Enhancing aerobic composting performance of high-salt oily food waste with Bacillus safensis YM1

To alleviate the inhibitory effects of salt and oil on food waste compost, the compost was inoculated with salt-tolerant and oil-degrading Bacillus safensis YM1. The YM1 inoculation could effectively improve compost maturation index. Compared with uninoculated group, the oil content and Cl- concentration in the 0.5% YM1-inoculated compost decreased significantly by 19.7% and 8.1%, respectively. The addition of the YM1 inoculant substantially altered the richness and composition of the microbial community during composting, as evidenced by the identification of 47 bacterial and 42 fungal biomarker taxa. The enrichment of some oil-degrading salt-tolerant microbes (Bacillus, Haloplasma, etc.) enhanced nutrient conversion, which is crucial for the improved maturity of the YM1 compost. This study demonstrated that YM1 could regulate both abiotic and biotic processes to improve high-salt and oily food waste composting, which may be an effective inoculant in the industrial-scale composting.

Health Economic Considerations in the Deployment of an Alzheimer's Prevention Therapy

INTRODUCTION

As treatments for secondary prevention of Alzheimer's disease (AD) are being studied, concerns about their value for money have appeared. We estimate cost-effectiveness of a hypothetical screening and prevention program.

METHODS

We use a Markov model to project cost-effectiveness of a treatment that reduces progression to symptomatic AD by 50% with either chronic treatment until progression to mild cognitive impairment or treatment for one year followed by monitoring with AD blood tests and retreatment with one dose in case of amyloid re-accumulation. Diagnoses would be made with an AD blood test with sensitivity and specificity of 80%, and inconclusive results in 20%. Individuals testing negative would be re-tested in five years and those with inconclusive results in one.

RESULTS

The program would generate per-person value of $53,721 from a payer (reduction of direct cost and patient QALY gains) and $69,861 from a societal perspective (adding valuation of reduced caregiver burden). With chronic treatment, it would be cost-effective up to annual drug prices of $7,000 and $10,300, respectively. Time-limited treatment would be cost-effective at annual drug prices of $54,257 and $78,458 from a payer and societal perspective, respectively. Higher specificity of the blood test would decrease cost per person with similar value generation DISCUSSION: A hypothetical prevention treatment for AD could be economically viable from a payer and societal perspective.

Insights into effects of salt stress on the oil-degradation capacity, cell response, and key metabolic pathways of Bacillus sp. YM1 isolated from oily food waste compost

A novel bacterial strain, Bacillus sp. YM1, was isolated from compost for the efficient degradation of oily food waste under salt stress. The strain's lipase activity, oil degradation ability, and tolerance to salt stress were evaluated in a liquid medium. Additionally, the molecular mechanisms (including key genes and functional processes) underlying the strain's salt-resistant degradation of oil were investigated based on RNA-Seq technology. The results showed that after 24 h of microbial degradation, the degradation rate of triglycerides in soybean oil was 80.23% by Bacillus sp. YM1 at a 30 g L-1 NaCl concentration. The metabolizing mechanism of long-chain triglycerides (C50-C58) by the YM1 strain, especially the biodegradation rate of triglycerides (C18:3/C18:3/C18:3), could reach 98.65%. The most substantial activity of lipase was up to 325.77 U·L-1 at a salinity of 30 g L-1 NaCl. During salt-induced stress, triacylglycerol lipase was identified as the crucial enzyme involved in oil degradation in Bacillus sp. YM1, and its synthesis was regulated by the lip gene (M5E02_13495). Bacillus sp. YM1 underwent adaptation to salt stress through various mechanisms, including the accumulation of free amino acids, betaine synthesis, regulation of intracellular Na+/K+ balance, the antioxidative response, spore formation, and germination. The key genes involved in Bacillus sp. YM1's adaptation to salt stress were responsible for the synthesis of glutamate 5-kinase, superoxide dismutase, catalase, Na+/H+ antiporter, general stress protein, and sporogenic proteins belonging to the YjcZ family. Results indicated that the isolated strain of Bacillus sp. YM1 could significantly degrade oil in a short time under salt stress. This study would introduce new salt-tolerant strains for coping with the biodegradation of oily food waste and provide gene targets for use in genetic engineering.

Employing salt-tolerant bacteria Serratia marcescens subsp. SLS for biodegradation of oily kitchen waste

The high oil and salt content of kitchen waste (KW) inhibit bioconversion and humus production. To efficiently degrade oily kitchen waste (OKW), a halotolerant bacterial strain, Serratia marcescens subsp. SLS which could transform various animal fats and vegetable oils, was isolated from KW compost. Its identification, phylogenetic analysis, lipase activity assays, and oil degradation in liquid medium were assessed, and then it was employed to carry out a simulated OKW composting experiment. In liquid medium, the 24 h degradation rate of mixed oils (soybean oil: peanut oil: olive oil: lard = 1:1:1:1, v/v/v/v) was up to 87.37% at 30 °C, pH 7.0, 280 rpm, 2% oil concentration and 3% NaCl concentration. The ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS) method demonstrated that the mechanism of SLS strain metabolizing long-chain triglycerides (TAGs) (C53-C60), especially the biodegradation of TAG (C18:3/C18:3/C18:3) by the strain can reach more than 90%. Degradation of 5, 10, 15% concentrations of total mixed oil were also calculated to be 64.57, 71.25, 67.99% respectively after a simulated composting duration of 15 days. The results suggest that the isolated strain of S. marcescens subsp. SLS is suitable for OKW bioremediation in high NaCl concentration within a reasonably short period of time. The findings introduced a salt-tolerant and oil-degrading bacteria, providing insights into the mechanism of oil biodegradation and offering new avenues of study for OKW compost and oily wastewater treatment.

Pleiotropic melatonin-mediated responses on growth and cadmium phytoextraction of Brassica napus: A bioecological trial for enhancing phytoremediation of soil cadmium

Melatonin (MT) has recently gained significant scientific interest, though its mechanism of action in enhancing plant vigor, cadmium (Cd) tolerance, and Cd phytoremediation processes are poorly understood. Therefore, here we investigated the beneficial role of MT in improving growth and Cd remediation potential of rapeseed (Brassica napus). Plants, with or without MT (200 µM L^-1), were subjected to Cd stress (30 mg kg¹). Without MT, higher Cd accumulation (up to 99%) negatively affected plant growth and developmental feature as well as altered expression of several key genes (DEGs) involved in different molecular pathways of B. napus. As compared to only Cd-stressed counterparts, MT-treated plants exhibited better physiological performance as indicated by improved leaf photosynthetic and gaseous exchange processes (3-48%) followed by plant growth (up to 50%), fresh plant biomass (up to 45%), dry plant biomass (up to 32%), and growth tolerance indices (up to 50%) under Cd exposure. MT application enhanced Cd tolerance and phytoremediation capacity of B. napus by augmenting (1) Cd accumulation in plant tissues and its translocation to above-ground parts (by up to 45.0%), (2) Cd distribution in the leaf cell wall (by up to 42%), and (3) Cd detoxification by elevating phytochelatins (by up to 8%) and metallothioneins (by upto 14%) biosynthesis, in comparison to Cd-treated plants. MT played a protective role in stabilizing hydrogen peroxide and malondialdehyde levels in the tissue of the Cd-treated plants by enhancing the content of osmolytes (proline and total soluble protein) and activities of antioxidant enzymes (SOD, CAT, APX and GR). Transcriptomic analysis revealed that MT regulated 1809 differentially expressed genes (828 up and 981 down) together with 297 commonly expressed DEGs (CK vs Cd and Cd vs CdMT groups) involved in plant-pathogen interaction pathway, protein processing in the endoplasmic reticulum pathway, mitogen-activated protein kinase signaling pathway, and plant hormone signal transduction pathway which ultimately promoted plant growth and Cd remediation potential in the Cd-stressed plants. These results provide insights into the unexplored pleiotropic beneficial action of MT in enhancing in the growth and Cd phytoextraction potential of B. napus, paving the way for developing Cd-tolerant oilseed crops with higher remediation capacity as a bioecological trial for enhancing phytoremediation of hazardous toxic metals in the environment.

