Machine learning-based identification of a consensus immune-derived gene signature to improve head and neck squamous cell carcinoma therapy and outcome.

Background: Head and neck squamous cell carcinoma (HNSCC), an extremely aggressive tumor, is often associated with poor outcomes. The standard anatomy-based tumor-node-metastasis staging system does not satisfy the requirements for screening treatment-sensitive patients. Thus, an ideal biomarker leading to precise screening and treatment of HNSCC is urgently needed. Methods: Ten machine learning algorithms-Lasso, Ridge, stepwise Cox, CoxBoost, elastic network (Enet), partial least squares regression for Cox (plsRcox), random survival forest (RSF), generalized boosted regression modelling (GBM), supervised principal components (SuperPC), and survival support vector machine (survival-SVM)-as well as 85 algorithm combinations were applied to construct and identify a consensus immune-derived gene signature (CIDGS). Results: Based on the expression profiles of three cohorts comprising 719 patients with HNSCC, we identified 236 consensus prognostic genes, which were then filtered into a CIDGS, using the 10 machine learning algorithms and 85 algorithm combinations. The results of a study involving a training cohort, two testing cohorts, and a meta-cohort consistently demonstrated that CIDGS was capable of accurately predicting prognoses for HNSCC. Incorporation of several core clinical features and 51 previously reported signatures, enhanced the predictive capacity of the CIDGS to a level which was markedly superior to that of other signatures. Notably, patients with low CIDGS displayed fewer genomic alterations and higher immune cell infiltrate levels, as well as increased sensitivity to immunotherapy and other therapeutic agents, in addition to receiving better prognoses. The survival times of HNSCC patients with high CIDGS, in particular, were shorter. Moreover, CIDGS enabled accurate stratification of the response to immunotherapy and prognoses for bladder cancer. Niclosamide and ruxolitinib showed potential as therapeutic agents in HNSCC patients with high CIDGS. Conclusion: CIDGS may be used for stratifying risks as well as for predicting the outcome of patients with HNSCC in a clinical setting.

Ultrafast underwater self-healing piezo-ionic elastomer via dynamic hydrophobic-hydrolytic domains.

The development of advanced materials capable of autonomous self-healing and mechanical stimulus sensing in aquatic environments holds great promise for applications in underwater soft electronics, underwater robotics, and water-resistant human-machine interfaces. However, achieving superior autonomous self-healing properties and effective sensing simultaneously in an aquatic environment is rarely feasible. Here, we present an ultrafast underwater molecularly engineered self-healing piezo-ionic elastomer inspired by the cephalopod's suckers, which possess self-healing properties and mechanosensitive ion channels. Through strategic engineering of hydrophobic C-F groups, hydrolytic boronate ester bonds, and ions, the material achieves outstanding self-healing efficiencies, with speeds of 94.5% (9.1 µm/min) in air and 89.6% (13.3 µm/min) underwater, coupled with remarkable pressure sensitivity (18.1 kPa-1) for sensing performance. Furthermore, integration of this mechanosensitive device into an underwater submarine for signal transmission and light emitting diode modulation demonstrates its potential for underwater robotics and smarter human-machine interactions.

The feasibility of level Ib-sparing intensity-modulated radiation therapy in patients with nasopharyngeal carcinoma and high-risk factors classified based on the International Guideline.

