Elucidating human gut microbiota interactions that robustly inhibit diverse Clostridioides difficile strains across different nutrient landscapes

The human gut pathogen Clostridioides difficile displays extreme genetic variability and confronts a changeable nutrient landscape in the gut. We mapped gut microbiota inter-species interactions impacting the growth and toxin production of diverse C. difficile strains in different nutrient environments. Although negative interactions impacting C. difficile are prevalent in environments promoting resource competition, they are sparse in an environment containing C. difficile-preferred carbohydrates. C. difficile strains display differences in interactions with Clostridium scindens and the ability to compete for proline. C. difficile toxin production displays substantial community-context dependent variation and does not trend with growth-mediated inter-species interactions. C. difficile shows substantial differences in transcriptional profiles in the presence of the closely related species C. hiranonis or C. scindens. In co-culture with C. hiranonis, C. difficile exhibits massive alterations in metabolism and other cellular processes, consistent with their high metabolic overlap. Further, Clostridium hiranonis inhibits the growth and toxin production of diverse C. difficile strains across different nutrient environments and ameliorates the disease severity of a C. difficile challenge in a murine model. In sum, strain-level variability and nutrient environments are major variables shaping gut microbiota interactions with C. difficile.

Changes in brain susceptibility in Wilson's disease patients: a quantitative susceptibility mapping study

AIM

To assess changes in the susceptibility of the caudate nucleus (CN), putamen, and globus pallidus (GP) in patients with neurological and hepatic Wilson's disease (WD) by quantitative susceptibility mapping (QSM).

MATERIAL AND METHODS

The brain MRI images of 33 patients diagnosed with WD and 20 age-matched controls were analysed retrospectively. All participants underwent brain T1-weighted, T2-weighted, and QSM imaging using a 1.5 T magnetic resonance imaging (MRI) machine. QSM maps were evaluated with the STISuite toolbox. The quantitative susceptibility levels of the CN, putamen, and GP were analysed using region of interest analysis on QSM maps. Differences among neurological WD patients, hepatic patients, and controls were determined.

RESULTS

Susceptibility levels were significantly higher for all examined structures (CN, putamen and GP) in patients with neurological WD compared with controls (all p<0.05) and hepatic WD patients (all p<0.05). No statistically significant differences were found in susceptibility levels between patients with hepatic WD and controls (all p>0.05).

CONCLUSION

The QSM technique is a valuable tool for detecting changes in brain susceptibility in WD patients, indicating abnormal metal deposition. Notably, the current findings suggest that neurological WD patients exhibit more severe susceptibility changes compared with hepatic WD patients. Therefore, QSM can be utilised as a complementary method to detect brain injury in WD patients.

[Preliminary application of recombinase -aided amplification in detection of Clonorchis sinensis metacercariae in freshwater fish]

OBJECTIVE

To evaluate the performance of recombinase-aided amplification (RAA) assay in detection of Clonorchis sinensis metacercariae in freshwater fish samples, so as to provide insights into standardization and field application of this assay.

METHODS

Wild freshwater fish samples were collected in the rivers of administrative villages where C. sinensis-infected residents lived in Jiangyan District, Xinghua County and Taixing County of Taizhou City, Jiangsu Province from June to September 2022. Genomic DNA was extracted from six freshwater fish specimens (5 g each) containing 0, 1, 2, 4, 8 and 16 C. sinensis metacercariae for fluorescent RAA assay, and the diagnostic sensitivity was evaluated. Fluorescent RAA assay was performed with genomic DNA from C. sinensis, Metorchis orientalis, Haplorchis pumilio and Centrocestus formosanus metacercariae as templates to evaluate its cross-reactions. In addition, the detection of fluorescent RAA assay and direct compression method for C. sinensis metacercariae was compared in field-collected freshwater fish samples.

RESULTS

Positive amplification was found in fresh-water fish specimens containing different numbers of C. sinensis metacercariae, and fluorescent RAA assay was effective to detect one C. sinensis metacercaria in 5 g freshwater fish specimens within 20 min. Fluorescent RAA assay tested negative for DNA from M. orientalis, H. pumilio and C. formosanus metacercariae. Fluorescent RAA assay and direct compression method showed 5.36% (93/1 735) and 2.88% (50/1 735) detection rates for C. sinensis metacercariae in 1 735 field-collected freshwater fish samples, with a statistically significant difference seen (χ2 = 478.150, P < 0.001). There was a significant difference in the detection of C. sinensis metacercariae in different species of freshwater fish by both the direct compression method (χ2 = 11.20, P < 0.05) and fluorescent RAA assay (χ2 = 20.26, P < 0.001), and the detection of C. sinensis metacercariae was higher in Pseudorasbora parva than in other fish species by both the direct compression method and fluorescent RAA assay (both P values < 0.05).

CONCLUSIONS

Fluorescent RAA assay has a high sensitivity for detection of C. sinensis metacercariae in freshwater fish samples, and has no cross-reactions with M. orientalis, H. pumilio or C. formosanus metacercariae. Fluorescent RAA assay shows a higher accuracy for detection of C. sinensis infections in field-collected freshwater fish than the direct compression method.

Morin protects chicks with T-2 toxin poisoning by decreasing heterophil extracellular traps, oxidative stress and inflammatory response

1. Fusarium tritici widely exists in a variety of grain feeds. The T-2 toxin is the main hazardous component produced by Fusarium tritici, making a serious hazard to poultry industry. Morin, belonging to the flavonoid family, can be extracted from mulberry plants and possesses anticancer, antioxidant and anti-inflammatory compounds, but whether morin protects chicks with T-2 toxin poisoning remains unclear. This experiment firstly established a chick model of T-2 toxin poisoning and then investigated the protective effects and mechanism of morin against T-2 toxin in chicks.2. The function of liver and kidney was measured by corresponding alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), blood urea nitrogen (BUN), creatinine (Cre) and uric acid (UA) kits. Histopathological changes were observed by haematoxylin-eosin staining. The status of oxidative stress was measured by MDA, SOD, CAT, GSH and GSH-PX kits. The mRNA levels of TNF-α, COX-2, IL-1β, IL-6, caspase-1, caspase-3 and caspase-11 were measured by quantitative real-time PCR. Heterophil extracellular trap (HET) release was analysed by immunofluorescence and fluorescence microplate.3. The model with T-2 toxin poisoning in chicks was successfully established. Morin significantly decreased T-2 toxin-induced ALT, AST, ALP, BUN, Cre and UA, and improved T-2 toxin-induced liver cell rupture, liver cord disorder and kidney interstitial oedema. Oxidative stress analysis showed that morin ameliorated T-2 toxin-induced damage by reducing malondialdehyde (MDA), increasing superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GSH-PX). The qRT-PCR analysis showed that morin reduced T-2 toxin-induced mRNA expressions of TNF-α, COX-2, IL-1β, IL-6, caspase-1, caspase-3 and caspase-11. Moreover, morin significantly reduced the release of T-2 toxin-induced HET in vitro and in vivo.4. Morin can protect chicks from T-2 toxin poisoning by decreasing HETs, oxidative stress and inflammatory responses, which make it a useful compound against T-2 toxin poisoning in poultry feed.

Single-cell analysis of multiple invertible promoters reveals differential inversion rates as a strong determinant of bacterial population heterogeneity

Population heterogeneity can promote bacterial fitness in response to unpredictable environmental conditions. A major mechanism of phenotypic variability in the human gut symbiont Bacteroides spp. involves the inversion of promoters that drive the expression of capsular polysaccharides, which determine the architecture of the cell surface. High-throughput single-cell sequencing reveals substantial population heterogeneity generated through combinatorial promoter inversion regulated by a broadly conserved serine recombinase. Exploiting control over population diversification, we show that populations with different initial compositions converge to a similar composition over time. Combining our data with stochastic computational modeling, we demonstrate that the differential rates of promoter inversion are a major mechanism shaping population dynamics. More broadly, our approach could be used to interrogate single-cell combinatorial phase variable states of diverse microbes including bacterial pathogens.

[Comparison of the disease burden of schistosomiasis globally and in China and Zimbabwe]

OBJECTIVE

To investigate the trends in the disease burden of schistosomiasis worldwide and in China, and Zimbabwe from 1990 to 2019, so as to provide insights into the formulation of the schistosomiasis control strategy in Zimbabwe.

METHODS

Based on Global Burden of Disease Study 2019 (GBD 2019) data sources, the age-standardized prevalence, mortality, disability-adjusted life year (DALY) rate of schistosomiasis were compared in the world, China, and Zimbabwe and the trends in the disease burden of schistosomiasis from 1990 to 2019 were investigated using Joinpoint regression analysis. In addition, the associations between the burden of schistosomiasis worldwide and in China and Zimbabwe from 1990 to 2019 and socio-demographic index (SDI) were examined using Pearson correlation analysis.

