[Exploratory study on detection of drug resistance of Mycobacterium tuberculosis in sputum specimens by next-generation sequencing]

Objective: To compare the diagnostic performance of next-generation sequencing (NGS) detection methods in sputum samples and Mycobacterium tuberculosis strains, in order to explore the feasibility of the NGS method to detect drug resistance in sputum specimens. Methods: In this retrospective study, the sputum specimens and corresponding clinical isolates of 50 pulmonary tuberculosis patients admitted to Beijing Chest Hospital from January 2017 to December 2017 were collected. The gene mutations of katG, inhA, rpoB, embA, embB, rpsL, rrs, gyrA, gyrB and tlyA in sputum specimens and corresponding clinical isolates were detected by NGS method. The phenotypic drug susceptibility test (DST) of the strains was carried out by the proportion method. Using DST results as a reference, the sensitivity, specificity, positive predictive value and negative predictive value of the NGS method for clinical strains and sputum specimens, as well as the consistency statistic (Kappa) with phenotype DST were calculated respectively. The Chi-square test was used to compare the accuracy of the NGS testing in sputum samples and strain samples. Results: The results showed that rpoB(63.83%, 30/47) and rrs(57.45%, 27/47) were the most common mutated genes, followed by katG(46.81%, 22/47), rpsL(29.79%, 14/47), gyrA(27.66%, 13/47), embB(21.28%, 10/47), tlyA(12.77%, 6/47), gyrB(8.51%, 4/47), and inhA promoter(19.15%, 9/47), embA promoter region (12.77%, 6/47) mutation. when the NGS method was compared with the resistance phenotype of isoniazid, rifampicin, ethambutol, second-line injectable drugs (streptomycin, capreomycin, kanamycin, amikacin), levofloxacin, the sensitivity were 85.71%, 91.67%, 77.78%, 81.82%, 100.00%, 87.50%, 100.00%, 69.23%, and the specificity were 100.00%, 94.12, 87.50%, 89.47%, 97.06%, 96.97%, 94.29%, 89.29% in sputum samples, while in strain samples, the sensitivity were 92.86%, 100.00%, 81.82%, 86.96%, 88.89%, 80.00%, 100.00%, 85.71%. The specificity were 100.00%, 92.86%, 87.10%, 94.74%, 100.00%, 100.00%, 97.14%, 92.86%. Compared with the phenotypic drug susceptibility results, the NGS method has better detection performance for isoniazid, rifampicin, capreomycin, kanamycin, and amikacin in sputum specimens (Kappa≥0.75); while among the strains, the NGS method had a good detection performance for isoniazid, rifampicin, streptomycin, capreomycin, kanamycin, amikacin and levofloxacin (Kappa≥0.75). With the accuracy of the NGS method for detecting strains as a reference, there was no statistically significant difference in the accuracy of all drug resistance detected between strains and sputum specimens. Conclusions: This study showed that the NGS technology was effective in predicting the resistance of isoniazid, rifampicin, and second-line injectable drugs (capreomycin, kanamycin and amikacin) by detecting sputum samples and strain genotypes, suggesting the feasibility and potential of direct detection of sputum samples by the NGS method as an early detection method for drug resistance.

Increasing COVID-19 Vaccination in the United States: Projected Impact on Cases, Hospitalizations, and Deaths by Age and Racial Group

Objectives

Minority populations in the United States face a disproportionate burden of illness from COVID-19 infection and have lower vaccination rates compared with other groups. This study estimated the equity implications of increased COVID-19 vaccination in the United States, with a focus on the number of cases, hospitalizations, and deaths avoided.

Study design

This was an observational real-world modeling study.

Methods

Data from the Centers for Disease Control and Prevention (CDC) were used to identify the remaining unvaccinated US population by county, age, and race as of October 22, 2021. The number of COVID-19 cases, hospitalizations, and deaths avoided were calculated based on case incidence and death data from the CDC, along with data on race- and age-specific hospitalization multipliers, under a scenario in which half of the remaining unvaccinated population per county, race, and age group obtained a full vaccine regimen.

Results

Vaccinating half of the remaining unvaccinated population in each age and race subgroup within counties would result in an estimated 22.09 million COVID-19 cases avoided, 1.38 million hospitalizations avoided, and 150,000 deaths avoided over 12 months. Some minority groups, particularly Black and Hispanic/Latino populations, were projected to experience substantial benefits from increased vaccination rates as they face both lower vaccination rates and worse outcomes if infected with COVID-19.