BACKGROUND AND PURPOSE: To examine the feasibility of level Ib-sparing intensity-modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC) who had high-risk factors classified based on the International Guideline (IG). MATERIALS AND METHODS: We evaluated 961 non-metastatic NPC cases based on IG recommendations for prophylactic Ib irradiation. Four high-risk factors were used to categorise patients into three cohorts: A, B, and C. Propensity score matching was used to balance baseline characteristics in Cohort C, resulting in a matched Cohort C. Recurrence rates at level Ib and regional relapse-free survival (RRFS) rates were evaluated. RESULTS: Among patients with negative Ib lymph nodes (LNs), 18, 54, 420, and 444 exhibited involvement of structures that drain to level Ib as the first echelon (FES), involvement of the submandibular gland (SMG), level II LNs with radiologic extranodal extension (rENE), and level II nodes with a maximal axial diameter (MAD) ≥ 2 cm, respectively. The recurrence rate was highest in Cohort A (11.1 %). Cohort B had no level Ib recurrence. In matched Cohort C, recurrence rates were low in both groups (Ib-sparing group: 0.6 % vs. Ib-covering group: 0.6 %, P > 0.999). No significant differences were observed in 5-year RRFS rates between the two groups in cohort A (p = 0.208), cohort B (p = 0.905), and matched cohort C (p = 0.423). CONCLUSIONS: Level Ib-sparing IMRT could be performed safely for NPC patients with level II LNs who had rENE and/or MAD ≥ 2 cm. Further research should determine the necessity of level Ib prophylactic irradiation for patients with FES or SMG involvement.

Prognostic value of the cervical lymph node necrosis ratio in nasopharyngeal carcinoma.

PURPOSE: Whether cervical lymph node necrosis (CNN) is an independent adverse prognostic factor in nasopharyngeal carcinoma (NPC) has not been determined. In this study, the CNN ratio was graded quantitatively to explore the prognostic value in NPC. PARTICIPANTS AND METHODS: We retrospectively reviewed a total of 648 pathologically confirmed as NPC. We outlined metastatic lymph nodes and necrotic area of lymph nodes slice by slice on the magneticresonanceimages (MRI) cross section, and calculated the corresponding CNN ratio. RESULTS: The median CNN ratio (17.37 %) was taken as the cut-off point, 256 (39.51 %) patients were divided into CNN1 group (<17.37 %, n = 128) and CNN2 group (≥17.37 %, n = 128), 392 (60.49 %) patients without lymph nodes necrosis were CNN0. Among the CNN0, CNN1 and CNN2 groups, five-year overall survival (OS) was 82.4 %, 76.6 % and 71.1 %, locoregional recurrence-free survival (LRRFS) was 91.3 %, 91.1 % and 90.5 %, distant metastasis-free survival (DMFS) was 83.7 %, 78.5 % and 68.7 %, progression-free survival (PFS) was 78.3 %, 71.7 % and 61.6 % respectively. By multivariate analysis, CNN was an independent prognostic factor for OS (P = 0.003), DMFS (P = 0.019) and PFS (P = 0.007). More than 3 cycles of chemotherapy significantly increased OS (P = 0.024) and DMFS (P = 0.015) in the CNN1 group. CONCLUSIONS: This study indicated that CNN is one of the factors with the negative prognosis of NPC. The CNN ratio might be used as one of the reference factors in the formulation of individualized treatment plan.

Effects of Chinese gallnut tannic acid on growth performance, blood parameters, antioxidative status, intestinal histomorphology, and cecal microbial shedding in broilers challenged with aflatoxin B1.

