Comparative genomics analysis and transposon mutagenesis provides new insights into high menaquinone-7 biosynthetic potential of Bacillus subtilis natto

This research combined Whole-Genome sequencing, intraspecific comparative genomics and transposon mutagenesis to investigate the menaquinone-7 (MK-7) synthesis potential in Bacillus subtilis natto. First, Whole-Genome sequencing showed that Bacillus subtilis natto BN-P15-11-1 contains one single circular chromosome in size of 3,982,436 bp with a GC content of 43.85 %, harboring 4,053 predicted coding genes. Next, the comparative genomics analysis among strain BN-P15-11-1 with model Bacillus subtilis 168 and four typical Bacillus subtilis natto strains proves that the closer evolutionary relationship Bacillus subtilis natto BN-P15-11-1 and Bacillus subtilis 168 both exhibit strong biosynthetic potential. To further dig for MK-7 biosynthesis latent capacity of BN-P15-11-1, we constructed a mutant library using transposons and a high throughput screening method using microplates. We obtained a YqgQ deficient high MK-7 yield strain F4 with a yield 3.02 times that of the parent strain. Experiments also showed that the high yield mutants had defects in different transcription and translation regulatory factor genes, indicating that regulatory factor defects may affect the biosynthesis and accumulation of MK-7 by altering the overall metabolic level. The findings of this study will provide more novel insights on the precise identification and rational utilization of the Bacillus subtilis subspecies for biosynthesis latent capacity.

Inflammatory factors mediated the effect of air pollution on ischemic stroke: a two-step, mediation Mendelian randomization study

OBJECTIVE

Numerous investigations have indicated a correlation between air pollution (AP) and an elevated ischemic stroke (IS) likelihood. The existing literature does not provide a consensus about the possible link between AP and IS. A two-sample Mendelian randomization (MR) analysis was utilized to systematically measure the causal link between AP and ischemic stroke. Furthermore, the mediating impact of inflammatory factors was also performed by a two-step MR.

MATERIALS AND METHODS

A two-sample MR analysis was utilized to examine the AP impact on the incidence of IS. Additionally, a two-step MR approach was carried out to account for possible mediating variables. The indirect impact was determined by employing the product approach, which included multiplying the AP impact on inflammatory factors by the inflammatory factors' impacts on IS. The MR effect was identified through inverse variance-weighted (IVW) meta-analysis of each Wald Ratio. Additionally, complementary studies were conducted using the weighted median and MR-egger approaches.

RESULTS

The IVW method with random effects showed that the per unit increase in genetically predicted PM2.5 was linked to the 0.362-fold elevated ischemic stroke risk (OR: 1.362, 95% CI: 1.032-1.796, p=0.029). Furthermore, the IVM technique, incorporating random effects, demonstrated that the per unit increase in genetically predicted PM2.5 was related to an elevated Interleukin (IL)-1β risk (OR: 1.529, 95% CI: 1.191-1.963, p=0.001), IL-6 (OR: 1.498, 95% CI: 1.094-2.052, p=0.012) and IL-17 (OR: 1.478, 95% CI: 1.021-2.139, p=0.038). IL-1β, IL-6, and IL-17 modulated the PM2.5 impact on ischemic stroke, while the proportion mediated by them was 59.5%.

CONCLUSIONS

A positive correlation between genetically predicted PM2.5 levels and elevated ischemic stroke risk is mediated by IL-1β, IL-6, and IL-17.

[Clinical characteristics and associated factors of mild cognitive impairment in patients with common cardiovascular diseases]

Objective: To analyze the clinical characteristics of patients with common cardiovascular diseases (CVD, including hypertension, coronary heart disease, atrial fibrillation, and heart failure) combined with mild cognitive impairment (MCI) and explore the potential risk factors of MCI in patients with CVD. Methods: A total of 2 294 patients with common cardiovascular diseases who met the criteria at Cardiology Medical Center in Beijing Anzhen Hospital, Capital Medical University, from June 1, 2021, to January 5, 2022, were retrospectively included. The patients were divided into the normal cognitive function group (1 107 cases) and the MCI group (1 187 cases). Demographic information and CVD status were collected. The information of cognitive function were collected using the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) scales. The difference between normal cognitive function and MCI were compared and analyzed. The logistic regression analysis was used to explored risk factors of MCI in CVD patients. Results: A total of 2 294 patients aged (60.6±10.4) years were included, among whom there were 29.99% (688 cases) females. Compared with patients in the normal cognitive function group, patients in the MCI group were older [ (57.9±11.4) vs (63.1±8.9) years old, P<0.001], with a higher proportion of women [26.47% (293 cases) vs 33.28% (395 cases), P<0.001]; there was a higher proportion of patients suffering from hypertension in the MCI group [59.62% (660 cases) vs 64.62% (767 cases), P=0.014］, and more components of CVD [(1.68±0.62) vs (1.74±0.65) components, P=0.017]. The risk factors of MCI in patients with common CVD were increased age, increased depression score, combined with hypertension, and ≥3 common components of CVD, with OR (95%CI) of 1.043 (1.032-1.054), 1.021 (1.004-1.037), 1.151 (1.142-3.439), and 1.137 (1.023-1.797), respectively (all P values <0.05). Increasing education level was observed to be associated with reduced risk of MCI with OR (95%CI) of 0.319 (0.271-0.378) (P<0.05). Conclusions: The incidence of MCI was high in CVD patients. The risk factors of MCI in CVD patients included hypertension and≥3 common components of CVD.

Testosterone promotes the migration, invasion and EMT process of papillary thyroid carcinoma by up-regulating Tnnt1

PURPOSE

To explore the key genes and molecular pathways in the progression of thyroid papillary carcinoma (PTC) promoted by testosterone using RNA-sequencing technology, and to provide new drug targets for improving the therapeutic effect of PTC.

METHODS

Orchiectomy (ORX) was carried out to construct ORX mouse models. TPC-1 cells were subcutaneously injected for PTC formation in mice, and the tumor tissues were collected for RNA-seq. The key genes were screened by bioinformatics technology. Tnnt1 expression in PTC cells was knocked down or overexpressed by transfection. Cell counting kit-8 (CCK-8), colony formation assay, scratch assay and transwell assay were adopted, respectively, for the detection of cell proliferation, colony formation, migration and invasion. Besides, quantification real-time polymerase chain reaction (qRT-PCR) and western blot were utilized to determine the mRNA and protein expression levels of genes in tissues or cells.