Conclusions

Increasing COVID-19 vaccination in the United States not only benefits the population as a whole but also serves as a potentially useful lever to reduce the disproportionate burden of COVID-19 illness among minority populations.

[A single-center retrospective analysis of 100 consecutive cases treated with lenalidomide/bortezomib/dexamethasone in newly diagnosed multiple myeloma]

Objective: To investigate the efficacy and safety of lenalidomide combined with bortezomib and dexamethasone (RVD) in patients with newly diagnosed multiple myeloma (NDMM). Methods: A total of 100 consecutive NDMM patients treated with RVD from August 2016 to September 2020 at Peking University People's Hospital were retrospectively analyzed, including response, drug toxicity, follow-up and survival, and subgroup analysis. Results: The median follow-up time was 19.5 (2.0-57.0) months. For patients undergoing autologous stem cell transplantation (ASCT) after RVD regimen, the objective response rate (ORR)/complete response+stringent complete response (CR+sCR)/≥very good partial response (VGPR) rates were 100%, 73.3% (33/45), 95.6% (43/45) respectively. For 54 patients not receiving transplantation, the ORR/CR+sCR/≥VGPR rates were 79.6% (43/54), 18.5% (10/54), 51.9% (28/54) respectively. As to the survival analysis, 2-year progression free survival (PFS) rates were 84.5% and 70.9% in transplant and non-transplant patients respectively (P=0.102). Two-year overall survival (OS) rates were 100% and 80.8% in transplant and non-transplant patients respectively (P=0.003). The common hematologic adverse events (AEs) were thrombocytopenia (33%) and neutropenia (25%). Abnormal liver function (43%) and peripheral neuropathy (24%) were recognized more as non-hematologic AEs. Conclusion: RVD as front-line regimen has high efficient response rate and acceptable safety in Chinese NDMM patients.

[Analysis of characteristics and trends of randomized controlled trials of gastric cancer between 2000 and 2019]

Objectives: To analyze the current development status of gastric cancer (GC) randomized controlled trials (RCT) between 2000 and 2019, and to review the basic characteristics of published RCT. Methods: ClinicalTrials.gov was searched for phase 3 or 4 RCT conducted between January 2000 and December 2019 with the keyword "gastric cancer", and the development trend of different types of RCT during different time periods was described. Basic features of registered RCT such as intervention, study area, single-center or multicenter, sample size, and funding were presented. PubMed and Scopus databases were searched to judge the publication status of studies completed until June 2016. The adequacy of the report was estimated by the Consolidated Standards of Reporting Trials (CONSORT) checklist. Design flaws were evaluated by Cochrane tool and/or whether a systematic literature review was cited. The data was analyzed by χ2 test or Fisher exact test. Results: There were 262 RCT including in the present study. The number of GC-RCT registered on ClinicalTrials.gov had been on the rise from 1 case in 2000 to 30 cases in 2015. The proportion of RCT associated with targeted therapy or immunotherapy increased from 0 during 2000-2004 to 37.1% (36/97) during2015-2019. The RCT registered in Asia was 191 cases, while that in non-Asia region was 71 cases. The proportion of multi-center RCT from non-Asia was higher than that from Asia (70.4% (50/71) vs. 50.3% (96/191), χ²=8.527, P=0.003). The proportion of RCT published was 59.1% (81/137). Among the published RCT, 65 (80.2%) studies were reported adequately, but 63 (77.8%) studies had avoidable design limitations. Conclusions: Targeted therapy and immunotherapy have become research hotspots in the treatment of GC. At present, there are inadequate multicenter RCT in Asia, and the publication rate of RCT is low. A considerable number of published RCT are reported inadequately and have avoidable design flaws.

[Analysis of characteristics and trends of randomized controlled trials of gastric cancer between 2000 and 2019]