RESULTS

The age-standardized prevalence, mortality, and DALY rate of schistosomiasis were 1 804.95/10⁵, 0.14/10⁵ and 20.92/10⁵ in the world, 707.09/10⁵, 0.02/10⁵ and 5.06/10⁵ in China, and 2 218.90/10⁵, 2.39/10⁵ and 90.09/10⁵ in Zimbabwe in 2019, respectively. The global prevalence, mortality, and DALY rate of schistosomiasis appeared a tendency towards a rise followed by a decline with age in 2019, while the prevalence and DALY rate of schistosomiasis appeared a tendency towards a sharp rise followed by a fluctuating decline in both China and Zimbabwe, and the mortality of schistosomiasis appeared a tendency towards a rise. The age-standardized prevalence [average annual percent change (AAPC) = -1.31%, -2.22% and -6.12%; t = -20.07, -83.38 and -53.06; all P values < 0.05)] and DALY rate of schistosomiasis (AAPC = -1.91%,-4.17% and -2.08%; t = -31.89, -138.70 and -16.45; all P values < 0.05) appeared a tendency towards a decline in the world, China and Zimbabwe from 1990 to 2019, and the age-standardized mortality of schistosomiasis appeared a tendency towards a decline in the world and China (AAPC = -3.46% and -8.10%, t = -41.03 and -61.74; both P values < 0.05), and towards a rise followed by a decline in Zimbabwe (AAPC = 1.35%, t = 4.88, P < 0.05). In addition, Pearson correlation analysis showed that the age-standardized prevalence (r = -0.75, P < 0.05), mortality (r = -0.73, P < 0.05), and DALY rate of schistosomiasis (r = -0.77, P < 0.05) correlated negatively with SDI in the world, China and Zimbabwe from 1990 to 2019.

CONCLUSIONS

The disease burden of schistosomiasis appeared a remarkable decline in China from 1990 to 2019, and the prevalence of schistosomiasis showed a tendency towards a decline in Zimbabwe from 1990 to 2019; however, the mortality and DALY rate of schistosomiasis in Zimbabwe topped in the world. A schistosomiasis control strategy with adaptations to local epidemiology and control needs of schistosomiasis is needed to facilitate the elimination of schistosomiasis in Zimbabwe.

[Publication and citation analyses of Chinese Journal of Schistosomiasis Control from 2011 to 2020]

OBJECTIVE

To investigate the publications and citations of Chinese Journal of Schistosomiasis Control from 2011 to 2020, so as to provide insights into improving the journal quality and impact.

METHODS

All publications were retrieved from 60 issues of 10 volumes of Chinese Journal of Schistosomiasis Control from 2011 to 2020, and publication and citation analyses were performed using a bibliometric method.

RESULTS

A total of 1 867 articles were published in Chinese Journal of Schistosomiasis Control from 2011 to 2020, with the largest number in 2012 (220 publications) and the lowest in 2020 (135 publications), and original article (36.48%), control experience (17.14%) and control study (10.34%) were the three most common article type. The overall proportion of grant-supported articles was 59.08% (1 103/1 867), and the number of grant per article was (2.34±1.58) grants. The mean duration from submission to publication was (173.48±105.84) days per article, and there was a significant difference in the mean duration from submission to publication among years (F = 30.883, P < 0.01). Jiangsu Province (492 publications, 26.35%), Shanghai Municipality (264 publications, 14.14%) and Hubei Province (230 publications, 12.32%) were the three most productive provinces where the first author lived, and disease control and prevention institutions were the predominant affiliations of the first author (67.22%), with Jiangsu Institute of Schistosomiasis Control, National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, and Wannan Medical College as the three most productive affiliations. The number of authors was 5.94 authors per publication, and the proportion of co-authored publications was 95.45% in Chinese Journal of Schistosomiasis Control from 2011 to 2020. Journal article was the predominant type of cited (89.97%), and the mean number of citations was (15.70±11.56) citations per publication, with a significant difference in the mean number of citations per publication among years (F = 2.205, P < 0.05). The impact factors of Chinese Journal of Schistosomiasis Control ranged from 0.877 to 1.676 during the period from 2011 to 2020, and the overall Price index was 47.59%.

CONCLUSIONS

Both the academic impact and national transmissibility of Chinese Journal of Schistosomiasis Control appeared a tendency towards a rise from 2011 to 2020. Seeking high-quality contributions, increasing interdisciplinary integration, shortening the duration from submission to publication, expanding the coverage of publication services and enhancing impact are the future priorities of the journal.

The lateral cervical stria approach to selective neck dissection: a preliminary study

BACKGROUND

This study aims to propose a lateral cervical stria approach for selective neck dissection (SND) in patients of early-stage oral malignancies.

MATERIAL AND METHODS

The lateral cervical stria approach was used in 11 patients undergoing SND between December 2020 and March 2022. The surgical incision was located in submandibular cervical stria, with a length of 5.0 cm. The ipsilateral SND was performed according to the pathological type, covering part or all of I-V levels. Perioperative variables including operation time, blood loss, drainage volume, number of lymph node as well as complications were assessed. The score of appearance using the University of Washington Quality of Life Questionnaire (UW-QOL) was recorded 6-month postoperatively.

RESULTS

Direct closure of primary lesion was performed in ten patients and a forearm free flap reconstruction was used in one patient. No wound breakdown or infection was found in all cases. The mean operative time of SND was 157.63±27.39 min. The volume of intraoperative blood loss and postoperative drainage was 120.45±36.77 ml and 314.09±98.82 ml, respectively. The mean number of retrieved lymph nodes was 17.89±6.03 (ranging from 12 to 31). Postoperative complications included mild static lower lip deviation (n=1), shoulder discomfort (n=1) and mild auricular paraesthesia (n=1). The mean score of appearance was 86.36±13.06, with 100 scores in 5 patients and 75 scores in 6 patients.

CONCLUSIONS

The lateral cervical stria approach for SND in early-stage oral malignancies is reliable, achieving to satisfactory functional and aesthetic outcomes.

Carbohydrate complexity limits microbial growth and reduces the sensitivity of human gut communities to perturbations

Dietary fibre impacts the growth dynamics of human gut microbiota, yet we lack a detailed and quantitative understanding of how these nutrients shape microbial interaction networks and responses to perturbations. By building human gut communities coupled with computational modelling, we dissect the effects of fibres that vary in chemical complexity and each of their constituent sugars on community assembly and response to perturbations. We demonstrate that the degree of chemical complexity across different fibres limits microbial growth and the number of species that can utilize these nutrients. The prevalence of negative interspecies interactions is reduced in the presence of fibres compared with their constituent sugars. Carbohydrate chemical complexity enhances the reproducibility of community assembly and resistance of the community to invasion. We demonstrate that maximizing or minimizing carbohydrate competition between resident and invader species enhances resistance to invasion. In sum, the quantitative effects of carbohydrate chemical complexity on microbial interaction networks could be exploited to inform dietary and bacterial interventions to modulate community resistance to perturbations.

[Identification of metabolic biomarkers associated with the onset of type 2 diabetes based on a nested case-control study]

Objective: To explore metabolic biomarkers associated with the onset of type 2 diabetes. Methods: Cluster random sampling method was used to select 10 867 local residents aged ≥ 20 years in Liangxi district of Wuxi City, Jiangsu Province in 2007. The baseline survey and physical examination were conducted to collect participants' information, including demographic characteristics, behavior and lifestyles, disease history, family history of diabetes, height, weight, waist circumference and blood pressure, etc. Blood samples were collected and biochemical indexes (high density lipoprotein cholesterol, total cholesterol, triglyceride, fasting blood glucose, etc.) were tested. By June 30, 2020, 220 newly diagnosed patients with type 2 diabetes during the follow-up were selected as cases, and 220 healthy individuals were matched as controls with age (±5 years) and the same sex. High performance liquid chromatography mass spectrometer was used to detect and identify metabolites in serum samples of two groups at baseline. Lasso regression and multivariate conditional logistic regression were used to explore the metabolites associated with the onset of type 2 diabetes. Results: The age of participants at baseline was (53±7) years, and 41.82% were male. 25 out of 1 579 metabolites were selected to be potentially associated with the onset of type 2 diabetes in the lasso regression model. The multivariable conditional logistic regression analysis showed that only 7-Methylxanthine had an independent effect on type 2 diabetes (P=0.019). The area under the receiver operating characteristic curve (AUC) (95%CI) of the prediction model of type 2 diabetes based on traditional risk factors was 0.80 (0.76-0.85). After the 7-methylxanthine in the model, the AUC (95%CI) increased to 0.92 (0.89-0.95) (P<0.001). From the second year, 7-methylxanthine could improve the prediction performance (P=0.007). Conclusion: The level of 7-methylxanthine is related to the onset of type 2 diabetes, and can be used as a biomarker to predict its incidence risk.