Plant growth promoting endophyte promotes cadmium accumulation in Solanum nigrum L. by regulating plant homeostasis

The homeostasis regulating mechanism of endophyte enhancing cadmium (Cd) extraction by hyperaccumulator is poorly understood. Here, an endophyte strain E3 that belonged to Pseudomonas was screened from Cd hyperaccumulator Solanum nigrum L., which significantly improved the Cd phytoextraction efficiency of S. nigrum by 40.26%. The content and translocation factor of nutrient elements indicated that endophyte might regulate Cd accumulation by affecting the uptake and transport of magnesium and iron in S. nigrum. Gene transcriptional expression profile further revealed that SnMGT, SnIRT1, and SnIRT2, etc., were the key genes involved in the regulation of S. nigrum elements uptake by endophyte. However, changes in elemental homeostasis did not negatively affect plant growth. Endophyte inoculation promoted plant growth by fortifying photosynthesis as well as recruiting specific bacteria in S. nigrum endosphere, e.g., Pseudonocardiaceae, Halomonas. Notably, PICRUSt2 analysis and biochemical characterization jointly suggested that endophyte regulated starch degradation in S. nigrum leaves to maintain photosynthetic balance. Our results demonstrated that microecological characteristics of hyperaccumulator could be reshaped by endophyte, also the homeostasis regulation in endophyte enhanced hyperaccumulator Cd phytoextraction was significant.

Unraveling the role of multi-walled carbon nanotubes in a corn-soil system: Plant growth, oxidative stress and heavy metal(loid)s behavior

In the age of nanotechnological advancement, carbon nanotubes (CNTs) are drawing global attention. However, few studies have been published on the crop growth responses to CNTs in heavy metal(loid)s contaminated environments. A pot experiment was conducted to assess the effect of multi-walled carbon nanotubes (MWCNTs) on plant development, oxidative stress, and heavy metal(loid)s behavior in a corn-soil system. Corn (Zea mays L.) seedlings were cultivated in soil containing Cadmium (Cd) and Arsenic (As) that had been primed with 0, 100, 500, and 1000 mg kg^-1 MWCNTs. The application of 100 and 500 mg kg^-1 MWCNTs improved shoot length by 6.45% and 9.21% after 45 days, respectively. Total plant dry biomass increased by 14.71% when treated with 500 mg kg^-1 MWCNTs but decreased by 9.26% when exposed to 1000 mg kg^-1 MWCNTs. MWCNTs treatment did not affect Cd accumulation in plants. On the other hand, the bio-concentration factor of As was inversely associated with plant growth (p < 0.05), which was declined in MWCNTs treatments. Oxidative stress was aggravated when plants were exposed to MWCNTs, thus activating the antioxidant enzymes system in the corn. In contrast, TCLP-extractable Cd and As in soil significantly decreased than in the control. Additionally, the soil nutrients were changed under MWCNTs treatments. Our findings also revealed that a particular concentration of MWCNTs can mitigate the toxicity of Cd and As in corn seedlings. Therefore, these results suggest the prospective application of CNTs in agricultural production, ensuring environmental and soil sustainability.

Insights into growth-promoting effect of nanomaterials: Using transcriptomics and metabolomics to reveal the molecular mechanisms of MWCNTs in enhancing hyperaccumulator under heavy metal(loid)s stress

Carbon nanotubes present potential applications in soil remediation, particularly in phytoremediation. Yet, how multi-walled carbon nanotubes (MWCNTs) induced hyperaccumulator growth at molecular level remains unclear. Here, physio-biochemical, transcriptomic, and metabolomic analyses were performed to determine the effect of MWCNTs on Solanum nigrum L. (S. nigrum) growth under cadmium and arsenic stresses. 500 mg/kg MWCNTs application significantly promoted S. nigrum growth, especially for root tissues. Specially, MWCNTs application yields 1.38-fold, 1.56-fold, and 1.37-fold enhancement in the shoot length, root length, and fresh biomass, respectively. Furthermore, MWCNTs significantly strengthened P and Fe absorption in roots, as well as the activities of antioxidative enzymes. Importantly, the transcriptomic analysis indicated that S. nigrum gene expression was sensitive to MWCNTs, and MWCNTs upregulated advantageous biological processes under heavy metal(loid)s stress. Besides, MWCNTs reprogramed metabolism that related to defense system, leading to accumulation of 4-hydroxyphenylpyruvic acid (amino acid), 4-hydroxycinnamic acid (xenobiotic), and (S)-abscisic acid (lipid). In addition, key common pathways of differentially expressed metabolites and genes, including "tyrosine metabolism" and "isoquinoline alkaloid biosynthesis" were selected via integrating transcriptome and metabolome analyses. Combined omics technologies, our findings provide molecular mechanisms of MWCNTs in promoting S. nigrum growth, and highlight potential application of MWCNTs in soil remediation.

Two plant growth-promoting bacterial Bacillus strains possess different mechanisms in affecting cadmium uptake and detoxification of Solanum nigrum L

Microorganisms affect cadmium (Cd) extraction by hyperaccumulators to varying degrees, but the potential mechanism has not been completely studied. Here, two plant growth-promoting bacteria (PGPB, Bacillus paranthracis NT1 and Bacillus megaterium NCT-2) were assessed for their influence on Cd uptake by Solanum nigrum L. and their influence mechanisms. The results showed that both two strains could regulate phytohormones secretion, alleviate oxidative stress and promote S. nigrum growth when exposed to Cd (dry weight was significantly increased by 21.51% (strain NCT-2) and 21.23% (strain NT1) compared with the control, respectively). Additionally, strain NCT-2 significantly elevated the translocation factor (TF) and bioconcentration factor (BCF), and thus significantly facilitated total Cd uptake by 41.80% of S. nigrum, whereas strain NT1 significantly reduced the BCF and TF, resulting in insignificant effect on total Cd uptake of S. nigrum compared with the control. Results of qPCR illustrated that the two strains influenced the detoxification of Cd in S. nigrum by affecting the expression of antioxidant enzyme genes and gene PDR2. Moreover, the differential expression of heavy metal transport genes IRT1 and HMA may lead to the difference of Cd accumulation in S. nigrum. Principal component analysis and Pearson correlation coefficient analysis further verified the positive roles of salicylic acid and indole-3-acetic acid on Cd detoxification of S. nigrum, and the positive correlation relationship between transportation of Cd from underground to shoot, plant biomass and Cd uptake. Altogether, our results demonstrated that these two PGPB have great potential in helping plants detoxify Cd and could provide insights into the mechanism of PGPB-assisted phytoremediation of Cd-contaminated soil.