Objectives: To analyze the current development status of gastric cancer (GC) randomized controlled trials (RCT) between 2000 and 2019, and to review the basic characteristics of published RCT. Methods: ClinicalTrials.gov was searched for phase 3 or 4 RCT conducted between January 2000 and December 2019 with the keyword "gastric cancer", and the development trend of different types of RCT during different time periods was described. Basic features of registered RCT such as intervention, study area, single-center or multicenter, sample size, and funding were presented. PubMed and Scopus databases were searched to judge the publication status of studies completed until June 2016. The adequacy of the report was estimated by the Consolidated Standards of Reporting Trials (CONSORT) checklist. Design flaws were evaluated by Cochrane tool and/or whether a systematic literature review was cited. The data was analyzed by χ² test or Fisher exact test. Results: There were 262 RCT including in the present study. The number of GC-RCT registered on ClinicalTrials.gov had been on the rise from 1 case in 2000 to 30 cases in 2015. The proportion of RCT associated with targeted therapy or immunotherapy increased from 0 during 2000-2004 to 37.1% (36/97) during 2015-2019. The RCT registered in Asia was 191 cases, while that in non-Asia region was 71 cases. The proportion of multi-center RCT from non-Asia was higher than that from Asia (70.4% (50/71) vs. 50.3% (96/191), χ²=8.527, P=0.003). The proportion of RCT published was 59.1% (81/137). Among the published RCT, 65 (80.2%) studies were reported adequately, but 63 (77.8%) studies had avoidable design limitations. Conclusions: Targeted therapy and immunotherapy have become research hotspots in the treatment of GC. At present, there are inadequate multicenter RCT in Asia, and the publication rate of RCT is low. A considerable number of published RCT are reported inadequately and have avoidable design flaws.

[Impacts of glycemic variability on the relationship between time in range and estimated glycated hemoglobin in patients with type 1 diabetes mellitus]

Objective: This study is to investigate the relationship between time in range (TIR) and glucose management indicator (GMI), and the impact of glycemic variability (GV) on their relationship in patients with type 1 diabetes mellitus (T1DM). Methods: The CGM data were collected from a multicenter randomized clinical trial of adults (≥18 years old) with T1DM, including 83 T1DM patients, respectively from the Third Affiliated Hospital of Sun Yat-sen University (72 cases), Drum Tower Hospital Affiliated to Nanjing University School of Medicine (2 cases), and the First Affiliated Hospital of University of Science and Technology of China (9 cases). All subjects wore the iPro^TM2 system for 14 days at baseline (0-2 weeks), 3 months (12-14 weeks), and 6 months (24-26 weeks). Data derived from iPro^TM2 sensor was used to calculate CGM parameters. Correlation between TIR and GMI was explored according to different stratification of glycemic variability assessed by glucose coefficient of variation (CV). Predicted TIR in the fixed GMI value was calculated via the linear regression equations performed in the respective interquartile group of CV. Results: From November 2017 to June 2021, a total of 233 CGM data were collected with 83 collected from baseline, 80 from the 3-month follow-up, 70 from the 6-month follow-up. Patients including 27 males had a median (Q₁, Q₃) age of 30.69 (25.22, 38.43) years, with a diabetes duration of 10.05(4.46, 13.92) years. The median (Q₁, Q₃) and effective wearing time of available CGM data was 13.92 (13.02, 14.00) days and 91.61% (84.96%, 95.94%), and the value of TIR, GMI and CV was 60.34%±13.03%, 7.14%±0.61% and 41.01%±7.64%, respectively. There was a strong negative correlation between TIR and GMI (r=-0.822, P<0.001). Multiple linear regression analysis showed that the predictive value of TIR calculated from a given GMI was 8.352% higher when CV was up to standard (36%) than that when CV was down to standard. Based on the multiple linear regression equations generated from quartiles of CV, the predicted TIR value was decreased across the ascending quartiles with 69.98 % in the lowest quartile of CV (≤35.91%), 64.57 % in 25^th-50^th quartile of CV (35.91%<CV≤40.08%), 60.96% in 50^th-75^th quartile of CV (40.08%<CV≤45.86%) and 56.44% in the highest quartile of CV (>75^th quartile, CV>45.86%) when GMI was set as 7%. Conclusions: There is a strong correlation between TIR and GMI in adult patients with T1DM in patients with type 1 diabetes mellitus. CV influenced the relationship between TIR and GMI.

[Establishment of artificial neural network model for predicting lymph node metastasis in patients with stage Ⅱ-Ⅲ gastric cancer]