The objective of the present study was to investigate the effects of tannic acid (TA) on growth performance, blood parameters, antioxidant capacity, and intestinal health in broilers challenged with aflatoxin B1 (AFB1). A total of 480 broilers aged 1 d were randomly allotted into four treatments: 1) CON, control diet; 2) AF, CON + 60 µg/kg AFB1 of feed during days 1 to 21, CON + 120 µg/kg AFB1 of feed during days 22 to 42; 3) TA1, AF + 250 mg/kg TA; and 4) TA2, AF + 500 mg/kg TA. Average daily gain (ADG) and average daily feed intake (ADFI) were increased in the TA1 during days 1 to 21, days 22 to 42, and days 1 to 42 compared with CON and AF treatments (P < 0.05). Broilers fed the TA2 diet had greater ADG and ADFI than those fed the CON and AF diets during the finisher and the whole period (P < 0.05). Administration of TA decreased the relative weight of liver and kidney compared with broilers fed the AF diet on day 42 (P < 0.05). The blood activity of alanine transferase (ALT) and gamma-glutamyl transferase (GGT) was increased in the AF treatment compared with the CON (P < 0.05). Broilers fed the TA1 decreased the ALT content on day 21, and the level of ALT and GGT was decreased in the TA2 compared with the AF group on day 42 (P < 0.05). The activity of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) in plasma, and the hepatic glutathione S-transferase (GST) was decreased in the AF group compared with the CON group (P < 0.05). The TA decreased plasma malondialdehyde concentration, and increased plasma T-SOD, GSH-Px, total antioxidant capacity, and hepatic GST activity compared with the AF (P < 0.05). The crypt depth of the jejunum was decreased in the TA1 treatment on day 21, and the villus height of the ileum was increased in the TA2 group on day 42 compared with the AF treatment (P < 0.05). The cecal Lactobacillus counts on day 21 were tended to increase in the TA treatments compared with the AF (P = 0.061). In conclusion, dietary inclusion of 250 and 500 mg/kg TA could improve the growth, antioxidant capacity, and partially protected the intestinal health of broilers challenged with AFB1.

Aflatoxin B1 (AFB1) is well known for its growth retardation, hepatotoxic, immunosuppressive, and other negative effects both in humans and poultry. Plant extracts such as tannic acid (TA) have been demonstrated as effective agents to control AFB1 contamination. The objective of this study was to evaluate the effects of Chinese gallnut TA in preventing aflatoxicosis in broilers. Broilers received one of four treatments: CON, control diet; AF, control diet with AFB1; TA1, AF + 250 mg/kg TA; TA2, AF + 500 mg/kg TA. Although AF did not decrease the growth performance of broilers, 250 and 500 mg/kg TA had greater average daily gain and average daily feed intake than those in the CON and AF. The relative weight of liver and kidney, blood alanine transferase, and gamma-glutamyl transferase activity were increased, and the antioxidant status was depressed in chicks fed the AF diet compared with the CON group. Dietary supplementation with 250 and 500 mg/kg TA ameliorated all the above-mentioned negative effects of AFB1. Moreover, the crypt depth of the jejunum was decreased, and the villus height of the ileum was increased in TA treatments compared with the AF. Conclusively, Chinese gallnut TA could be considered as a potential natural agent for the prevention of AFB1-induced oxidative and intestinal damage of broilers.

Failure Patterns of Recurrence and Metastasis After Intensity-Modulated Radiotherapy in Patients With Nasopharyngeal Carcinoma: Results of a Multicentric Clinical Study.

PURPOSE: This study aimed to explore factors associated with recurrence and metastasis after intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma (NPC) and provide evidence for NPC treatment. METHODS: We retrospectively analysed the treatment dose and survival outcomes of 645 patients with nasopharyngeal carcinoma without distant metastases treated with IMRT for the first time at three treatment centres in the Guangxi Zhuang Autonomous Region, China, between January 2009 and December 2012. RESULTS: There were 9.3% of patients (60/645) had recurrence and 17.5% (113/645) had distant metastasis 5 years after treatment. The 1-year, 3-year and 5-year local recurrence rates were 0.9%, 6.5% and 9.0% respectively. And the 1-year, 3-year and 5-year distant metastasis rates were 3.4%, 10% and 17.2%, respectively. In the 60 patients with recurrence, the in-field, marginal-field, and out-field recurrence rates were 93.3% (56/60), 5.0% (3/60) and 1.7% (1/60), respectively. Recurrence failures occurring within the first three years after treatment accounted for 81.7% (49/60). In the 113 patients with metastasis, the size of the cervical lymph node, the presence of lower cervical lymph node metastasis, the residual cervical lymph node size and the time of residual cervical lymph node complete response (CR) were independent prognostic factors for DMFS (P <0.05). CONCLUSION: Most recurrences occured in the first three years after IMRT. In-field recurrence was the most common pattern for loco-regional failure of NPC treatment. The risk of distant metastasis was positively correlated with higher N stage, lower neck nodal metastasis, larger size of cervical lymph nodes, and longer time to response for residual NPC in cervical adenopathy.