A sustainable approach for bioremediation of secondary salinized soils: Studying remediation efficiency and soil nitrate transformation by bioaugmentation

Nitrate is the main nitrogen source for plant growth, but it can also pollute the environment. A major cause of soil secondary salinization is the rising level of nitrates in the soil, which poses a threat to the sustainability and fertility of global greenhouse soils. Herein, Bacillus megaterium NCT-2 was used as a microbial agent to remove nitrate by bioaugmentation, and the remediation efficiency of secondary salinized soil in different degrees was evaluated. The findings showed that the highest nitrate removal rate of 62.76% was in a medium degree of secondary salinized soil. Moreover, the results of 16S rRNA high-throughput sequencing and quantitative real-time PCR (qPCR) demonstrated that NCT-2 agent reduced the microbial diversity, increased the microbial community stability, and changed the composition and function of the microbial community were changed by NCT-2 agent in all districts soil. Further analysis demonstrated that the NCT-2 bacterial agent significantly increased the key enzyme genes of the assimilation pathway (nitrite reductase gene NasD, 87-404 times, and glutamine reduction enzyme gene GlnA, 13-52 times) and dissimilatory reduction to ammonium (DNRA) (nitrate reductase gene NarG, 14-56 times) in different degrees of secondary salinized soils. This proved that NCT-2 agent could promote the nitrate assimilation and the dissimilation and reduction to ammonium in secondary salinized soil. Thus, the current findings suggested that the NCT-2 agent has a significant potential for reducing excessive nitrate levels in secondary salinized soil. The remediation efficiency was related to the microbial community composition and the degree of secondary salinization. This study could provide a theoretical basis for the remediation of secondary salinized soil in the future.

Prognostic implication of the neoadjuvant rectal score and other biomarkers of clinical outcome in Hong Kong Chinese patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy

BACKGROUND

Neoadjuvant chemoradiotherapy is a standard treatment for locally advanced rectal cancer, for which pathological complete response is typically used as a surrogate survival endpoint. Neoadjuvant rectal score is a new biomarker that has been shown to correlate with survival. The main objectives of this study were to investigate factors contributing to pathological complete response, to validate the prognostic significance of neoadjuvant rectal score, and to investigate factors associated with a lower neoadjuvant rectal score in a cohort of Hong Kong Chinese.

METHODS

Data of patients with locally advanced rectal cancer who received neoadjuvant chemoradiotherapy from August 2006 to October 2018 were retrieved from hospital records and retrospectively analysed.

RESULTS

Of 193 patients who had optimal response to neoadjuvant chemoradiotherapy and surgery, tumour down-staging was the only independent prognostic factor that predicted pathological complete response (P<0.0001). Neoadjuvant rectal score was associated with overall survival (hazard ratio [HR]=1.042, 95% confidence interval [CI]=1.021-1.064; P<0.0001), disease-free survival (HR=1.042, 95% CI=1.022-1.062; P<0.0001), locoregional recurrence-free survival (HR=1.070, 95% CI=1.039-1.102; P<0.0001) and distant recurrence-free survival (HR=1.034, 95% CI=1.012-1.056; P=0.002). Patients who had pathological complete response were associated with a lower neoadjuvant rectal score (P<0.0001), but pathological complete response was not associated with survival. For patients with intermediate neoadjuvant rectal scores, late recurrences beyond 72 months from diagnosis were observed.

CONCLUSION

Neoadjuvant rectal score is an independent prognostic marker of survival and disease recurrence in a cohort of Hong Kong Chinese patients who received neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

Comparative cytology combined with transcriptomic and metabolomic analyses of Solanum nigrum L. in response to Cd toxicity

Cadmium (Cd) triggers molecular alterations in plants, perturbs metabolites and damages plant growth. Therefore, understanding the molecular mechanism underlying the Cd tolerance in plants is necessary for assessing the persistent environmental impact of Cd. In this study, Solanum nigrum was selected as the test plant to investigate changes in biomass, Cd translocation, cell ultrastructure, metabolites and genes under hydroponic conditions. The results showed that the plant biomass was significantly decreased under Cd stress, and the plant has a stronger Cd transport capability. Transmission electron microscopy revealed that increased Cd concentration gradually damaged the plant organs (roots, stems and leaves) cell ultrastructure, as evidenced by swollen chloroplasts and deformed cell walls. Additionally, metabolomics analyses revealed that Cd stress mainly affected seven metabolism pathways, including 19 differentially expressed metabolites (DEMs). Moreover, 3908 common differentially expressed genes (DEGs, 1049 upregulated and 2859 downregulated) were identified via RNA-seq among five Cd treatments. Meanwhile, conjoint analysis found several DEGs and DEMs, including laccase, peroxidase, D-fructose, and cellobiose etc., are associated with cell wall biosynthesis, implying the cell wall biosynthesis pathway plays a critical role in Cd detoxification. Our comprehensive investigation using multiple approaches provides a molecular-scale perspective on plant response to Cd stress.

When nanoparticle and microbes meet: The effect of multi-walled carbon nanotubes on microbial community and nutrient cycling in hyperaccumulator system

Carbon nanotubes can potentially stimulate phytoremediation of heavy metal contaminated soil by promoting plant biomass and root growth. Yet, the regulating mechanism of carbon nanotubes on the rhizosphere microenvironment and their potential ecological risks remain poorly characterized. The purpose of this study was to systematically evaluate the effects of multi-walled carbon nanotubes (MCNT) on the diversity and structure of rhizosphere soil bacterial and fungal communities, as well as soil enzyme activities and nutrients, in Solanum nigrum L. (S. nigrum)-soil system. Here, S. nigrum were cultivated in heavy metal(loid)s contaminated soils applied with MCNT (100, 500, and 1000 mg kg^-1 by concentration, none MCNT addition as control) for 60 days. Our results demonstrated more significant urease, sucrase, and acid phosphatase activities in MCNT than in control soils, which benefit to promoting plant growth. Also, there were significant reductions in available nitrogen and available potassium contents with the treatment of MCNT, while the organic carbon and available phosphorus were not affected by MCNT application. Notably, the alpha diversity of bacterial and fungal communities in the MCNT treatments did not significantly vary relative to control. However, the soil microbial taxonomic compositions were changed under the application of MCNT. Compared to the control, MCNT application increased the relative abundances of the Micrococcaceae family, Solirubrobacteraceae family, and Conexibacter genus, which were positively correlated with plant growth. In addition, the non-metric multidimensional scaling (NMDS) analysis revealed that the community structure of bacterial and fungal communities did not significantly change among all the treatments, and bacterial community structure was significantly correlated with soil organic carbon. At the same time, sucrase activity had the highest relation to fungal community structure. This study highlighted soil microbes have strong resistance and adaptation ability to carbon nanotubes with existence of plants, and revealed linkage between the rhizosphere microenvironment and plant growth, which well improved our understanding of carbon nanotubes in heavy metal phytoremediation.