Objective: To establish a neural network model for predicting lymph node metastasis in patients with stage II-III gastric cancer. Methods: Case inclusion criteria: (1) gastric adenocarcinoma diagnosed by pathology as stage II-III (the 8th edition of AJCC staging); (2) no distant metastasis of liver, lung and abdominal cavity in preoperative chest film, abdominal ultrasound and upper abdominal CT; (3) undergoing R0 resection. Case exclusion criteria: (1) receiving preoperative neoadjuvant chemotherapy or radiotherapy; (2) incomplete clinical data; (3) gastric stump cancer.Clinicopathological data of 1231 patients with stage II-III gastric cancer who underwent radical surgery at the Fujian Medical University Union Hospital from January 2010 to August 2014 were retrospectively analyzed. A total of 1035 patients with lymph node metastasis were confirmed after operation, and 196 patients had no lymph node metastasis. According to the postoperative pathologic staging. 416 patients (33.8%) were stage Ⅱ and 815 patients (66.2%) were stage III. Patients were randomly divided into training group (861/1231, 69.9%) and validation group (370/1231, 30.1%) to establish an artificial neural network model (N+-ANN) for the prediction of lymph node metastasis. Firstly, the Logistic univariate analysis method was used to retrospectively analyze the case samples of the training group, screen the variables affecting lymph node metastasis, determine the variable items of the input point of the artificial neural network, and then the multi-layer perceptron (MLP) to train N+-ANN. The input layer of N+-ANN was composed of the variables screened by Logistic univariate analysis. Artificial intelligence analyzed the status of lymph node metastasis according to the input data and compared it with the real value. The accuracy of the model was evaluated by drawing the receiver operating characteristic (ROC) curve and obtaining the area under the curve (AUC). The ability of N+-ANN was evaluated by sensitivity, specificity, positive predictive values, negative predictive values, and AUC values. Results: There were no significant differences in baseline data between the training group and validation group (all P>0.05). Univariate analysis of the training group showed that preoperative platelet to lymphocyte ratio (PLR), preoperative systemic immune inflammation index (SII), tumor size, clinical N (cN) stage were closely related to postoperative lymph node metastasis. The N+-ANN was constructed based on the above variables as the input layer variables. In the training group, the accuracy of N+-ANN for predicting postoperative lymph node metastasis was 88.4% (761/861), the sensitivity was 98.9% (717/725), the specificity was 32.4% (44/136), the positive predictive value was 88.6% (717/809), the negative predictive value was 84.6% (44/52), and the AUC value was 0.748 (95%CI: 0.717-0.776). In the validation group, N+-ANN had a prediction accuracy of 88.4% (327/370) with a sensitivity of 99.7% (309/310), specificity of 30.0% (18/60), positive predictive value of 88.0% (309/351), negative predictive value of 94.7% (18/19), and an AUC of 0.717 (95%CI:0.668-0.763). According to the individualized lymph node metastasis probability output by N+-ANN, the cut-off values of 0-50%, >50%-75%, >75%-90% and >90%-100% were applied and patients were divided into N0 group, N1 group, N2 group and N3 group. The overall prediction accuracy of N+-ANN for pN staging in the training group and the validation group was 53.7% and 54.1% respectively, while the overall prediction accuracy of cN staging for pN staging in the training group and the validation group was 30.1% and 33.2% respectively, indicating that N+-ANN had a better prediction than cN stage. Conclusions: The N+-ANN constructed in this study can accurately predict postoperative lymph node metastasis in patients with stage Ⅱ-Ⅲ gastric cancer. The N+-ANN based on individualized lymph node metastasis probability has better accurate prediction for pN staging as compared to cN staging.

Odontogenesis by Endocytosis of Peptide Embedding Bioactive Glass Composite

Limited therapeutic options are available for treating deep caries. Those materials with potential of a dual effect to remineralize hard tissue and regenerate defective dentin tissues could be used as a new strategy for deep caries treatment. However, the application of the single component remains a challenge mainly because they lack calcium and phosphorus, are easily degraded, and are difficult to retain in the intricate body fluid environment. Considering the abundant source of calcium and phosphorus as well as the delivery performance of mesoporous bioactive glass (MBG), an amelogenin-derived peptide (QP5), which has a significant role in hard tissue remineralization, was loaded to fabricate a novel composite. After the synthesis of highly ordered MBG using a sol-gel method, the QP5 peptide was loaded increasingly by its extensive porous structure and enhanced electrostatic absorption. When used in an acidic environment, the MBG/QP5 composite presented pH-responsiveness, releasing therapeutic ions and functional peptides in a sequential cascade, and eventually adjusted the pH to a neutral state. The composite was internalized by dental pulp cells through a clathrin-mediated pathway and influenced by cell membrane lipid raft regulation. It could be also transported through the macro-pinocytotic pathway. Compared to the single treatment of peptide QP5 in 48 h, the composite facilitated a higher level of retention of the intracellular peptides. The composite further promoted migration and odontogenesis of dental pulp cells, including the improved activity of alkaline phosphatase, increased formation of mineralized nodules, and upregulated expression of mineralization-related genes compared to using MBG or QP5 alone. The composite further induced the dentin-like layer in a rat pulp capping model. The results suggested that this intelligent material with pH-responsiveness provides a promising alternative treatment method for biomimetic restoration of deep caries.

