Isolation and characterization of antagonistic bacteria with the potential for biocontrol of soil-borne wheat diseases

AIM

The aim of this study was to identify efficient plant-beneficial rhizobacterium that has the potential to be developed as biocontrol agent for the control of wheat soil-borne diseases.

METHODS AND RESULTS

Rhizosphere soil samples were collected from a wheat field located in Taian City. Numerous bacteria were isolated and screened for antagonistic activity against soil-borne plant pathogenic fungi by performing dual-culture assays. Among them, XH-9 was selected for its highly antagonistic activity and others growth-promoting characteristics. Subsequently, the strain was identified as Bacillus amyloliquefaciens subsp. plantarum based on phylogenetic analysis of 16S rDNA sequence. Pot experiment indicated that XH-9 has good capacities for wheat, corn, and chili root colonization and considerably increased the biometric parameters of wheat seedlings. Quantitative real-time polymerase chain reaction experiments showed that the amount of Fusarium oxysporum associated with the XH-9 after treatment significantly decreased compared with control group.

CONCLUSIONS

Bacillus amyloliquefaciens subsp. plantarum XH-9 has the potential as biocontrol agent when applied in local arable land to prevent damage caused by F. oxysporum and other phytopathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

The development of biocontrol strategies for reducing the damage caused by plant pathogens is fully in accord with the current principles of sustainability.

A novel technique for endobronchial blocker placement for one-lung ventilation in children under 2 years

BACKGROUND

The present study aimed to report our clinical experience with intraluminal calculated distance for endobronchial blocker placement (ICEB) and to find out whether ICEB could reduce the number of hypoxemia episodes during blocker placement compared with extraluminal blocker placement for one-lung ventilation in children under the age of 2 years.

METHODS

The medical records of all children under the age of 2 years with a 5 French (F) or 4F WeiLi (WeiLi medical Inc, Guangzhou, China) endobronchial blocker for one-lung ventilation in thoracic surgery from July 2015 through July 2016 were retrospectively reviewed. After November 2015, one-lung ventilation was achieved using the ICEB technique, while before November 2015, extraluminal blocker placement was used. The success rate of blocker placement, quality of lung deflation, number of hypoxemia episodes, blocker dislodgement, and successful reposition after dislodgement were compared between the two groups.

RESULT

The incidence of hypoxemia episodes during blocker placement was lower in the ICEB group compared to the extraluminal placement group. Moreover, the success rate of blocker reposition during the operation was higher in the ICEB group than the extraluminal placement group. The success rate of endobronchial blocker placement was similar between the two groups.

CONCLUSIONS

Intraluminal calculated distance for endobronchial blocker placement is a feasible method to achieve lung isolation and could reduce hypoxemia episodes during blocker placement in children under the age of 2 years.

Microdomain elements of airway smooth muscle in calcium regulation and cell proliferation

Airway remodeling manifested by hyperplasia of airway smooth muscle cells (ASMCs) and other structural and functional changes is a pathological condition in asthma not addressed by current treatment. Ca²⁺ signaling is crucial for ASMC proliferation. Inositol-1,4,5-trisphosphate receptor (IP3R) and ryanodine receptor (RyR) mediate Ca²⁺ release from endoplasmic reticulum/sarcoplasmic reticulum (ER/SR). Upon sensing the depletion of Ca²⁺ in ER/SR, stromal interaction molecule 1 (STIM1) aggregates and redistributes at the microdomain of ER/SR-plasma membrane (PM) and activates Orai1, a component of the store-operated Ca²⁺ (SOC) channels, to initiate Ca²⁺ influx. The STIM1/Orai1-mediated SOC entry is the main cause of a sustained intracellular calcium ([Ca²⁺]_i) elevation, which is different from a transient rise of [Ca²⁺]_i mediated by IP₃R and RyR. Extended-synaptotagmin 1 (E-Syt1) is recruited to the ER/SR-PM junction and anchors to the PM lipid phosphatidylinositol-4,5-bisphosphate (PI(_4,5)P₂) in a SOC-dependent manner. The subsequent strengthening of the ER/SR-PM connection by E-Syt1 facilitates the phosphatidylinositol (PI) transfer protein, Nir2, to supplement PI, a PI(_4,5)P₂ substrate, for the generation of IP3 and the propagation of Ca²⁺ signaling. Calcineurin and nuclear factor of activated T cells are the downstream signaling factors of elevated [Ca²⁺]_i contributing to ASMC proliferation. Mitochondrial Ca²⁺ uptake/efflux, mitochondrial fission/fusion and mitochondrial-ER/SR coupling also play important roles in modulating [Ca²⁺]_i and ASMC proliferation. Together, these pathways and mechanisms represent new therapeutic targets for airway remodeling. The present review provides an overview of our current understanding of the mechanisms of ASMC proliferation involving Ca²⁺ and highlights potential directions to control airway remodeling in asthma.

