DPSCs regulate epithelial-T cell interactions in oral submucous fibrosis

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous lesion characterized by fibrous tissue deposition, the incidence of which correlates positively with the frequency of betel nut chewing. Prolonged betel nut chewing can damage the integrity of the oral mucosal epithelium, leading to chronic inflammation and local immunological derangement. However, currently, the underlying cellular events driving fibrogenesis and dysfunction are incompletely understood, such that OSF has few treatment options with limited therapeutic effectiveness. Dental pulp stem cells (DPSCs) have been recognized for their anti-inflammatory and anti-fibrosis capabilities, making them promising candidates to treat a range of immune, inflammatory, and fibrotic diseases. However, the application of DPSCs in OSF is inconclusive. Therefore, this study aimed to explore the pathogenic mechanism of OSF and, based on this, to explore new treatment options.

METHODS

A human cell atlas of oral mucosal tissues was compiled using single-cell RNA sequencing to delve into the underlying mechanisms. Epithelial cells were reclustered to observe the heterogeneity of OSF epithelial cells and their communication with immune cells. The results were validated in vitro, in clinicopathological sections, and in animal models. In vivo, the therapeutic effect and mechanism of DPSCs were characterized by histological staining, immunohistochemical staining, scanning electron microscopy, and atomic force microscopy.

RESULTS

A unique epithelial cell population, Epi1.2, with proinflammatory and profibrotic functions, was predominantly found in OSF. Epi1.2 cells also induced the fibrotic process in fibroblasts by interacting with T cells through receptor-ligand crosstalk between macrophage migration inhibitory factor (MIF)-CD74 and C-X-C motif chemokine receptor 4 (CXCR4). Furthermore, we developed OSF animal models and simulated the clinical local injection process in the rat buccal mucosa using DPSCs to assess their therapeutic impact and mechanism. In the OSF rat model, DPSCs demonstrated superior therapeutic effects compared with the positive control (glucocorticoids), including reducing collagen deposition and promoting blood vessel regeneration. DPSCs mediated immune homeostasis primarily by regulating the numbers of KRT19 + MIF + epithelial cells and via epithelial-stromal crosstalk.

CONCLUSIONS

Given the current ambiguity surrounding the cause of OSF and the limited treatment options available, our study reveals that epithelial cells and their crosstalk with T cells play an important role in the mechanism of OSF and suggests the therapeutic promise of DPSCs.

[The mediating effect of resilience on anxiety and subjective well-being in occupational population]

Objective: To explore the current situation of anxiety, subjective well-being in occupational population and the mediating effect of resilience. Methods: From March 24th to 26th, 2020, a cross-sectional survey was conducted among occupational population aged ≥18 years old using online questionnaires. A total of 2134 valid questionnaires were obtained, with respondents from 30 provinces, autonomous regions, and municipalities directly under the Central Government. Their general demographic data, subjective well-being, anxiety, and resilience were collected. Pearson χ(2) test and Spearson correlation analysis were used for data analysis, and structural equation model was used to explore the mediating effect of resilience on anxiety and subjective well-being. Results: The age of the respondents ranged from 18 to 60 years old, with an average age of (31.19±7.09) years old, including 1075 (50.4%) women and 1059 (49.6%) men. The positive rates of low subjective well-being and anxiety were 46.5% (992/2134) and 28.4% (607/2134), respectively. Anxiety scores were significantly negatively correlated with subjective well-being scores and resilience scores (r(s)=-0.52, -0.41, P<0.05), while resilience was significantly positively correlated with subjective well-being (r(s)=0.32, P<0.05). Structural equation models showed that anxiety had a negative predictive effect on subjective well-being, while resilience not only had a positive predictive effect on subjective well-being, but also played a mediating role between anxiety and subjective well-being, with a mediating effect of 9.9%. Conclusion: The situation of anxiety and well-being in the occupational population is still not optimistic, and resilience has a mediating effect between anxiety and subjective well-being.

[Current status of research on short-term urogenital function after transanal total mesorectal excision and laparoscopic total mesorectal excision]

Thanks to the new surgical approach, transanal total mesorectal excision (taTME) has a better operative field exposure than laparoscopic-assisted total mesorectal excision (laTME), especially for male patients with obesity, pelvic stenosis or prostate hypertrophy. Nevertheless, whether the urogenital function and quality of life after taTME are better as compared to laTME requires further study. According to the existing studies, taTME and laTME are not significantly different in symptoms of the urology system for male patients, but some large sample clinical studies show that the incidence of urethral mechanical injury after taTME is higher. Unfortunately, there is no elaboration on that for females. The sexual function of male patients after taTME and laTME is both impaired. The sexual function of male patients will be relieved to different degrees over time, but there is no significant difference. Compared with laTME, taTME shows advantages in the sexual function for female patients. There is no significant difference in short-term urogenital system function between taTME and laTME at present. As a new surgical approach, the impact on urogenital system function after taTME is acceptable. However, whether there is a significant difference in urogenital function between taTME and laTME needs further research. In addition, functional results still need comprehensive evaluation, and preoperative baseline evaluation also needs to be enhanced. The functional evaluation for male and female should be carried out separately rather than confused. Questionnaire for evaluation of functional results also needs to be verified.

Arthrobacter wenxiniae sp. nov., a novel plant growth-promoting rhizobacteria species harbouring a carotenoids biosynthetic gene cluster

A bacterial strain, designated AETb3-4^T was isolated from the rhizosphere of lily. Comparison of 16S rRNA gene sequences showed that the sequence from strain AETb3-4^T exhibits high sequence similarity with those of Arthrobacter silviterrae KIS14-16^T (97.9%), Arthrobacter livingstonensis LI2^T (97.2%) and Arthrobacter stackebrandtii CCM 2783^T (97.0%). Whole genome average nucleotide identity (ANI) and the digital DNA-DNA hybridization (dDDH) values between strain AETb3-4T and the reference strains A. silviterrae DSM 27180^T, A. livingstonensis L12^T and A. stackebrandtii DSM 16005^T were below 83.6% and 27.7%, respectively, values which are considerably below the proposed thresholds for the species delineation, consistent with the proposal that strain AETb3-4^T represents a novel species. The genome size of strain AETb3-4^T is 4.33 Mb and the genomic DNA G + C content is 67.3%. The main polar lipids were identified as phosphatidylglycerol, diphosphatidylglycero, phosphatidylinositol and an unidentified glycolipid. The major fatty acids (> 10%) were identified as anteiso-C_{15: 0} and anteiso-C_{17: 0}. The predominant menaquinone was found to be menaquinone 9 (MK-9) (H₂) (82.2%). Phenotypic tests allowed the strain to be differentiated from its close phylogenetic neighbors. Based on the results obtained, it is proposed that the strain AETb3-4^T (= CFCC 16390^T = LMG 31708^T) represents a novel species in the genus Arthrobacter, for which the names Arthrobacter wenxiniae sp. nov. is proposed. In addition, the novel strain AETb3-4^T has multiple plant growth-promoting characters including ACC-deaminase activity and production of IAA. Furthermore, the genome contains secondary metabolite biosynthesis gene clusters, including a carotenoid biosynthetic gene cluster, suggesting potential capacities for secondary metabolite synthesis. These data suggest that strain AETb3-4^T may have potential applications both in medicine and sustainable agriculture.