[Impact of probiotics on the lung development of Bama minipig after premature birth]

Objectives: To examine the impact of probiotics on the lung development of preterm birth of Bama pig. Methods: From April 2020 to October 2021, this animal experimental research was performed by setting up preterm (birth at gestation 104 d), full-term (birth at gestation 113 d), preterm with probiotics (birth at gestation 104 d treated with probiotics given at 3 d after birth), and full-term with probiotics (birth at gestation 113 d treated with probiotics given at 3 d after birth) groups and using the preterm Bama minipig model, the body weights were recorded and lung, ileum, and intestinal content samples were collected at birth, 4 days, 9 days, and 21 days after births of the piglets in preterm and full-term groups, the same samples were collected on 9 days after births of the piglets in preterm with probiotics and full-term with probiotics groups. The body weight and radial alveolar counts (RAC) were compared to evaluate the lung development of the piglets. The lengths of ileal villus were compared to evaluate the development of ileum. The composition structures of bacteria in ileum were analyzed by 16 S rRNA sequencing. The statistical analyses between different groups were performed by t test. Results: There were totally 30 piglets (16 female piglets and 14 male piglets) involving 12 piglets in preterm and full-term groups respectively and 3 piglets in preterm with probiotics and full-term with probiotics groups respectively. The body weights of the piglets in preterm group were lower than those in full-term group at 4, 9 and 21 d after birth ((507±27) vs. (694±56) g, (620±35) vs. (1 092±154) g, (1 660±210) vs. (2 960±418) g,t=2.96, 2.99, 2.78, all P<0.05). The alveolarization of the preterm piglets at 9 days after birth was significantly lower than that of the full-term piglets at the equivalent time point (4.00±0.29 vs. 6.11±0.35, t=4.64, P<0.01). The bacteria genus with the highest abundance in ileum were all different between the preterm and the full-term groups at 4, 9 and 21 d after birth (4 d Escherichia-Shigella (26.63%) and Enterococcus (30.48%) respectively;9 d Turicibacter (35.94%) and Lactobacillus (27.33%) respectively;21 d Escherichia-Shigella (28.02%) and Lactobacillus (46.29%) respectively). The heights of ileal villus of the preterm piglets at 9 d after birth were significantly lower than those of the full-term minipigs at the equivalent time point ((297±21) vs. (411±32) μm, t=3.01, P=0.007).There were both no differences in the body weight and alveolarization ((692±36) vs. (767±67) g, 5.44±0.34 vs. 5.89±0.26, t=0.74, 1.04, both P>0.05) between the piglets in preterm with probiotics group and those in full-term with probiotics group. Turicibacter was the dominant genus in the piglets of both preterm with probiotics and the full-term with probiotics groups. The heights of ileal villus of the piglets in preterm with probiotics group were significantly longer that those of the piglets in preterm group ((371±13) vs. (297±21) μm, t=3.04, P=0.006), and were both not significantly different from those of the piglets in full-term with probiotics group and full-term group ((371±13) vs. (338±12) and (411±32) μm, t=1.90, 1.15, both P>0.05). Conclusions: Premature birth could impact the lung alveolarization of piglets. The probiotics could improve the lung alveolarization of preterm minipigs by promoting the development of ileum.

Dynamic Allostery Highlights the Evolutionary Differences between the CoV-1 and CoV-2 Main Proteases

The SARS-CoV-2 coronavirus has become one of the most immediate and widely-studied systems since its identification and subsequent global outbreak from 2019-2021. In an effort to understand the biophysical changes as a result of mutations, the mechanistic details of multiple different proteins within the SARS-CoV-2 virus have been studied and compared with SARS-CoV-1. Focusing on the main protease (mPro), we first explored the long-range dynamics using the Dynamic Coupling Index (DCI) to investigate the dynamic coupling between the catalytic site residues and the rest of the protein, both inter and intra chain, for the CoV-1 and CoV-2 mPro. We found that there is significant cross-chain coupling between these active sites and specific distal residues in the CoV-2 mPro not present in CoV-1. The enhanced long distance interactions, particularly between the two chains, suggest subsequently enhanced cooperativity for CoV-2. A further comparative analysis of the dynamic flexibility using the Dynamic Flexibility Index (DFI) between the CoV-1 and CoV-2 mPros shows that the inhibitor binding near active sites induces change in flexibility to a distal region of the protein, opposite in behavior between the two systems; this region becomes more flexible upon inhibitor binding in CoV-1 while it becomes less flexible in the CoV-2 mPro. Upon inspection, we show that, on average, the dynamic flexibility of the sites substituted from CoV-1 to CoV-2 changes significantly less than the average calculated across all residues within the structure, indicating that the differences in behaviors between the two systems is likely the result of allosteric influence, where the new substitutions in CoV-2 induce flexibility and dynamical changes elsewhere in the structure.