[Advances of tight junction damage in the corneal epithelial barrier in the pathogenesis of corneal diseases]

The cornea is a transparent tissue with significant refractive and barrier functions. Corneal epithelium constitutes the first line of defense against foreign pathogens. Corneal epithelial cells interact to form a functionally selective permeability barrier. Dysfunction of this barrier leads to corneal impairment followed by a series of ocular surface diseases and even blindness. Tight junctions (TJ), located at the top of the intercellular space of corneal epithelial superficial cells, play a critical role in establishing and maintaining the barrier function. Previous studies have shown that destruction of the TJ acts as a crucial step of the occurrence and progression of multiple ocular surface diseases. Understanding the fundamental features and functions of the TJ, noticing the risk factors of TJ disruption, and clarifying the key role of TJ in the pathogenesis of various ocular surface diseases will help to better understand and treat ocular surface diseases.

[Effect of dyslipidemia on clinical outcome of infertility patients receiving donor eggs]

Objective: To explore the effect of dyslipidemia on the clinical outcome of intracytoplasmic sperm injection-embryo transfer (ICSI-ET) in infertility patients receiving donor eggs. Methods: A total of 118 patients were selected to receive egg donors and ICSI-ET at the First Affiliated Hospital of Nanjing Medical University between April 2007 and December 2020. According to the levels of triacylglycerol, serum cholesterol, high density lipoprotein (HDL), and low density lipoprotein, they were divided into dyslipidemia group (35 cases) and normal blood lipids group (83 cases). The influence of body mass index (BMI) and age was adjusted by 1∶1 propensity score matching, and the general condition and clinical outcome of the two groups were analyzed retrospectively. Finally, the relationship between lipid composition and clinical outcome was analyzed according to patients' age and BMI. Results: (1) Comparing the pre-matching dyslipidemia group with the normal blood lipids group, the BMI of the dyslipidemia group was significantly higher than that of the normal blood lipids group [(23.5±2.4) vs (22.4±2.7) kg/m²], and the embryo implantation rate was significantly lower than that of the normal blood lipids group [13.6% (8/59) vs 27.3% (36/132)], the differences were statistically significant (both P<0.05). (2) There were no significant differences in years of infertility, number of pregnancies, number of abortions, number of transplanted embryos, protocol of endometrial preparation, endometrial thickness on transplantation day and high quality embryo rate between the two groups, through propensity score matching (all P>0.05). The biochemical pregnancy rate [28.6% (10/35)], embryo implantation rate [13.6% (8/59)] and live birth rate [20.0% (7/35)] in dyslipidemia group were significantly lower than those in the normal blood lipids group (P<0.05). The clinical pregnancy rate was lower than that of the normal blood lipids group (P>0.05). (3) The results of stratified analysis showed that the level of HDL in the clinically non-pregnant group was significantly lower than that in the pregnant group in patients ≤ 35 years old [(1.5±0.3) vs (1.8±0.5) mmol/L; P<0.05]. In the overweight recipient patients, the level of HDL of the clinically non-pregnant group was lower than that of the pregnant group (P>0.05). Conclusions: Dyslipidemia significantly reduces the biochemical pregnancy rate, embryo implantation rate and live birth rate in patients with receiving donor eggs. Especially in patients aged ≤35 years old, the reduction of HDL is closely related to adverse pregnancy outcomes.

[Surgical treatment of papillary thyroid carcinoma involving larynx and trachea]

Objective: To evaluate the efficacy of surgical treatment of papillary thyroid carcinoma (PTC) involving larynx and trachea. Methods: A total of 1 436 cases of thyroid malignant tumors were admitted to the Department of Otolaryngology, Qilu Hospital of Shandong University from 2004 to 2019, including 110 cases of PTC involving larynx and trachea, and of which 105 cases with complete follow-up data were retrospectively analyzed. There were 42 males and 63 females, with a male/female ratio of 1∶1.5, aged from 28 to 81 years. All lesions involved trachea, including 11 cases involving both trachea and larynx. Of those 83 cases underwent laryngeal and airway wall tumor excision, and 22 cases underwent radical tumor excision plus laryngeal and trachea repair. Extubation rate was analyzed and the postoperative survival curve of patients was analyzed by Kaplan-Meier method. Results: Among 105 cases, 16 cases underwent tracheotomy and 12 cases were successfully extubated. The overall 3- 5- and 10-year survival rates were 100.0%, 86.4% and 72.5%, and the disease-free survival rates were 93.1%, 81.6% and 57.7%, respectively. There was significant difference in survival curve between the two groups (χ²=4.21, P=0.040). The 5-year and 10-year survival rates were 94.6% and 77.3% in laryngeal and tracheal tumor exclusion group, and 85.7% and 51.4% in the radical tumor resection group. There was no significant difference in the survival curves between the two groups (χ²=3.50, P=0.061). Conclusion: PTC patients with laryngeal and tracheal involvement can achieve long survival and good quality of life through reasonable surgical treatment.

POS0521 RISKS OF SEVERE INFECTION AFTER THE INTRODUCTION OF bDMARDs IN NEWLY DIAGNOSED RHEUMATOID ARTHRITIS PATIENTS: A POPULATION-BASED INTERRUPTED TIME-SERIES ANALYSIS

Background

Biological disease-modifying anti-rheumatic drugs (bDMARDs) are effective in suppressing inflammation and preventing joint damage. But bDMARDs may be associated with increased risk of severe infection. Evidence on this is contradictory with some studies showing increased risk, whereas others reporting no significant changes.

Objectives

To determine the impact of the introduction of bDMARDs on severe infection among patients newly diagnosed with RA compared with non-RA individuals.

Methods

In this age- and gender-matched cohort study using administrative health data for the population of BC, Canada, all incident RA patients diagnosed between 1995–2007 were identified. Non-RA individuals were randomly selected from the general control population to match with RA. Incident RA/non-RA individuals were then divided into quarterly cohorts according to their diagnosis date. Two outcomes were examined: (1) first severe infection (FSI) after RA onset necessitating hospitalization or occurring during hospitalization; and (2) all severe infections (ASI) after RA onset. We calculated the 8-year FSI and ASI rate for each cohort. We conducted interrupted time-series analyses to compare levels and trends of FSI and ASI in RA and non-RA individuals diagnosed during pre-bDMARDs (1995–2001) and post-bDMARDs (2003–2007) periods. Adjusted 8-year FSI and ASI rates for RA and non-RA cohorts diagnosed five years after bDMARDs introduction were compared with expected rates assuming no bDMARDs introduction, based on extrapolation of pre-bDMARDs trends.

Results

A total of 60,226 and 588,499 incident RA/non-RA individuals were identified. We identified 8,954 FSI and 14,245 ASI in RA, and 56,153 FSI and 79,819 ASI in non-RA. The 8-year FSI rates among RA patients diagnosed in the pre-bDMARDs period decreased over time but leveled off among those diagnosed in the post-period (Figure 1). The adjusted difference between the post- and pre-bDMARDs secular trends of 8-year FSI rates was 0.68 (p=0.03) in RA and 0.03 (p=0.67) in non-RA (Table 1). The 8-year ASI rates among RA patients diagnosed in the pre-bDMARDs period decreased over time but increased significantly among those diagnosed in the post-period (Figure 1). The adjusted difference between the post- and pre-bDMARDs secular trends of 8-year ASI rates was 1.85 (p=0.001) in RA and 0.12 (p=0.29) in non-RA (Table 1). For RA cohort diagnosed 5 years after bDMARDs introduction, ASI rate increased by 20.4% than expected rates assuming no bDMARDs introduction. In contrast, ASI rate in non-RA increased by only 10.9%.

Table 1.

Results of interrupted time-series analysis of FSI/ASI rates, adjusting for age, gender, chronic obstructive pulmonary disease, Romano Charlson Comorbidity Index, diabetes, chronic kidney diseases, alcoholism, cancer, prior hospitalization with infection and socio-economic status at disease diagnosis year, using stepwise model selection

OutcomeParameterRANon-RAUnadj. Diff (95% CI)Adj. Diff (95% CI)Unadj. Diff (95% CI)Adj. Diff (95% CI)p-valuep-valuep-valuep-valueFSITrend0.63 (0.03, 1.22) 0.04410.68 (0.09, 1.27) 0.02920.08 (-0.08, 0.25) 0.32370.03 (-0.12, 0.19) 0.6728Level (1 year post-intervention)0.50 (-2.00, 2.99) 0.69890.31 (-1.88, 2.49) 0.78470.41 (-0.21, 1.03) 0.20410.26 (-0.24, 0.75) 0.31035 years post-intervention3.01 (-0.85, 6.87) 0.13313.02 (-0.48, 6.52) 0.09860.75 (-0.24, 1.73) 0.14330.39 (-0.46, 1.25) 0.3721ASITrend1.84 (0.83, 2.84) 0.00091.85 (0.81, 2.89) 0.00110.28 (0.04, 0.53) 0.03050.12 (-0.10, 0.34) 0.2877Level (1 year post-intervention)-1.21 (-5.41, 3.00) 0.5763-1.44 (-5.44, 2.56) 0.48501.46 (0.42, 2.49) 0.00851.20 (0.38, 2.02) 0.00645 years post-intervention6.14 (0.26, 12.01) 0.04665.97 (0.02, 11.93) 0.05602.60 (1.08, 4.12) 0.00171.69 (0.45, 2.92) 0.0109Figure 1.