Caulobacter endophyticus sp. nov., an endophytic bacterium harboring three lasso peptide biosynthetic gene clusters and producing indoleacetic acid isolated from maize root

A novel Gram-stain-negative, aerobic and rod-shaped bacterium with a single polar flagellum or a stalk at the end of the cell, was isolated from maize roots in the Fangshan District of Beijing, People's Republic of China. The new strain designated 774^T produced indole acetic acid (IAA). The 16S rRNA gene sequence analysis indicated that strain 774^T belongs to the genus Caulobacter and is closely related to Caulobacter flavus RHGG3^T, Caulobacter zeae 410^Tand Caulobacter radices 695^T, all with sequence similarities of 99.9%. The genome size of strain774^T was 5.4 Mb, comprising 5042 predicted genes with a DNA G+C content of 68.7%.Three striking lasso peptide biosynthetic gene clusters and two IAA synthesis genes belonging to the TPM pathway were also found in the genome of strain 774^T. The average nucleotide identity values and digital DNA-DNA hybridization values of the strain774^T with its closely phylogenetic neighbours were less than 91.5% and 45.0%, respectively, indicating a new Caulobacter species. The major fatty acids of strain774^T were identified as C16: 0 (27.7%), summed feature 3 (C16: 1ω6c and/or C16: 1ω7c) (12.6%) and summed feature 8 (C18: 1ω7c and/or C18: 1ω6c) (42.9%).The major polar lipids consisted of phosphatidyl-glycerol and glycolipids. The predominant ubiquinone was identified as Quinone 10. Based on the polyphasic characterization, strain 774^T represents a novel species of the genus Caulobacter, for which the name Caulobacter endophyticus sp. nov. is proposed with 774^T (= CGMCC 1.16558^T = DSM 106777^T) as the type strain.

[The development process and new requirements of structured training on transanal total mesorectal resection]

Due to the technical difficulty and long learning curve, the benefits of Transanal total mesorectal excision may be obscured by surgical complications that arise from rapid, large-scale development, therefore the surgeons need to receive sufficient training before performing this surgery. At present, a mature structured training system has been formed, but the development of structured training has not met the needs of existing surgical development. In order to standardize the development of transanal total mesorectal excision, the European Society of Colorectal Diseases and 14 international surgical societies recently launched the "International Expert Consensus Guidelines for the Indication, Implementation and Quality Evaluation of Transanal Total Mesorectum Resection". The consensus involves the requirements for trainees, the content and process of training, as well as the evaluation and registration of training results. Training in cadaver is the core of structured training. Beginners should receive repeated training and conduct the surgery under the guidance of instructors.

Rhizobium rhizophilum sp. nov., an indole acetic acid-producing bacterium isolated from rape (Brassica napus L.) rhizosphere soil

A novel Gram-stain-negative, aerobic, rod-shaped and indole acetic acid-producing strain, designated 7209-2^T, was isolated from rhizosphere of rape (Brassica napus L.) grown in the Yakeshi City, Inner Mongolia, PR China. The 16S rRNA gene sequence analysis indicated that strain 7209-2^T belongs to the genus Rhizobium and is closely related to Rhizobium rosettiformans W3^T, Rhizobium ipomoeae shin9-1^T and Rhizobium wuzhouense W44^T with sequence similarities of 98.2, 98.1 and 97.9 %, respectively. Phylogenetic analysis based on concatenated housekeeping recA and atpD gene sequences showed that strain 7209-2^T formed a group together with R. wuzhouense W44^T and R. rosettiformans W3^T, with sequences similarities of 92.6 and 91.1 %, respectively. The genome size of strain 7209-2^T was 5.25 Mb, comprising 5027 predicted genes with a DNA G+C content of 61.2 mol%. The average nucleotide identity and digital DNA-DNA hybridization comparisons among 7209-2^T and reference strains for the most closely related species showed values below the accepted threshold for species discrimination. The major fatty acids of strain 7209-2^T were summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c) and summed feature 2 (C_12 : 0 aldehyde and/or unknown 10.953) . The major polar lipids were found to consist of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and an unidentified aminophospholipid. The predominant ubiquinone was identified as quinone 10. Based on all the above results, strain 7209-2^T represents a novel species of the genus Rhizobium, for which the name Rhizobium rhizophilum sp. nov. is proposed with 7209-2^T (=CGMCC 1.15691^T=DSM 103161^T) as the type strain.

[Moderating effect of sense of coherence between occupational stress and depression]

Objective: To explore the moderating effect of sense of coherence in the relationship between occupational stress and depression. Methods: From June to September in 2018, migrant workers were purposively selected from the urban (including office buildings, shopping malls, barber shops or restaurants and other service enterprises) and suburban (including microelectronics, internet, clothing processing and art design and other factories) areas of Shanghai. A total of 3 034 people were investigated and 2 573 valid questionnaires were collected. Patient health questionnaire (PHQ), sense of coherence questionnaire (SOC) and job content questionnaire (JCQ) were used to investigate the levels depression, sense of coherence and occupational stress. Hierarchical regression analysis was used to analyze the moderating effect of sense of coherence on occupational stress and depression, and SPSS PROCESS macro program and Bootstrap method were used to further explore the moderating effect of sense of coherence. Results: The age of total 2 573 migrant workers was (28.24±7.33) years old and 49.79% of them were males. The scores of depression, occupational stress and sense of coherence were 6.67±4.74, 28.45±4.38 and 62.02±10.89, respectively. The depression level was positively correlated with occupational stress (r=0.33, P=0.007), and negatively correlated with sense of coherence (r=-0.53, P=0.003). The hierarchy regression analysis suggested that the interaction between occupational stress and sense of coherence was associated with depression symptom (β=-0.07, P=0.001). Bootstrap analysis showed that occupational stress was not associated with depression symptom with high level of sense of sense of coherence (β=0.04, 95%CI=-0.01-0.10), while occupational stress was associated with depression symptom with low level of sense of sense of coherence (β=0.19, 95%CI=0.14-0.23). Conclusion: The high level of sense of coherence has a moderating effect on the relationship between occupational stress and depressive symptoms, while the low level of sense of coherence does not have this effect.

Paenibacillus apii sp. nov., a novel nifH gene-harbouring species isolated from the rhizospheres of vegetable plants grown in different regions of northern China

Two nifH gene-harbouring bacterial strains were isolated from rhizospheres of different vegetable plants grown in different regions of northern PR China. The two strains possessed almost identical 16S rRNA gene sequences. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains were 99.21 and 93.6% respectively, suggesting they belong to one species. Based on 16S rRNA gene phylogeny, the two strains were clustered together with Paenibacillus rhizophilus 7197^T, Paenibacillus sabinae T27^T and Paenibacillus forsythiae T98^T, but on a separate branch. Novelty of the species was confirmed by ANI and dDDH comparisons between the type strain 7124^T and its closest relatives, since the obtained values were considerably below the proposed thresholds for the species delineation. The genome size of strain 7124^T was 5.40 Mb, comprising 5050 predicted genes with a DNA G+C content of 52.3 mol%. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three unidentified lipids. The major cellular fatty acids were anteiso-C_{15  :  0} (52.9%) and C_{16  :  0} (23.4 %). Menaquinone-7 was reported as the major respiratory quinone. The diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. Based on phylogenetic, genomic, chemotaxonomic and phenotypic data, the two isolates are considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus apii sp. nov. is proposed, with 7124^T (=DSM 103172^T=CGMCC 1.15689^T) as type strain.

[CbCYP716A261, a New β-Amyrin 28-Hydroxylase Involved in Conyzasaponin Biosynthesis from Conyza blinii]

Conyzasaponins produced by the traditional Chinese herb Conyza blinii are oleanane-type saponins with a wide range of biological activities. Here, we identified a gene, designated CbCYP716A261, encoding a β-amyrin 28-hydroxylase in conyzasaponins biosynthesis. Ten full putative CYP sequences were isolated from Conyza blinii transcript tags. The CbCYP716A261 gene product was selected as the putative β-amyrin 28-hydroxylase by phylogenetic analysis and transcriptional activity analysis of methyl jasmonate-treated Conyza blinii. To identify the enzymatic activity, we performed enzymatic activity experiments in vitro and in vivo. The HPLC results revealed that CbCYP716A261 catalyzes the hydroxylation of β-amyrin at the C-28 position to yield oleanolic acid. Our findings provide new information about the conyzasaponin biosynthesis pathway and widen the list of isolated β-amyrin 28-hydroxylases.