Prospective plasma efavirenz concentration assessment in Chinese HIV-infected adults enrolled in a large multicentre study

OBJECTIVES

Few studies have explored the optimal dosing for efavirenz in individuals from China. We investigated plasma efavirenz concentrations and their association with efficacy and tolerance of efavirenz 600 mg daily in Chinese HIV-infected adults.

METHODS

An analysis was performed using plasma samples from 455 patients enrolled in a prospective multicentre trial in China. A total of 1198 plasma samples collected at weeks 4, 24 and 48 following antiretroviral therapy initiation were analysed. The mid-dose interval efavirenz concentrations (C12 ) were determined using high-performance liquid chromatography.

RESULTS

The median efavirenz concentration (interquartile range) steadily increased over time from 3.02 (2.28-4.23) to 3.71 (2.91-4.91) mg/L from week 4 to 48 (P < 0.001). The proportion of patients with C12 > 4.0 mg/L also rose from 28.0% to 34.2% and 43.8%, measured at 4, 24 and 48 weeks, respectively (P < 0.001). Five patients had efavirenz concentrations < 1.0 mg/L at week 4, 24 or 48. In the multivariable regression analysis, lower body weight and non-Han ethnicities were associated with higher efavirenz concentrations over time. At each time-point, patients with a body weight < 60 kg had significantly higher efavirenz C12 compared with those with body weight ≥ 60 kg (P < 0.05).

CONCLUSIONS

Efavirenz concentrations increased steadily over 48 weeks, and a substantial proportion of participants had efavirenz C12 above the upper limit of the proposed therapeutic window, especially those with low body weight (< 60 kg). Based upon these findings, a dosage reduction of efavirenz to 400 mg daily may warrant consideration in this population, especially for those with lower body weight.

[Prognosis-related clinicopathologic characteristics of FIGO stage Ⅰ Müllerian adenosarcoma of uterus]

Objective: To investigate the clinicopathological features of FIGO stage Ⅰ uterine Müllerian adenosarcoma and clinical prognosis. Methods: Fifteen cases of uterine Müllerian adenosarcoma at FIGO stage Ⅰ were collected at PLA General Hospital from 2005 to 2017. Twelve cases with complete follow-up data were divided into 2 groups: group A (7 patients with survival) and group B(5 patients of death or tumor progression). Clinicopathologic features were compared between the two groups. Results: The median age of the patients was 43 years and 56 years, and the tumor size was 4.3 cm and 7.3 cm for group A and B, respectively. Cases in group A were FIGO ⅠA and ⅠB stage tumors and were mainly low grade in histology (5/7) with rare tumor hemorrhagec, necrosis (1/7) and sarcomatous overgrowth. In contrast, most cases in group B were high grade sarcomas(3/5) with frequent hemorrhage, necrosis(3/5) and sarcomatous overgrowth(4/5). Most cases of group A expressed ER, PR and CD10 (6/7) and low Ki-67 index of ≤20%(5/7). While most group B cases lost expression of ER and PR (3/5), significantly reduced expression of CD10 and higher Ki-67 index of ≥30%(4/5). Conclusions: Most of uterine adenosarcomas are of low malignant potential. The main prognostic indicator is advanced tumor stage. For patients at stage Ⅰ, sarcomatous overgrowth, high-grade histology, deep myometrial invasion, decreased or absent expression of CD10, ER and PR, increased Ki-67 index(≥30%) and hemorrhagic necrosis may indicate poor prognosis. Müllerian adenosarcomas arising from endomeriosis may present unusual growth patterns.