Unadjusted rates.

Conclusion

Arthritis onset after bDMARDs introduction is associated with an elevated risk of severe infection in RA patients, compared with matched non-RA individuals.

Acknowledgements

We would like to thank the Ministry of Health of British Columbia and Population Data BC for providing access to the administrative data. All inferences, opinions, and conclusions drawn in this publication are those of the authors, and do not reflect the opinions or policies of the Data Stewards or the [British Columbia] Ministry of Health. No personal identifying information was made available as part of this study. Procedures used were in compliance with British Columbia’s Freedom in Information and Privacy Protection Act. Ethics approval was obtained from the University of British Columbia’s Behavioral Research Ethics Board (H15-00887).

Disclosure of Interests

None declared.

POS0503 RISKS OF CARDIOVASCULAR EVENTS AFTER THE INTRODUCTION OF bDMARDs IN NEWLY DIAGNOSED RHEUMATOID ARTHRITIS PATIENTS: A POPULATION-BASED INTERRUPTED TIME-SERIES ANALYSIS

Background

Rheumatoid arthritis (RA) is associated with increased risk of cardiovascular (CV) events. Biological disease-modifying anti-rheumatic drugs (bDMARDs) are effective in suppressing inflammation and preventing joint damage and may help lower the risk of CV events. However, recent epidemiological studies have shown mixed results with some suggesting a lower risk of CV events, while others reporting no significant differences.

Objectives

To determine the impact of the introduction of bDMARDs on incident cardiovascular disease (CVD) among patients newly diagnosed with RA compared with matched non-RA individuals.

Methods

In this age- and gender-matched cohort study using administrative health data for the population of BC, Canada, all incident RA patients diagnosed between 1995–2007 were identified. Non-RA individuals were randomly selected from the general control population to match with RA. Incident RA and non-RA individuals were then divided into quarterly cohorts according to their diagnosis date. The outcome of interest was incident CVD event after RA onset, which include acute myocardial infarction, cerebrovascular accident, and venous thromboembolism. We calculated the 8-year incident CVD rate for each cohort. We conducted interrupted time-series analyses to compare levels and trends of CVD in RA and non-RA individuals diagnosed during pre-bDMARDs (1995–2001) and post-bDMARDs (2003–2007) periods with intervention time set at year of 2002. Adjusted 8-year CVD rates for RA and non-RA cohorts diagnosed five years after bDMARDs introduction were compared with expected rates assuming no bDMARDs introduction, based on extrapolation of pre-bDMARDs trends.

Results

A total of 60,226 and 588,499 incident RA and non-RA individuals were identified. We identified 6,740 and 48,653 incident CVD events in total in RA and non-RA individuals, respectively. We observe no change in the secular trends of the 8-year CVD rates in both RA and non-RA individuals diagnosed in pre- and post-bDMARDS periods (Figure 1): the adjusted difference between the post- and pre-bDMARDs secular trends of 8-year CVD rates was 0.23 (p=0.26) for RA patients and -0.07 (p=0.33) for non-RA individuals (Table 1). However, we observed a reduction in the level of CVD rates among RA patients diagnosed in the post-bDMARDs period and no change in non-RA (Figure 1): the adjusted difference in level comparing points immediately before and after the intervention, and accounting for pre-intervention trend was -1.61 (p=0.03) in RA, while it was -0.02 (p=0.93) in non-RA (Table 1).

Table 1.

Results of interrupted time-series analysis of incident CVD rates, adjusting for age, gender, chronic obstructive pulmonary disease, Romano Charlson Comorbidity Index, diabetes, angina, hypertension, chronic kidney disease, peripheral vascular disease, atrial fibrillation, glucocorticoid, non-steroidal anti-inflammatory drugs, CVD medications, fibrates, contraceptives, and aspirin use at disease diagnosis year, using stepwise model selection

OutcomeParameterRANon-RAUnadj. Diff (95% CI)Adj. Diff (95% CI)Unadj. Diff (95% CI)Adj. Diff (95% CI)p-valuep-valuep-valuep-valueCVDTrend-0.15 (-0.72, 0.42) 0.60860.23 (-0.17, 0.64) 0.2620-0.09 (-0.27, 0.08) 0.3084-0.07 (-0.20, 0.07) 0.3290Level (1 year post-intervention)-1.36 (-3.17, 0.45) 0.1474-1.61 (-2.96, -0.25) 0.02510.22 (-0.41, 0.84) 0.5011-0.02 (-0.44, 0.40) 0.93455 years post-intervention-1.96 (-4.48, 0.55) 0.1332-0.67 (-2.80, 1.46) 0.5418-0.15 (-1.06, 0.75) 0.7421-0.29 (-0.97, 0.39) 0.4102Figure 1.

Unadjusted rates.

Conclusion

Arthritis onset after bDMARDs introduction is associated with a significant reduction in the risk of incident CVD events among RA patients, but not in the matched non-RA individuals.

Acknowledgements

We would like to thank the Ministry of Health of British Columbia and Population Data BC for providing access to the administrative data. All inferences, opinions, and conclusions drawn in this publication are those of the authors, and do not reflect the opinions or policies of the Data Stewards or the [British Columbia] Ministry of Health. No personal identifying information was made available as part of this study. Procedures used were in compliance with British Columbia’s Freedom in Information and Privacy Protection Act. Ethics approval was obtained from the University of British Columbia’s Behavioral Research Ethics Board (H15-00887).

Disclosure of Interests

None declared.

Robust and tunable signal processing in mammalian cells via engineered covalent modification cycles

Engineered signaling networks can impart cells with new functionalities useful for directing differentiation and actuating cellular therapies. For such applications, the engineered networks must be tunable, precisely regulate target gene expression, and be robust to perturbations within the complex context of mammalian cells. Here, we use bacterial two-component signaling proteins to develop synthetic phosphoregulation devices that exhibit these properties in mammalian cells. First, we engineer a synthetic covalent modification cycle based on kinase and phosphatase proteins derived from the bifunctional histidine kinase EnvZ, enabling analog tuning of gene expression via its response regulator OmpR. By regulating phosphatase expression with endogenous miRNAs, we demonstrate cell-type specific signaling responses and a new strategy for accurate cell type classification. Finally, we implement a tunable negative feedback controller via a small molecule-stabilized phosphatase, reducing output expression variance and mitigating the context-dependent effects of off-target regulation and resource competition. Our work lays the foundation for establishing tunable, precise, and robust control over cell behavior with synthetic signaling networks.

Polysaccharide utilization loci in Bacteroides determine population fitness and community-level interactions

Polysaccharide utilization loci (PULs) are co-regulated bacterial genes that sense nutrients and enable glycan digestion. Human gut microbiome members, notably Bacteroides, contain numerous PULs that enable glycan utilization and shape ecological dynamics. To investigate the role of PULs on fitness and inter-species interactions, we develop a CRISPR-based genome editing tool to study 23 PULs in Bacteroides uniformis (BU). BU PULs show distinct glycan-degrading functions and transcriptional coordination that enables the population to adapt upon loss of other PULs. Exploiting a BU mutant barcoding strategy, we demonstrate that in vitro fitness and BU colonization in the murine gut are enhanced by deletion of specific PULs and modulated by glycan availability. PULs mediate glycan-dependent interactions with butyrate producers that depend on the degradation mechanism and glycan utilization ability of the butyrate producer. Thus, PULs determine community dynamics and butyrate production and provide a selective advantage or disadvantage depending on the nutritional landscape.