RESULTS

Both estradiol and testosterone promoted the growth of PTC xenografts. The key gene Tnnt1 was screened and obtained by bioinformatics technology. Functional analysis revealed that overexpression of Tnnt1 could markedly promote the proliferation, colony formation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) process of PTC cells, as well as could activate p38/JNK pathway. In addition, si-Tnt1 was able to inhibit the cancer-promoting effect of testosterone.

CONCLUSION

Based on the outcomes of bioinformatics and basic experiments, it is found that testosterone can promote malignant behaviors such as growth, migration, invasion and EMT process of PTC by up-regulating Tnnt1 expression. In addition, the function of testosterone may be achieved by activating p38/JNK signaling pathway.

Molecular screening of Entamoeba spp. (E. histolytica, E. dispar, E. coli, and E. hartmanni) and Giardia intestinalis using PCR and sequencing

A wide range of intestinal protozoan parasites inhabit the human gut. To establish a more comprehensive molecular screening, we designed PCR-sequencing screening methods for Entamoeba spp., including commensal species, and Giardia intestinalis, and performed such methods using 174 stool samples collected from Kenyan children. The prevalences of the target species were as follows: E. histolytica (2/174, 1.1%), E. dispar (20/174, 11.5%), E. coli (107/174, 61.5%), E. hartmanni (77/174, 44.3%), and G. intestinalis (54/174, 31.0%). PCR amplicons specific to G. intestinalis was differentiated to assemblages A (8/174, 4.6%) and B (46/174, 26.4%). PCR specificity for Entamoeba spp. was quite high, except for some cross-reactions between E. hartmanni detection primers and G. intestinalis, although the false-positive amplicons were discernible by the band size. The 18S rRNA PCR primers that was designed by Monis et al. in 1999 for G. intestinalis, have specificity issue, therefore amplicon sequencing was essential not only to determine assemblage classifications but also to confirm the positive results by eliminating potential non-specific reactions. The detection sensitivity of both the Entamoeba universal PCR and the G. intestinalis PCR was more than 100 copies of the target loci, which is sufficient for detecting a single trophozoite or cyst of both species.

Primary human thyrocytes maintained the function of thyroid hormone production and secretion in vitro

PURPOSE

Thyroid cell lines are useful tools to study the physiology and pathology of the thyroid, however, they do not produce or secrete hormones in vitro. On the other hand, the detection of endogenous thyroid hormones in primary thyrocytes was often hindered by the dedifferentiation of thyrocytes ex vivo and the presence of large amounts of exogenous hormones in the culture medium. This study aimed to create a culture system that could maintain the function of thyrocytes to produce and secrete thyroid hormones in vitro.

METHODS

We established a Transwell culture system of primary human thyrocytes. Thyrocytes were seeded on a porous membrane in the inner chamber of the Transwell with top and bottom surfaces exposed to different culture components, mimicking the 'lumen-capillary' structure of the thyroid follicle. Moreover, to eliminate exogenous thyroid hormones from the culture medium, two alternatives were tried: a culture recipe using hormone-reduced serum and a serum-free culture recipe.

RESULTS

The results showed that primary human thyrocytes expressed thyroid-specific genes at higher levels in the Transwell system than in the monolayer culture. Hormones were detected in the Transwell system even in the absence of serum. The age of the donor was negatively related to the hormone production of thyrocytes in vitro. Intriguingly, primary human thyrocytes cultured without serum secreted higher levels of free triiodothyronine (FT3) than free thyroxine (FT4).

CONCLUSION

This study confirmed that primary human thyrocytes could maintain the function of hormone production and secretion in the Transwell system, thus providing a useful tool to study thyroid function in vitro.

Dose Painting Radiotherapy Guided by Diffusion-Weighted Magnetic Resonance vs. 18F-FDG-PET/CT in Locoregionally Advanced Nasopharyngeal Carcinoma: A Randomized, Controlled Clinical Trial

PURPOSE/OBJECTIVE(S)

This phase II randomized controlled trial aimed at comparing the efficacy and toxicity of diffusion-weighted magnetic resonance imaging (DWI)-guided dose painting radiotherapy (DP-RT), FDG-PET/CT-guided DP-RT, and conventional MRI-based radiotherapy (RT) in locoregionally advanced nasopharyngeal carcinoma (NPC).

MATERIALS/METHODS

A total of 330 patients with stage III-IVa NPC disease were randomly assigned in a 1:1:1 ratio to receive induction chemotherapy followed by concurrent chemoradiotherapy by DWI-guided DP-RT (group A, n = 110), FDG-PET/CT-guided DP-RT (group B, n = 110), or conventional MRI-based RT (group C, n = 110). All patients received volumetric modulated arc therapy (VMAT). In group A, subvolume GTVnx-DWI (gross tumor volume of nasopharynx in DWI) was defined as the areas within the GTVnx (gross tumor volume of nasopharynx) with an apparent diffusion coefficient (ADC) below the mean ADC (ADC < mean). In group B, subvolume GTVnx-PET (gross tumor volume of nasopharynx in PET images) was defined within GTVnx as the SUV50%max isocontour. The doses to GTVnx-DWI in group A and GTVnx-PET in group B were escalated to 75.2 Gy/32 fx in patients with T1-2 disease and to 77.55 Gy/33 fx in those with T3-4 disease in 2.35 Gy per fraction. In group C, planning gross tumor volume of nasopharynx (PGTVnx) was irradiated at 70.4 to 72.6 Gy/32 to 33 fx in 2.2 Gy per fraction. This trial is registered with chictr.org.cn (ChiCTR2200057476).

