The potential of cadmium ion-immobilized Rhizobium pusense KG2 to prevent soybean root from absorbing cadmium in cadmium-contaminated soil

AIMS

Because the effect of Cd2+ -immobilized microbe on Cd uptake of plants in Cd-contaminated soil remains underexplored, this study focuses on the effect of Cd2+ -immobilized rhizobia on Cd uptake of soybean.

METHODS AND RESULTS

Strain KG2 from soybean nodule was identified as Rhizobium pusense KG2 by phylogenetic analysis. Rhizobium pusense KG2 showed the 120 mg l-1 of minimal lethal concentration for Cd2+ . In 50 and 100 mg l-1 of Cd2+ liquid, approximately 2 × 1010 cells removed 56·71 and 22·11% of Cd2+ , respectively. In pot soil containing 50 and 100 mg kg-1 of Cd2+ , strain KG2 caused a 45·9 and 35·3% decrease in soybean root Cd content, respectively. Meanwhile, KG2 improved the root and shoot length, nitrogen content and biomass of soybean plants and superoxide dismutase activity.

CONCLUSIONS

The Cd2+ -immobilized rhizobia could inhibit soybean plants to absorb Cd2+ from soil, promote plant growth and improve plant's tolerance against Cd. This study is the first time to report that R. pusense is an effective nodulating rhizobium of legume.

SIGNIFICANCE AND IMPACT OF THE STUDY

Some Cd2+ -immobilized microbe lowering Cd uptake of plant and promoting plant growth should be considered as an effective strategy for producing safety crops in the Cd-contaminated agricultural soil.

[Clinical significance of exosomal miR-1231 in pancreatic cancer]

Objective: To investigate the expression and clinical significance of exosomal miR-1231 in plasma of pancreatic cancer (PC) patients and pancreatic cancer cells. Methods: A total of 16 patients who were diagnosed with pancreatic cancer in Hunan Cancer Hospital were collected from April 2016 to August 2017. Meanwhile, 16 healthy volunteers were recruited as the healthy control group at the same period. The plasma exosomes were extracted, and the levels of miR-1231 were detected by qRT-PCR in PC and healthy control groups. Moreover, the clinicopathological significance of exosomal miR-1231 expression was analyzed. Furthermore, the expression of exosomal miR-1231 was detected in several pancreatic cancer cells (MIA PaCa-2, PANC-1, SW1990, AsPC-1 and BxPc-3) and two normal pancreatic epithelial cells (HPDE and human primary pancreatic epithelial cell). Results: qRT-PCR results showed that the expression level of miR-1231 in plasma exosomes of pancreatic cancer patients (1.06±0.46) was significantly lower than that in healthy controls (2.30±0.99; P<0.05). The levels of exosomal miR-1231 in patients with stage Ⅰ-Ⅱ (1.515±0.531), no distant metastasis (1.236±0.461) and no lymph node metastasis (1.337±0.522) were significantly higher than those with stage Ⅲ-Ⅳ (0.848±0.224), distant metastasis (0.757±0.278) and lymph node metastasis (0.838±0.261), respectively (P<0.05 for all). In addition, there were no correlation between exosomal miR-1231 expression and age, sex, smoking history, CA19-9 levels and tumor sites (P>0.05). Furthermore, the expression level of exosomal miR-1231 in pancreatic cancer cell lines (0.142±0.135) was significantly lower than that in normal epithelial cells (1.127±0.179; P<0.05). Conclusions: The downregulation of exosomal miR-1231 in plasma of pancreatic cancer patients and pancreatic cancer cells suggests that it is related to the initiation and development of PC. It may be a new diagnostic and prognostic marker for PC.

Negative Association of Serum URIC Acid with Peripheral Blood Cellular Aging Markers

OBJECTIVES

We aimed to explore the association between serum UA and cellular aging markers.

DESIGN

The current cross-sectional analysis was based on data collected within a type 2 diabetes project.

SETTINGS

Serum uric acid (UA), which has both antioxidant and pro-oxidant properties, is thought to be involved in cellular aging processes.