[Clinical characteristics of human adenovirus infection in hospitalized children with acute respiratory infection in Beijing]

Objective: To compare the clinical characteristics of different types of human adenovirus (HAdV) infection in hospitalized children with acute respiratory infection in Beijing, and to clarify the clinical necessity of adenovirus typing. Methods: In a cross-sectional study, 9 022 respiratory tract specimens collected from hospitalized children with acute respiratory infection from November 2017 to October 2019 in Affiliated Children's Hospital, Capital Institute of Pediatrics were screened for HAdV by direct immunofluorescence (DFA) and (or) nucleic acid detection. Then the Penton base, Hexon and Fiber gene of HAdV were amplified from HAdV positive specimens to confirm their HAdV types by phylogenetic tree construction. Clinical data such as laboratory results and imaging data were analyzed for children with predominate type HAdV infection using t, U, or χ² test. Results: There were 392 cases (4.34%) positive for HAdV among 9 022 specimens from hospitalized children with acute respiratory infection. Among those 205 cases who were successfully typed, 131 were male and 74 were female, age of 22.6 (6.7, 52.5) months,102 cases (49.76%) were positive for HAdV-3 and 86 cases (41.95%), HAdV-7, respectively, while 17 cases were confirmed as HAdV-1, 2, 4, 6, 14 or 21. In comparison of clinical characteristics between the predominate HAdV type 7 and 3 infection, significant differences were shown in proportions of children with wheezing (10 cases (11.63%) vs. 25 cases (24.51%)), white blood cell count >15 ×10⁹/L (4 cases (4.65%) vs.14 cases (13.73%)), white blood cell count <5×10⁹/L (26 cases (30.23%) vs.11 cases (10.78%)), procalcitonin level>0.5 mg/L (43 cases (50.00%) vs. 29 cases (28.43%)), multilobar infiltration (45 cases (52.33%) vs.38 cases (37.25%)), pleural effusion (23 cases (26.74%) vs. 10 cases (9.80%)), and severe adenovirus pneumonia (7 cases (8.14%) vs. 2 cases (1.96%)) with χ²=5.11, 4.44, 11.16, 9.19, 4.30, 9.25, 3.91 and P=0.024, 0.035, 0.001, 0.002, 0.038, 0.002, 0.048, respectively, and also in length of hospital stay (11 (8, 15) vs. 7 (5, 13) d, Z=3.73, P<0.001). Conclusions: HAdV-3 and 7 were the predominate types of HAdV infection in hospitalized children with acute respiratory tract infection in Beijing. Compared with HAdV-3 infection, HAdV-7 infection caused more obvious inflammatory reaction, more severe pulmonary symptoms, longer length of hospital stay, suggesting the clinical necessity of further typing of HAdVs.

Efficacy of surgical navigation in zygomaticomaxillary complex fractures: randomized controlled trial

Accurate reduction is of vital importance in the treatment of zygomaticomaxillary complex (ZMC) fractures. Computer-assisted navigation systems (CANS) have been employed in ZMC fractures to improve the accuracy of surgical reduction. However, randomized controlled trials on this subject are rare and the benefits of CANS remain controversial. The aim of this study was to compare reduction errors between navigation-aided and conventional surgical treatment for ZMC fractures. Thirty-eight patients with unilateral type B ZMC fractures were enrolled. Preoperative computed tomography data were imported into ProPlan software for virtual surgical planning. Open reduction and internal fixation was performed with CANS (experimental group) or without CANS (control group). Postoperative computed tomography scans were obtained to examine the difference between surgical planning and the actual postoperative outcome, namely reduction errors. The median translational reduction errors in the X, Y, and Z axes were 0.80 mm, 0.40 mm, and 0.80 mm, respectively, in the experimental group and 0.53 mm, 0.86 mm, and 0.83 mm, respectively, in the control group (P > 0.05). The median rotational reduction errors in pitch, roll, and yaw were 0.92°, 2.47°, and 1.54°, respectively, in the experimental group and 1.45°, 3.68°, and 0.76°, respectively, in the control group (P > 0.05). In conclusion, compared with conventional reduction surgery, navigation-aided surgery showed no significant improvement in reduction accuracy in the treatment of type B ZMC fractures (Chinese Clinical Trial Registry, registration number ChiCTR1800015559).

Negative interactions determine Clostridioides difficile growth in synthetic human gut communities

Understanding the principles of colonization resistance of the gut microbiome to the pathogen Clostridioides difficile will enable the design of defined bacterial therapeutics. We investigate the ecological principles of community resistance to C. difficile using a synthetic human gut microbiome. Using a dynamic computational model, we demonstrate that C. difficile receives the largest number and magnitude of incoming negative interactions. Our results show that C. difficile is in a unique class of species that display a strong negative dependence between growth and species richness. We identify molecular mechanisms of inhibition including acidification of the environment and competition over resources. We demonstrate that Clostridium hiranonis strongly inhibits C. difficile partially via resource competition. Increasing the initial density of C. difficile can increase its abundance in the assembled community, but community context determines the maximum achievable C. difficile abundance. Our work suggests that the C. difficile inhibitory potential of defined bacterial therapeutics can be optimized by designing communities featuring a combination of mechanisms including species richness, environment acidification, and resource competition.

[Clinical characteristics of children infected with different subtypes/genotypes of human respiratory syncytial virus in Beijing from 2009 to 2017]

Objective: To explore the different clinical characteristics of children infected with different subtype/genotype of human respiratory syncytial virus (HRSV) in Beijing. Methods: Respiratory specimens for positive HRSV were randomly collected from children with acute respiratory tract infection (ARTI) in the epidemic season of HRSV from November of each year to January of the next year during 2009 and 2017. G genes of HRSV were amplified and sequenced for subtyping and genotyping by bioinformatics analysis. Clinical data were collected and analyzed. Results: Out of 590 children, 376 (63.7%) with subtype A, and 214 (36.3) with subtype B. The annual dominant subtypes of HRSV from 2009 to 2017 were B-A-A-B-AB-A-A-B-A, respectively, whilst a total of 10 genotypes were detected with 95.8% assigned to genotype ON1 and NA1 of subtype A, and genotype BA9 of subtype B. Children infected with subtype B (96 cases, 44.9%) were more likely aged 0-3 month old than those with subtype A (118 cases, 31.4%) (P=0.001), and more likely to be admitted to Intensive Care Unit(ICU) ((124 cases, 57.9%) than those with subtype A (172 cases, 45.7%)) (P=0.005). Statistical significance were shown among children infected with genotype ON1, NA1 or BA9, in the possibility of infection in children aged 0-3 month (P=0.003), proportion of admission into ICU (P=0.007), length of stay in hospital (P=0.001), and clinical outcome (P=0.001), respectively. Conclusion: Children infected with different subtype or genotype of HRSV have different clinical characteristics, which stresses the important role of the monitoring HRSV subtypes and genotypes among children.

[Psychological and behavioral functioning of children and adolescents during long-term home-schooling]

Objective: To study the characteristics and risk factors of psychological and behavioral problems of children and adolescents of different ages and genders in long-term home-schooling during the coronavirus disease-2019 pandemic. Further, to provide scientific basis for more targeted psychological intervention and coping strategies in the future. Methods: A cross-sectional survey using an online questionnaire was conducted on students aged 6-16 years old in five representative cities of North (Beijing), East (Shanghai), West (Chongqing), South (Guangzhou) and Middle (Wuhan) in China. In this study, the social behavior and psychological abnormalities which was defined as the positive of any dimension were investigated in multiple dimensions during long-term home-schooling. The influencing factors of psycho-behavioral problems were analyzed by Logistic regression, and the confounding factors were corrected with graded multivariable adjustment. Results: A total of 6 906 valid questionnaires were collected including 3 592 boys and 3 314 girls, of whom 3 626 were children (6-11 years old) and 3 280 were adolescents (12-16 years old). The positive detection rate of psychosocial-behavioral problems were 13.0% (900/6 906) totally, 9.6% (344/3 592) in boys and 16.8% (556/3 314) in girls respectively, and 7.3%(142/1 946) in boys aged 6-11, 14.0%(235/1 680) in girls aged 6-11, 12.3%(202/1 646) in boys aged 12-16, 19.6%(321/1 634) in girls aged 12-16 respectively. There were significant differences between the psychological problems group and the non-psychological problems group in gender, parent-offspring conflict, number of close friends, family income change, sedentary time, homework time, screen exposure time, physical activity, dietary problems (χ²=78.851, 285.264, 52.839, 26.284, 22.778, 11.024, 10.688, 36.814, 70.982, all P<0.01). The most common symptoms in boys aged 6-11 years were compulsive activity, schizoid and depression, in girls aged 6-11 years were schizoid/compulsive activity, hyperactivity and social withdrawal, in boys aged 12-16 years were hyperactivity, compulsive activity and aggressive behavior, and in girls aged 12-16 years were schizoid, anxiety/compulsive activity and depression/withdrawal, respectively. After graded multivariable adjustment, besides the common risk factors, homework time and online study time were the risk factors of 6-11 years old groups [boys OR(95%CI): 1.750 (1.32-2.32), 1.214(1.00-1.47), girls: 1.579(1.25-1.99), 1.222(1.05-1.42), all P<0.05], videogames time were the risk factors of 12-16 years old groups [ boys: 2.237 (1.60-3.13), girls: 1.272 (1.00-1.61), all P<0.05]. Conclusions: Some children and adolescents may have psychological and behavioral problems during long-term home-schooling. The psychological and behavioral manifestations differed in age and gender subgroups, which deserve special attention in each subgroups. Schools, families and specialists should actively provide precise psychological support and comprehensive intervention strategies according to special features and risk factors.