Mesorhizobium rhizophilum sp. nov., a 1-aminocyclopropane-1-carboxylate deaminase producing bacterium isolated from rhizosphere of maize in Northeast China

A novel 1-aminocyclopropane-1-carboxylate deaminase producing bacterium, Gram- stain-negative, aerobic, motile, rod-shaped strain designated YM1C-6-2^T was isolated from rhizosphere of maize grown in Northeast China. The 16S rRNA gene sequence analysis indicated that strain YM1C-6-2^T belongs to the genus Mesorhizobium and is closely related to Mesorhizobium alhagi CCNWXJ12-2^T and M. camelthorni CCNWXJ40-4^T with sequence similarities of 98.4% and 97.9%, respectively. Multilocus sequence analysis of other housekeeping genes revealed that the new isolates YM1C-6-2^T forms a phylogenetically group with some species in the genus Mesorhizobium. The genome size of strain YM1C-6-2^T was 5.51 Mb, comprising 5378 predicted genes with a DNA G+C content of 64.5%. The average nucleotide identity and digital DNA-DNA hybridization comparisons between YM1C-6-2^T and the most related type strains showed values below the accepted threshold for species discrimination. The major fatty acids of strain YM1C-6-2^T were C_19:0 cyclo ω8c (47.5%), summed feature 8 (C_18:1ω7c and/or C_18:1ω6c) (19.5%) and C_16:0 (15.1%), which differed from the closely related reference strains in their relative abundance. The major polar lipids consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified aminophospholipid. The predominant ubiquinone was identified as Quinone 10. Phenotypic and biochemical analysis results indicated that strain YM1C-6-2^T can be distinguished from closely related type strains. Based on the above results, strain YM1C-6-2^T represents a novel species of the genus Mesorhizobium, for which the name Mesorhizobium rhizophilum sp. nov. is proposed with YM1C-6-2^T (= CGMCC 1.15487^T = DSM 101712^T) as the type strain.

[Current status of research on short-term quality of life after sphincteric-saving surgery in rectal cancer patients]

Sphincteric-saving surgery (SSS) is currently a hot spot in the treatment of mid-low rectal cancer. Although it preserves the anatomical continuity of the colon and anus, the postoperative functional outcomes and quality of life (QOL) remains to be confirmed. Current studies have shown that quality of life worsens at the first month after surgery, improves within 3-6 months, and stabilizes at about 1 year. The QOL was associated with patient-related factors, tumor-related factors, treatment-related factors and postoperative complications. For patient-related factors, younger patients have worse role function and sexual function but better cognitive function and physical function. Male patients deteriorate significantly in sexual and social function. For tumor-related factors, patients with lower rectal cancer have poorer defecation function. Those with advanced rectal cancer are more likely to suffer from side-effects related to chemotherapy. For treatment-related factors, patients undergoing intersphincteric resection have worse role function, body image and sexual interest. Preventive ileostomy results in the deterioration of role function, body image and sexual interest. Chemotherapy causes taste changes and chest pain. For postoperative complication, patients with anastomotic leakage have worse bowel function and psychological state. Patients with major low anterior resection syndrome and genitourinary dysfunction have worse global health score, social function and role function. In conclusion, short-term quality of life after sphincteric-saving surgery is acceptable. To improve QOL, specific intervention and guidance should be given to patients in this stage. Meanwhile, since many factors influence the quality of life simultaneously, researchers are confused about the questionnaire outcomes. Therefore, more specific and comprehensive tools are needed to evaluate QQL after sphincteric-saving surgery.

Paenibacillus rhizophilus sp. nov., a nitrogen-fixing bacterium isolated from the rhizosphere of wheat (Triticum aestivum L.)

A novel Gram-stain-variable, endospore-forming, motile, rod-shaped, facultative aerobic bacterium, designated 7197^T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) collected from Yakeshi County, Inner Mongolia, PR China. This isolate was found to have the highest 16S rRNA gene sequence similarity to Paenibacillussabinae T27^T (98.0 %), followed by Paenibacillussophorae S27^T (97.9 %) and Paenibacillusforsythiae T98^T (97.7 %). To ascertain the genomic relatedness of this strain to its phylogenetic neighbours, its genome sequence was determined. The average nucleotide identity values of genome sequences between the novel isolate and the type strains of related species P. sabinae T27^T, P. sophorae S27^T and P. forsythiae T98^T were 87.9 %, 85.8 and 83.9 %, respectively. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unidentified aminophospholipids and one unidentified aminolipid. The major cellular fatty acids were anteiso-C_15 : 0 (56.3 %), C_16 : 0 (15.7 %) and iso-C_15 : 0 (14.1 %).The genome size of strain 7197^T was 5.21 Mb, comprising 4879 predicted genes with a DNA G+C content of 51.9 mol%. Menaquinone-7 was reported as the major respiratory quinone. The diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. Based on phylogenetic, genomic, chemotaxonomic and phenotypic characteristics, strain 7197^T was classified as a novel species within the genus Paenibacillus, for which the name Paenibacillus rhizophilus sp. nov. is proposed. The type strain of Paenibacillus rhizophilus is 7197^T (=DSM 103168^T=CGMCC 1.15699^T).

[Mediating effect of work engagement between job stress and depressive symptoms in State Grid employees]

Objective: To explore the relationship between job stress, work engagement and depressive symptoms of State Grid workers, and to analyze the mediating effect of work engagement between job stress and depressive symptoms. Methods: A cross-sectional survey was conducted to investigate 845 employees from a State Grid company, using the brief job stress questionnaire, the Patient Health Questionnaire (PHQ-9) and 9-item Utrecht Work Engagement Scale (UWES-9) in March 2017. Results: The average score of work engagement was 4.49±1.42, the mean value of job stress was 1.15±0.33, the average score of depressive symptoms was 6.44±4.30, and the positive rate of depressive symptoms was 66.9%.There was a negative correlation between work engagement with both job stress and depressive symptoms (r=-0.193, -0.397, both P<0.01) , and job stress was positively correlated with depressive symptoms (r=0.260, P<0.01) . The relationship between job stress and depressive symptoms was partly mediated by work engagement, and the mediating effect accounted for 27.2% of the total effect. Conclusion: The work engagement of State Grid staff acts as the mediator between job stress and depressive symptoms, alleviating the depressive symptoms caused by job stress.

[Association between Long Working Hours and Job Stress and Depression among Employees from a State Grid Company]

Objective: This study was to understand the current situation of long working hours and identify the association of long working hours and job stress and depression among workers from one district company of state grid. Methods: The project was done with the cross-sectional survey. All questionnaires were completed by self-administered with informed consent. Employees' weekly working hours was reported by themselves; Using the PHQ-9 scale to assess depression, the JDC Model to evaluate job stress, and SPSS software to analyze data, the single factor chi-square test and multivariate Logistic analysis were performed to identify the association between long working hours and job stress, depression. Results: there were 35.3 percent employees with over 44 hours a week. The association between increasing weekly working hours and job stress and depression was statistically significant. Compared to the reference group (≤44 h) , for those who worked more than 44 hours per week, the odds ratio of job stress was 2.02 (95%CI=1.27-3.23) times increased, and the odds ratio of depression was 1.60 (95%CI=1.01-2.55) times increased, especially for those (≥60 h) , the odds ratio was 3.69 (95%CI=1.45-9.41) and 2.76 (95%CI=1.09-7.03) respectively. Conclusion: Long working hours can significantly increase the risk of job stress and depression among workers. When their weekly working hours exceeds 60, long working hours will be the independent risk factor for both job stress and depression.

Caulobacter zeae sp. nov. and Caulobacter radicis sp. nov., novel endophytic bacteria isolated from maize root (Zea mays L.)