A229 GUT MICROBIOTA PROFILES, DIET AND SHORT-CHAIN FATTY ACIDS AS PREDICTORS OF GENERALIZED ANXIETY DISORDER

Background

Generalized anxiety disorder (GAD) is a debilitating chronic condition with a lifetime prevalence of 4–7% worldwide. Both diet and gut microbiota have been previously associated with anxiety.

Aims

To investigate whether bacterial taxa and/or nutrients associate with GAD, and whether they differ from those of healthy controls (HC).

Methods

Patients with GAD (n=82) and matched HC (n=97) were assessed by validated questionnaires for anxiety (DASS-21), gastrointestinal (GI) symptoms (Rome III, Short-Form Leeds Dyspepsia), and dietary profiles by the Dietary Questionnaire for Epidemiological Studies. We quantified several blood and stool biomarkers, including inflammatory and neuroactive metabolites, as well as short-chain fatty acids. Stool microbiota profiles were assessed by16S rRNA gene sequencing through Illumina. The data was then analyzed following the pipelines of dada2 and by multiple factor analysis (MFA), mean comparisons, correlation, LEfSe and XGBoost using R software (v.1.2.1335). Multiple comparison results were corrected allowing 5% of FDR.

Results

Using MFA to analyze all variables, we identified 3 clusters: one mainly composed of HC (n=99, 91% HC, GI symptoms in 25% of subjects), a second mixed cluster (n=30, 80% GAD, GI symptoms in 80%) and a third cluster mainly composed of GAD patients (n=50, 98% GAD, GI symptoms in 86%). When focusing only on the HCs of cluster 1 (n=90) and GADs of cluster 3 (n=49), we found higher GI symptoms, body mass index, serum C-reactive protein and stool calprotectin levels (adj. p=1.3x10-9, 0.001, 0.017 and 0.017, respectively) and lower concentrations of propionate, butyrate and acetate in GAD compared to HC. GADs also reported overall lower caloric intake (kJ/day; adj. p=1.7x10-4) in the food frequency questionnaire. Fibre (g/day) was the macronutrient most negatively associated with anxiety scores (R=-0.44; adj. p=4.2x10-5). Bacteroides was the only bacterial taxon significantly associated with GAD, as well as with anxiety scores (R=0.31, adj. p=0.003). Interestingly, Bacteroides/fiber ratio was strongly correlated to anxiety scores (R=0.58, adj. p=2.7x10-09). Furthermore, demographic, biomarkers and bacterial taxa data were predictive of the patients’ disease state with 92.8% accuracy. The features that aid the model to predict disease state were Bacteroides/fiber ratio, GI symptoms and stool acetate levels.

Conclusions

Our results suggest that most GAD patients differ in dietary and microbiota profiles from HCs, and that the Bacteroides/fiber ratio, stool acetate and GI symptoms might be good predictors of disease state. Furthermore, these data strongly support the role of microbiota-gut-brain axis in genesis of psychiatric diseases, and they will inform mechanistic studies in gnotobiotic mouse models.

Funding Agencies

NIH

A13 GUT MICROBIOTA MODULATES CGRP PRODUCTION BY DRG NEURONS IN FEMALE MICE

Background

Abdominal pain is a common complaint in patients with chronic gastrointestinal disorders. Accumulating evidence suggests that gut microbiota is an important determinant of gut function, including visceral sensitivity. Germ-free (GF) mice have been shown to display visceral hypersensitivity, which normalizes after colonization. Thus, gut microbiota is involved in the regulation of gut nociception but the underlying mechanisms remain poorly understood.

Aims

To investigate the role of gut microbiota in abdominal pain.

Methods

Method: Adult female and male conventionally raised (SPF) or GF mice were used. Their visceral sensitivity was assessed by visceromotor responses to colorectal distension, at baseline (vehicle: Tween 80 10%, Ethanol 10%, saline 80%) and after intracolonic administration of a TRPV1 agonist capsaicin (30 μg), or a mixture of G-protein coupled receptors agonists (GPCR: bradykinin, histamine and serotonin; 30 μg). Neuronal excitability of dorsal root ganglia (DRG) neurons was assessed by calcium imaging using a fluorescent probe Fluo-4 (1 mM) after stimulation with capsaicin (12.5 nM, 125 nM and 1250 nM) or GPCR agonists (0.3 μM, 3 μM and 30 μM). The neuronal production of substance P (SP) and calcitonin gene-related peptide (CGRP) in response to capsaicin (1250 nM) or GPCR agonists (30 μM) was measured by ELISA.

