeding. For women with more than 1 day of bleeding, compared with women without bleeding, estimated fetal weight was 68-107 g smaller from 35 to 39 weeks of gestation. Mean birth weight at term was 88 g smaller, confirming differences in calculated fetal weight, and SGA neonates were delivered to 148 (8.5%), 9 (5.7%), and 33 (15.7%) women in the no bleeding, 1 day, and more than 1 day of bleeding groups, respectively. CONCLUSION: More than 1 day of first-trimester vaginal bleeding was associated with smaller estimated fetal weight late in pregnancy driven by smaller abdominal circumference. The magnitude of decrease in birth weight was small, albeit comparable with observed decreases associated with maternal smoking. It remains unknown whether early pregnancy bleeding is associated with short-term or long-term morbidity and whether additional intervention would be of benefit. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT00912132.

An integrated strategy using UPLC-QTOF-MSE and UPLC-QTOF-MRM (enhanced target) for pharmacokinetics study of wine processed Schisandra Chinensis fructus in rats.

Currently the pharmacokinetic (PK) research of herbal medicines is still limited and facing critical technical challenges on quantitative analysis of multi-components from biological matrices which often accompanied by lacking of authentic standards and low concentration. This present work contributes to the development of an integrated strategy for extensive pharmacokinetics assessments, and a selective and sensitive method independent of authentic standards for multi-components analysis based on the use of ultra-performance liquid chromatography/quadrupole-time-of-flight/MSE (UPLC-TOF-MSE) and UPLC-TOF-MRM (rnhanced target). Initially, phytochemicals were identified by UPLC-TOF-MSE analysis, subsequently the identified components were matched with authentic standards and pre-classified, and UPLC-QTOF-MRM method optimized and developed. To guarantee reliable results, three rules are necessary: (1) detection with a mass error of less than 5ppm; (2) same class chemical compositions with structural high similarity between analytes with and without authentic reference substance; (3) a matching retention time between TOF-MRM mode and TOF-MSE within 0.2min. The developed and validated method was applied for the simultaneous determination of 12 lignans in rat plasma after administered with wine processed Schisandra Chinensis fructus (WPSCF) extract. Such an approach was found capable of providing extensive pharmacokinetic profiles of multi-components absorbed into blood after oral administrated with WPSCF extract. The results also indicated that significant difference in pharmacokinetics parameters of dibenzocyclooctadiene lignans was observed between schizandrin and gomisin compounds. For lignans, the absorption via gastrointestinal tract were all rapid and maintained relatively long retention time, especially for schisantherin A and schisantherin B with higher plasma exposure.

Endogenous L-Carnosine Level in Diabetes Rat Cardiac Muscle.

A novel method for quantitation of cardiac muscle carnosine levels using HPLC-UV is described. In this simple and reliable method, carnosine from the rat cardiac muscle and the internal standard, thymopentin, were extracted by protein precipitation with acetonitrile. The method was linear up to 60.96 µg·mL(-1) for L-carnosine. The calibration curve was linear in concentration ranges from 0.5 to 60.96 µg·mL(-1). The relative standard deviations obtained for intra- and interday precision were lower than 12% and the recoveries were higher than 90% for both carnosine and internal standard. We successfully applied this method to the analysis of endogenous carnosine in cardiac muscle of the diabetes rats and healthy control rats. The concentration of carnosine was significantly lower in the diabetes rats group, compared to that in the healthy control rats. These results support the usefulness of this method as a means of quantitating carnosine and illustrate the important role of L-carnosine in cardiac muscle.

[Marker-assisted selection and pyramiding for three blast resistance genes, Pi-d(t)1, Pi-b, Pi-ta2, in rice].

G46B is a promising holding line used for three-lines breeding strategy in hybrid rice, but it is susceptible to blast disease caused by Pyricularia grisea. To improve its blast resistance, three rice varieties, Digu, BL-1, and Pi-4, with blast resistance genes, Pi-d(t), Pi-b, and Pi-ta2, respectively, were used to be crossed with G46B, and 15 plants with these three blast resistance genes, Pi-d(t)1, Pi-b, and Pi-ta2, were selected from their F2 and B1C1 populations via a marker-aided crossing procedure. Among them, four plants were heterozygotes in the three resistance genes, with the genotype of Pi-d(t)1 pi-d(t)/Pi-b pi-b/ Pi-ta2 pi-ta2; ten plants were heterozygotes in two of the three resistance genes, of which six with the genotype of Pi-d(t)1 Pi-d(t)1/Pi-b pi-b/Pi-ta2 pi-ta2, three with the genotype of Pi-d(t)1 pi-d(t)1/Pi-b pi-b/Pi-ta2 Pi-ta2, and one with the genotype of Pi-d(t)1pi-d(t)1/Pi-b Pi-b/Pi-ta2 pi-ta2; and only one plant was homozygote in two of the three resistance genes with the genotype of Pi-d(t)1 Pi-d(t)/Pi-b pi-b/Pi-ta2 Pi-ta2. These results demonstrate the capacity of maker-assisted selection (MAS) in gene pyramiding for rice blast resistance and its enhancement for the efficiency in rice resistance breeding.

[Accelerated improvement of bacterial blight resistance of 'Shuhui527' using molecular marker-assisted selection].

'Shuhui527' is a promising restorer line bred by Rice Research Institute of Sichuan Agricultural University in recent years. However, this line is susceptible to Bacterial Blight (BB), which limits its use. The IRBB60, from the International Rice Research Institute (IRRI), contains dominant genes Xa21 and Xa4 conferring resistance to BB. The objective of this study is to improve the BB resistance of 'Shuhui527' by introgressing Xa21 and Xa4, the two broad-spectrum BB resistance genes, into 'Shuhui527' with IRBB60 as the donor, pTA248 and MP12, linking tightly with Xa21 and Xa4 respectively as DNA markers. BC1 F1 progenies of (Shuhui527 x IRBB60), containing Xa21 and Xa4 identified using PCR screening and with agronomic traits including plant type, grain type and days to heading etc similar to those of 'Shuhui527', were subsequently backcrossed to 'Shuhui527' and self-pollinated to generate BC2 F1 and BC1 F2 . The BC3 F1 and BC3 F2 were subsequently developed using the same approach. Among the 20 BC3 F2 plants, homozygous Xa21 and Xa4,10 plants were the most similar to 'Shuhui527' in the agronomic traits, and were screened using 120 pairs SSR and 100 pairs RAPD markers. Based on the results of the background screening and the performance of the agronomic traits, 5 plants were identified as improved-'Shuhui527' and designated as 527R-5, 527R-6, 527R-8, 527R-9 and 527R-10. The improved-' Shuhui527' lines expressed high resistance to Xanthomonas oryzae pv . oryzae (Xoo) stains C I - C VII, P1 and P6. The evaluation of the polymorphisms and selection accuracies of pTA248 and MP12 demonstrated that the polymorphisms of the two markers were obvious and co-dominant and the accuracies were more than 97% and 83% respectively, indicating the two markers are good for Xa21 and Xa4 in Molecular Marker-assisted Selection.