RESULTS

Group A and B showed significant higher complete response (CR) rates than group C (100%, 100%, and 96.4% for group A, B and C, respectively, p = 0.036). In groups A, B and C, the 1-year local recurrence-free survival (LRFS) rates were 100%, 100%, and 94.5%, respectively (p = 0.002). The 1-year disease-free survival (DFS) rates were 100%, 99.1%, and 92.7%, respectively (p = 0.001). The 1-year distant metastasis-free survival (DMFS) rates were 100%, 99.1%, and 93.6%, respectively (p = 0.004). The 1-year overall survival (OS) rates were 100%, 100%, and 95.4%, respectively (p = 0.006). Group A and B had significantly higher 1-year LRFS, DFS, DMFS, and OS than those in group C. No significant differences were observed in LRFS, DFS, DMFS and OS between group A and B. Group B (PET/CT group) had a higher incidence of grade 3-4 acute ototoxicity (3.6%) than group A (0%) and group C (0%, p = 0.036). No significant differences in other grade 3-4 acute adverse events and late toxic effects were observed among the three groups, and no patient had grade 5 toxicities. Multivariate analysis showed that dose painting (DWI-guided DP-RT and PET/CT-guided DP-RT vs conventional MRI-based RT) was associated with improved LRFS, DFS, DMFS and OS.

CONCLUSION

Both DWI-guided DP-RT and PET/CT-guided DP-RT plus chemotherapy are associated with improved LRFS, DFS, DMFS and OS compared with conventional MRI-based RT among patients with locoregionally advanced NPC. DWI-guided DP-RT does not increase toxicities, but PET/CT-guided DP-RT has higher incidence of acute ototoxicity.

Outcome Supervised Deep Learning Model on Pathological Whole Slide Images for Survival Prediction of Immunotherapy in Non-Small Cell Lung Cancer Patients: A Multicenter Study

PURPOSE/OBJECTIVE(S)

Although PD-(L)1 inhibitors were marked by durable efficacy in non-small cell lung cancer patients (NSCLC), about 60% of patients still suffer from recurrence and metastasis after PD-(L)1 inhibitors treatment. And there were no robust biomarkers of the response of PD-(L)1 inhibitors. Whole slide images (WSIs) of H&E-stained specimens have been found to characterize the tumor microenvironment, and might be the potential prognostic predictors of NSCLC patients. To accurately predict the response to PD-(L)1 inhibitors, we presented the deep learning model based on WSI of H&E-stained specimens of NSCLC patients.

MATERIALS/METHODS

Two independent cohorts of NSCLC patients receiving PD-(L)1 inhibitors from two hospitals were enrolled for model training and testing respectively. The WSI images of H&E-stained histological specimens were obtained from these patients, and patched into 1024×1024 pixels. The labels of patched images were determined due to their progression free survival (PFS) with the interval of 4 months. The patch-level model was firstly trained based on Vit to identify the predictive patches in training cohort, and patch-level probability distribution was performed. Then we trained patient-level survival model-based Vit-RNN framework, and tested it in external validation cohort.

RESULTS

A total of 291 WSI images of H&E-stained histological specimens from 198 NSCLC patients in primary cohort and 62 WSI images from 30 NSCLC patients in testing cohort were included for model training and external validation. All patients were divided into 4 groups due to their PFS after PD-(L)1 inhibitors. There were 246,318 patches from 291 images in primary cohort after image pre-processing, and all images were randomly divided into train cohort and validation cohort with the proportion of 7:3. The patch-level Vit model with the highest accuracy was saved and the predictive patches were selected after 50 epochs training. All patches were ranked by the probability of correct prediction, and the first 50 top-ranked patches from each WSI image are sequentially passed to the patient-level Vit-RNN model. The Vit-RNN survival achieved an accuracy of 88.6% in the validation cohort, and an accuracy of 81% in the testing cohort. The multivariate cox analysis also indicated the Vit-RNN survival model remained a statistically independent predictor of survival from PD-(L)1 inhibitors (P = 0.0085).

CONCLUSION

The outcome supervised Vit-RNN survival model based on pathological WSIs could be used to predict the efficacy the PD-(L)1 inhibitors in NSCLC patients, laying the foundation for the deployment of computational pathomics in clinical practice of immunotherapy.

Adaptive Radiotherapy Guided by PET/CT in Patients with Locally Advanced Non-Small Cell Lung Cancer: A Phase II Randomized Study

PURPOSE/OBJECTIVE(S)

The aim of this study was to determine whether adaptive radiotherapy guided by functional imaging with flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) can improve local tumor control in patients with locally advanced non-small cell lung cancer (LA-NSCLC).

MATERIALS/METHODS

This was a phase II randomized study comparing the efficacy and safety between PET-guided adaptive radiotherapy and conventional radiotherapy. The primary end point was 2-year local-regional tumor control (LRTC) rate. Secondary end points included local-regional progression-free survival (LR-PFS), progression-free survival (PFS), overall survival (OS), and radiation-related toxicities.

RESULTS

Between November 2012 and June 2017, 72 patients were 1:1 randomized to adaptive and conventional arms. The 2- and 5-year LRTC rates were 63.2% and 58.0% versus 43.0% and 37.6% (P = 0.035) in the adaptive and conventional arms, respectively. The median LR-PFS (14.3 versus 12.0 months; P = 0.010) and PFS (12.8 versus 8.9 months; P = 0.034) were significantly longer in the adaptive arm than in the conventional arm. The median OS was 36.3 months in the adaptive arm and 28.8 months in the conventional arm (P = 0.266). The esophageal volume of receiving ≥60 Gy (V60) in the adaptive arm was lower than that in the conventional arm (P = 0.011), while the V30 for the heart in the adaptive arm was lower than that in the conventional arm (P = 0.077). Other radiological metrological parameters of tumor, organs at risk, and the incidence of ≥grade 2 radiation-related toxicities were not significantly different between the 2 arms.

CONCLUSION

Compared with conventional radiotherapy, PET-guided adaptive radiotherapy significantly improved the 2-year LRTC rate, LR-PFS, and PFS without increased risks of radiation-related toxicities in patients with LA-NSCLC.