Characterizing the impact of high temperature during grain filling on phytohormone levels, enzyme activity and metabolic profiles of an early indica rice variety

Global warming results in high temperature stress (HTS), which presents severe challenges worldwide for modern agricultural production and will have significant impacts on the yield and quality of crops. Accumulation of photosynthetic products, activity of enzymes involved in sucrose-starch metabolism, phytohormone levels and metabolic profiling using LC-MS were analysed in the flag leaves and/or developing grains subjected to HTS during the grain-filling stage of an indica rice. HTS induced significant yield loss and reduced the grain quality, with lower amylose content. HTS reduced photosynthetic product accumulation in flag leaves and reduced starch accumulation in developing grains, compared to growth under normal temperatures. The activity of enzymes related to sucrose-starch metabolism were dis-regulated in developing grains grown under high temperature (HT). Moreover, phytohormone homeostasis in flag leaves and developing grains was also dramatically disturbed by HT. Metabolic profiling detected many metabolites with remarkably different relative fold abundances at different time points in the developing grain at HT versus normal temperatures, these metabolites were enriched in several HTS response pathways. The change in phytohormone ratio and auxin level might be associated with the reduction in photosynthetic products and their translocation, and ultimately with reduced starch accumulation in the developing grain. The detected metabolites might have different roles in response to the HTS in developing grain at different development stages. These results provide a theoretical reference and basis for future rice production towards higher quality and yield when grown under HTS.

[Molecular epidemiology of norovirus associated with pediatric acute gastroenteritis in Beijing in 2020]

Objective: To investigate the molecular epidemiology of norovirus associated with pediatric acute gastroenteritis in Beijing under the Working Mechanism for Joint Prevention and Control of the Epidemic in 2020. Methods: This was a retrospective, repeated cross-sectional study. Fecal or vomit samples (1 213 cases) were collected from children visited the Capital Institute of Pediatrics Affiliated Children's Hospital for acute gastroenteritis from January 1 to December 31, 2020. First, real-time reverse PCR (RT-PCR) was used to screen the samples for norovirus, and then RdRp gene and capsid gene VP1 of norovirus-positive samples were amplified by conventional RT-PCR for genotyping based on the nucleotide sequence. The χ² test was used to compare the positive rates and genotypes of norovirus among different specimen types, genders of children, and different age groups. Results: Among the 1 213 samples were collected, 215 samples were positive for norovirus, with a positivity rate of 17.7% for the whole year. The peak of norovirus infection observed mainly in the cold seasons, as the positive rates were 28.6% (18/63), 26.2% (16/61), 22.8% (77/338) and 17.1% (89/520) in January, October, November and December, respectively. The positive rate of norovirus in fecal sample was significantly higher than that in vomit sample (χ² = 9.692, P<0.01). There was no significant difference between genders (χ²=0.041, P>0.05), but significant difference was found between age groups with the highest rate in the 6-48 months group (χ²=103.112, P<0.01). Three genogroups (GⅠ, GⅡ and GⅨ) of the circulating virus were detected by G-gene typing, and GⅡgenogroup was predominant, accounting for 98.5% (196/199). Among the GⅡ positive samples, genotype GⅡ.4 Sydney (55.1%, 108/196) was the most common, followed by GⅡ.2 (29.6%, 58/196), while the GⅡ.3 norovirus (10.2%, 20/196) which was common in previous years was not as much as before. Based on the P-type, GⅡ.P16 was predominant (61.5%, 96/156), followed by GII.P31 (19.9%, 31/156). The dual genotyping revealed that GⅡ.4 Sydney [P16] (36.4%, 56/154) and GⅡ.2 [P16] (24.7%, 38/154) were predominant. Conclusion: The prevalence of norovirus in children in 2020 in Beijing is not much different from those of the previous years, but the genotypes composition has changed significantly, and there are multiple genotypes circulating simultaneously.

Towards a deeper understanding of microbial communities: integrating experimental data with dynamic models

Microbial communities and their functions are shaped by complex networks of interactions among microbes and with their environment. While the critical roles microbial communities play in numerous environments have become increasingly appreciated, we have a very limited understanding of their interactions and how these interactions combine to generate community-level behaviors. This knowledge gap hinders our ability to predict community responses to perturbations and to design interventions that manipulate these communities to our benefit. Dynamic models are promising tools to address these questions. We review existing modeling techniques to construct dynamic models of microbial communities at different scales and suggest ways to leverage multiple types of models and data to facilitate our understanding and engineering of microbial communities.

Genome sequencing of pancreatic cancer: differential expression by location

The results demonstrated that pancreatic ductal carcinoma (PDAC) of the body/tail was associated with more transcriptional and genomic changes, and correlated with worse prognosis, than PDAC of the pancreatic head. The different mutation types and gene expression of tumour locations provide deep insight into the carcinogenesis or metastasis of PDAC, and suggest different early diagnostic and therapeutic strategies. SNV, single-nucleotide variations; NLS, Nuclear localization sequence; MB, million base-pairs; UTR, untranslated region.

[Implication of enhanced recovery after surgery in the surgical management of hypopharyngeal squamous cell carcinoma]

Objective: To investigate the safety and efficacy of enhanced recovery after surgery (ERAS) in the clinical management of hypopharyngeal squamous cell carcinoma (HSCC). Methods: In this retrospective study, a total of 168 patients with pyriform sinus carcinoma in Qilu Hospital of Shandong University from January 2015 to January 2019 were divided into two groups, based on the different perioperative interventions that patients received, i.e. the ERAS group (n=64) and the conventional group (n=104), including 164 males and 4 females, whose ages ranged from 42 to 84 years old. The difference between two groups in the operative time, postoperative nutritional status, incidences of postoperative complications and postoperative hospitalization time were compared using the student's t test, Chi-squared test or Fisher's exact test. Results: Compared with the conventional group, patients in the ERAS group had significantly shorter operative time [(166.8±58.2) min vs. (183.3±39.9) min,t=-2.72, P=0.031], higher levels of postoperative serum albumin [(38.3±4.2) μmol/L vs. (36.6±3.3) μmol/L, t=2.73, P=0.007] and more body weight [(65.4±9.4) kg vs. (62.1±9.4) kg, t=2.22, P=0.028], lower incidences of postoperative subcutaneous infection [7.8% (5/64) vs. 20.2% (21/104), χ²=4.64, P=0.03] and severe pneumonia [4.7% (3/64) vs. 15.4% (16/104), χ²=4.52, P=0.03], and shorter postoperative hospitalization time [(16.5±3.9) d vs. (18.2±4.3) d, t=-2.65, P<0.05]. Conclusion: ERAS is effective and safe in the surgical management of HSCC, with benefits in reducing the operative stress via saving operation time, shortening the hospitalization time, ameliorating nutritional status and decreasing the incidences of complications.

dCas9 regulator to neutralize competition in CRISPRi circuits

CRISPRi-mediated gene regulation allows simultaneous control of many genes. However, highly specific sgRNA-promoter binding is, alone, insufficient to achieve independent transcriptional regulation of multiple targets. Indeed, due to competition for dCas9, the repression ability of one sgRNA changes significantly when another sgRNA becomes expressed. To solve this problem and decouple sgRNA-mediated regulatory paths, we create a dCas9 concentration regulator that implements negative feedback on dCas9 level. This allows any sgRNA to maintain an approximately constant dose-response curve, independent of other sgRNAs. We demonstrate the regulator performance on both single-stage and layered CRISPRi-based genetic circuits, zeroing competition effects of up to 15-fold changes in circuit I/O response encountered without the dCas9 regulator. The dCas9 regulator decouples sgRNA-mediated regulatory paths, enabling concurrent and independent regulation of multiple genes. This allows predictable composition of CRISPRi-based genetic modules, which is essential in the design of larger scale synthetic genetic circuits.

The long non-coding RNA DDX11-AS1 facilitates cell progression and oxaliplatin resistance via regulating miR-326/IRS1 axis in gastric cancer

OBJECTIVE

The long non-coding RNA DDX11 antisense RNA 1 (DDX11-AS1) was found to be highly expressed in gastric cancer (GC). This study was to explore the role and molecular mechanism in oxaliplatin (OXA) resistance.

PATIENTS AND METHODS

The levels of DDX11-AS1, microRNA-326 (miR-326) and insulin receptor substrate 1 (IRS1) were measured by quantitative Real-time polymerase chain reaction (qRT-PCR). Cell proliferation, migration, invasion and apoptosis were examined by methylthiazolyldiphenyl-tetrazolium bromide (MTT), transwell and flow cytometry assays, respectively. Levels of all protein were detected using Western blot. The correlation between miR-326 and DDX11-AS1/IRS1 was confirmed by Dual-Luciferase reporter and RNA immunoprecipitation (RIP) assays. The xenograft model was constructed to explore the effect of DDX11-AS1 in vivo.