Four bacterial strains designated 410^T, 441, 695^T and 736 were isolated from maize root in Beijing, P. R. China. Based on 16S rRNA gene phylogeny, the four strains formed two clusters in the genus Caulobacter. Since strain 441 was a clonal variety of strain 410^T, only three strains were selected for further taxonomic studies. The whole genome average nucleotide identity (ANI) value between strains 410^T and 695^T was 94.65%, and both strains shared less than 92.10% ANI values with their close phylogenetic neighbors Caulobacter vibrioides DSM 9893^T, Caulobacter segnis ATCC 21756^T and Caulobacter flavus CGMCC 1.15093^T. Strains 410^T and 695^T contained Q-10 as the sole ubiquinone and their major fatty acids were C_{16:0, 11-methyl C18:1ω 0}, 11-methyl C_{18: 1}ω7c, summed feature 3 (C_{16:1ω7c and/or C16:1ω 1}ω7c and/or C_{16: 1}ω6c) and summed feature 8 (C_{18:1ω7c and/or C18:1ω 1}ω7c and/or C_{18: 1}ω6c). Their major polar lipids consisted of glycolipids and phosphatidylglycerol, and phenotypic tests differentiated them from their closest phylogenetic neighbors. Based on the results obtained, it is proposed that the three strains represent two novel species, for which the names Caulobacter zeae sp. nov. (type strain 410^T=CGMCC 1.15991=DSM 104304) and Caulobacter radicis sp. nov. (type strain 695^T=CGMCC 1.16556=DSM 106792) are proposed.

Linear-shear-current modified Schrödinger equation for gravity waves in finite water depth

A nonlinear Schrödinger equation for the propagation of two-dimensional surface gravity waves on linear shear currents in finite water depth is derived. In the derivation, linear shear currents are assumed to be a linear combination of depth-uniform currents and constant vorticity. Therefore, the equation includes the combined effects of depth-uniform currents and constant vorticity. Next, using the equation, the properties of the modulational instability of gravity waves on linear shear currents are investigated. It is showed that shear currents significantly modify the modulational instability properties of weakly nonlinear waves. Furthermore, the influence of linear shear currents on Peregrine breather which can be seen as a prototype of freak waves is also studied. It is demonstrated that depth-uniform opposing currents can reduce the breather extension in both the time and spatial domain in intermediate water depth, but following currents has the adverse impact, indicating that a wave packets with freak waves formed on following currents contain more hazardous waves in finite water depth. However, the corresponding and coexisting vorticity can counteract the influence of currents. Additionally, if the water depth is deep enough, shear currents have negligible effect on the characteristics of Peregrine breathers.

Rhizobium wenxiniae sp. nov., an endophytic bacterium isolated from maize root

A novel Gram-stain-negative, aerobic, rod-shaped strain designated 166T was isolated from surface-sterilized root tissue of maize planted in the Fangshan District of Beijing, PR China. The 16S rRNA gene sequence analysis indicated that strain 166T belongs to the genus Rhizobium and is closely related to Rhizobium cellulosilyticum ALA10B2T and Rhizobium yantingense H66T with sequence similarities of 98.8 and 98.3 %, respectively. According to atpD and recA sequence analysis, the highest sequence similarity between strain 166T and R. cellulosilyticum ALA10B2T is 93.8 and 84.7 %, respectively. However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to R. cellulosilyticum DSM 18291T (20.8±2.3 %) and Rhizobium yantingense CCTCC AB 2014007T (47.2±1.4 %). The DNA G+C content of strain 166T was 59.8 mol%. The main polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, an unidentified aminophospholipid and an unidentified aminolipid. The major fatty acids of strain 166T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The results of the physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 166T from the type strains of closely related species, R. cellulosilyticum DSM 18291T and R. yantingense CCTCC AB 2014007T. Strain 166T represents a novel species within the genus Rhizobium, for which the name Rhizobium wenxiniae sp. nov. is proposed, with the type strain 166T (=CGMCC 1.15279T=DSM 100734T).

[Clinical treatment of metastatic papillary thyroid carcinoma in cervical lymph nodal with occult primary sites]

Objective:To discuss the diagnosis, treatment and prognosis of metastatic papillary thyroid carcinoma in cervical lymph nodal with occult primary sites. Method:The clinical data of 5 patients involved papillary thyroid carcinoma with cervical lymph nodal metastasis with occult primary sites from 2009 to 2015 were analyzed. Result:According to preoperation examinations, two of them only underwent neck lymph node resection and three patients underwent asubtotal or total thyroidectomy plus neck lymph node dissection. All the pathological results showed that there were metastatic papillary thyroid carcinoma in cervical lymph nodal, but the primary sites of thyroid tissue were normal. After 1 to 7 year follow-up, there was no recurrence. Conclusion:Whether to take the thyroidectomy need to be carefully considered thyroidectomy in patients with metastatic papillary thyroid carcinoma in cervical lymph nodal with occult primary sites.

[Workplace social capital and intention to stay among Chinese nurses: a structural equation model]

Objective: To explore a model that workplace social capital is associated with intention to stay (ITS) in the nursing profession and that this association is partially mediated by organizational commitment, job satisfaction, and job stress among Chinese nurses. Methods: A cross-sectional, observationalstudy was conducted in Shanghai, China between September and December 2014. Two thousandforty-two nurses from 23 healthcare organizations were recruited for the current study using a two-stage sampling process.Intention to stay, workplace social capital, job satisfaction, organizational commitment, and job stress was measured by validated scale. Measured variable path analysis (MVPA) was used to test their hypothesized relationships. Results: There were significant positive direct effects from workplace social capital (β=0.11, P<0.01) , organizational commitment (β=0.81, P<0.01) and job satisfaction (β=0.03, P<0.01) to ITS, and a negative direct effects from job strain to ITS (β=-0.03, P<0.01) . The model explained 84% of the variability in ITS. Additionally, workplace social capital had significant positive direct effects on organizational commitment (β=0.65, P<0.01) , job satisfaction (β=0.44, P<0.01) and negative direct effects on job strain (β=-0.35, P<0.01) . The indirect effect of social capital to ITS was 0.55. Job satisfaction was positively associated with organizational commitment (r=0.47, P<0.01) , and negtively associated with job stress (r=-0.12, P<0.01) . Job stress was negtively associated with organizational commitment (r=-0.20, P<0.01) . Conclusion: This study suggests that greater workplace social capital may lead to higher ITS in nursing primarily by increasing commitment to the nursing occupation and their job satisfaction and by reducing their sense of job stress.

[An adolescent with Hashimoto's encephalopathy after surgery and ¹³¹I radiotherapy for papillary thyroid carcinoma: one case report]

Hashimoto's encephalopathy is a rare brain disease. Its etiology is still unknown. In this paper, we reported a 15-year-old female patient underwent total thyroidectomy and lymph node dissection, due to a multifocal papilliferous carcinoma of the right lobus. Forty-two days after surgery, the patient was treated by ¹³¹I radiotherapy in another hospital and begun to have a headache after 48 hours. At last, the patient was diagnosed by HE on the basis of all considerations. She recovered from by i.v. Immunoglobulin. Till now, the patient has not relapsed for more than 4 years follow-up.

[Association between sense of coherence and occupational stress of workers in modern service industry in Shanghai, China]

Objective: To investigate understand the current status of the sense of coherence and occupational stress in modern service workers, and to analyze the association between occupational stress and the sense of coherence. Methods: From March to April, 2016, 834 modern service workers from 3 companies in Shanghai, China (in air transportation industry, marketing industry, and travel industry) were surveyed by non-ran-dom sampling. The self-completion questionnaires were filled out anonymously given the informed consent of the workers. The occupational stress questionnaire was used to evaluate occupational stress, and the Chinese version of the Sense of Coherence Scale (SOC-13) was used to assess the mental health. Results: The mean score for the sense of coherence of the respondents was 61.54±10.46, and 50.1% of them were self-rated as having occupational stress. There were significant differences in SOC score between groups with different ages, marital status, positions, lengths of service, family per capita monthly income, and weekly work hours (P<0.05). The occupational stress score differed significantly across groups with different marital status, lengths of service, and weekly work hours (P<0.05). The scores for working autonomy, social support, and occupational stress differed significantly between groups with different SOC levels (P<0.05). There were significant differences in SOC score and the distribution of low-SOC respondents between groups with different levels of working autonomy, social support, and occupational stress. High SOC is a protective factor for occupational stress (OR=0.39, 95%CI 0.26~ 0.59). Conclusion: Modern service workers in Shanghai have high SOC and moderate occupational stress. Therefore, improving SOC may reduce occupational stress.