Study on Dosimetric Benefits of Adaptive Brachytherapy in the Treatment of Postoperative Cervical Cancer Patients

PURPOSE/OBJECTIVE(S)

Image-guided adaptive brachytherapy (IGABT) has been proven to improve the local control and survival rate of cervical cancer patients, while reducing the side effects. However, IGABT is time-consuming and difficult to achieve in countries or hospitals with intense medical resources. Compared with radical cervical cancer patients, the anatomical change of postoperative patients during brachytherapy is small. We hypothesis that the dosimetric benefits of adaptive brachytherapy in the treatment of postoperative cervical cancer patients is limited. This study investigates whether there is a balance between the treatment quality and treatment efficiency in postoperative cervical cancer patients without using IGABT.

MATERIALS/METHODS

We retrospectively studied 30 postoperative cervical cancer patients who underwent brachytherapy. Each patient had a primary CT (PCT) and an adaptive CT (ACT). The plan developed on the PCT (PCT plan) was introduced into ACT for dose calculation (P-ACT plan) to evaluate the dosimetric effect of anatomy change. The dose difference between P-ACT plan and ACT plan and was compared.

RESULTS

The mean value of HRCTV D100% and V150% in P-ACT plan are 4.95% and 0.75% lower than those of ACT plan, the difference is not statistically significant (P>0.05). The D0.1cm³ of bladder, rectum and sigmoid in P-ACT plan are higher 2.13%, 3.17%, and 0.71% than ACT plan, respectively, but the increment is insignificant (P>0.05). The D2cm³ of bladder and rectum is slightly lower in ACT plan, while the D2cm³ of sigmoid is slightly lower in P-ACT plan. The dosimetric benefits of IGABT is not remarkable for postoperative cervical cancer patients.

CONCLUSION

The preliminary results of this study show that IGBAT is optional for postoperative patients with cervical cancer in countries or hospitals with tight medical resources. It is necessary to conduct a larger sample and more detailed research further.

Efficacy and Toxicity of Different Target Volume Delineations of Radiotherapy Based on the Updated RTOG/NRG and EORTC Guidelines in Patients with High Grade Glioma: A Randomized, Controlled Clinical Trial

PURPOSE/OBJECTIVE(S)

Postoperative radiotherapy with concomitant and adjuvant temozolomide (TMZ) is the standard of care for newly diagnosed high grade glioma, but the optimal method for target volume delineations for intensity modulated radiation therapy (IMRT) is still unclear. We hypothesized that compared with the EORTC guidelines, IMRT based on the updated RTOG/NRG guidelines was equally effective, without increasing toxicities for patients with high-grade glioma. The purpose of this randomized phase 2 study was to compare the efficacy and toxicity of IMRT based on different target volume delineations (updated RTOG/NRG versus EORTC guidelines) with concomitant and adjuvant TMZ for patients with high grade glioma.

MATERIALS/METHODS

A total of 302 patients with newly diagnosed high-grade glioma (WHO grade 3-4) were randomly assigned (1:1) to receive postoperative IMRT based on either updated RTOG/NRG guidelines (RTOG/NRG group, n = 151) or EORTC guideline (EORTC group, n = 151), with concomitant and adjuvant TMZ. In the RTOG/NRG group, an initial volume consisting of enhancement, postoperative cavity, plus surrounding edema (or fluid-attenuated inversion recovery [FLAIR] abnormality defined by magnetic resonance imaging [MRI]) and a 2-cm margin received 46 Gy in 23 fractions followed by a boost of 14 Gy in 7 fractions to the area of enhancement plus the cavity and a 2-cm margin. In the EORTC group, a single planning volume was used to deliver 60 Gy in 30 fractions to the area of enhancement and the cavity with a 2-cm margin. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS) and toxicities associated with each treatment.

RESULTS

No statistically significant differences were observed between groups for 1-year OS (71.8% for RTOG/NRG group and 69.9% for EORTC group, respectively; P = 0.759) or 1-year PFS (46.7% for RTOG/NRG group and 43.6% for EORTC group, respectively; P = 0.674). Efficacy did not differ by MGMT methylation status. There were no differences in grade 3-4 toxicities (leukopenia, lymphopenia, neutropenia, thrombocytopenia, fatigue, nausea and vomiting) between the two groups. No grade 5 toxicities were observed in both groups. Multivariate analyses showed that tumor MGMT status (methylated vs unmethylated) and WHO grade (grade 3 vs grade 4) were associated with OS and PFS. However, radiation type (RTOG/NRG group vs EORTC), sex, age, and Karnofsky scale did not significantly influence OS or PFS.

CONCLUSION

Compared with EORTC guidelines for postoperative radiotherapy, IMRT based on RTOG/NRG guidelines was equally effective, without increasing toxicities for patients with high-grade glioma. This trial is registered with chictr.org.cn, number ChiCTR2100046667.

Alcohol dehydrogenase-1B represses the proliferation, invasion and migration of breast cancer cells by inactivating the mitogen-activated protein kinase signalling pathway

Breast cancer (BRCA) is a serious life-threatening cancer, especially triple-negative breast cancer (TNBC). Alcohol dehydrogenase-1B (ADH1B) has recently been revealed to be associated with poor prognosis of BRCA patients. This study identified the exact function of ADH1B on the progression of BRCA and TNBC. ADH1B effect on the prognosis of BRCA and TNBC patients was researched based on online databases and clinical samples. The function of ADH1B on the proliferation, invasion and migration, and growth of BRCA and TNBC cells was investigated by cell counting kit-8, Transwell, and in vivo assays. Western blot was utilized to determine the effect of ADH1B on the mitogen-activated protein kinase (MAPK) signalling pathway activity. As a result, ADH1B was down-regulated in BRCA and TNBC patients and cells, predicting unfavorable prognosis (P<0.05). ADH1B overexpression suppressed the proliferation, invasion and migration, and inactivated the MAPK signalling pathway in BRCA and TNBC cells (P<0.01). ADH1B synergized with Selumetinib (inhibitor of the MAPK signalling pathway) to attenuate the proliferation, invasion and migration of BRCA and TNBC cells (P<0.001). Conversely, Vacquinol-1 (activator of the MAPK signalling pathway) abolished the suppression of ADH1B on the proliferation, invasion and migration of BRCA and TNBC cells (P<0.05). ADH1B suppressed in vivo growth of TNBC cells (P<0.001). Thus, ADH1B may inhibit the proliferation, invasion and migration of BRCA and TNBC cells by inactivating the MAPK signalling pathway. It may be a promising target for the clinical treatment of BRCA and TNBC.