Design of a Continuous Flow Centrifugal Pediatric Ventricular Assist Device

Thousands of pediatric patients suffering from cardiomyopathy or single ventricular physiologies secondary to debilitating heart defects may benefit from long-term mechanical circulatory support due to the limited number of donor hearts available. This article presents the initial design of a fully implantable centrifugal pediatric ventricular assist device (PVAD) for 2 to 12 year olds. Conventional pump design equations, including a nondimensional scaling approach, enabled performance estimations of smaller scale versions (25 mm and 35 mm impeller diameters) of our adult support VAD. Based on this estimated performance, a computational model of the PVAD with a 35 mm impeller diameter was generated. Employing computational fluid dynamics (CFD) software, the flow paths through the PVAD and overall performance were analyzed for steady state flow conditions. The numerical simulations involved flow rates of 2 to 5 LPM for rotational speeds of 2750 to 3250 RPM and incorporated a k-epsilon fluid turbulence model with a logarithmic wall function to characterize near-wall flow conditions. The CFD results indicated best efficiency points ranging from 25% to 28%, which correlate well with typical values of blood pumps. The results further demonstrated that the pump could deliver 2 to 5 LPM at 70 to 95 mmHg for desired physiologic conditions in resting 2 to 12 year olds. Scalar stress levels remained below 300 Pa, thereby signifying potentially low levels of hemolysis. Several flow regions in the pump exhibited signs of vortices, retrograde flow, and stagnation points, which require optimization and further study. This CFD model represents a reasonable starting point for future model enhancements, leading to prototype manufacturing and experimental validation.

Correlation analysis of ankle-brachial index and brachial-ankle pulse wave velocity with cardiac structures and functions in patients with essential hypertension

OBJECTIVE

To investigate the correlation of ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) with cardiac structures and functions changes in patients with essential hypertension (EH).

PATIENTS AND METHODS

A total of 202 patients with hypertension meeting the inclusion criteria were recruited in our hospital from June 2016 to August 2017. They were divided into 4 groups: the low ABI value group, the normal ABI value group, the increased baPWV value group and the normal baPWV group. Clinical data were collected, including medical histories and received physical examinations, blood pressure measurement, biochemical tests and other examinations through the automatic atherosclerosis tester (VP-l00) and echocardiography.

RESULTS

Interventricular septal thickness (IVST) of the low ABI value group was significantly larger than that of the normal ABI value group (p<0.05). Compared with those of the normal ABI value group, left ventricular ejection fraction (LVEF) and the ratio of peak velocity flow in the E wave to peak velocity flow in the A wave (E/A) of the low ABI value group were significantly decreased (p<0.05). Left atrium diameter (LAD) and IVST of the increased baPWV group were significantly greater than those of the normal baPWV group (p<0.05), and left ventricular ejection fraction (LVEF) of the former was smaller than that of the latter (p<0.05). Correlation analyses showed that ABI was negatively correlated with IVST (r=-0.713, p<0.05) but positively correlated with LVEF and E/A (r=0.685 and 0.572, respectively, p<0.05); baPWV was positively related to LAD and LVST (r=0.413 and 0.527, respectively, p<0.05) but negatively related to LVEF (r=-0.546, p<0.05).

CONCLUSIONS

ABI and baPWV are significantly associated with changes in cardiac structures and functions in patients with EH, which provide a basis for early intervention in clinical.