PARTICIPANTS

There are 536 participants included in total, 65.3% of which are women. The average serum UA in women was 267.8 umol/l, lower than in men of 337.7 umol/l (P<0.001).

MEASUREMENTS

Serum UA, blood lipid profile, HbA1c, plasma glucose and insulin were determined. The peripheral blood leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNAcn) were assessed using a real-time PCR assay. Logistic regressions were used to analyze the associations between serum UA and cellular aging markers.

RESULTS

In Spearman's correlation analysis, there were significantly negative correlations between serum UA and LTL in both women and men (r=-0.162, P=0.006; and r=-0.232, P=0.004, respectively). The logistic regression adjusted for age, BMI, WC, daily energy intake, HbA1c, TG, and LDL-C revealed that the ORs of shorter LTL comparing the extreme serum UA quintiles was 5.52 (95% CI 1.69-18.02; P for trend =0.025) in women and 6.49 (95% CI 1.38-30.45; P for trend =0.108) in men. Furthermore, the OR (95% CI) for shorter LTL per 1 SD increment in serum UA was 1.51(1.10-2.07) in women and 1.64(1.01-2.65) in men. In regard to mtDNAcn, the association between elevated serum UA and lower mtDNAcn only reached significance in men when comparing the second and fifth quintiles with reference quintile (OR=3.73(1.07-13.04) and 3.76(1.01-14.09) , separately, and P for trend=0.066).

CONCLUSIONS

Our results indicate a significant negative association between serum UA and peripheral blood cellular aging markers. Serum UA might play a role in promoting cellular aging.

[Effect of enteral nutrition on accidental upper gastrointestinal injury in children]

Objective: To evaluate the effectiveness of enteral nutrition in children with accidental upper gastrointestinal injury. Methods: The medical records of 128 patients with mechanical or chemical gastrointestinal mucosal injury, who were hospitalized in Department of Gastroenterology, Children's Hospital of Zhejiang University School of Medicine from January 1, 2011 to December 30, 2017, were collected. All cases were treated with enteral nutrition. The clinical features and etiologies were retrospectively analyzed. Weight-for-age Z score and lab findings including white blood cells, C-reactive protein, neutrophils, albumin, prealbumin, urea nitrogen and hemoglobin before and after treatment were extracted. The clinical characteristics, the duration of enteral nutrition and gastrointestinal mucosal healing between different etiologies were further analyzed. Normal distribution variables and categorized variables were compared with t test and χ(2) test respectively, and abnormal distribution data was compared with Wilcoxon test. Results: Among all the cases, 77 were males and 51 were females. The average age was (29±22) months. The mean duration of hospitalization and enteral nutrition were (11±7)d and (27±20)d respectively. Vomiting was the most common clinical presentation (72 cases, 56.3%). In 79 cases the problems were caused by mechanical injury, among which coins were most commonly seen. The rest 49 cases were caused by chemical injury. However, the duration of hospitalization ((13±8) d vs. (10±6)d, t=-3.089, P=0.002) and enteral nutrition ((39±22) vs. (19±14) d, t=-5.365, P=0.000) were longer in children with chemical injury than those with mechanical injury. A total of 112 cases got complete blood count and C-reactive protein both before and after enteral nutrition. Inflammatory markers, including leukocytes ((7.7±2.7) ×10(9)/L vs. (13.7±5.0) ×10(9)/L, t=12.244, P <0.05), neutrophils ((3.4±1.9)×10(9)/L vs. (9.4±4.6) ×10(9)/L, t=13.655, P<0.05), and C-reactive proteins (5.0(3.0,7.8) vs. 13.5(6.0,40.5) mg/L, Z=7.776, P <0.05) were significantly decreased. The nutritional markers, including the weight-for-age z score (-0.1 ± 1.0 vs. 0.0 ± 1.0, t=-2.622, P=0.010) and the prealbumin (0.1 ± 0.1 vs. 0.2 ± 0.0 g/L, t=-3.671, P=0.001) were significantly increased. Fifty-five (82.1%) children in mechanical injury group recovered in 4 weeks, while 27 (79.4%) children in chemical injury group recovered in 7 weeks. Conclusion: Enteral nutrition can provide adequate nutritional requirements for children with upper gastrointestinal injury, and may help to decrease imflammation and improve mucosal healing.