Results

At baseline, GF male mice exhibited higher responses to colorectal distension compared to SPF males, while SPF and GF females displayed similar visceral sensitivity. In contrast, both intracolonic capsaicin and GPCR agonists increased visceral sensitivity in GF females compared to SPF females, while responses were comparable in male groups.

DRG neuronal activation after stimulation with capsaicin or GPCR agonists was similar in SPF and GF mice of both sexes. While stimulated production of SP by DRG neurons was similar in SPF and GF mice, regardless of sex, the production of CGRP in response to GPCR agonists was higher in GF female than SPF female mice.

Conclusions

Our data suggest that visceral sensitivity in vivo differs according to the gut microbiota status, sex and the activation of TRPV1 and GPCR pathways. At the level of DRG neurons, the absence of gut microbiota does not affect the neuronal activation or production of SP. However, GPCR agonists-stimulated release of CGRP is higher in GF female compared to SPF female mice. All together, our data demonstrate that the gut microbiota modulates visceral sensitivity by regulating the production of CGRP in the sensory neurons, especially in female mice. Further mechanistic studies are needed to investigate the role of gut microbiota in visceral sensitivity.

Funding Agencies

CIHR

A14 THE INTESTINAL MICROBIOTA CONTRIBUTES TO AGE-RELATED MEMORY DECLINE

Background

Age-related deterioration of cognitive function and memory capacity occur in both humans and rodents. For example, significant memory deficits have been reported in conventionally raised (SPF) old mice compared to conventionally raised young mice submitted to a spatial memory task (Prevot et al., 2019, Mol Neuropsychiatry 5, 84–97). Microbiota-to-brain signaling is now well established in mice and humans, but the extent to which it influences age-associated memory decline is unknown.

Aims

Our study examines whether the intestinal microbiota contributes to age-associated changes in brain function. We address the specific hypothesis that age-associated cognitive decline is attenuated in the absence of the intestinal microbiota.

Methods

We assessed anxiety-like and depressive-like behavior, locomotor activity and spatial memory performance in young germ-free (GF) mice (2–3 months of age, n=24) and senescent GF mice (13–27 months old, n=22) maintained in axenic conditions, and compared them to conventionally raised (SPF) mice of the same age. Anxiety-like behavior, locomotor activity and depressive-like behavior were measured using the light-dark preference, open-field, and tail suspension tests. We also used the Y-maze test based on a spontaneous alternation task to assess cognition, with the alternation rate as a proxy of spatial working memory. The age-associated inflammation was assessed with IL-6 cytokine plasma concentrations measured by ELISA.

Results

Anxiety-like behavior and depressive-like behavior did not change with the age regardless of the microbial status. However, old SPF mice traveled less distance (866.8 cm) than young SPF mice (1375 cm, p < 0.01) in the open-field. Similarly, old GF mice also traveled less distance (458.9 cm) than young GF mice (875.7 cm, p < 0.0001). In contrast to old SPF mice, old GF mice did not show memory impairment in the spatial memory task. Indeed, old SPF mice displayed lower alternation rate of 58.3%, compared to that found in young SPF mice (76.9%, p < 0.05) while both old and young GF mice had an identical alternation rate of 73.3% ( p > 0.05). In addition, IL-6 plasma levels revealed that old GF mice did not show signs of age-associated inflammation that was evident in old SPF mice (3.68 vs. 13.93 pg/ml, p < 0.05).

Conclusions

We conclude that the absence of age-related memory deficit in old germ-free mice is consistent with a role for the microbiota in age-related cognitive decline, likely mediated via the immune system, as suggested by the absence of age-associated inflammation in germ-free mice. We propose that novel microbiota-targeted therapeutic strategies may prevent or delay the cognitive decline of aging.