Individualized cumulative cisplatin dose for locoregionally-advanced nasopharyngeal carcinoma patients receiving induction chemotherapy and concurrent chemoradiotherapy.

OBJECTIVES: To screen subgroup potentially benefiting from cumulative cisplatin dose (CCD) ≥ 200 mg/m2 during concurrent chemoradiotherapy (CCRT) of patients with locoregionally-advanced nasopharyngeal carcinoma (LA-NPC) receiving induction chemotherapy (IC) and CCRT. MATERIALS AND METHODS: In total, 2 063 patients with non-disseminated LA-NPC diagnosed from 2009 to 2015 receiving IC plus CCRT were enrolled. Patients were restaged based on proposed stage groupings and risk groupings was established. After propensity score matching, survival outcomes were compared within different risk groupings with 200 mg/m2 CCD. Post-IC gross primary tumor (GTVp) and lymph node (GTVnd) volumes were calculated from planning computed tomography. The role of risk groupings and post-IC tumor volume to CCD was explored. RESULTS: Compared with the low-risk group, the high-risk group showed poor survival outcomes in terms of 5-year progression-free survival (PFS), overall survival (OS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS). CCD ≥ 200 mg/m2 improved survival in terms of 5-year PFS, OS and DMFS in the high-risk group but not in the low-risk group. High-risk patients with unfavorable response to IC benefited from CCD ≥ 200 mg/m2 with respect to PFS and DMFS; while those in low-risk group or with favorable response to IC didn't. CONCLUSIONS: Risk groupings was effective for risk stratification. Combining risk groupings and post-IC tumor volume is a simple and useful method to guide individualized CCD treatment of CCRT for patients with LA-NPC receiving IC and CCRT. CCD ≥ 200 mg/m2 may be indicated for high-risk patients with unfavorable response to IC.

An anti-passivation ink for the preparation of electrodes for use in electrochemical immunoassays / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

p-Nitrophenylphosphate (PNPP) is usually employed as the substrate for enzyme-linked immunosorbent assays. p-Nitrophenol (PNP), the product of PNPP, with the catalyst alkaline phosphatase (ALP), will passivate an electrode, which limits applications in electrochemical analysis. A novel anti-passivation ink used in the preparation of a graphene/ionic liquid/chitosan composited (rGO/IL/Chi) electrode is proposed to solve the problem. The anti-passivation electrode was fabricated by directly writing the graphene-ionic liquid-chitosan composite on a single-side conductive gold strip. A glassy carbon electrode, a screen-printed electrode, and a graphene-chitosan composite-modified screen-printed electrode were investigated for comparison. Scanning electron microscopy was used to characterize the surface structure of the four different electrodes and cyclic voltammetry was carried out to compare their performance. The results showed that the rGO/IL/Chi electrode had the best performance according to its low peak potential and large peak current. Amperometric responses of the different electrodes to PNP proved that only the rGO/IL/Chi electrode was capable of anti-passivation. The detection of cardiac troponin I was used as a test example for electrochemical immunoassay. Differential pulse voltammetry was performed to detect cardiac troponin I and obtain a calibration curve. The limit of detection was 0.05 ng/ml.

Evaluation of meibomian gland dysfunction after phacoemulsification surgery / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM: To evaluate meibomian gland dysfunction (MGD) after phacoemulsification surgery,and to discuss the potential impact of ocular surface. ·METHODS: A perspective, self-controlled clinical trial was conducted. Fifty-six eyes of 56 patients with MGD underwent phacoemulsification and were evaluated the ocular surface disease index (OSDI), meibography score,lid margin abnormalities, Schirmer test, tear film break - up time ( BUT ) at preoperatively and postoperatively 2wk,1 and 3mo. ·RESULTS: Schirmer test did not change significantly postoperatively ( P > 0. 05 ). The OSDI scores, meibography score, lid margin abnormalities increased at 2wk, 1 and 3mo postoperatively compared to before operation (all P<0.05);BUT decreased (P<0.05). · CONCLUSION: Meibomian gland function may be aggravated after phacoemulsification surgery.