Changes in soil bacterial and fungal communities in response to Bacillus megaterium NCT-2 inoculation in secondary salinized soil

Background

Secondary salinized soil in greenhouses often contains excess nitrate. Inoculation of Bacillus megaterium NCT-2 with nitrate assimilation ability represents an attractive approach for soil remediation. However, the effects of NCT-2 on the structure and function of soil microbial communities have not been explored.

Methods

Greenhouse experiments were carried out to investigate changes in soil properties, Brassica chinensis L. growth, bacterial, and fungal community structure and function in response to NCT-2 inoculation.

Results

The NCT-2 inoculant significantly reduced the nitrate content in B. chinensis and inhibited the rebound of soil nitrate in the later stage. The shifts of bacterial community structure and function by NCT-2 was negligible, and a greater disturbance of soil fungal community structure and function was observed, for example the strong inhibitory effect on ectomycorrhizal fungi. These results indicated that the NCT-2 inoculant likely achieved the remediation effect in secondary salinized soil by shifting fungal community. The present findings add to the current understanding of microbial interactions in response to bacterial inoculation and can be of great significance for the application of NCT-2 inoculants in secondary salinized soil remediation.

Impact of COVID-19 pandemic restrictions on pregnancy duration and outcome in Melbourne, Australia

OBJECTIVE

To investigate the effect of restriction measures implemented to mitigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission during the coronavirus disease 2019 (COVID-19) pandemic on pregnancy duration and outcome.

METHODS

A before-and-after study was conducted with cohort sampling in three maternity hospitals in Melbourne, Australia, including women who were pregnant when restriction measures were in place during the COVID-19 pandemic (estimated conception date between 1 November 2019 and 29 February 2020) and women who were pregnant before the restrictions (estimated conception date between 1 November 2018 and 28 February 2019). The primary outcome was delivery before 34 weeks' gestation or stillbirth. The main secondary outcome was a composite of adverse perinatal outcomes. Pregnancy outcomes were compared between women exposed to restriction measures and unexposed controls using the χ-square test and modified Poisson regression models, and duration of pregnancy was compared between the groups using survival analysis.

RESULTS

In total, 3150 women who were exposed to restriction measures during pregnancy and 3175 unexposed controls were included. Preterm birth before 34 weeks or stillbirth occurred in 95 (3.0%) exposed pregnancies and in 130 (4.1%) controls (risk ratio (RR), 0.74 (95% CI, 0.57-0.96); P = 0.021). Preterm birth before 34 weeks occurred in 2.4% of women in the exposed group and in 3.4% of women in the control group (RR, 0.71 (95% CI, 0.53-0.95); P = 0.022), without evidence of an increase in the rate of stillbirth in the exposed group (0.7% vs 0.9%; RR, 0.83 (95% CI, 0.48-1.44); P = 0.515). Competing-risks regression analysis showed that the effect of the restriction measures on spontaneous preterm birth was stronger and started earlier (subdistribution hazard ratio (HR), 0.81 (95% CI, 0.64-1.03); P = 0.087) than the effect on medically indicated preterm birth (subdistribution HR, 0.89 (95% CI, 0.70-1.12); P = 0.305). The effect was stronger in women with a previous preterm birth (RR, 0.42 (95% CI, 0.21-0.82); P = 0.008) than in parous women without a previous preterm birth (RR, 0.93 (95% CI, 0.63-1.38); P = 0.714) (P for interaction = 0.044). Composite adverse perinatal outcome was less frequent in the exposed group than in controls (all women: 2.1% vs 2.9%; RR, 0.73 (95% CI, 0.54-0.99); P = 0.042); women with a previous preterm birth: 4.5% vs 8.4%; RR, 0.54 (95% CI, 0.25-1.18); P = 0.116).

CONCLUSIONS

Restriction measures implemented to mitigate SARS-CoV-2 transmission during the COVID-19 pandemic were associated with a reduced rate of preterm birth before 34 weeks. This reduction was mainly due to a lower rate of spontaneous prematurity. The effect was more substantial in women with a previous preterm birth and was not associated with an increased stillbirth rate. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Influence of Cd toxicity on subcellular distribution, chemical forms, and physiological responses of cell wall components towards short-term Cd stress in Solanum nigrum

Solanum nigrum is a well-documented cadmium (Cd) hyperaccumulator; however, its Cd-induced tolerance capability and detoxification mechanism remain elusive. Hence, a short-term hydroponic experiment was performed in a multiplane glasshouse to determine the influence of Cd toxicity on subcellular distribution, chemical forms, and the physiological responses of cell wall towards Cd stress in a 4-week-old plant. The experiment was conducted following completely randomized design (CRD) with five treatments (n = 4 replicates). The results showed that Cd stress showed dose-dependent response towards growth inhibition. The subcellular distribution of Cd in S. nigrum was in the order of cell wall > soluble fractions > organelles, and Cd was predominantly extracted by 1 M NaCl (29.87~43.66%). The Cd contents in different plant tissues and cell wall components including pectin, hemicellulose 1 (HC1), hemicellulose 2 (HC2), and cellulose were increased with the increase in Cd concentrations; however, the percentage of Cd concentration decreased in pectin and cellulose. Results of the polysaccharide components such as uronic acid, total sugar contents, and pectin methylesterase (PME) activity showed Cd-induced dose-dependent increase relative to exposure Cd stress. The pectin methylesterase (PME) activity was significantly (p < 0.05) enhanced by 125.78% at 75 μM Cd in root, 105.78% and 73.63% at 100 μM Cd in stem and leaf, respectively. In addition, the esterification, amidation, and pectinase treatment of cell wall and Fourier transform infrared spectroscopy (FTIR) assay exhibited many functional groups that were involved in cell wall retention Cd, especially on carboxyl and hydroxyl groups of cell wall components that indicated that the -OH and -COOH groups of S. nigrum cell wall play a crucial role in Cd fixation. In summary, results of the current study will add a novel insight to understand mobilization/immobilization as well as detoxification mechanism of cadmium in S. nigrum.