Funding Agencies

CIHRBalsam Family Foundation

A bibliometric review of peripartum cardiomyopathy compared to other cardiomyopathies using artificial intelligence and machine learning

As developments in artificial intelligence and machine learning become more widespread in healthcare, their potential to transform clinical outcomes also increases. Peripartum cardiomyopathy is a rare and poorly-characterised condition that presents as heart failure in the last trimester prior to delivery or within 5-6 months postpartum. The lack of a definitive understanding of the molecular causes and clinical progress of this condition suggests that bibliometrics will be well-suited to creating new insights into this serious clinical problem. We examine similarities and differences between peripartum and its closely related familial dilated cardiomyopathy and idiopathic dilated cardiomyopathy. Using PubMed as the source of bibliometric data, we apply artificial intelligence-supported natural language processing to compare extracted data and genes association with these cardiomyopathies. Gene data were enhanced with additional metadata from third-party datasets and then analysed for their impact and specificity for peripartum cardiomyopathy. Artificial intelligence identified 14 genes that distinguished peripartum from both dilated and familial dilated cardiomyopathy. They are as follows: CTSD, RLN2, MMP23B*, SLC17A5, ST2*, PTHLH, CFH*, CFI, GPT, MR1, Rln1, SRI, STAT5A* and THBD. We then used the Human Protein Atlas website that uses affinity-purified rabbit polyclonal antibodies to identify genes that are expressed at the protein level (bold), or as RNA transcripts (*) in healthy human left ventricles. Additional analysis focussed on the full set of peripartum genes on linkage and specificity to cardiomyopathy yielded a different set of thirteen genes (bold font indicates those expressed in cardiomyocytes: PRL, RLN2, PLN, ST2, CTSD, F2, ACE, STAT3, TTN, SPP1, LGALS3, miR-146a, GNB3, SRI). This type of analysis can highlight new avenues for research, aimed at improving genomics-driven peripartum cardiomyopathy diagnosis as well as potential pathological and clinical sub-classification. We expect that this will allow for future improvements in identification, treatment and management of this condition. The first step in the application of these bibliometric-based artificial intelligence methods is to understand the current knowledge, and it is the aim of this paper to show how this might be achieved.

[Analysis on vaccination willingness and related factors of influenza, pneumonia, and herpes zoster vaccine among people over 50 years old in Minhang district of Shanghai]

Objective: To determine the knowledge of influenza, pneumonia, herpes zoster and related vaccines, willingness to vaccinate under multiple payment scenarios, and corresponding risk factors among people over 50 years old in Minhang District of Shanghai. Methods: A total of 1 672 respondents aged 50-69 from 13 communities/towns in Minhang district of Shanghai were included in this study using a stratified random sampling strategy on December 2020. The knowledge of influenza, pneumonia, herpes zoster and vaccines was investigated using a questionnaire, and the differences in the willingness under multiple payment scenarios were determined using chi-square test. The consistency in the willingness under multiple payment scenarios was compared using Cohen's Kappa and the risk factors of the willingness was determined using ordinal logistic regression. Results: The average age of 1 672 respondents was (60.48±5.96) years old, including 777 (46.47%) males and 895 (53.53%) females. A total of 1 350 subjects (80.74%) had local household registration in Shanghai. The proportion of the willingness to vaccinate for themselves, spouses, and parents under any payment scenario was determined to be 80.6% (influenza vaccine), 81.5% (pneumonia vaccine), and 74.0% (herpes zoster vaccine). The willingness to vaccinate against influenza and pneumonia under multiple payment scenarios remained stable (Kappa value ≥0.6), while that against herpes zoster infection was inconsistent (Kappa value ≤0.35). Logistic regression analysis showed that respondents who had higher knowledge of influenza and influenza vaccine [OR (95%CI): 1.111 (1.054-1.170), 1.182 (1.126-1.240), respectively], aged 50-59 [1.305 (1.085-1.531)] and local household registration in Shanghai [1.372 (1.079-1.721)] had higher willingness to vaccinate against influenza, while males had lower willingness [0.733 (0.551-0.910)]. Respondents who had higher knowledge of pneumonia and pneumonia vaccine [OR (95%CI): 1.837 (1.152-2.517), 2.217 (1.541-2.893), respectively] had higher willingness to receive pneumonia vaccine. Respondents aged 50-59 [1.327 (1.059-1.537)] and with local household registration in Shanghai [2.497 (1.417-4.400)] were more likely to be vaccinated against herpes zoster, while those with middle school degree or below [0.664 (0.396-0.992)] and high school degree [0.559 (0.324-0.964)] were less likely to be vaccinated. Conclusion: Among people aged over 50 years old in Minhang district of Shanghai, the willingness to vaccinate for themselves, spouses, and parents against influenza, pneumonia and herpes zoster infection is quite different under multiple payment scenarios, especially for herpes zoster vaccine.