RESULTS

DDX11-AS1 was overexpressed in OXA-resistant GC tissues and cells, and DDX11-AS1 knockdown inhibited cell proliferation, migration, invasion and OXA resistance, and promoted apoptosis in OXA-resistant GC cells. Mechanically, DDX11-AS1 directly targeted miR-326 and miR-326 could bind to IRS1 in OXA-resistant GC cells. Functionally, silencing DDX11-AS1 repressed the progression and OXA resistance in OXA-resistant GC cells by down-modulating IRS1 expression via sponging miR-326 in vitro and in vivo.

CONCLUSIONS

DDX11-AS1 accelerated the progression and OXA chemoresistance of GC cells in vitro and in vivo by sponging miR-326, thus increasing the expression of IRS1, suggesting DDX11-AS1 might be a promising prognostic biomarker and therapeutic target in GC.

[Probability of premature mortality caused by four major non-communicable diseases and its impact on life expectancy in Wuxi, 2008-2018]

Objective: To analyze the trend of premature death of non-communicable diseases (NCDs) in Wuxi from 2008 to 2018 and evaluate the influence of premature mortality probability caused by four main NCDs on life expectancy. Methods: Based on the mortality data collected by Wuxi Mortality Registration System and the population data collected by Wuxi Public Security Bureau during 2008-2018, this study analyzes the trend of the probability of premature death on malignant tumors, cardiovascular and cerebrovascular diseases, chronic respiratory diseases, and diabetes. The impact on life expectancy was analyzed by using the methods of abridged life table, Joinpoint regression, and life expectancy contribution decomposition. Results: From 2008 to 2018, the total probability of premature death of four main NCDs in Wuxi were declined consistently from 11.25% to 9.25% (AAPC = -2.0%, 95%CI: -2.6--1.5), higher in female (from 7.74% to 5.91%) than that in male (from 14.49% to 12.51%). The Wuxi resident's life expectancy increased by 1.86 years (from 78.66 to 80.52 years), in males and 1.26 years (from 83.85 to 85.11 years) in females, respectively. The decline of premature death of malignant tumors, cardiovascular and cerebrovascular diseases and chronic respiratory system diseases had a positive contribution to life expectancy, which contributed 0.34 years (23.90%), 0.15 years (10.50%), and 0.03 years (2.36%) to the life expectancy growth, respectively. Among which, premature death of cardiovascular and cerebrovascular diseases in men aged 40-55y had a negative contribution to life expectancy (-0.04 years). The probability of premature death of males with diabetes was on the rise (AAPC = 7.1%, 95%CI: 2.8-11.6), which negatively contributed to life expectancy for both males and females, reducing life expectancy by 0.03 years (-2.14%) in Wuxi. Conclusion: The premature death probability of four main NCDs in Wuxi declined consistently from 2008 to 2018, which played a positive role in the growth of life expectancy. Compared with females, males had a higher premature death probability and a slower rate of decline. More intervention and health management of premature male death on cardiovascular and cerebrovascular diseases and diabetes should be conducted to improve life expectancy further.

An endoribonuclease-based feedforward controller for decoupling resource-limited genetic modules in mammalian cells

Synthetic biology has the potential to bring forth advanced genetic devices for applications in healthcare and biotechnology. However, accurately predicting the behavior of engineered genetic devices remains difficult due to lack of modularity, wherein a device's output does not depend only on its intended inputs but also on its context. One contributor to lack of modularity is loading of transcriptional and translational resources, which can induce coupling among otherwise independently-regulated genes. Here, we quantify the effects of resource loading in engineered mammalian genetic systems and develop an endoribonuclease-based feedforward controller that can adapt the expression level of a gene of interest to significant resource loading in mammalian cells. Near-perfect adaptation to resource loads is facilitated by high production and catalytic rates of the endoribonuclease. Our design is portable across cell lines and enables predictable tuning of controller function. Ultimately, our controller is a general-purpose device for predictable, robust, and context-independent control of gene expression.

Asymptomatic COVID-19 infection in patients with cancer at a cancer-specialized hospital in Wuhan, China - Preliminary results

OBJECTIVE

Patients with cancer are usually immunosuppressive and susceptible to COVID-19 infection. Asymptomatic COVID-19 cases are infective and cannot be identified by symptom-based screening. There is an urgent need to control virus spread by asymptomatic carriers at cancer centres. We aim to describe the characteristics, screening methods, and outcomes of cancer patients with asymptomatic COVID-19 infection and to further explore anti-tumour treatment for this population.

PATIENTS AND METHODS

We reviewed patients with cancer who were admitted to Hubei Cancer Hospital in Wuhan from February 1, 2020, to April 4, 2020. We collected demographic data, laboratory findings, treatment information, nucleic acid and serum test results, chest computed tomography (CT) information and survival status of cancer patients diagnosed with asymptomatic COVID-19 infection.

RESULTS

A total of 16 cancer patients with asymptomatic COVID-19 infection were confirmed. The most common cancer type was breast cancer. The blood cell counts of most patients were in the normal range. Lymphocytes of 100% of asymptomatic carriers were in the normal range. Thirteen (81.3%) patients were positive for virus-specific IgM antibodies, and three (18.8%) were positive by PCR; only one (6.3%) patient showed novel coronavirus pneumonia features on CT. Three (18.3%) patients died, and the cause of death was considered malignancy caused by delaying anti-tumour treatment.

CONCLUSIONS

Our study shows that the lymphocytes of 100% of asymptomatic carriers were in the normal range. This result indicates that the host immunity of asymptomatic carriers is not significantly disrupted by COVID-19. Single PCR detection is not sufficient to screen among asymptomatic individuals, and a combination of PCR tests, serological tests and CT is of great importance. Unless the tumour is life-threatening or rapidly progressing, we advise restarting active anti-tumour therapy after PCR tests become negative.

The importance of proper and prompt treatment of ocular syphilis: a lesson from permanent vision loss in 52 eyes

BACKGROUND

Ocular involvement can occur at any stage of syphilis. Prompt diagnosis and proper treatment of ocular syphilis are vital to avoid long-term consequences.

OBJECTIVES

To describe the risk factors for ocular syphilis and clinical features of blindness caused by syphilis.

METHODS

We report risk factors for ocular syphilis amongst patients seen at the Shanghai Skin Disease Hospital between October 2009 and October 2017. We identify patients with ocular syphilis resulting in blindness and report the clinical characteristics, laboratory findings and treatment outcomes of these patients.

RESULTS

A total of 8310 new cases of syphilis were seen, of which 213 patients had ocular disease and 50 patients had blindness due to syphilis. Increasing age and higher RPR titres were associated with ocular involvement but there was no association with HIV status. Blindness in syphilis was restricted predominantly to patients with optic nerve involvement and not patients with isolated uveitis. Fifty patients (and a total of 67 eyes) met the WHO definition of blindness prior to treatment for syphilis. At the end of follow-up, vision had improved in 24 of 67 eyes (35.8%) after treatment. Successful treatment of uveitis was associated with the best improvement in visual acuity, whilst patient with underlying optic atrophy prior to treatment had the worst visual outcome.

CONCLUSIONS

Ocular involvement is an important manifestation of syphilis which may result in blindness. Our data demonstrate outcomes for ocular syphilis are poor if detected late; early recognition and diagnosis is therefore vital to avoid permanent visual loss.

[Comparisons of clinical characteristics and prognosis between patients with primary and secondary thyroid lymphoma]

Objective: To compare clinical characteristics and prognosis between patients with primary (PTL) and secondary thyroid lymphoma (STL) . Methods: A retrospective analysis was performed on 46 patients with thyroid lymphoma (PTL 19, STL 27) from January 2002 to October 2018. Results: ①PTL group included 4 males and 15 females, with a median age of 57 years. The STL group included 10 males and 17 females, with a median age of 61 years. Diffuse large B-cell lymphoma (DLBCL) was the main pathological subtype in both PTL and STL groups, with 14 cases (73.7%) and 20 cases (74.1%) respectively. In terms of clinical manifestations, goiter was the most common symptom in PTL patients 100.0% (19/19) , while 29.6% (8/27) STL had goiter (P<0.001) . The incidences of increased thyroglobulin antibody (TRAb) /thyroid peroxidase antibody (TPO) were 81.3% (13/16) in PTL group and 43.8% (7/16) in STL group (P=0.028) respectively. Concerning the clinical features of patients, only two PTL patients (10.5%) with advanced Ann Arbor stage (Ⅲ/Ⅳ) , while 21 (77.8%) STL experienced advanced Ann Arbor stage (P<0.001) . Elevated serum β(2)-MG were appeared in 1 (7.1%) PTL and 9 (47.4%) STL patients (P=0.013) , and advanced IPI score (3-5) was more common in STL than PTL (59.3% vs 5.3%, P<0.001) . ②Among the 17 PTL patients who received treatments, 15 (88.2%) achieved remission; as for STL patients received treatments, 23/25 (92.0%) were in remission. The 5-year overall survival (OS) rates of PTL (n=17) and STL groups (n=25) were (87.4±8.4) % and (70.0±13.1) % (P=0.433) respectively. ③The 5-year OS rate in 41 patients with B-cell thyroid lymphoma was (81.1±7.5) %. Univariate analysis showed that IPI score of 3-5 (P=0.040) and high level of serum IL-8 (P=0.022) were significantly associated with poor outcome. Conclusion: DLBCL was the most common subtype in both PTL and STL, and goiter was the major symptom in PTL. IPI score of 3-5 and high level of serum IL-8 were unfavorable prognostic factors for patients with B-cell thyroid lymphoma.