Dyadobacter endophyticus sp. nov., an endophytic bacterium isolated from maize root

A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain, designated 65T, was isolated from surface-sterilized root tissue of maize, collected from Fangshan District of Beijing, People's Republic of China, and was subjected to a taxonomic study by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 65T belonged to the genus Dyadobacter and had highest 16S rRNA gene sequence similarity to Dyadobacter jiangsuensis CGMCC 1.12969T (99.1 %), Dyadobacter beijingensis CGMCC 1.6375T (98.8 %), Dyadobacter fermentans DSM 18053T (98.6 %) and Dyadobacter soli KCTC 22481T (98.6 %). However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to D. jiangsuensis CGMCC 1.12969T (18.2±1.3 %), D. beijingensis CGMCC 1.6375T (14.2±2.0 %), D. fermentans DSM 18053T (14.1±2.0 %) and D. soli KCTC 22481T (13.8±0.6 %). The predominant respiratory quinone was menaquinone-7 (MK-7) and the major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω5c, iso-C15 : 0 3-OH, C16 : 0 3-OH and C16 : 0. The polar lipid profile of strain 65T revealed the presence of phosphatidylethanolamine, four aminolipids and two unidentified phospholipids. The DNA G+C content was 46.6 mol%. The results of physiological and biochemical tests and the differences in the fatty acid profiles allowed the clear phenotypic differentiation of strain 65T from closely related species of the genus Dyadobacter. Strain 65T thus represents a novel species within the genus Dyadobacter, for which the name Dyadobacterendophyticus sp. nov. is proposed. The type strain is 65T (=CGMCC 1.15288T=DSM 100786T).

Sphingomonaszeicaulis sp. nov., an endophytic bacterium isolated from maize root

A novel Gram-staining-negative, aerobic and rod-shaped strain designated 541T was isolated from surface-sterilized root tissue of maize, collected from the Fangshan District of Beijing, People's Republic of China, and was subjected to a taxonomic study using a polyphasic approach. According to a phylogenetic tree based on 16S rRNA gene sequences, strain 541T represented a member of the genus Sphingomonas and clustered with Sphingomonas sanxanigenens DSM 19645T, with which it shared the highest 16S rRNA gene sequence similarity (98.8 %). The predominant respiratory quinone was ubiquinone-10 (Q-10), the major polyamine was sym-homospermidine and the major cellular fatty acids were C18 : 1ω7c (50.9 %), C16 : 0 (22.0 %) and C14 : 0 2-OH (11.4 %). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and sphingoglycolipid. The DNA G+C content was 64.7 mol%. DNA-DNA relatedness between strain 541T and its closest phylogenetic relative Sphingomonas sanxanigenens DSM 19645T was 50.8 %. The results of physiological and biochemical tests and the differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 541T from closely related species of the genus Sphingomonas. Strain 541T represents a novel species within the genus Sphingomonas, for which the nameSphingomonas zeicaulis sp. nov. is proposed, with the type strain 541T (=CGMCC 1.15008T=DSM 100587T).

Filimonas zeae sp. nov., an endophytic bacterium isolated from maize root

A novel Gram-stain-negative, aerobic, motile by gliding and filamentous strain, designated 772^T,was isolated from surface-sterilized root tissue of maize planted in the Fangshan District of Beijing, China. 16S rRNA gene sequence analysis indicated that strain 772^T was closely related to Filimonas endophytica SR2-06^T andFilimonas lacunae YT21^T of the family Chitinophagaceae with sequence similarities of 99.0 and 96.9 %, respectively. However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to Filimonas. endophytica KCTC 42060^T (18.7±1.8 %) and Filimonas. lacunae DSM 21054^T (17.9±2.0%). The DNA G+C content of strain 772^T was 44.9 mol%. The respiratory quinone was menaquinone-7 and the polar lipid profile consisted of phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified phospholipids and one unidentified lipid. The major fatty acids were iso-C15 : 0 and iso-C15 : 1 G. The results of the physiological and biochemical tests and minor differences in the fatty acid profiles allowed the clear phenotypic differentiation of strain 772^T from the closely related species Filimonas. endophytica andF. lacunae. Strain 772^T thus represents a novel species within the genus Filimonas, for which the name Filimonas zeae sp. nov. is proposed. The type strain is 772^T (=CGMCC 1.15290^T=DSM 100760^T).

CXCR1 Regulates Pulmonary Anti-Pseudomonas Host Defense

Pseudomonas aeruginosa is a key opportunistic pathogen causing disease in cystic fibrosis (CF) and other lung diseases such as chronic obstructive pulmonary disease (COPD). However, the pulmonary host defense mechanisms regulating anti-P. aeruginosa immunity remain incompletely understood. Here we demonstrate, by studying an airway P. aeruginosa infection model, in vivo bioluminescence imaging, neutrophil effector responses and human airway samples, that the chemokine receptor CXCR1 regulates pulmonary host defense against P. aeruginosa. Mechanistically, CXCR1 regulates anti-Pseudomonas neutrophil responses through modulation of reactive oxygen species and interference with Toll-like receptor 5 expression. These studies define CXCR1 as a novel, noncanonical chemokine receptor that regulates pulmonary anti-Pseudomonas host defense with broad implications for CF, COPD and other infectious lung diseases.

Paenibacillus radicis sp. nov., an endophytic bacterium isolated from maize root

A novel Gram-stain-positive, aerobic, endospore-forming, and rod-shaped strain designated 694^T was isolated from surface-sterilized root tissue of a maize planted in the Fangshan District of Beijing, People's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Paenibacillus. High levels of 16S rRNA gene sequence similarity were found between strain 694^T and Paenibacillus xinjiangensis DSM 30034^T (98.5 %) and Paenibacillus glycanilyticus (98.1 %), respectively. However, the DNA-DNA hybridization values between strain 694^T and its close relatives P. xinjiangensis 16970^T and Paenibacillus algorifonticola CGMCC 1.10223^T were 30.0 % and 36.7 % respectively. The DNA G+C content of strain 694^T was determined to be 46.9 mol%. The predominant respiratory quinone was identified as menaquinone-7 and the polar lipid profile was found to be composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were found to be anteiso-C_15 : 0 (42.1 %), iso-C_15 : 0 (18.4 %), iso-C_16 : 0 (11.2 %) and C_16 : 0 (12.1 %). The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 694^T from the closely related species in the genus Paenibacillus. Strain 694^T is concluded to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus radicis sp. nov. is proposed, with the type strain 694^T ( = CGMCC 1.15286^T = DSM 100762^T).

Flavobacterium endophyticum sp. nov., a nifH gene-harbouring endophytic bacterium isolated from maize root

A novel Gram-stain-negative, aerobic, rod-shaped bacterium, designated strain 522T, was isolated from surface-sterilized root tissue of maize planted in Fangshan District of Beijing, China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belonged to the genus Flavobacterium and showed less than 93.9 % similarity to the type strains of all recognized species of the genus Flavobacterium. The predominant respiratory quinone was menaquinone-6 and the polar lipid profile was composed of the major lipids phosphatidylethanolamine, phosphatidylserine and two unidentified amino lipids. The major fatty acids were C15 : 0, iso-C15 : 0, iso-C15 : 1 G and iso-C16 : 0.The G+C content of the DNA was 37.7 mol%. The results of physiological and biochemical tests and the differences in fatty acid profiles allowed the clear phenotypic differentiation of strain 522T from closely related species of the genus Flavobacterium. Strain 522T therefore represents a novel species within the genus Flavobacterium, for which the name Flavobacterium endophyticum sp. nov. is proposed. The type strain is 522T ( = ACCC 19708T = DSM 29537T).