Outcomes of Proton Therapy for Patients with Infradiaphragmatic Lymphoma

PURPOSE/OBJECTIVE(S)

While the role of proton radiation (PT) in treating supradiaphragmatic targets in lymphoma patients is becoming increasingly well-established, outcomes of PT for infradiaphragmatic locations have not been reported. We report on the radiation planning details, doses achieved to key organs at risk (OARs), and clinical outcomes for a cohort of lymphoma patients treated with PT to infradiaphragmatic locations.

MATERIALS/METHODS

This is a single institution retrospective study of patients with biopsy-proven lymphoma who received PT to an infradiaphragmatic target between 2011-2022. Patient, disease, and radiation details were collected. Comparison photon plans were generated for a subset of patients. Toxicity was reported using CTCAE version 5.0. Dosimetric and clinical factors associated with toxicity and oncologic outcomes were assessed via linear regression, Wilcoxon rank sum test, Fisher's exact test, and/or independent t-test while the paired t-test or Wilcoxon signed rank test was used for dosimetric analyses.

RESULTS

38 patients comprising 40 PT courses were included. Median age was 63 years and median follow-up was 48 months. The most common diagnoses were DLBCL (58%) and Hodgkin lymphoma (18%). 28% of PT courses had direct overlap with a prior radiation field and 20% were palliative. Median dose was 30.6 GyE over 17 fractions to the retroperitoneum (30%), spine/paraspinal region (30%), pelvis (18%), inguinals (8%), spleen (3%), or other (8%). Top G1 toxicities were fatigue (65%), dermatitis (28%), and nausea (23%). 10% of PT courses led to a G2 toxicity and there were no G3+ toxicities. Higher number of fractions was associated with increased incidence of dermatitis (mean 16 vs. 19, p = 0.008), but no OAR parameters were associated with CTCAE toxicities. Among patients treated with curative intent, 44% experienced progression of disease (PD) at a median time of 3 months after PT; of these progressions, 60% were distant only, 20% were marginal only, 10% was marginal and distant, and 10% was in-field and distant. Higher number of systemic therapy lines received prior to PT was associated with increased likelihood of PD (mean 1.4 vs. 4.1, p = 0.01), and PD increased the risk of death (OR 15.3, 95% CI 2.5-95.2). 5/39 patients were diagnosed with a second malignancy after PT, two of which were hematologic. Among the 10 patients with photon comparison plans, PT provided a significant decrease in kidney doses (mean and V5), small bowel V5 Gy, large bowel V5 Gy, bowel bag V15 Gy, and mean liver (all p = 0.045 or less). However, average spinal cord/cauda Dmax was slightly higher with PT (24 vs. 25 Gy, p = 0.0156).

CONCLUSION

PT is a well-tolerated treatment for infradiaphragmatic lymphoma that leads to excellent outcomes with minimal high-grade toxicities. Compared to photon therapy, PT can significantly reduce doses to key abdominopelvic OARs.

[Association between atrial fibrillation reoccurrence and new-onset ischemic stroke among patients with nonvalvular atrial fibrillation]

Objective: Explore the association between atrial fibrillation (AF) reoccurrence and new-onset ischemic stroke (IS) in patients with nonvalvular AF, and explore whether there is a high-risk period of IS after recurrent episodes of AF. Methods: A nested case-control study design was used. A total of 565 nonvalvular AF patients with new-onset IS after a follow-up of at least 2 years in the China-AF cohort were enrolled as the case group, and 1 693 nonvalvular AF patients without new-onset IS were matched as the control group at a ratio of 1∶3. Frequency and types of recurrent AF in the previous 1 or 2 years were compared between two groups, and the adjusted associations of AF reoccurrence with new onset IS were explored using conditional logistic regression analysis. The proportion of recurrent AF was compared between the case period and control period, and conditional logistic regression analysis was performed to calculate adjusted associations of case-period AF with IS. Results: The nested case-control study design results showed that the proportion of at least one record of recurrent AF in the previous 1 year was higher in the case group than in the control group (72.0% vs. 60.8%, P<0.05), and the recurrent AF was positively correlated with new-onset IS (adjusted OR=1.80, P<0.001). Similar results were also observed in the previous 2 years period. The case-crossover study design analysis showed that among 565 patients with new-onset IS, recurrent AF in the case period was positively correlated with IS (adjusted OR=1.61, P=0.003). Conclusion: Recurrent AF is associated with IS, and there may be a high-risk period of IS after recurrent episodes of AF.

Tissue Distribution of mtDNA Copy Number And Expression Pattern of An mtDNA-Related Gene in Three Teleost Fish Species

Teleosts are the most speciose vertebrates and have diverse swimming performance. Based on swimming duration and speed, teleosts are broadly divided into sustained, prolonged, and burst swimming fish. Teleosts with different swimming performance have different energy requirements. In addition, energy requirement also varies among different tissues. As mitochondrial DNA (mtDNA) copy number is correlated with ATP production, we speculated that mtDNA copy number varies among fish with different swimming performance, as well as among different tissues. In other species, mtDNA copy number is regulated by tfam (mitochondrial transcription factor A) through mtDNA compaction and mito-genome replication initiation. In order to clarify the tissue distribution of mtDNA copy number and expression pattern of tfam in teleosts with disparate swimming performance, we selected representative fish with sustained swimming (Pseudocaranx dentex), prolonged swimming (Takifugu rubripes), and burst swimming (Paralichthys olivaceus). We measured mtDNA copy number and tfam gene expression in 10 tissues of these three fish. The results showed the mtDNA content pattern of various tissues was broadly consistent among three fish, and high-energy demanding tissues contain higher mtDNA copy number. Slow-twitch muscles with higher oxidative metabolism possess a greater content of mtDNA than fast-twitch muscles. In addition, relatively higher mtDNA content in fast-twitch muscle of P. olivaceus compared to the other two fish could be an adaptation to their frequent burst swimming demands. And the higher mtDNA copy number in heart of P. dentex could meet their oxygen transport demands of long-distance swimming. However, tfam expression was not significantly correlated with mtDNA copy number in these teleosts, suggesting tfam may be not the only factor regulating mtDNA content among various tissues. This study can lay a foundation for studying the role of mtDNA in the adaptive evolution of various swimming ability in teleost fish.