[Impacts of EGFR 19 exon mutations on brain metastases in treatment-naïve patients with lung adenocarcinoma]

Objective: To investigate the relationship between the status of epidermal growth factor receptor (EGFR) mutations and brain metastases in patients with lung adenocarcinoma. Methods: From August 2010 to May 2015, a total of 1 063 lung adenocarcinoma patients with identified status of EGFR mutations in Shanxi Cancer Hospital were enrolled, of which 456 patients had EGFR mutations. Multivariate Logistic regression model was used to analyze the correlation between EGFR mutation status and brain metastases in patients with lung adenocarcinoma. Results: In 125 patients with brain metastases before initial treatment, 65 patients had EGFR mutations, including 36 patients with deletion mutations in exon 19. The frequency of EGFR 19 exon mutation was 28.8% (36/125). Among 456 patients with EGFR mutations, 65(14.3%) patients were with brain metastases, in which 36(55.0%) had deletion mutations in exon 19. The multivariate analysis showed that age, Eastern Cooperative Oncology Group (ECOG) score, EGFR mutations and N staging were associated with brain metastases(P<0.05). Further subgroup multivariate analyses showed that age, ECOG score, mutation status in exon 19 and N staging were associated with brain metastases (P<0.05). Conclusions: EGFR mutation status is related to brain metastases. Mutations in EGFR exon 19 is an independent risk factor for brain metastases.

A randomized phase II study of weekly paclitaxel with or without pelareorep in patients with metastatic breast cancer: final analysis of Canadian Cancer Trials Group IND.213

BACKGROUND

Pelareorep, a serotype 3 reovirus, has demonstrated preclinical and early clinical activity in breast cancer and synergistic cytotoxic activity with microtubule targeting agents. This multicentre, randomized, phase II trial was undertaken to evaluate the efficacy and safety of adding pelareorep to paclitaxel for patients with metastatic breast cancer (mBC).

METHODS

Following a safety run-in of 7 patients, 74 women with previously treated mBC were randomized either to paclitaxel 80 mg/m² intravenously on days 1, 8, and 15 every 4 weeks plus pelareorep 3 × 10¹⁰ TCID₅₀ intravenously on days 1, 2, 8, 9, 15, and 16 every 4 weeks (Arm A) or to paclitaxel alone (Arm B). Primary endpoint was progression-free survival (PFS). Secondary endpoints were objective response rate, overall survival (OS), circulating tumour cell counts, safety, and exploratory correlative analyses. All comparisons used a two-sided test at an alpha level of 20%. Survival analyses were adjusted for prior paclitaxel.

RESULTS

Final analysis was performed after a median follow-up of 29.5 months. Pelareorep was well tolerated. Patients in Arm A had more favourable baseline prognostic variables. Median adjusted PFS (Arm A vs B) was 3.78 mo vs 3.38 mo (HR 1.04, 80% CI 0.76-1.43, P = 0.87). There was no difference in response rate between arms (P = 0.87). Median OS (Arm A vs B) was 17.4 mo vs 10.4 mo (HR 0.65, 80% CI 0.46-0.91, P = 0.1).

CONCLUSIONS

This first, phase II, randomized study of pelareorep and paclitaxel in previously treated mBC did not show a difference in PFS (the primary endpoint) or RR. However, there was a significantly longer OS for the combination. Further exploration of this regimen in mBC may be of interest.

First-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance therapy for patients with advanced EGFR mutation-positive lung adenocarcinoma (CONVINCE): a phase 3, open-label, randomized study

BACKGROUND

Icotinib has been previously shown to be non-inferior to gefitinib in non-selected advanced non-small-cell lung cancer patients when given as second- or further-line treatment. In this open-label, randomized, phase 3 CONVINCE trial, we assessed the efficacy and safety of first-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance in lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutation.

PATIENTS AND METHODS

Eligible participants were adults with stage IIIB/IV lung adenocarcinoma and exon 19/21 EGFR mutations. Participants were randomly allocated (1 : 1) to receive oral icotinib or 3-week cycle of cisplatin plus pemetrexed for up to four cycles; non-progressive patients after four cycles were maintained with pemetrexed until disease progression or intolerable toxicity. The primary end point was progression-free survival (PFS) assessed by independent response evaluation committee. Other end points included overall survival (OS) and safety.