Streptomyces griseorubens JSD-1 promotes rice straw composting efficiency in industrial-scale fermenter: Evaluation of change in physicochemical properties and microbial community

The influence of Streptomyces griseorubens JSD-1 on microbial community succession during rice straw composting in an industrial-scale fermenter was assessed by high-throughput sequencing technology. Compared to uninoculated control, JSD-1 inoculation effectively raised composting temperature and improved other maturation indices. JSD-1 inoculation increased the relative abundance of Actinobacteria in thermophilic phase and Firmicutes in cooling and maturation phases. At the genus level, JSD-1 inoculation increased the abundance of organic matter degrading bacteria (Virgibacillus) and lignocellulose degrading fungi (Chaetomium and Melanocarpus); while it decreased the abundance of pathogenic fungi (Geosmithia and Acremonium). Moreover, JSD-1 changed microbes that differed significantly and altered the key connecting nodes of microbial community. Organic matter and temperature were the most significant indices that had mutual influences on bacterial and fungal communities, respectively. This study demonstrated that JSD-1 was an effective inoculant on rice straw fast composting in the industrial-scale fermenter.

Investigation and Improvement of Bond Performance of Synthetic Macro-Fibres in Concrete

Strength and stiffness are the key parameters characterising the bond performance of fibres in concrete. However, a straightforward procedure for estimating the bond parameters of a synthetic macro-fibre does not exist. This study employs pull-out tests to investigate the bond behaviour of synthetic macro-fibres. Two types of macro-fibres available in the market were investigated. A gripping system was developed to protect the fibres from local damage. The experimental campaign consisted of two stages. At the first stage, 32 concrete specimens were manufactured for performing 96 pull-out tests (three fibre samples were embedded in each cube perpendicular to the top surface and two sides). Two types of macro-fibres with either 10 or 20 mm embedment length were tested. The obtained load–displacement diagrams from pull-out tests demonstrate that the bond performance (characterised by the strength and deformation modulus) of the “top” fibres is almost 20% weaker than fibres positioned to the side surfaces. At the second stage, one type of macro-fibre was chosen for further experimentation of the feasibility of improving the bond performance through the use of colloidal silica or steel micro-fibres. This investigation stage employed an additional 36 concrete specimens. The use of steel micro-fibres was found to be an efficient alternative. The success of this solution requires a suitable proportioning of the concrete.

Rice straw as renewable components of horticultural growing media for purple cabbage

This study was conducted to estimate the influence of composted rice straw (CRS) on the growth and nutritional composition of purple cabbage (Brassica oleracea L. var. capitate L.). In order to select the proper preparation method of CRS based media, growing media were prepared by mixing peat, perlite, vermiculite and sand with CRS in different ratios. The general proportions of CRS in substrates were 25% and 50% (v/v). A mixture of 50% peat with 50% perlite (v/v) was the control (CK). Completely randomized design was used in the experiment under greenhouse conditions. The physicochemical characteristics of all growing media were determined before transplanting. Plant growth parameters as well as the mineral elements were also measured. In general, plants grown in most CRS based media were improved in growth and element nutrition in comparison with control. 25% CRS addition was the most-suitable rate for the growth of purple cabbage. The highest leaves yield obtained from T3 (25% CRS: 25% peat: 50% vermiculite, v:v:v) increased by 105.99% compared to control. CRS can be an alternative constituent to replace the generally using peat in growing media.

Two plant growth promoting bacterial Bacillus strains possess different mechanisms in adsorption and resistance to cadmium

Microorganisms are promising biosorbents for decontaminating cadmium-polluted soil or water systems, but the underlying remediation mechanisms are still unclear. In this study, the cadmium biosorption mechanisms and capabilities of plant growth-promoting microorganisms (Bacillus megaterium NCT-2 and Bacillus paranthracis NT1) were investigated. Batch biosorption experiments showed that the optimal biosorption conditions for B. megaterium NCT-2 and B. paranthracis NT1 were pH 6.0, a biomass dosage of 1.0 g L^-1, and an initial Cd²⁺ concentration of 10 mg L^-1, and pH 8.0, a biomass dosage of 1.0 g L^-1, and an initial Cd²⁺ concentration of 10 mg L^-1, respectively. The biosorption processes of both biosorbents were well described by the pseudo-second order kinetic model, which indicated that the biosorption of Cd²⁺ was mainly chemisorption. The intracellular accumulation portion of adsorbed Cd²⁺ in B. megaterium NCT-2 was much higher than in B. paranthracis NT1 (43.11% and 3.25%, respectively), which resulted in the lower cadmium tolerance (14 mg L^-1 and 280 mg L^-1, respectively) and higher cadmium removal efficiency (46.79% and 20.45%, respectively) of B. megaterium NCT-2 compared to B. paranthracis NT1. SEM-EDS and FTIR analysis suggested the probable interactions of Cd²⁺ with the biosorbent surface ligands, such as -OH, -NH, -SO₃, CO and -COOH during surface adsorption. Results of qRT-PCR illustrated that the difference in cadmium resistant mechanism and adsorption performance between B. megaterium NCT-2 and B. paranthracis NT1 may be regulated by the genes cadA, zitB, khtT, and bshA and cadA, trkA, czcD, and bshA, respectively. Our results revealed that these two biosorbents have the potential for further use in the development of cadmium remediation technologies and could provide insight into the mechanisms of cadmium biosorption.

Dynamic bacterial assembly driven by Streptomyces griseorubens JSD-1 inoculants correspond to composting performance in swine manure and rice straw co-composting

The effect of Streptomyces griseorubens JSD-1 inoculant on composting performance and bacterial community assembly during the swine manure and rice straw co-composting was studied by a high-throughput pyrosequencing technology. The JSD-1 inoculant contributed to a higher temperature (maximum 66.8 °C), a longer thermophilic phase (46 days), and a lower bacterial diversity in JSD-1 compost. The principle component analysis confirmed that JSD-1 inoculant significantly reshaped the microbial communities. The difference in genera significantly increased during both composting processes. The predominant biomarkers were members of Bacteroidetes in JSD-1 composting. The network analysis also showed different chief "connecting" genera in both composts. Moreover, JSD-1 inoculant increased the total nitrogen, phosphorus, and potassium content in composts. The redundancy analysis showed that the bacterial community was mainly influenced by temperature; additionally, the nutrient contents were positively correlated with temperature. These results demonstrated that JSD-1 inoculant drove the bacterial assembly to induce physicochemical property changes in co-composting.