[Analysis of factors associated with anxiety in patients with atrial fibrillation and their caregivers]

Objective: To explore the risk factors of anxiety in patients with atrial fibrillation and their caregivers. Methods: From September 2020 to March 2021, patients with atrial fibrillation and one primary family member as caregiver of each patient from Beijing Anzhen Hospital were enrolled. Basic data of patients and their caregivers were collected, and anxiety of patients and caregivers were evaluated by Generalized Anxiety Disorder-7 scale (GAD-7). A total of 374 patients with atrial fibrillation and their caregivers were included in this study. Multivariate logistic regression analysis was used to analyze the risk factors of anxiety of patients and their caregivers. Results: The mean age of the patients was (58.3±10.6) years, and 124 (33.2%) were female. The caregivers were (53.6±11.6) years old, and 247 (66%) were female. 69 (18.4%) patients and 38 (10.2%) caregivers had mild anxiety (GAD-7:5-9 scores), 13 (3.5%) patients and 9 (2.4%) caregivers had moderate or higher anxiety (GAD-7:10-21 scores). Multivariate analysis showed that the risk factors of anxiety in patients with atrial fibrillation included EHRA score≥3 (OR=1.73,95%CI:1.03-2.89,P=0.039) and female sex (OR=1.90,95%CI:1.06-3.40,P=0.032). EHRA score of patients≥3 (OR=2.11,95%CI:1.05-4.24, P=0.036) or anxiety of patients (OR=2.76,95%CI:1.36-5.60,P=0.005) were associated with higher anxiety of caregivers. Moreover, age of≥65 years old (OR=3.97,95%CI:1.68-9.38,P=0.002), female sex (OR=3.83,95%CI:1.64-8.93,P=0.002) and number of comorbidities of caregivers≥2 (OR=2.57,95%CI:1.03-6.41,P=0.043) were also associated with anxiety of caregivers. Conclusions: Patients with severe symptoms have a higher proportion of anxiety, and their caregivers are more likely to experience anxiety. Anxiety rate is higher in caregivers of patients with anxiety.

[Expression and protective effect of chemerin in idiopathic pulmonary fibrosis]

Objective: To explore the expression and the role of chemerin in idiopathic pulmonary fibrosis (IPF). Methods: Quantitative PCR and Western blotting were used to determine the mRNA and protein levels of chemerin in lung tissues from IPF patients and the controls. Clinical serum level of chemerin was analyzed by enzyme-linked immunosorbent assay. The mouse lung fibroblasts isolated and cultured in vitro were divided into the control, TGF-β, TGF-β+chemerin and chemerin groups. Immunofluorescence staining was used to observe the expression of α-smooth muscle actin (α-SMA). C57BL/6 mice were randomly divided into the control, bleomycin, bleomycin+chemerin, and chemerin groups. Masson and immunohistochemical staining were performed to evaluate the severity of pulmonary fibrosis. Expression of epithelial to mesenchymal transition (EMT) markers was detected by quantitative PCR and immunohistochemical staining in the in vitro and in vivo models of pulmonary fibrosis, respectively. Results: Compared with the control group, the expression of chemerin was downregulated in both the lung tissue and the serum of IPF patients. Immunofluorescence showed that treatment of fibroblasts with TGF-β alone resulted in a robust expression of α-SMA, whereas treatment with TGF-β and chemerin together exhibited the similar expression levels of α-SMA as the control group. Masson staining indicated that the bleomycin-induced pulmonary fibrosis model was constructed successfully, while treatment of chemerin partially alleviated the damage of lung tissue. Immunohistochemical staining showed that the expression of chemerin in the lung tissue was significantly decreased in the bleomycin group. Quantitative PCR and immunohistochemistry showed that chemerin attenuated EMT induced by TGF-β and bleomycin both in vitro and in vivo. Conclusions: The expression of chemerin was reduced in patients with IPF. Chemerin may play a protective role in the development of IPF by regulating EMT, providing a new idea for the clinical treatment of IPF.

[Relationship between carotid atherosclerotic plaque characteristics in magnetic resonance imaging and perioperative hemodynamic instability]

Objective: To analyze the relationship between carotid atherosclerotic plaque characteristics in magnetic resonance imaging (MRI) and perioperative hemodynamic instability in patients with severe carotid artery stenosis undergoing carotid artery stenting (CAS). Methods: A total of 89 patients with carotid artery stenosis who underwent CAS treatment at Beijing Tsinghua Changgung Hospital affiliated to Tsinghua University from January 1, 2017, to December 31, 2021, were prospectively included. Among them, 74 were male and 15 were female, with an age range of 43 to 87 years (mean age: 67.8±8.2 years). Preoperative examinations included carotid artery MRI vessel wall imaging to analyze the existence of large lipid-rich necrotic core (LRNC), intraplaque hemorrhage (IPH), and fibrous cap rupture in carotid artery plaques. Plaques without the above-mentioned risk factors were defined as stable plaque group (34 cases), while those with such risk factors were defined as vulnerable plaque group (55 cases). The number of risk factors present in each plaque was also calculated. Intraoperative changes in blood pressure and heart rate were recorded, and the use of dopamine postoperatively was noted. Using the risk factors that the plaque has as independent variables and the clinical outcomes as dependent variables, the RR values were calculated, and the differences in clinical outcomes of patients with different risk factors were compared. Results: The incidence rates of hypotension and bradycardia were higher in patients with vulnerable plaques than those with stable plaques (60.0% (33/55) vs 14.7%(5/34) and 38.2%(21/55) vs 14.7%(5/34), respectively; both P<0.05). Based on MRI imaging features, the large LRNC was present in 45 cases, with RR values for hypotension and bradycardia of 3.15 (1.69-5.87) and 2.20 (1.07-4.53), respectively; IPH was present in 37 cases, with RR values for hypotension and bradycardia of 2.70 (1.61-4.55) and 2.25 (1.15-4.39), respectively; and fibrous cap rupture was present in 29 cases, with RR values for hypotension and bradycardia of 1.50 (0.94-2.40) and 1.29 (0.67-2.49), respectively. The higher the number of risk factors in vulnerable plaques, the higher the incidence of intraoperative blood pressure and heart rate decrease: when the number of risk factors ranged from 0 to 3, the incidence of blood pressure decrease was 14.7% (5/34), 9/18, 11/18, and 13/19, respectively (P<0.001), and the incidence of heart rate decrease was 14.7% (5/34), 6/18, 7/18, and 8/19, respectively (P=0.022). There was no significant difference in the number of cases of dopamine use between the two groups (P>0.05). Conclusion: Patients with a higher number of risk factors for vulnerable carotid plaques, as indicated by carotid artery MRI vessel wall imaging, are at a higher risk of experiencing blood pressure and heart rate decrease during CAS surgery.