Cell-bound complement activation products (CB-CAPs) have high sensitivity and specificity in pediatric-onset systemic lupus erythematosus and correlate with disease activity

OBJECTIVE

Elevated levels of cell-bound complement activation products (CB-CAPs) (C4d deposition on B lymphocytes (BC4d) and/or erythrocytes (EC4d)) are sensitive and specific in diagnosis and monitoring of adult systemic lupus erythematosus (SLE). Our objective was to evaluate the role of CB-CAPs for diagnosis and monitoring of pediatric-onset SLE (pSLE).

METHODS

A prospective cohort study of 28 pSLE and 22 juvenile arthritis patients was conducted. SLE disease activity was determined using a clinical Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) that excluded serologies. Autoantibodies were measured using solid-phase immunoassays, C3 and C4 using immunoturbidimetry, and CB-CAPs using quantitative flow cytometry. Abnormal CB-CAPs were defined as EC4d or BC4d above the 99th percentile for healthy adults (>14 and > 60 net mean fluorescence intensity (MFI), respectively). Performance characteristics of CB-CAPs were assessed using area under the curve (AUC) for receiver operating characteristics. Linear mixed effect models evaluated the correlation between CB-CAPs and clinical SLEDAI over 6 months.

RESULTS

BC4d yielded higher AUC (0.91 ± 0.04) than C3 (0.63 ± 0.08) and C4 (0.67 ± 0.08) ( p < 0.05). Abnormal CB-CAPs were 78% sensitive and 86% specific for diagnosis of pSLE (Youden's index = 0.64 ± 0.11). In contrast to BC4d, EC4d levels correlated with clinical SLEDAI ( p < 0.01).

CONCLUSION

CB-CAPs (EC4d and BC4d) have higher sensitivity and specificity than low complement in pSLE, and may help with diagnosis of pSLE. EC4d could provide a useful biomarker for disease activity monitoring.

Highly efficient extraction and purification of low-density lipoprotein from hen egg yolk

Low-density lipoprotein (LDL) from hen egg yolk has high nutritional value and plays an important role in the fields of biology, medicine, and materials. To develop fundamental research about LDL, a highly efficient extraction method is necessary. We found that 30% saturated ammonium sulfate can extract more crude LDL than 40% saturation. We selected polyethylene glycol (PEG; nonionic type) to obtain crude LDL. Three factors were employed, namely, degree of polymerization, concentration of PEG, and pH of egg yolk plasma. The optimized condition was 5% PEG 4,000 and plasma pH 6.0, and the best extraction efficiency was 68.1 ± 0.5 g lipid /100 g DM and 69.9 ± 2.0% protein. The crude LDL oil of PEG precipitation was very significantly higher (P < 0.01) than ammonium sulfate precipitation (ASP), while there was no significant difference in protein, which indicates that PEG can extract more crude LDL. When ascorbic acid was added, hydrosulfuryl (SH) groups and lipids oxidation degree of crude LDL extracted by PEG (PEG-LDL) was very significantly lower than ASP (P < 0.01). We also obtained both purified LDL and yolk immunoglobulin (IgY) with an appropriate purification column. This paper proposes a highly efficient method to extract LDL with high activity using PEG and ensures co-purification of LDL and IgY.