Optimization of NPK fertilization combined with phytoremediation of cadmium contaminated soil by orthogonal experiment

In the current experiment, influence of NPK composition on the Cd contaminated soil-plant (Solanum nigrum L.) system as well as the phytoremediation efficiency were comprehensively studied. The composition of NPK was optimized for a sustainable phytoremediation and simultaneous agronomic technique in Cd-contaminated soil by orthogonal (L₁₄) experiment, aimed to achieve plant productivity and maximum phytoremediation potential enhancement. Results showed that different treatments of NPK composition enhanced soil properties including saccharase, urease, catalase and acid phosphatase activities as compared to the control treatment, however, soil pH was slightly decreased by 3.64%~6.67% with different composition of NPK treatments. Plant biomass and Cd concentration in the aboveground part (stem and leaves) of S. nigrum were significantly (P < 0.05) enhanced by 14.19%~48.97% and 38.50%~127.15% as compared to control plants with the addition of NPK fertilizers having different composition. Meanwhile, with the application of NPK fertilizer root/shoot Cd ratio and translocation factor (TF) was significantly decreased, however, bioconcentration factor (BCF) was increased as compared to control. Additionally, different composition of NPK fertilizers significantly increased photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids) and soluble protein in comparison to control. The activities of antioxidant enzymes in S. nigrum including ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and glutathione reductase (GR) were increased, while malonaldehyde (MDA) and proline contents were decreased. Principal component analysis (PCA) showed that N₃P₂K₂ treatment had the highest comprehensive score amongst other studied treatments of NPK composition, owing to its optimal composition for the investigated soil-S. nigrum system. Moreover, it was found that optimal composition (N₃P₂K₂) of fertilizer resulted in increase of the plant resistance to Cd and the efficiency of phytoextraction. Therefore, it is suggested to all the small-holder famers and scientific community that precise composition of NPK fertilizer should be utilized according to soil properties, environmental conditions and plant requirements under Cd-stress condition in order to achieve maximum biomass, Cd uptake efficiency as well phytoremediation potential in moderately Cd contaminated soil.

Microencapsulation of Bacillus megaterium NCT-2 and its effect on remediation of secondary salinization soil

Aim: To prolong the shelf life of Bacillus megaterium NCT-2 by preparing microcapsules through spray drying, and evaluate their efficiency in secondary salinisation soil remediation.Methods: The wall material and spray drying conditions were optimised. Morphological characteristics of microcapsule were measured, and soil remediation effects were tested under field conditions.Results: A relatively higher survival rate of B. megaterium microcapsule was obtained with 1:1 of chitosan/maltodextrin (w/w) when spray drying was performed at 150.0 °C, with the feed flow rates of 800 mL h^-1 and 1000 mL h^-1, respectively. The span value of 0.93 ± 0.01 was obtained under above conditions. Microcapsule survival rate was 64.09 ± 0.12% after 6 months of storage. Moreover, microcapsule successfully decreased NO₃^- and EC value in strongly saline soil by 46.5 ± 1.48% and 45.2 ± 1.51%, respectively.Conclusion: Bacillus megaterium NCT-2 microcapsules have application potential in the remediation of secondary salinisation soil.

2161Redox-mediated PKA-RIalpha localisation to the lysosome inhibits myocardial calcium release and robustly reduces myocardial injury

Background

Kinase oxidation is a critical signalling mechanism through which changes in the intracellular redox state alter cardiac function. In the myocardium, type-1 protein kinase A (PKARIα) can be reversibly oxidised, forming interprotein disulphide bonds within the holoenzyme complex. However, the effect of PKARIα oxidation on downstream signalling in the heart, particularly under states of oxidative stress, remains unexplored.

Purpose

To determine the direct functional consequences of PKARIα oxidation in the heart and investigate their impact on ischaemia/reperfusion (I/R) injury.

Methods and results

Experiments using the AKAR3ev FRET biosensor in murine left ventricular (LV) myocytes and Fluorescence Recovery After Photobleaching (FRAP) of GFP-tagged wild-type (WT) and mutant RIα proteins expressed in RIα-null fibroblasts showed that PKARIα oxidation does not increase the kinases' catalytic activity, but enhances its binding to A-kinase anchoring proteins (AKAP; n=30–39/N=3, p<0.01). Super-resolution microscopy revealed localisation of oxidised PKARIα to lysosomes in WT myocytes, which was completely absent in “redox dead” Cys17Ser PKARIα knock-in mice (KI; panel A; n=38–41/N=3, p<0.01) and reduced when AKAP binding was prevented using the RIAD disruptor peptide (30.6±5.1% reduction; n=35–37/N=3, p<0.01).

Displacement of PKARIα from lysosomes resulted in spontaneous sarcoplasmic reticulum calcium release and dramatic calcium oscillations in KI LV myocytes (panel B), which were preventable by ryanodine receptor blockade (1 mM tetracaine; n=14, p<0.01), acute depletion of endolysosomal calcium stores (100 nM bafilomycin; n=7; p<0.01), or lysosomal two-pore channel inhibition (5 μM Ned-19; n=9; p<0.05).

I/R (secondary to cardiopulmonary bypass) was found to induce PKARIα oxidation in the myocardium of patients undergoing cardiac surgery (panel C; n=18, p<0.05). Absence of this response in KI mouse hearts resulted in 2-fold larger infarcts (p<0.01) and a concomitant reduction in LV contractile recovery (final LVDP of 55.9±8.6 vs 82.5±7.1 mmHg in WT; n=7–8, p<0.05), both which were prevented by addition of Ned-19 at the time of reperfusion (panel D; n=4, p<0.01).

Conclusions

Oxidised PKARIα acts as a potent inhibitor of intracellular calcium release in the heart through its redox-dependent interaction with the lysosome. In the setting of I/R, where PKARIα oxidation is induced, this regulatory mechanism is critical for protecting the heart from injury and offers a novel target for the design of cardioprotective therapeutics.

Acknowledgement/Funding

British Heart Foundation CH/12/3/29609, RG/16/12/32451; Garfield-Weston Foundation MPS/IVIMS-11/12-4032; Wellcome Trust Fellowship 0998981Z/12/Z

A rare case of Listeria monocytogenes causing mycotic aneurysm of the common femoral artery: A case report

•

Immunosuppressed patients may not display typical clinical or biochemical features associated with mycotic aneurysms.

•

Clinicians should have a high index of suspicion for infective aetiology when treating aneurysmal disease in immunocompromised patients.

•

It is important to obtain intraoperative tissue samples for histopathology and microbiological assessment in immunocompromised patients for detection of rare pathogens.

•

Autogenous vein should be used in infected surgical fields to avoid the risk of prosthetic graft infection.

Introduction

Mycotic aneurysms are an uncommon occurrence, withStaphylococcus and Salmonella species found to be the causative pathogen in up to 95% of cases. We believe this is the first described case of a common femoral artery mycotic aneurysm due to Listeria monocytogenes.

Presentation of case

A 66-year-old male presented with a two-month history of an increasing painful mass in his left groin, on the background of immunosuppression treatment for ankylosing spondylitis. He was afebrile on assessment, with a normal white cell count. Contrast enhanced CT scan showed a common femoral artery aneurysm, with no infective features. His aneurysm was excised and repaired with a Dacron tube graft. L. monocytogenes was cultured from the aneurysm tissue, and he was commenced on appropriate antibiotic treatment. The prosthetic graft was also replaced with a venous bypass of the aneurysm.

Discussion

L. monocytogenes is a rare cause of mycotic aneurysm with less than 40 cases reported in the literature. Immunosuppression is a recognised risk factor for Listerial infections. Immunocompromised patients may not display typical clinical or biochemical features associated with a mycotic aneurysm. Prosthetic graft infections are associated with significant mortality, with excision of the prosthetic material and venous reconstruction associated with good outcomes for eradicating infection.

Conclusion

This report highlights the importance of obtaining intraoperative tissue samples for microbiological and histopathological assessment in immunocompromised patients. This is important for the detection of rare organisms such as L.monocytogenes, requiring targeted antibiotic therapy. Inappropriate treatment of Listerial infections can result in serious invasive illness.