RESULTS

Between January 2013 and August 2014, 296 patients were randomized, and 285 patients were treated (148 to icotinib, 137 to chemotherapy). Independent response evaluation committee-assessed PFS was significantly longer in the icotinib group (11.2 versus 7.9 months; hazard ratio, 0.61, 95% confidence interval 0.43-0.87; P = 0.006). No significant difference for OS was observed between treatments in the overall population or in EGFR-mutated subgroups (exon 19 Del/21 L858R). The most common grade 3 or 4 adverse events (AEs) in the icotinib group were rash (14.8%) and diarrhea (7.4%), compared with nausea (45.9%), vomiting (29.2%), and neutropenia (10.9%) in the chemotherapy group. AEs (79.1% versus 94.2%; P < 0.001) and treatment-related AEs (54.1% versus 90.5%; P < 0.001) were significantly fewer in the icotinib group than in the chemotherapy group.

CONCLUSIONS

First-line icotinib significantly improves PFS of advanced lung adenocarcinoma patients with EGFR mutation with a tolerable and manageable safety profile. Icotinib should be considered as a first-line treatment for this patient population.

Effect of Cdc42 on myocardial ischemia-reperfusion of rats

To investigate the effects and their possible mechanisms of cell division cycle 42 (Cdc42) to neonatal rat myocardial cells subjected to the ischemia-repefusion. Neonatal rat cardiomyocytes were cultured and then subjected to the ischemia-reperfusion. Experimental groups 1. Control group; 2. Ischemia-repefusion group (I/R group); 3. Oligofectamine group (Oli group); 4. Oligofectamine and antisense oligodeoxynucleotide (AS-ODN) group (As group); 5. Oligofectamine and missense oligodeoxynucleotide (MS-ODN) group (Ms group); 6. SP600125 and Oligofectamine and AS-ODN group (SP600125/As group); 7. SP600125 and Oligofectamine and MS-ODN group (SP600125/Ms group). The cardiacmyocyte apoptosis rate was detected by AnnexinV/PI with flow cytometry. Cdc42, JNK, p-JNK, Bax and Bcl-2 were detected by western blot. In comparison with control group, Cdc42, the cardiacmyocyte apoptosis rate and phosphorylation of JNK were increased and the ratio of Bcl-2/Bax was reduced in the I/R group; Cdc42, the cardiacmyocyte apoptosis rate and phosphorylation of JNK in As group was lower than the I/R group, Oli group and the Ms group, and the ratio of Bcl-2/Bax was the highest in the four groups; Cdc42, cardiacmyocyte apoptosis rate, phosphorylation of JNK and the ratio of Bcl-2/Bax showed no differences in the I/R group, Oli group and the Ms group. Compared with As group, phosphorylation of JNK was lower in the SP600125/As group, phosphorylation of JNK in SP600125/Ms group was lower than the Ms group, and it showed no differences between the SP600125 &amp; As group and the SP600125 &amp; Ms group. Cdc42 in myocardial I/R can promote cardiacmyocyte apoptosis rate. AS-ODN of Cdc42 can decrease the cardiacmyocyte apoptosis rate in I/R. Cdc42 may played a role in myocardial I/R via JNK , Bcl-2 and Bax signal pathway.

Characterization of tissue chromogranin A (CgA) immunostaining and clinicohistopathological changes for the 125 Chinese patients with primary small cell carcinoma of the esophagus