Role of IL-17 gene polymorphisms in the susceptibility to gastric cancer

We conducted a study to investigate the role of three IL-17 gene single nucleotide polymorphisms (SNP) (rs2275913G>A, rs3748067C>T, and rs763780 T>C) in the development of gastric cancer. A total of 252 patients with gastric cancer and 252 control subjects were collected between May 2012 and May 2014. The SNP genotyping of IL-17A rs2275913G>A and rs3748067C>T and IL-17F rs763780 T>C was performed using the Sequenom MassARRAY platform (Sequenom, San Diego, CA, USA) according to the manufacturer instructions. By conditional regression analysis, individuals carrying the AA and the GA+AA genotypes of rs2275913G>A were correlated with an elevated risk of gastric cancer when compared with those carrying the GG genotype, and the adjusted ORs (95%CIs) were 2.05 (1.13-3.76) for the AA genotype and 1.45 (1.03-2.08) for the GA+AA genotype. In conclusion, our results suggest that the IL-17A rs3748067C>T and IL-17F rs763780 T>C polymorphisms play an important role in the risk of gastric cancer in a Chinese population.

Optical and magneto-optical anisotropies in large-area two-dimensional Co antidots film

In this work, we investigate the plasmon-induced optical and magneto-optical anisotropies in the large-area square-ordered Co antidots film. It shows that both the outline of reflectivity spectrum and Kerr spectrum are significantly modified by surface plasmon polarition (SPP) resonances. Moreover, the magnitude of Kerr angle reaches to about 10 minutes at the azimuthal angle 45°, which is over 3 times of that of pure Co film. These phenomena are attributed to the SPP resonances with different diffraction orders of reciprocal lattice vectors.

Increased prospective memory interference in normal and pathological aging: different roles of motor and verbal processing speed

This is a study on prospective memory (PM) and the PM interference effect in normal and pathological aging. One hundred and seven subjects, including 41 healthy young adults, 40 non-demented older adults and 26 patients with mild Alzheimer's disease (AD) participated in this study using a laboratory event-based PM task. PM task performance was comparable between the non-demented older and young adults, but impaired in the AD patients. The PM interference effect increased progressively from the healthy young adults, the non-demented older adults, to the AD patients. Path analysis revealed that the possible mechanism mediating the increased PM interference was the slow motor processing speed in normal aging, while it was the slow verbal speed in pathological aging. It is suggested that different neuropsychological mechanisms may underpin the affected performance of PM task in normal and pathological aging.

Qualitative and quantitative analyses of nucleosides and nucleobases in Ganoderma spp. by HPLC–DAD-MS

A high-performance liquid chromatography-diode array detector-mass spectrometry (HPLC-DAD-MS) analytical method was developed for detection of the nucleosides and nucleobases in two species of Lingzhi, the dried sporophore of Ganoderma lucidum and G. sinense. The method, combining advantages of both DAD and MS, was successfully used to qualitatively identify for six nucleosides namely, adenosine, cytidine, guanosine, inosine, thymidine, uridine and five nucleobases namely, adenine, guanine, hypoxanthine, thymine and uracil in Lingzhi samples. Quantitative analyses showed that uridine was the most abundant nucleoside in these Lingzhi samples and the contents of nine target analytes were found to be different in pileus and stipes of the fruiting bodies and among the different species of G. spp. The established method might apply as an alternative approach for the quality assessment of Lingzhi.

GC-MS fingerprint of Pogostemon cablin in China

Pogostemon cablin, originating in Malaysia and India, is cultivated in southern China including Guangdong and Hainan Province, which was called GuangHuoXiang to differentiate it from the HuoXiang of the north, the species Agastache rugosa, that it resembles. Essential oil of P. cablin mainly contributes to the pharmacological activities and the therapeutic properties of the essential oils are directly correlated with their qualitative and quantitative composition. For controlling the quality, standard fingerprint of P. cablin collected from different regions was developed by using GC-MS. Nine compounds including beta-patchoulene, caryophyllene, alpha-guaiene, seychellene, beta-guaiene, delta-guaiene, spathulenol, patchouli alcohol and pogostone were identified among 10 main peaks in P. cablin. Hierarchical clustering analysis based on characteristics of 10 investigated peaks in GC profiles showed that 18 samples were divided into three main clusters, patchouliol-type, pogostone-type and an interim-type, which was the one between the two chemotypes. The simulative mean chromatogram for the three types P. cablin was generated using the Computer Aided Similarity Evaluation System. The fingerprint can help to distinguish the substitute or adulterant, and further assess the differences of P. cablin grown in various areas of China.

Phosphorus-free membrane lipids of Sinorhizobium meliloti are not required for the symbiosis with alfalfa but contribute to increased cell yields under phosphorus-limiting conditions of growth

The microsymbiont of alfalfa, Sinorhizobium meliloti, possesses phosphatidylglycerol, cardiolipin, phosphatidylethanolamine, and phosphatidylcholine as major membrane phospholipids, when grown in the presence of sufficient accessible phosphorus sources. Under phosphate-limiting conditions of growth, S. meliloti replaces its phospholipids by membrane lipids that do not contain any phosphorus in their molecular structure and, in S. meliloti, these phosphorus-free membrane lipids are sulphoquinovosyl diacylglycerols (SL), ornithine-containing lipids (OL), and diacylglyceryl-N,N,N-trimethylhomoserines (DGTS). In earlier work, we demonstrated that neither SL nor OL are required for establishing a nitrogen-fixing root nodule symbiosis with alfalfa. We now report the identification of the two structural genes btaA and btaB from S. meliloti required for DGTS biosynthesis. When the sinorhizobial btaA and btaB genes are expressed in Escherichia coli, they cause the formation of DGTS in this latter organism. A btaA-deficient mutant of S. meliloti is unable to form DGTS but can form nitrogen-fixing root nodules on alfalfa, demonstrating that sinorhizobial DGTS is not required for establishing a successful symbiosis with the host plant. Even a triple mutant of S. meliloti, unable to form any of the phosphorus-free membrane lipids SL, OL, or DGTS is equally competitive for nodule occupancy as the wild type. Only under growth-limiting concentrations of phosphate in culture media did mutants that could form neither OL nor DGTS grow to lesser cell densities.

Identification of a gene required for the formation of lyso-ornithine lipid, an intermediate in the biosynthesis of ornithine-containing lipids

Under phosphate-limiting conditions, some bacteria replace their membrane phospholipids by lipids not containing any phosphorus. One of these phosphorus-free lipids is an ornithine-containing lipid (OL) that is widespread among eubacteria. In earlier work, we had identified a gene (olsA) required for OL biosynthesis that probably encodes an O-acyltransferase using acyl-acyl carrier protein (acyl-AcpP) as an acyl donor and that converts lyso-ornithine lipid into OL. We now report on a second gene (olsB) required for OL biosynthesis that is needed for the incorporation of radiolabelled ornithine into OL. Overexpression of OlsB in an olsA-deficient mutant of Sinorhizobium (Rhizobium) meliloti leads to the transient accumulation of lyso-ornithine lipid, the biosynthetic intermediate of OL biosynthesis. Overexpression of OlsB in Escherichia coli is sufficient to cause the in vivo formation of lyso-ornithine lipid in this organism and is the cause for a 3-hydroxyacyl-AcpP-dependent acyltransferase activity forming lyso-ornithine lipid from ornithine. These results demonstrate that OlsB is required for the first step of OL biosynthesis, in which ornithine is N-acylated with a 3-hydroxy-fatty acyl residue in order to obtain lyso-ornithine lipid. OL formation in a wild-type S. meliloti is increased upon growth under phosphate-limiting conditions. Expression of OlsB from a broad host range vector leads to the constitutive formation of relatively high amounts of OL (12-14% of total membrane lipids) independently of whether strains are grown in the presence of low or high concentrations of phosphate, suggesting that in S. meliloti the formation of OlsB is usually limiting for the amount of OL formed in this organism. Open reading frames homologous to OlsA and OlsB were identified in many eubacteria and although in S. meliloti the olsB and olsA gene are 14 kb apart, in numerous other bacteria they form an operon.