Anti-tumor Effects of Yiqi Jiedu Recipe and Analysis of Its Bioinformatics / 广州中医药大学学报

Objective To observe the inhibitory effects of Yiqi Jiedu Recipe(YJR)on transplanted Lewis lung cancer in mice and to explore its relative mechanism. Methods In-vivo mouse model of transplanted Lewis lung cancer was established. Twenty modeled mice were divided into model group,low- and high-dose YJR groups, and cisplatin group, 5 mice in each group. After treatment, the mouse general situations, body mass, body mass excluding tumor mass,tumor mass,tumor index,tumor volume,and tumor-inhibition rate were detected. In the in-vitro experiments, the inhibitory effect of YJR on the proliferation of A549 and H1299 cells was evaluated by CCK8 assays, and the effect of YJR on the apoptosis of A549 and H1299 cells was evaluated by flow cytometry assay. Bioinformatics analysis was carried out to identify the critical function,pathways and genes with bioinformatics mining method. Results Compared with the model group, high-dose YJR group and cisplatin group significantly inhibited the tumor growth of the transplanted Lewis lung cancer in mice(P<0.05 or P < 0.001). The experimental results in vitro showed that YJR significantly inhibited lung cell growth, and induced lung cell apoptosis. Bioinformatics analysis results showed that the inhibitory effects of YJR was probably related to multiple paths including apoptosis,cell cycle,autophagy,etc.,and promoting apoptosis may be the important way. YJR played a role in promoting apoptosis via AKT, HSP90, BCL2, CASP9 and activation of PI3K-AKT pathway. Conclusion YJR exhibits anti-tumor actions through regulating the targets AKT,HSP90, BCL2, CASP9 and affecting PI3K-AKT pathway to promote apoptosis and inhibit cell proliferation, thus to suppress the growth of transplanted tumor.

Characterization of Salt-Induced Epigenetic Segregation by Genome-Wide Loss of Heterozygosity and its Association with Salt Tolerance in Rice (Oryza sativa L.).

In a breeding effort to develop salt tolerant (ST) rice varieties by designed QTL pyramiding, large numbers of progenies derived from four crosses between salt- or drought- tolerant BC2F5 IR64 introgression lines, were subjected to severe salt stress, resulting in 422 ST plants. The progeny testing of the selected F3 lines under more severe salt stress resulted in identification of 16 promising homozygous lines with high levels of ST. Genetic characterization of the 422 ST F3 progeny and 318 random F2 plants from the same four crosses using 105 segregating SSR markers lead to three interesting discoveries: (1) salt stress can induce genome-wide epigenetic segregation (ES) characterized by complete loss of heterozygosity (LOH) and nearly complete loss of an allele (LOA) in the F3 progenies of four rice populations in a single generation; (2) ∼25% of the stress-induced ES loci were transgenerational and inherited from their salt- and drought- selected parents; and (3) the salt-induced LOH and LOA loci (regions) appeared to contain genes/alleles associated with ST and/or drought tolerance. 32 genomic regions that showed one or more types of salt-induced ES in the random and salt-selected progenies from these crosses. The same or different types of ES were detected with two large genomic regions on chromosomes 1 and 6 where more and the strongest ES were found across different populations. 14 genomic regions were found where the salt-induced ES regions were overlapping with QTL affecting ST related traits. The discovery of the three types of salt-induced ES showed several interesting characteristics and had important implications in evolution and future breeding for developing stress-resilient rice and crops.