Protective effects of Herpetospermum caudigerum extracts against liver injury induced by carbon tetrachloride in mouse

Herpetospermum caudigerum (H. caudigerum; HC), popularly known as “Sejimeiduo” in Tibet, it is widely used in Tibetan traditional medicine for the treatment of dyspepsia, liver and colic diseases. This study was designed to evaluate the effect of H. caudigerum extract (HCE) on suppressing liver injury induced by carbon tetra chloride (CCl4). For this purpose, we used CCl4 to induce acute liver injury in mouse model. The protective effects of HCE against liver injury were evaluated by biochemical parameters, histopathological and immunohistochemical staining. The results showed that the superoxide dismutase (SOD) activity was significantly increased with the increasing dose of HCE as compared to the CCl4-treated group (p less than 0.01); while AST and ALT levels in serum, MDA and MPO in liver were reduced in a dose-dependent manner. The histopathology showed that HCE treatment promoted the recovery of histopathological changes in liver in a dose-dependent way. Meanwhile, there was a higher expression of caspase-3 and NF-κB in the nucleus of several liver cells in the CCl4-induced group, and a low expression of caspase-3 and NF-κB were found with the increasing dose of HCE. Therefore, the present study suggests that HCE is a potent hepatoprotective agent that can treat acute liver injury and this ability may be attributed towards its anti-inflammatory and antioxidant potential.

Alternaria alternata challenge at the nasal mucosa results in eosinophilic inflammation and increased susceptibility to influenza virus infection

BACKGROUND

Eosinophils in the nasal mucosa are an elemental feature of allergic rhinitis.

OBJECTIVE

Our objective was to explore eosinophilic inflammation and its impact on respiratory virus infection at the nasal mucosa.

METHODS

Inflammation in the nasal mucosae of mice was evaluated in response to repetitive stimulation with strict intranasal volumes of a filtrate of Alternaria alternata. Mice were then challenged with influenza virus.

RESULTS

Repetitive stimulation with A. alternata resulted in eosinophil recruitment to the nasal passages in association with elevated levels of IL-5, IL-13 and eotaxin-1; eosinophil recruitment was diminished in eotaxin-1^-/- mice, and abolished in Rag1^-/- mice. A. alternata also resulted in elevated levels of nasal wash IgA in both wild-type and eosinophil-deficient ∆dblGATA mice. Interestingly, A. alternata-treated mice responded to an influenza virus infection with profound weight loss and mortality compared to mice that received diluent alone (0% vs 100% survival, ***P < .001); the lethal response was blunted when A. alternata was heat-inactivated. Minimal differences in virus titre were detected, and eosinophils present in the nasal passages at the time of virus inoculation provided no protection against the lethal sequelae. Interestingly, nasal wash fluids from mice treated with A. alternata included more neutrophils and higher levels of pro-inflammatory mediators in response to virus challenge, among these, IL-6, a biomarker for disease severity in human influenza.

CONCLUSIONS AND CLINICAL RELEVANCE

Repetitive administration of A. alternata resulted in inflammation of the nasal mucosae and unanticipated morbidity and mortality in response to subsequent challenge with influenza virus. Interestingly, and in contrast to findings in the lower airways, eosinophils recruited to the nasal passages provided no protection against lethal infection. As increased susceptibility to influenza virus among individuals with rhinitis has been the subject of several clinical reports, this model may be used for further exploration of these observations.

Effects of coexisting BDE-47 on the migration and biodegradation of BDE-99 in river-based aquifer media recharged with reclaimed water

Two prominent polybrominated diphenyl ether (PBDE) congeners have been included in the persistent organic pollutant list, 2,2',4,4',5-tetrabromodiphenyl ether (BDE-99) and 2,2,4,4'-tetrabromodiphenyl ether (BDE-47), which have been detected in treated municipal wastewater, river water, and sediments in China. A lab-scale column experiment was established to investigate the effects of the competitive sorption of BDE-47 on BDE-99 biodegradation and migration in two types of river-based aquifer soils during groundwater recharge with reclaimed water. Two types of recharge columns were used, filled with either silty clay (SC) or black carbon-amended silty clay (BCA). The decay rate constants of BDE-99 in the BCA and SC systems were 0.186 and 0.13 m^-1 in the single-solute system and 0.128 and 0.071 m^-1 in the binary-solute system, respectively, showing that the decay of BDE-99 was inhibited by the coexistence of BDE-47. This was particularly evident in the SC system because the higher hydrophobicity of BDE-99 determined the higher affinity and competition for sorption sites onto black carbon. The biodegradation of BDE-99 was suppressed by the coexistence of BDE-47, especially in the SC system. Lesser-brominated congeners (BDE-47 and BDE-28) and higher-brominated congeners (BDE-100, BDE-153, BDE-154, and BDE-183) were generated in the four recharge systems, albeit at different ratios. Bacterial biodiversity was influenced by the presence of BDE-47 in the SC system, while it had no significant effect on the BCA system, because the high sorption capacity of black carbon on the hydrophobic PBDEs effectively reduced their toxicity. The ranking order of the most abundant classes changed markedly due to the coexistence of BDE-47 in both the SC and BCA systems. The ranking order of the most abundant genera changed from Azospira, Methylotenera, Desulfovibrio, Methylibium, and Bradyrhizobium to Halomonas, Hyphomicrobium, Pseudomonas, Methylophaga, and Shewanella, which could be involved in PBDE degradation.