Mesorhizobium septentrionale sp. nov. and Mesorhizobium temperatum sp. nov., isolated from Astragalus adsurgens growing in the northern regions of China

Ninety-five rhizobial strains isolated from Astragalus adsurgens growing in the northern regions of China were classified into three main groups, candidate species I, II and III, based on a polyphasic approach. Comparative analysis of full-length 16S rRNA gene sequences of representative strains showed that candidate species I and II were Mesorhizobium, while candidate species III, which consisted of non-nodulating strains, was closely related to Agrobacterium tumefaciens. The phylogenetic relationships of the three candidate species and some related strains were also confirmed by the sequencing of glnA genes, which were used as an alternative chromosomal marker. The DNA–DNA relatedness was between 11·3 and 47·1 % among representative strains of candidate species I and II and the type strains of defined Mesorhizobium species. Candidate III had DNA relatedness of between 4·3 and 25·2 % with type strains of Agrobacterium tumefaciens and Agrobacterium rubi. Two novel species are proposed to accommodate candidate species I and II, Mesorhizobium septentrionale sp. nov. (type strain, SDW014T=CCBAU 11014T=HAMBI 2582T) and Mesorhizobium temperatum sp. nov. (type strain, SDW018T=CCBAU 11018T=HAMBI 2583T), respectively. At least two distinct nodA sequences were identified among the strains. The numerically dominant nodA sequence type was most similar to that from the Mesorhizobium tianshanense type strain and was identified in strains belonging to the two novel species as well as other, as yet, undefined genome types. Host range studies indicate that the different nodA sequences correlate with different host ranges. Further comparative studies with the defined Agrobacterium species are needed to clarify the taxonomic identity of candidate species III.

Identification of a gene required for the biosynthesis of ornithine-derived lipids

Phospholipids are the membrane-forming constituents in all living organisms. In addition to phosphorus-containing lipids, the membranes of numerous bacteria contain significant amounts of phosphorus-free polar lipids, often derived from amino acids. Although lipids derived from the amino acid ornithine are widespread among bacteria, their biosynthesis is unknown. Here, we describe the isolation of mutants of Sinorhizobium meliloti deficient in the biosynthesis of ornithine-derived lipids (OL). Complementation of such mutants with a sinorhi-zobial cosmid gene bank, subcloning of the complementing fragment and sequencing of the subclone led to the identification of a gene (olsA) coding for a presumptive acyltransferase. Amplification of this gene and its expression in OL-deficient mutant backgrounds of S. meliloti demonstrates that it is required for OL biosynthesis. An OL-deficient mutant of S. meliloti disrupted in olsA shows wild type-like growth behaviour and is capable of inducing nitrogen-fixing nodules on legume hosts. A lyso-ornithine lipid-dependent acyltransferase activity forming OL requires acyl-AcpP as the acyl donor and expression of the olsA gene.

The endogenous opioid spinorphin blocks fMet-Leu-Phe-induced neutrophil chemotaxis by acting as a specific antagonist at the N-formylpeptide receptor subtype FPR

Spinorphin is an endogenous heptapeptide (leucylvalylvalyltyrosylprolyltryptophylthreonine), first isolated from bovine spinal cord, whose sequence matches a conserved region of beta-hemoglobin. Also referred to as LVV-hemorphin-4 and a member of the nonclassical opioid hemorphin family, spinorphin inhibits enkephalin-degrading enzymes and is analgesic. Recently, spinorphin was reported to block neutrophil activation induced by the chemotactic N-formylpeptide N-formylmethionylleucylphenylalanine (fMLF), suggesting a potential role as an endogenous negative regulator of inflammation. Here we use both gain- and loss-of-function genetic tests to identify the specific mechanism of spinorphin action on neutrophils. Spinorphin induced calcium flux in normal mouse neutrophils, but was inactive in neutrophils from mice genetically deficient in the fMLF receptor subtype FPR (N-formylpeptide receptor). Consistent with this, spinorphin induced calcium flux in human embryonic kidney 293 cells transfected with mouse FPR, but had no effect on cells expressing the closely related fMLF receptor subtype FPR2. Despite acting as a calcium-mobilizing agonist at FPR, spinorphin was a weak chemotactic agonist and effectively blocked neutrophil chemotaxis induced by fMLF at concentrations selective for FPR. Spinorphin did not affect mouse neutrophil chemotaxis induced by concentrations of fMLF that selectively activate FPR2. Thus, spinorphin blocks fMLF-induced neutrophil chemotaxis by acting as a specific antagonist at the fMLF receptor subtype FPR.

Contrasting evolution of the human leukocyte N-formylpeptide receptor subtypes FPR and FPRL1R

N-formylpeptides are phagocyte chemoattractants that act by binding to two structurally related receptors, FPR (formylpeptide receptor) and FPRL1R (FPR-like-1 receptor), which are encoded by the human genes FPR1 and FPRL1. Single nucleotide polymorphisms (SNPs) in the FPR coding region have been reported and two have been associated with the disease juvenile periodontitis; however, their frequency and linkage relationships are unknown. Here we systematically analyzed polymorphism in the open reading frames of FPR1 and FPRL1 by direct sequencing of cloned alleles from random blood donors from North America. For FPR1 we detected five non-synonymous SNPs and two synonymous SNPs in a sample of 26 chromosomes one each from 17 Caucasian and nine black random blood donors. Although all five non-synonymous SNPs were common in Caucasians, Blacks, and Asians, notable differences in allele frequency were found for each SNP in the different racial groups, suggesting differential selective pressures. We found that the FPR1 polymorphisms are linked in 15 common haplotypes. No polymorphisms were detected in FPRL1 after sampling 44 chromosomes from 36 random blood donors from the same three racial groups. Thus FPR1 and FPRL1, though they originated from a common gene, appear to have undergone markedly different evolutionary events.

Synthetic peptide MMK-1 is a highly specific chemotactic agonist for leukocyte FPRL1

Human phagocytic leukocytes express the seven-transmembrane G-protein-coupled receptors formyl peptide receptor (FPR) and FPR-like 1 (FPRL1). MMK-1, a synthetic peptide derived from a random peptide library, is reported to induce calcium mobilization specifically in human FPRL1 gene-transfected cells. However, its actions on human phagocytic leukocytes remain poorly defined. We found that MMK-1 is a potent chemotactic and calcium-mobilizing agonist for human monocytes, neutrophils, and FPRL1-transfected human embryonic kidney (HEK) 293 cells but is inactive in cells transfected with FPR. MMK-1 also activated HEK 293 cells transfected with FPR2, a mouse counterpart of human FPRL1. Furthermore, MMK-1 increased pertussis toxin-sensitive production of inflammatory cytokines in human monocytes. MMK-1 signaling in human phagocytes was completely desensitized by a well-defined FPRL1 agonist, suggesting that FPRL1 is likely a receptor that mediates the action of MMK-1 in primary cells. Since MMK-1 is one of the most potent FPRL1-specific agonists identified so far, it can serve as a modulator of the host defense and a useful agent for further studying the signaling and function of FPRL1.