BTLA-expressing CD11c antigen presenting cells in patients with active tuberculosis exhibit low capacity to stimulate T cell proliferation.

Despite past extensive studies on B and T lymphocyte attenuator (BTLA)-mediated negative regulation of T cell activation, the role of BTLA in antigen presenting cells (APCs) in patients with active pulmonary tuberculosis (ATB) remains poorly understood. Here, we demonstrate that BTLA expression on CD11c APCs increased in patients with ATB. Particularly, BTLA expression in CD11c APCs was likely associated with the attenuated stimulatory capacity on T cells (especially CD8+ T cell) proliferation. BTLA-expressing CD11c APCs showed lower antigen uptake capacity, lower CD86 expression, higher HLA-DR expression, and enhanced IL-6 secretion, compared to counterpart BTLA negative CD11c APCs in healthy controls (HC). Interestingly, BTLA-expressing CD11c APCs from ATB patients displayed lower expression of HLA-DR and less IL-6 secretion, but higher expression of CD86 than those from HC volunteers. Mixed lymphocyte reaction suggests that BTLA expression is likely associated with positive rather than conventional negative regulation of CD11c APCs stimulatory capacity. This role is impaired in ATB patients manifested by low expression of HLA-DR and low production of IL-6. This previous unappreciated role for BTLA may have implications in the prevention and treatment of patients with ATB.

Design and Application of Remote Medical Information System / 医学信息学杂志

Combining with the actual circumstances of the First Affiliated Hospital of Jinan University,the paper introduces the design and application of the Internet-based remote medical information system in hospitals,elaborates the overall architecture,specifically describes the application of remote medical information system,Electrocardiogram (ECG) system,Intensive Care Unit (ICU) system,etc.and analyzes the application effects,points out that the system could link the digital channels between primary hospitals and celebrity hospitals,and improve the primary medical and health service capabilities.

Strategy and management of cardiopulmonary bypass with cardiac surgery for pregnant women / 局解手术学杂志

Objective To evaluate the strategy and management of cardiopulmonary bypass ( CPB) with cardiac surgery for pregnant women.Methods The clinical data of 4 pregnant women with severe cardiac diseases ,who received cardiac surgery with CPB in our hospital form January 2016 to June 2017 were retrospectively analyzed ,meanwhile the maternal and neonatal outcomes were reviewed also .Results Among 4 patient s,there were 1 case of subacute bacterial endocarditis ,2 cases of congenital heart disease complicated with subacute bacterial endocarditis,1 case of rheumatic heart disease.The New York Heart Association(NYHA) functional classification:there were 2 cases with class Ⅲand 2 cases with classⅣ.Operations included 2 mitral valve replacement and tricuspid valve plasty ,1 right coronary artery fistula re-pair and aortic valve replacement ,1 patent ductus arteriosus closure and mitral valve repalcement ,aortic valve replacememnt ,pulmonary valve replacement,tricuspid valve plasty.The CPB time ranged from 85 to 287 minutes(median 135 minutes),the aortic cross clamp time ranged from 52 to 178 minutes (median 89 minutes),the gestational age of pateints received cardia surgery ranged from 25 to 32 weeks(median 29 weeks).All patients were followed up for 1 to 16months(median 6 months),with no death;4 neonatal outcomes included 3 of full-term labor with cesarean section ,all of the 3 newborns were alive and no malformation ,1 of death in the uterus and spontaneous abortion at 2 days post-operative .Conclusion Cardiac surgery can be performed with relative safety during pregnancy .According to the physiological characteristics of pregnancy ,a reasonable CPB plan should be formulated pre-operative ,better maternal and fetal survival rates may be achieved by optimized management of CPB and used fetal mornitoring perioperative ,reduce the incidence of complications .