The rarity of primary small cell carcinoma of the esophagus (PSCE) has limited the clinical feature and survival analysis with large sample size. Tissue chromogranin A (CgA) protein expression has been reported to be a useful biomarker for diagnosing PSCE. Interestingly, recent studies have indicated tissue CgA as a significant prognostic marker in multiple human cancers, but without PSCE. The present study, thus, was undertaken to characterize the clinicopathological changes and to evaluate the associations of tissue CgA expression with clinical response on Chinese PSCE patients. All the 125 PSCE patients were enrolled from our 500,000 esophageal and gastric cardia carcinoma databases (1973-2015), constructed by the cooperative team from more than 700 hospitals in China and established by Henan Key Laboratory for Esophageal Cancer Research in Henan, China. Immunostaining for CgA showed that CgA was mainly located in cytoplasm of tumor cells with a positive detection rate of 44.6%. The CgA positive expression rate in PSCE at lower segment of the esophagus (72.2%) was higher than that at middle segment (41.5%) (P = 0.001). However, CgA protein expression did not correlated with lymph node metastasis (P = 0.767), TNM staging (P = 0.740), tumor invasion (P = 0.253), gender (P = 0.262), and age (P = 0.250). Multivariate survival analysis showed that the patients with higher CgA protein expression had a superior long survival than those without CgA expression (P = 0.037). The clinicopathological analysis showed that PSCE occurred predominantly in male (M:F = 1.9:1) at the middle segment (68%) of the esophagus. Histologically, 89.6% were pure PSCE and 10.4% were mixed type with either squamous cell carcinoma (8%) or adenocarcinoma (2.4%). It was noteworthy that, with the in-depth invasion from T1 to T2 and T3, the positive lymph node metastasis rate increased dramatically from 38%, 56% to 74%, respectively. The survival rates of 1-, 2-, 3-, and 5-year were 64%, 35%, 18%, and 7%, respectively. The Kaplan-Meier survival analysis showed that the young patients (≤60 years) had longer survival than the elderly (P = 0.011). Interestingly, multivariate survival analysis revealed that the patients with mixed PSCE had a significantly better survival than those with pure PSCE (P = 0.015). Furthermore, the median survival time for the patients with and without lymph node metastasis was 1.16 and 2.03 years, respectively. But, the difference was not significant (P = 0.143). Univariate analysis did not show any survival influence by gender, tumor location, tumor invasion depth, and TNM staging. It was noteworthy that, of the 13 early PSCE patients (T1N0M0), only one patient had more than 5 year survival, the others died with less than one or two year (65%). The present study indicates that the PSCE is of badly worsen prognosis, even in the pathological early stage. Tissue CgA protein expression is a promising maker not only for diagnosis and also for prognosis. Further assessment is needed to establish specific PSCE pathological staging system and to clarify the mechanisms of CgA protein in PSCE progression and prognosis.

Plastic deformation mechanisms in a new Ni-base single crystal superalloy at room temperature

The evolution of dislocation configurations in a new Ni-base single crystal superalloy, M4706, during tensile deformation at room temperature is characterised by transmission electron microscopy. Experimental results show that contrary to previous reports, numerous isolated superlattice stacking faults and extended stacking faults are formed in the slightly deformed specimens with and without tertiary γ' precipitates. Meanwhile, it is also found that as the plastic deformation proceeds, the dominant deformation mechanism changes from stacking fault shearing to antiphase boundary shearing. Finally, based on experimental observations, the reasons for the formation of these faults and the transition in the deformation mechanism are discussed.

Rapid in-focus corrections on quantitative amplitude and phase imaging using transport of intensity equation method

Transport of intensity equation (TIE) method can acquire sample phase distributions with high speed and accuracy, offering another perspective for cellular observations and measurements. However, caused by incorrect focal plane determination, blurs and halos are induced, decreasing resolution and accuracy in both retrieved amplitude and phase information. In order to obtain high-accurate sample details, we propose TIE based in-focus correction technique for quantitative amplitude and phase imaging, which can locate focal plane and then retrieve both in-focus intensity and phase distributions combining with numerical wavefront extraction and propagation as well as physical image recorder translation. Certified by both numerical simulations and practical measurements, it is believed the proposed method not only captures high-accurate in-focus sample information, but also provides a potential way for fast autofocusing in microscopic system.

Horizontal transfer and functional evaluation of high pathogenicity islands in Avian Escherichia coli

High pathogenicity islands (HPIs) inEscherichia coliencode genes that are primarily involved in iron uptake and regulation, and confer virulence and pathogenicity. The aim of this study was to investigate the transfer ofHPIs in avianE. coliand identify the function ofHPIin the acceptor strain. TheHPItransfer strain was obtained under conditions of low temperature and low iron abundance, and the donor and acceptor strains were confirmed.E. coli HPIs are transferred by horizontal gene transfer events, which are likely mediated primarily by homologous recombination inHPI-adjacent sequences. Assays for biological activity and pathogenicity changes in the acceptor strain indicated thatHPIs might not be involved in pathogenesis in avianE. coli, and thus the main function ofHPIs in this strain of bacteria may be to regulate iron nutrition.