SAT0175 IMPACT OF ANTIMALARIAL ADHERENCE ON MORTALITY AMONG PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A POPULATION-BASED COHORT STUDY

Background:

Evidence has consistently shown that adherence to AM is poor in systemic lupus erythematosus (SLE) patients. However, data on the impact of adherence to AM on mortality is scarce.

Objectives:

To assess the effect of AM adherence on all-cause mortality in SLE patients from the general population.

Methods:

This study used administrative databases from British Columbia, Canada. We created an incident SLE cohort between January 01, 1997, and March 31, 2015, using the physician billing data and a 7-year washout period. The inclusion criteria were at least two physician visits, at least two months apart, within two years, with an ICD-9 code (710.0) or ICD-10 code (M32.1, M32.8, M32.9) for SLE. Follow-up started at the first day of having both SLE and AM, i.e., at the SLE index date (second ICD code) for those whose first AM use occurred before the SLE index date, or the date of the first AM use if otherwise. Our outcome was all-cause mortality, obtained from the vital statistics registry. In the analysis, the follow-up time was divided into 30-days windows, for a total of 293,190 person-months. For each window, a measure of adherence, the proportion of days covered (PDC), was calculated and categorized as adherent (PDC≥0.90), non-adherent (0<PDC<0.90), and discontinuer (no drug or PDC = 0). We used both Cox’s proportional hazards models and marginal structural models (MSM) to estimate the effect of AM adherence on all-cause mortality. Both analysis controlled for baseline demographics (age, sex, residence, income quintile), as well as the following baseline and time-varying covariates: immunosuppressive and other medications, hospitalizations, impatient, and other visits, and Charlson comorbidity index. To account for the possibility of a few time-varying covariates being mediators in the causal pathway from AM adherence to mortality, which may cause the Cox model to yield biased estimates of the adherence effects, we conducted the MSM analysis that can produce valid estimates as it balances the distributions of time-varying confounders among the three adherence groups via inverse probability weighting.

Results:

We identified 3,385 individuals with incident SLE (mean age 47.3 years, 89% were women) who had at least one filled AM prescription. Over the mean follow-up of 6.66 years, 288 (8.5%) incident SLE patients died. The incidence rate (IR) of mortality for AM adherent, non-adherent, and discontinuer patients were 4.31, 11.86, and 19.51 per 1000 person-years, respectively. Using the Cox model, the adjusted hazard ratio (HRs) obtained for AM adherent and non-adherent SLE patients were 0.20 and 0.66, respectively, compared to discontinuer SLE patients (Table 1). Using MSM, those adjusted HRs were found as 0.18 and 0.64. Also, the adjusted HRs for adherers compared to the non-adherers were 0.30 (Cox) and 0.28 (MSM). A statistically significant linear trend in the HRs of mortality risk over the adherence levels was found (Table 1, Linear Trend).

Table 1.Adherence LevelsNo. of DeathsIR Ratios (95%CI)Adjusted Cox HRs (95%CI)Adjusted MSM HRs (95%CI)Discontinuer (Reference)198Non-adherent470.61(0.44-0.84)0.66(0.47-0.93)0.64(0.46-0.89)Adherent430.22(0.16-0.31)0.20(0.14-0.28)0.18(0.12-0.25)Contrast: Partial vs. Full0.36(0.24-0.55)0.30(0.19-0.46)0.28(0.18-0.42)Linear Trend0.32(0.25-0.41)0.29(0.23-0.37)

Conclusion:

SLE patients that adhere to AM therapy have a lower risk of death than patients who do not adhere or who discontinue AM (5 and 3 times, respectively) in both the MSM and Cox analysis. Our findings support the importance of AM adherence to prevent premature deaths in SLE patients.

Disclosure of Interests:

None declared

The quorum-sensing molecule 2-phenylethanol impaired conidial germination, hyphal membrane integrity and growth of Penicillium expansum and Penicillium nordicum

AIMS

The aim of the study was to investigate the antifungal effects of a quorum sensing-molecule, 2-phenylethanol, against the food spoilage moulds Penicillium expansum and Penicillium nordicum.

METHODS AND RESULTS

Conidial germination of the tested Penicillium spp. (three strains in total) were inhibited by treatments with 2-phenylethanol in a concentration-dependent manner. Germinated conidia was significantly reduced from 4·4-16·7% at 7·5 mmol l^-1 and completely inhibited at 15 mmol l^-1 2-phenylethanol. Integrity of conidial cell membranes was unaffected by 2-phenylethanol resulting in reversible inhibition pattern of germination. In contrast, membrane permeability of actively growing hyphae was severely compromised, showing 63·5 - 75·7% membrane damage upon treatment with 15 mmol l^-1 2-phenylethanol. The overall inhibitory effect of 2-phenylethanol on colony development and growth of P. expansum and P. nordicum was additionally confirmed.

CONCLUSIONS

2-phenylethanol inhibits conidial germination and growth of P. expansum and P. nordicum in a nonlethal, reversible and concentration-dependent manner.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study indicates that 2-phenylethanol can find potential application as an antifungal agent for biological control of moulds in the food industry.

The Nab experiment: A precision measurement of unpolarized neutron beta decay

Neutron beta decay is one of the most fundamental processes in nuclear physics and provides sensitive means to uncover the details of the weak interaction. Neutron beta decay can evaluate the ratio of axial-vector to vector coupling constants in the standard model, λ = gA/gV, through multiple decay correlations. The Nab experiment will carry out measurements of the electron-neutrino correlation parameter a with a precision of δa/a = 10−3 and the Fierz interference term b to δb = 3 × 10−3 in unpolarized free neutron beta decay. These results, along with a more precise measurement of the neutron lifetime, aim to deliver an independent determination of the ratio λ with a precision of δλ/λ = 0.03% that will allow an evaluation of Vud and sensitively test CKM unitarity, independent of nuclear models. Nab utilizes a novel, long asymmetric spectrometer that guides the decay electron and proton to two large area silicon detectors in order to precisely determine the electron energy and an estimation of the proton momentum from the proton time of flight. The Nab spectrometer is being commissioned at the Fundamental Neutron Physics Beamline at the Spallation Neutron Source at Oak Ridge National Lab. We present an overview of the Nab experiment and recent updates on the spectrometer, analysis, and systematic effects.

Liquid Chromatographic Determination of Maleic Hydrazide in Technical and Formulated Products: Collaborative Study

Fourteen collaborating laboratories assayed maleic hydrazide (MH), 6-hydroxypyridazin-3(2H)-one, in technical and formulated products by reversed-phase liquid chromatography (LC) with sulfanilic acid as an internal standard. The active MH in the samples (6 lots) ranged from 16% (expressed as the potassium salt) to 98% (MH in the technical). A small amount of 1 M KOH was added to the technical MH and analytical standards to create the potassium salt of the analyte which is soluble in water. Test samples and standards were extracted with water containing the internal standard before analysis by LC on a C8 column with an ion-pairing eluting solution and UV detection at 254 nm. The concentration of MH was calculated by comparing the peak area response ratios of the analyte and the internal standard with those in the analytical standard solution. Eleven laboratories weighed each test sample twice with single analysis. Three laboratories weighed each sample once and made duplicate injections on the LC system. The data were analyzed using the 11 laboratories' results. A second data analysis was done including all laboratory results using a Youden pair approach, selecting one of 2 duplicate assay values randomly for each laboratory and sample. In the first data analysis, the repeatability standard deviation ranged from 0.07 to 1.39%; reproducibility standard deviation ranged from 0.22 to 1.39%. In the second data analysis (using all laboratory data), repeatability standard deviation ranged from 0.09 to 0.86%; reproducibility standard deviation ranged from 0.22 to 1.31%.