Imagery Training of Blind Elite Paralympic Swimmer / 中国康复理论与实践

Objective To develop and design the imagery training program,according with the nature of swimming and taking into ac-count with the mental characteristics and individual needs of the disabled. Methods According to the International Classification of Func-tioning,Disability and Health(ICF),the orientation function of the blind swimming athletes and the orientation function of the body posi-tion and the image training were analyzed theoretically.Imagery training was used as the independent variable,and the specific role of imag-ery training in improving athletic performance is observed in the imagery training intervention of the outstanding blind Olympic swimmer Li.Results and Conclusion Imagery training was an effective method for the blind swimmer to establish the orientation direction and body position function,and it can help the blind swimmer keep a straight line,reduce dependence on touch lane,and improve the performance.

Persistently high prevalence of primary resistance and multidrug resistance of tuberculosis in Heilongjiang Province, China.

BACKGROUND: The spread of multidrug-resistant tuberculosis (MDR-TB) Mycobacterium tuberculosis (M. tuberculosis) strains has been a big challenge to the TB control and prevention in China. Knowledge about patterns of drug resistance in TB high-burden areas of China is crucial to develop appropriate control strategies. We conducted a comprehensive investigation of the resistance pattern of M. tuberculosis in Heilongjiang Province. METHODS: 1427 M. tuberculosis clinical strains were isolated from pulmonary TB patients hospitalized between 2007 and 2012. The susceptibility of the isolates to the first-line anti-TB drugs and the resistance of MDR M. tuberculosis to fluoroquinolones were examined. We also performed a statistical analysis to identify the correlated risk factors for high burden of MDR-TB. RESULTS: The global resistance rates of 2007-2012 to the first-line drugs and MDR were 57.0 and 22.8 %, respectively. Notably, the primary MDR-TB and pan-resistance rates were as high as 13.6 and 5.0 %, respectively. Of MDR M. tuberculosis isolates (2009), approximately 13 % were not susceptible to any of the fluoroquinolones tested. Being age of 35 to 54, high re-treatment proportion, the presence of cavity lesion, and high proportion of shorter hospitalization are correlated with the development of MDR-TB. CONCLUSIONS: The high prevalence of drug resistant, MDR-TB, and fluoroquinolone-resistant MDR-TB is a big concern for TB control. More importantly, in order to control the development of MDR-TB effectively, we need to pay more attention to the primary resistance. Targeting reducing the prevalence of the risk factors may lead to better TB control in China.

Complex molecular mechanisms underlying seedling salt tolerance in rice revealed by comparative transcriptome and metabolomic profiling.

To understand the physiological and molecular mechanisms underlying seedling salt tolerance in rice (Oryza sativa L.), the phenotypic, metabolic, and transcriptome responses of two related rice genotypes, IR64 and PL177, with contrasting salt tolerance were characterized under salt stress and salt+abscisic acid (ABA) conditions. PL177 showed significantly less salt damage, lower Na(+)/K(+) ratios in shoots, and Na(+) translocation from roots to shoots, attributed largely to better salt exclusion from its roots and salt compartmentation of its shoots. Exogenous ABA was able to enhance the salt tolerance of IR64 by selectively decreasing accumulation of Na(+) in its roots and increasing K(+) in its shoots. Salt stress induced general and organ-specific increases of many primary metabolites in both rice genotypes, with strong accumulation of several sugars plus proline in shoots and allantoin in roots. This was due primarily to ABA-mediated repression of genes for degradation of these metabolites under salt. In PL177, salt specifically up-regulated genes involved in several pathways underlying salt tolerance, including ABA-mediated cellular lipid and fatty acid metabolic processes and cytoplasmic transport, sequestration by vacuoles, detoxification and cell-wall remodeling in shoots, and oxidation-reduction reactions in roots. Combined genetic and transcriptomic evidence shortlisted relatively few candidate genes for improved salt tolerance in PL177.

Temporal profiling of primary metabolites under chilling stress and its association with seedling chilling tolerance of rice (Oryza sativa L.).