Impacting on factors promoting intra-group aggression in secure psychiatric settings

Three preliminary and linked studies investigate the impact of making alterations to factors considered relevant to engaging in and experiencing intra-group aggression (bullying) among adult male patients detained in a single secure forensic hospital. Study one (n = 44) outlines the institutional factors, attitudes towards bullying and environmental factors that increase the likelihood of engaging in bullying and/or being victimised. Study two (n = 53 patients and 167 staff) assesses the effect of three variations of intervention that aimed to reduce intra-group aggression through direct alteration of the physical and psychosocial environment, using data from both patients and staff. Study three (n = 414) looks at the effects of two variations of the intervention used in study two, which offered patients’ participation in individual and communal activities. It was predicted that changes to the physical and social environment would produce a reduction in the factors shown to predict intra-group aggression. Attitudes supportive of bullying and the presence of social hierarchies each increased the likelihood of engaging in bullying. Indirect changes to the social environment on the wards had more positive effects than those incorporating direct alterations to the physical and social environment. The differences in effectiveness of the two approaches are discussed in relation to the established predictors of intra-group aggression. The research concludes by noting the preliminary nature of the research and outlining potential directions for future research and intervention.

Short communication: Genotyping and single nucleotide polymorphism analysis of bovine leukemia virus in Chinese dairy cattle

Bovine leukemia virus (BLV) causes enzootic leucosis in cattle and is classified into 10 genotypes with a worldwide distribution, except for several European countries, Australia, and New Zealand. Although BLV is widespread in Chinese cows with the positive rate of 49.1% at the individual level, very little is known about the BLV genotype in dairy cattle in China. To determine BLV genetic variability in cows in China, 112 BLV-positive samples from 5 cities in China were used for BLV molecular characterization in this study. Phylogenetic analysis using the neighbor-joining method on partial env sequence encoding gp51 obtained from 5 Chinese cities and those available in GenBank (n = 53, representing BLV genotype 1-10) revealed the Chinese strains belonged to genotype 6. Seven unique SNP were identified among Yancheng, Shanghai, and Bengbu strains out of the total 12 SNP identified in Chinese strains. The genotyping coupled with SNP analysis of BLV can serve as a useful molecular epidemiological tool for tracing the source of pathogens. This study highlights the importance of genetic analysis of geographically diverse BLV strains to understand BLV global genetic diversity.

Cesarean section and risks of overweight and obesity in school-aged children: a population-based study

BACKGROUND

Obesity puts a great health burden in the world. Previous studies suggest that caesarean section (CS) may increase the risk of obesity in children, but it is still uncertain whether this association is causal or due to residual confounding by medical indication.

AIM

To assess the association between CS, CS without medical indications in particular and the risk of overweight and obesity in school-aged children.

DESIGN

Cross-sectional survey.

METHODS

The 2014 Shanghai Child Health, Education and Lifestyle Evaluation was a large population-based survey with cluster random probability sampling in 26 primary schools in Shanghai, China, in 2014. The mode of delivery was reported by parents. The height, weight and waist circumference of the children were measured. Logistic regression models with SURVEYLOGISTIC procedure were used to estimate the risk of childhood obesity. Pupils delivered vaginally were served as the reference group.

RESULTS

A total of 17 571 pupils completed this survey, and 13 724 of them who were singleton, born term and between 5 and 13 years old were included in our analysis. CS was associated with increased risks of overweight and obesity (BMI: adjusted OR = 1.28 [95%CI 1.13-1.45] and 1.44 [1.26-1.66], respectively; weight for height ratio [WHtR] >0.46: 1.33 [1.20-1.48]). Similar results were found in CS without medical indication (BMI: overweight = 1.24 [1.05-1.47], obesity = 1.43 [1.19-1.72]; WHtR > 0.46: 1.30 [1.13-1.50]).

CONCLUSIONS

CS overall and CS without medical indications were associated with increased risks of overweight and obesity in primary school children.

Enhanced removal of nitrate in the maize rhizosphere by plant growth-promoting Bacillus megaterium NCT-2, and its colonization pattern in response to nitrate

High soil nitrate concentrations can lead to the secondary salinization of soils. Bacillus megaterium NCT-2 is a wild-type strain isolated from secondary salinized soil and is very effective in reducing nitrate. Laboratory and greenhouse experiments were carried out to investigate its nitrate reduction capabilities, colonization pattern, and plant growth promotion responses to nitrate content in the soil. B. megaterium NCT-2 was marked with a green fluorescent protein (gfp) gene and was left to successfully colonize maize roots and the rhizosphere. Inoculation with gfp-tagged NCT-2 significantly promoted nitrate removal from the soil and improved plant growth. Confocal microscopy results revealed that NCT-2 is an endophyte that can colonize the meristematic and elongation zones of the root tip, and the middle segment of the root. Soil nitrate concentration had no significant effect on NCT-2 distribution. The gfp-tagged NCT-2 populations in the roots and rhizosphere soil first increased, but then decreased, and at the end of the experiment, colonization levels in the rhizosphere soil stabilized at ∼5 × 10⁴ CFU g^-1 soil. However, the levels in the roots increased again to 1-3 × 10⁴ CFU g^-1 root in the different treatments. The NCT-2 population in the roots was significantly affected by nitrate content. A nitrate-nitrogen concentration of 72 mg kg^-1 was the optimum concentration for NCT-2 colonization of maize roots. This study will improve the agricultural application of NCT-2 as a biofertilizer for nitrate removal and plant growth promotion.

Comparison of Advanced Imaging Resources, Radiology Workforce, and Payment Methodologies between the United States and Canada

The purpose of this Practice Perspectives was to review the United States and Canadian approaches to health care access and payment for advanced imaging. The historical background, governmental role, workforce, coding, payment, radiologic challenges, cost, resource intensity, and overall outcomes in longevity are reviewed.

Optimal paths on the road network as directed polymers

We analyze the statistics of the shortest and fastest paths on the road network between randomly sampled end points. We find that, to a good approximation, the optimal paths can be described as directed polymers in a disordered medium, which belong to the Kardar-Parisi-Zhang universality class of interface roughening. Comparing the scaling behavior of our data with simulations of directed polymers and previous theoretical results, we are able to point out the few characteristics of the road network that are relevant to the large-scale statistics of optimal paths. Indeed, we show that the local structure is akin to a disordered environment with a power-law distribution which become less important at large scales where long-ranged correlations in the network control the scaling behavior of the optimal paths.