Preoperative prediction of microvascular invasion and perineural invasion in pancreatic ductal adenocarcinoma with 18F-FDG PET/CT radiomics analysis

AIM

To develop and validate a predictive model based on 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/computed tomography (CT) radiomics features and clinicopathological parameters to preoperatively identify microvascular invasion (MVI) and perineural invasion (PNI), which are important predictors of poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

Preoperative ¹⁸F-FDG PET/CT images and clinicopathological parameters of 170 patients in PDAC were collected retrospectively. The whole tumour and its peritumoural variants (tumour dilated with 3, 5, and 10 mm pixels) were applied to add tumour periphery information. A feature-selection algorithm was employed to mine mono-modality and fused feature subsets, then conducted binary classification using gradient boosted decision trees.

RESULTS

For MVI prediction, the model performed best on a fused subset of ¹⁸F-FDG PET/CT radiomics features and two clinicopathological parameters, with an area under the receiver operating characteristic curve (AUC) of 83.08%, accuracy of 78.82%, recall of 75.08%, precision of 75.5%, and F1-score of 74.59%. For PNI prediction, the model achieved best prediction results only on the subset of PET/CT radiomics features, with AUC of 94%, accuracy of 89.33%, recall of 90%, precision of 87.81%, and F1 score of 88.35%. In both models, 3 mm dilation on the tumour volume produced the best results.

CONCLUSIONS

The radiomics predictors from preoperative ¹⁸F-FDG PET/CT imaging exhibited instructive predictive efficacy in the identification of MVI and PNI status preoperatively in PDAC. Peritumoural information was shown to assist in MVI and PNI predictions.

Apical Papilla Regulates Dental Follicle Fate via the OGN-Hh Pathway

Root apical complex, including Hertwig's epithelial root sheath, apical papilla, and dental follicle (DF), is the germinal center of root development, wherein the DF constantly develops into periodontal tissue. However, whether DF development is regulated by the adjacent apical papilla remains largely unknown. In this study, we employed a transwell coculture system and found that stem cells from the apical papilla (SCAPs) inhibit the differentiation and maintain the stemness of dental follicle stem cells (DFSCs). Meanwhile, partial SCAP differentiation markers were upregulated after DFSC coculture. High-throughput RNA sequencing revealed that the Hedgehog (Hh) pathway was significantly downregulated in DFSCs cocultured with SCAPs. Upregulation or downregulation of the Hh pathway can respectively activate or inhibit the multidirectional differentiation of DFSCs. Osteoglycin (OGN) (previously known as mimecan) is highly expressed in the dental papilla, similarly to Hh pathway factors. By secreting OGN, SCAP regulated the stemness and multidirectional differentiation of DFSCs via the OGN-Hh pathway. Finally, Ogn^-/- mice were established using the CRISPR/Cas9 system. We found that the root length growth rate was accelerated during root development from PN0 to PN30 in Ogn^-/- mice. Moreover, the hard tissues (including dentin and cementum) of the root in Ogn^-/- mice were thicker than those in wild-type mice. These phenotypes were likely due to Hh pathway activation and the increased cell proliferation and differentiation in both the apical papilla and DF. The current work elucidates the molecular regulation of early periodontal tissue development, providing a theoretical basis for future research on tooth root biology and periodontal tissue regeneration.

Recurrent syncope in an 84-year-old man

An 84-year-old man with hypertension and type 2 diabetes presented with recurrent transient loss of consciousness within 2 hours after dinner at home. Physical examination, electrocardiogram, and laboratory studies were unremarkable except hypotension. Blood pressures were measured in different postures and within 2 hours after meal, but neither orthostatic hypotension nor postprandial hypotension was detected. Further, history taking revealed that the patient was tube-fed with a fluid food pump with an inappropriate rapid infusion rate of 1500 mL per minute at home. He was eventually diagnosed as having syncope due to postprandial hypotension, which was caused by the inappropriate way of tube feeding. The family was educated about appropriate way of tube-feeding and the patient did not develop any episode of syncope during a two-year follow-up. This case highlights the importance of careful history taking in the diagnostic evaluation of syncope and the increased risk of syncope due to postprandial hypotension in the elderly.

[Construction and evaluation of an artificial intelligence-based risk prediction model for death in patients with nasopharyngeal cancer]

OBJECTIVE

To screen the risk factors for death in patients with nasopharyngeal carcinoma (NPC) using artificial intelligence (AI) technology and establish a risk prediction model.

METHODS

The clinical data of NPC patients obtained from SEER database (1973-2015). The patients were randomly divided into model building and verification group at a 7∶3 ratio. Based on the data in the model building group, R software was used to identify the risk factors for death in NPC patients using 4 AI algorithms, namely eXtreme Gradient Boosting (XGBoost), Decision Tree (DT), Least absolute shrinkage and selection operator (LASSO) and random forest (RF), and a risk prediction model was constructed based on the risk factor identified. The C-Index, decision curve analysis (DCA), receiver operating characteristic (ROC) curve and calibration curve (CC) were used for internal validation of the model; the data in the validation group and clinical data of 96 NPC patients (collected from First Affiliated Hospital of Bengbu Medical College) were used for internal and external validation of the model.