BACKGROUND: Chilling stress is a major factor limiting rice production. Rice genotypes differ greatly in their seedling chilling tolerance (CT), which is known to involve differential expression of large numbers of genes and proteins. To further understand the metabolomic responses of rice to chilling stress, profiles of the 106 primary metabolites of a CT japonica variety, Lijiangxintuanhegu (LTH) and a chilling sensitive indica line, IR29, were investigated under a time-series of chilling stress and non-stress control conditions at the seedling stage. RESULTS: We identified 106 primary metabolites that were temporally and genotype-dependently regulated in LTH and IR29 under the time-series chilling stress and subsequent recovery. Three major groups of primary metabolites, amino acids (AAs), organic acids (OAs) and sugars, showed distinct change patterns in both genotypes in response to the chilling stress: a more general accumulation of most AAs, more dramatic decreased levels of most OAs, and greatly reduced levels for most sugars at early time points of stress but increased levels of specific sugars at the later time points of stress. Compared to IR29, LTH had more metabolites showing chilling induced changes, greater levels of these metabolomic changes and a greater ability to recover after stress, implying that LTH used a positive energy-saving strategy against chilling stress. During subsequent recovery, more metabolites were significantly and exclusively up-regulated in LTH, indicating their positive role in chilling tolerance. A comparative analysis of these metabolites data and differentially expressed genes data allowed identification of 7 AAs and related genes that were both chilling responsive and contributed greatly to the CT of LTH. CONCLUSIONS: The metabolomic responses of rice to chilling stress at the seedling stage were dynamic and involved large numbers of the metabolites. The chilling induced changes of three major groups of metabolites, AAs, OAs and sugars, in rice were well coordinated. The high level seedling CT of LTH was apparently attributed to its increased levels of most AAs and reduced energy consumption that resulted in increased glycolysis and strong resilience on recovery. The results of this study extend our understanding of molecular mechanisms of chilling stress tolerance in rice.

Three genetic systems controlling growth, development and productivity of rice (Oryza sativa L.): a reevaluation of the 'Green Revolution'.

The Green Revolution (GR-I) included worldwide adoption of semi-dwarf rice cultivars (SRCs) with mutant alleles at GA20ox2 or SD1 encoding gibberellin 20-oxidase. Two series of experiments were conducted to characterize the pleiotropic effects of SD1 and its relationships with large numbers of QTLs affecting rice growth, development and productivity. The pleiotropic effects of SD1 in the IR64 genetic background for increased height, root length/mass and grain weight, and for reduced spikelet fertility and delayed heading were first demonstrated using large populations derived from near isogenic IR64 lines of SD1. In the second set of experiments, QTLs controlling nine growth and yield traits were characterized using a new molecular quantitative genetics model and the phenotypic data of the well-known IR64/Azucena DH population evaluated across 11 environments, which revealed three genetic systems: the SD1-mediated, SD1-repressed and SD1-independent pathways that control rice growth, development and productivity. The SD1-mediated system comprised 43 functional genetic units (FGUs) controlled by GA. The SD1-repressed system was the alternative one comprising 38 FGUs that were only expressed in the mutant sd1 backgrounds. The SD1-independent one comprised 64 FGUs that were independent of SD1. GR-I resulted from the overall differences between the former two systems in the three aspects: (1) trait/environment-specific contributions; (2) distribution of favorable alleles for increased productivity in the parents; and (3) different responses to (fertilizer) inputs. Our results suggest that at 71.4 % of the detected loci, a QTL resulted from the difference between a functional allele and a loss-of-function mutant, whereas at the remaining 28.6 % of loci, from two functional alleles with differentiated effects. Our results suggest two general strategies to achieve GR-II (1) by further exploiting the genetic potential of the SD1-repressed and SD1-independent pathways and (2) by restoring the SD1-mediated pathways, or 'back to the nature' to fully exploit the genetic diversity of those loci in the SD1-mediated pathways which are virtually inaccessible to most rice-breeding programs worldwide that are exclusively based on sd1.