Heterologous expression and biochemical characterization of assimilatory nitrate and nitrite reductase reveals adaption and potential of Bacillus megaterium NCT-2 in secondary salinization soil

Large accumulation of nitrate in soil has resulted in "salt stress" and soil secondary salinization. Bacillus megaterium NCT-2 which was isolated from secondary salinization soil showed high capability of nitrate reduction. The genes encoding assimilatory nitrate and nitrite reductase from NCT-2 were cloned and over-expressed in Escherichia coli. The optimum co-expression condition was obtained with E. coli BL21 (DE3) and 0.1mM IPTG for 10h when expression was carried out at 20°C and 120rpm in Luria-Bertani (LB) medium. The molecular mass of nitrate reductase was 87.3kDa and 80.5kDa for electron transfer and catalytic subunit, respectively. The large and small subunit of nitrite reductase was 88kDa and 11.7kDa, respectively. The purified recombinant enzymes showed broad activity range of temperature and pH. The maximum activities were obtained at 35°C and 30°C, pH 6.2 and 6.5, which was similar to the condition of greenhouse soils. Maximum stimulation of the enzymes occurred with addition of Fe³⁺, while Cu²⁺ caused the maximum inhibition. The optimum electron donor was MV+Na₂S₂O₄+EDTA and MV+Na₂S₂O₄, respectively. Kinetic parameters of K_m and V_max were determined to be 670μM and 58U/mg for nitrate reductase, and 3100μM and 5.2U/mg for nitrite reductase. Results of quantitative real-time PCR showed that the maximum expression levels of nitrate and nitrite reductase were obtained at 50mM nitrate for 8h and 12h, respectively. These results provided information on novel assimilatory nitrate and nitrite reductase and their properties presumably revealed adaption of B. megaterium NCT-2 to secondary salinization condition. This study also shed light on the role played by the nitrate assimilatory pathway in B. megaterium NCT-2.

Coronavirus infections in horses in Saudi Arabia and Oman

Equine coronaviruses (ECoV) are the only coronavirus known to infect horses. So far, data on ECoV infection in horses remain limited to the USA, France and Japan and its geographic distribution is not well understood. We carried out RT‐PCR on 306 nasal and 315 rectal swabs and tested 243 sera for antibodies to detect coronavirus infections in apparently healthy horses in Saudi Arabia and Oman. We document evidence of infection with ECoV and HKU23 coronavirus by RT‐PCR. There was no conclusive evidence of Middle East respiratory syndrome coronavirus infection in horses. Serological data suggest that lineage A betacoronavirus infections are commonly infecting horses in Saudi Arabia and Oman but antibody cross‐reactivities between these viruses do not permit us to use serological data alone to identify which coronaviruses are causing these infections.

CD200 modulates macrophage cytokine secretion and phagocytosis in response to poly(lactic co-glycolic acid) microparticles and films

Biocompatibility is a major concern for developing biomaterials used in medical devices, tissue engineering and drug delivery. Poly(lactic-co-glycolic acid) (PLGA) is one of the most widely used biodegradable materials, yet still triggers a significant foreign body response that impairs healing. Immune cells including macrophages respond to the implanted biomaterial and mediate the host response, which can eventually lead to device failure. Previously in our laboratory, we found that CD200, an immunomodulatory protein, suppressed macrophage inflammatory activation in vitro and reduced local immune cell infiltration around a biomaterial implant. While in our initial study we used polystyrene as a model material, here we investigate the effect of CD200 on PLGA, a commonly used biomaterial with many potential clinical applications. We fabricated PLGA with varied geometries, modified their surfaces with CD200, and examined macrophage cytokine secretion and phagocytosis. We found that CD200 suppressed secretion of the pro-inflammatory cytokine TNF-α and enhanced secretion of the anti-inflammatory cytokine IL-10, suggesting a role for CD200 in promoting wound healing and tissue remodeling. In addition, we found that CD200 increased phagocytosis in both murine macrophages and human monocytes. Together, these data suggest that modification with CD200 leads to a response that simultaneously prevents inflammation and enhances phagocytosis. This immunomodulatory feature may be used as a strategy to mitigate inflammation or deliver drugs or anti-inflammatory agents targeting macrophages.

IL-15 super-agonist (ALT-803) enhances natural killer (NK) cell function against ovarian cancer

OBJECTIVE

Natural killer (NK) cells represent a powerful immunotherapeutic target as they lyse tumors directly, do not require differentiation, and can elicit potent inflammatory responses. The objective of these studies was to use an IL-15 super-agonist complex, ALT-803 (Altor BioScience Corporation), to enhance the function of both normal and ovarian cancer patient derived NK cells by increasing cytotoxicity and cytokine production.

METHODS

NK cell function from normal donor peripheral blood mononuclear cells (PBMCs) and ovarian cancer patient ascites was assessed using flow cytometry and chromium release assays ±ALT-803 stimulation. To evaluate the ability of ALT-803 to enhance NK cell function in vivo against ovarian cancer, we used a MA148-luc ovarian cancer NOD scid gamma (NSG) xenogeneic mouse model with transferred human NK cells.

RESULTS

ALT-803 potently enhanced functionality of NK cells against all ovarian cancer cell lines with significant increases seen in CD107a, IFNγ and TNFα expression depending on target cell line. Function was also rescued in NK cells derived from ovarian cancer patient ascites. Finally, only animals treated with intraperitoneal ALT-803 displayed an NK dependent significant decrease in tumor.

CONCLUSIONS

ALT-803 enhances NK cell cytotoxicity against ovarian cancer in vitro and in vivo and is able to rescue functionality of NK cells derived from ovarian cancer patient ascites. These findings suggest that ALT-803 has the potential to enhance NK cell-based immunotherapeutic approaches for the treatment of ovarian cancer.

Clinical outcome of neoadjuvant chemoradiation in locally advanced rectal cancer at a tertiary hospital

OBJECTIVES

To review the clinical outcome of locally advanced rectal cancer treated with neoadjuvant chemoradiation followed by definitive surgery with or without adjuvant chemotherapy and to elucidate the prognostic factors for treatment outcome.

METHODS

This historical cohort study was conducted at a tertiary public hospital in Hong Kong. All patients who had undergone neoadjuvant chemoradiation for locally advanced rectal cancer in our department from November 2005 to October 2014 were recruited. Local recurrence-free survival, distant metastasis-free survival, disease-free survival, and overall survival of patients were documented.

RESULTS

A total of 135 patients who had received neoadjuvant chemoradiation during the study period were reviewed. There were 130 patients who had completed neoadjuvant chemoradiation and surgery. The median follow-up time was 35.1 months. The 3- and 5-year local recurrence-free survival, distant metastasis-free survival, disease-free survival, as well as overall survival rates were 91.8% and 86.7%, 73.9% and 72.1%, 70.1% and 64.6%, as well as 86.5% and 68.4%, respectively. The rate of pathological complete response was 13.8%. The T and N downstaging rate was 49.2% and 63.1%, respectively. The rate of conversion from threatened circumferential resection margin to clearance of margin was 90.6%. Of the 42 cases that were initially deemed to require abdominal perineal resection, 15 (35.7%) were converted to sphincter-sparing surgery.

CONCLUSIONS

The treatment outcome of neoadjuvant chemoradiation for locally advanced rectal cancer was comparable with overseas data in terms of local control rate and overall survival. This strategy may increase the chance of achieving a clear surgical margin by downstaging the tumour, especially in patients who presented with threatened circumferential margin.