Development of a data-processing method based on Bayesian k-means clustering to discriminate aneugens and clastogens in a high-content micronucleus assay

Genotoxicants can be identified as aneugens and clastogens through a micronucleus (MN) assay. The current high-content screening-based MN assays usually discriminate an aneugen from a clastogen based on only one parameter, such as the MN size, intensity, or morphology, which yields low accuracies (70-84%) because each of these parameters may contribute to the results. Therefore, the development of an algorithm that can synthesize high-dimensionality data to attain comparative results is important. To improve the automation and accuracy of detection using the current parameter-based mode of action (MoA), the MN MoA signatures of 20 chemicals were systematically recruited in this study to develop an algorithm. The results of the algorithm showed very good agreement (93.58%) between the prediction and reality, indicating that the proposed algorithm is a validated analytical platform for the rapid and objective acquisition of genotoxic MoA messages.

Steroid 5-alpha-reductase type 2 (SRD5A2) gene V89L polymorphism and hypospadias risk: A meta-analysis

BACKGROUND

Hypospadias is a common congenital malformation in males, in which the urethral orifice is found on the ventral side of the penis as a result of incomplete fusion of urethral folds. The etiology of hypospadias is poorly understood, and may be multifactorial, including genetic, endocrine and environmental factors. The steroid 5-alpha-reductase type 2 (SRD5A2) gene, which is mainly expressed in the ventral side of the urethra in the process of male genital development, plays an important role in urethral shaping.

OBJECTIVE

To investigate, with database searches of related published papers, whether SRD5A2 gene V89L polymorphism has an association with hypospadias risk.

METHODS

The following databases were searched for relevant papers, and all published case-control studies of hypospadias were used to perform a meta-analysis: PubMed, Embase, Springer Link, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, and Weipu. A quality assessment was performed using the Newcastle-Ottawa scale of a case-control study. To assess the strength of the association under various genetic models, odds ratio (OR) and its 95% confidence interval (CI) were calculated using fixed-effect or random-effects model according to the heterogeneity. Overall and stratified subgroup analyses, including ethnicity, source of controls, sample for DNA extraction, and hypospadias classification, were performed. All data were analyzed using Review Manager 5.3.

RESULTS

This analysis included six eligible case-control studies with 1130 cases and 1279 controls. Overall, there was a statistically significant association between hypospadias risk and V89L polymorphism for allele contrast (C vs G: OR 1.91, 95% CI 1.13-3.23), P = 0.02), codominant model (CC vs GG: OR 2.97, 95% CI 1.25-7.04, P = 0.01; GC vs GG: OR 2.36, 95% CI 1.35-4.13, P = 0.003), dominant model (GC + CC vs GG: OR 2.46, 95% CI 1.28-4.72, P = 0.007), and recessive model (CC vs GC + GG: OR 1.91, 95% CI 1.00-3.66, P = 0.05). Moreover, there was also a statistically significant association in some subgroups. The positive results are shown in the Summary Table.

CONCLUSION

This meta-analysis suggested that the V89L polymorphism definitely increases the risk of hypospadias, and the C allele is a genetic risk factor for hypospadias occurrence.