Amyloid-beta induces chemotaxis and oxidant stress by acting at formylpeptide receptor 2, a G protein-coupled receptor expressed in phagocytes and brain

Amyloid-beta, the pathologic protein in Alzheimer's disease, induces chemotaxis and production of reactive oxygen species in phagocytic cells, but mechanisms have not been fully defined. Here we provide three lines of evidence that the phagocyte G protein-coupled receptor (N-formylpeptide receptor 2 (FPR2)) mediates these amyloid-beta-dependent functions in phagocytic cells. First, transfection of FPR2, but not related receptors, including the other known N-formylpeptide receptor FPR, reconstituted amyloid-beta-dependent chemotaxis and calcium flux in HEK 293 cells. Second, amyloid-beta induced both calcium flux and chemotaxis in mouse neutrophils (which express endogenous FPR2) with similar potency as in FPR2-transfected HEK 293 cells. This activity could be specifically desensitized in both cell types by preincubation with a specific FPR2 agonist, which desensitizes the receptor, or with pertussis toxin, which uncouples it from G(i)-dependent signaling. Third, specific and reciprocal desensitization of superoxide production was observed when N-formylpeptides and amyloid-beta were used to sequentially stimulate neutrophils from FPR -/- mice, which express FPR2 normally. Potential biological relevance of these results to the neuroinflammation associated with Alzheimer's disease was suggested by two additional findings: first, FPR2 mRNA could be detected by PCR in mouse brain; second, induction of FPR2 expression correlated with induction of calcium flux and chemotaxis by amyloid-beta in the mouse microglial cell line N9. Further, in sequential stimulation experiments with N9 cells, N-formylpeptides and amyloid-beta were able to reciprocally cross-desensitize each other. Amyloid-beta was also a specific agonist at the human counterpart of FPR2, the FPR-like 1 receptor. These results suggest a unified signaling mechanism for linking amyloid-beta to phagocyte chemotaxis and oxidant stress in the brain.

NO mediated increase of Fos protein and NMDA1A R mRNA expression in rat spinal cord during morphine withdrawal

AIM

To investigate the effects of nitric oxide (NO) on activation of the rat spinal cord neurons during naloxone-precipitated morphine withdrawal.

METHODS

Fos immunocytochemistry, NADPH-d histochemistry, Fos/NADPH-d double-labeling, intrathecal injection, antisense oligonucleotides (AS-ONs) techniques, and RT-PCR were used.

RESULTS

Acute administration of naloxone and chronic administration of morphine did not change the expression of Fos protein and NADPH-d positive neurons, and there was no expression of Fos/NADPH-d double-labeled neurons in the spinal cord of rats. Morphine withdrawal increased the expression of Fos protein, NADPH-d positive, and Fos/NADPH-d double-labeled neurons, and they were observed in all the laminae of the rat spinal cord. Intrathecal injection of nNOS antisense oligonucleotides (nNOS-AS) inhibited the increase of Fos protein and NMDA(1A)R mRNA expression in the rat spinal cord during morphine withdrawal and decreased the scores of morphine withdrawal symptoms. The effect of nNOS-AS was greater than that of eNOS-AS. There was no effect in nNOS sense oligonucleotides (nNOS-S) group.

CONCLUSION

NO mediated the increase of Fos protein and NMDA1A R mRNA expression in the rat spinal cord during morphine withdrawal.

Involvement of the receptor for formylated peptides in the in vivo anti-migratory actions of annexin 1 and its mimetics

An innovative avenue for anti-inflammatory therapy is inhibition of neutrophil extravasation by potentiating the action of endogenous anti-inflammatory mediators. The glucocorticoid-inducible protein annexin 1 and derived peptides are effective in inhibiting neutrophil extravasation. Here we tested the hypothesis that an interaction with the receptor for formylated peptide (FPR), so far reported only in vitro, could be the mechanism for this in vivo action. In a model of mouse peritonitis, FPR antagonists abrogated the anti-migratory effects of peptides Ac2-26 and Ac2-12, with a partial reduction in annexin 1 effects. A similar result was obtained in FPR (knock-out) KO mice. Binding of annexin 1 to circulating leukocytes was reduced (>50%) in FPR KO mice. In vitro, annexin binding to peritoneal macrophages was also markedly reduced in FPR KO mice. Finally, evidence of direct annexin 1 binding to murine FPR was obtained with HEK-293 cells transfected with the receptor. Overall, these results indicate a functional role for FPR in the anti-migratory effect of annexin 1 and derived peptides.

Mice lacking the chemokine receptor CCR1 show increased susceptibility to Toxoplasma gondii infection

Chemokines are critical for the recruitment of effector immune cells to sites of infection. Mice lacking the chemokine receptor CCR1 have defects in neutrophil trafficking and proliferation. In the present study, we tested the susceptibility of CCR1 knockout mice to infection with the obligate intracellular protozoan parasite Toxoplasma gondii. In comparison with parental wild-type mice, CCR1(-/-) mice exhibited dramatically increased mortality to T. gondii in association with an increased tissue parasite load. No differences were observed in Ag-specific T cell proliferation or in cytokine responses between mutant and wild-type mice. However, the influx of PMNs to the peripheral blood and to the liver were reduced in CCR1(-/-) mice during early infection. Our results suggest that CCR1-dependent migration of neutrophils to the blood and tissues may have a significant impact in controlling parasite replication.

Cloning, mRNA distribution, and functional expression of an avian counterpart of the chemokine receptor/HIV coreceptor CXCR4

The chemokine signaling system, which coordinates the basal and emergency trafficking of leukocytes, presumably coevolved with the hematopoietic system. To study its phylogenetic origins, we used the open reading frame (ORF) of the human chemokine receptor CXCR4 as a genomic probe, since in mammals it is the most highly conserved chemokine receptor known. CXCR4 cross-hybridized to genomic DNA from mouse and chicken, but not zebrafish, Drosophila, or Caenorhabditis elegans. Accordingly, we cloned the corresponding chicken cDNA. The ORF is 359 codons long versus 352 for human CXCR4, and encodes a protein 82% identical to human CXCR4. In a calcium flux assay of receptor function, CHO-K1 cells stably transfected with the chicken cDNA responded specifically to human SDF-1, the specific ligand for CXCR4, but not to a panel of other chemokines tested at 100 nM. SDF-1 activated the cells in a dose-dependent manner (EC50 approximately 5 nM), whereas parental CHO-K1 cells did not respond. The CHO-K1 cell transfectants also bound 125I-SDF-1 specifically. Leukocytes from chicken peripheral blood expressed chCXCR4 mRNA and responded to human SDF-1 in a calcium flux assay with an EC50 similar to that for chCXCR4-transfected CHO cells, suggesting that this response is mediated by native chCXCR4. Analysis of chicken genomic DNA with the chicken cDNA as probe revealed a pattern consistent with a single copy gene, and the absence of any closely related genes. mRNA was detected in brain, bursa, liver, small and large intestine, embryonal fibroblasts, and blood leukocytes, but not in stomach or pancreas. These results, which identify the first functional non-viral, non-mammalian chemokine receptor, suggest that the origins of a functional chemokine system extend at least to birds and suggest that, as in mammals, CXCR4 functions in many avian tissues.

Amyloid (beta)42 activates a G-protein-coupled chemoattractant receptor, FPR-like-1

Amyloid beta (Abeta) is a major contributor to the pathogenesis of Alzheimer's disease (AD). Although Abeta has been reported to be directly neurotoxic, it also causes indirect neuronal damage by activating mononuclear phagocytes (microglia) that accumulate in and around senile plaques. In this study, we show that the 42 amino acid form of beta amyloid peptide, Abeta(42), is a chemotactic agonist for a seven-transmembrane, G-protein-coupled receptor named FPR-Like-1 (FPRL1), which is expressed on human mononuclear phagocytes. Moreover, FPRL1 is expressed at high levels by inflammatory cells infiltrating senile plaques in brain tissues from AD patients. Thus, FPRL1 may mediate inflammation seen in AD and is a potential target for developing therapeutic agents.