RESULTS

The clinical data of a total of 2116 NPC patients were included (1484 in model building group and 632 in verification group). Risk factor screening showed that age, race, gender, stage M, stage T, and stage N were all risk factors of death in NPC patients. The risk prediction model for NPC-related death constructed based on these factors had a C-index of 0.76 for internal evaluation, an AUC of 0.74 and a net benefit rate of DCA of 9%-93%. The C-index of the model in internal verification was 0.740 with an AUC of 0.749 and a net benefit rate of DCA of 3%-89%, suggesting a high consistency of the two calibration curves. In external verification, the C-index of this model was 0.943 with a net benefit rate of DCA of 3%-97% and an AUC of 0.851, and the predicted value was consistent with the actual value.

CONCLUSIONS

Gender, age, race and TNM stage are risk factors of death of NPC patients, and the risk prediction model based on these factors can accurately predict the risks of death in NPC patients.

Super diffraction limit spectral imaging detection and material type identification of distant space objects

The image information of distant objects shows a diffuse speckle pattern due to diffraction limit, non-uniform scattering, etc., which is difficult to achieve object discrimination. In this study, we have developed a staring spectral video imaging system mounted on a ground-based telescope observation platform to detect the high orbit space objects and gain their spectral images for six groups of GEO targets. The speckle remains basically the same characteristic as the projection structure of the object due to "the balloon inflation phenomenon of near parallel light during long-distance atmospheric transmission" under the premise of considering the bi-directional reflection distribution function (BRDF), Rayleigh scattering theory, and the memory effect. Based on this phenomenon, a mathematical model of remote target scattering spectrum imaging is established where the speckle can be treated as both a global speckle and speckle combination of texture blocks caused by various components of the target. The radial basis function (RBF) neural network is separately used to invert the global speckle and the speckle combination of the texture blocks on account of the typical target material database. The results show that the target materials are of relatively fewer kinds in the global inversion with only including gallium arsenide panel (GaAs) and carbon fiber (CF), for which the highest goodness of curve fitting is only 77.97. An improved algorithm makes their goodness of fit reach 90.29 and 93.33, respectively, in view of one conjecture that the target surface contains unknown materials. The spectral inversion result of the texture blocks shows that the types of materials in each target texture block increase significantly, and that the area ratio of different materials inverted in the block is different from each other. It is further confirmed that the speckle image contains the overall projection structure of distant target and the spectral image projection of each component is relatively fixed, which is the result of the comprehensive action of various mechanisms of ultra-long-haul atmospheric transmission and optical system focusing imaging after BRDF spectral scattering. The spectral image fine inversion is expected to restore the clear structure of the target. This discovery provides important support for the remote imaging and identification of distant and ultra-diffractive targets.

[Correlation between serum uric acid and creatinine ratio and metabolic syndrome based on physical examination population in Nantong area]

To investigate the relationship between serum uric acid to creatinine ratio (SUA/Cr) and metabolic syndrome (MS) and other indexes on physical examination population in Nantong area. Using the method of cross-sectional study, 8 148 physical examiners in the physical examination center of the Affiliated Hospital of Nantong University from January 2017 to April 2020 were used as the research objects, and the clinical data and serum biochemical indicators such as smoking and alcohol addiction, physical examination and so on were collected. According to the standard diagnosis of MS of Diabetes Society of Chinese Medical Association, the patients were grouped according to the quartile of SUA/Cr and the clinical data of each group were compared. Pearson correlation analysis and logistic regression analysis were used to explore the correlation between SUA/Cr and clinical indicators and the relationship between SUA/Cr and the risk of MS. The results showed that UA and SUA/Cr were the lowest in normal metabolism group, followed by abnormal metabolism group and the highest in MS group, The difference between the two groups was statistically significant (H=919.21 and 629.34, P<0.001). According to the SUA/Cr quartile, the population was divided into four groups. After adjusting for gender, age, smoking history and drinking history, SUA/Cr in group Q₁ was positively correlated with BMI and TG (r=0.061 and 0.080, P<0.05), but negatively correlated with HDL-C (r=-0.057, P<0.05). Multivariate logistic regression results showed that after adjusting for age, sex, smoking history and drinking history, the risk of MS for BMI, SBP, DBP, FBG, TG, HDL-C and SUA/Cr [OR (95%CI)] were: 1.44 (1.41-1.47), 1.07 (1.06-1.07), 1.10 (1.10-1.11), 1.83 (1.73-1.92), 1.89 (1.79-1.99), 0.08 (0.06-0.10) and 1.54 (1.47-1.62). Compared with SUA/Cr group Q₁, the risk of MS in group Q₂, Q₃ and Q₄ increased by 75%, 162% and 346%, respectively. In conclusion, there was an independent positive correlation between SUA/Cr and MS risk in Nantong area.

[A comparison of CAS risk model and CHA2DS2-VASc risk model in guiding anticoagulation treatment in Chinese patients with non-valvular atrial fibrillation]

Objective: To compare the differences between CAS risk model and CHA₂DS₂-VASc risk score in predicting all cause death, thromboembolic events, major bleeding events and composite endpoint in patients with nonvalvular atrial fibrillation. Methods: This is a retrospective cohort study. From the China Atrial Fibrillation Registry cohort study, the patients with atrial fibrillation who were>18 years old were randomly divided into CAS risk score group and CHA₂DS₂-VASc risk score group respectively. According to the anticoagulant status at baseline and follow-up, patients in the 2 groups who complied with the scoring specifications for anticoagulation were selected for inclusion in this study. Baseline information such as age and gender in the two groups were collected and compared. Follow-up was performed periodically to collect information on anticoagulant therapy and endpoints. The endpoints were all-cause death, thromboembolism events and major bleeding, the composite endpoint events were all-cause death and thromboembolism events. The incidence of endpoints in CAS group and CHA₂DS₂-VASc group was analyzed, and multivariate Cox proportional risk model was used to analyze whether the incidence of the endpoints was statistically different between the two groups. Results: A total of 5 206 patients with AF were enrolled, average aged (63.6±12.2) years, and 2092 (40.2%) women. There were 2 447 cases (47.0%) in CAS risk score group and 2 759 cases (53.0%) in CHA₂DS₂-VASc risk score group. In the clinical baseline data of the two groups, the proportion of left ventricular ejection fraction<55%, non-paroxysmal atrial fibrillation, oral warfarin and HAS BLED score in the CAS group were lower than those in the CHA₂DS₂-VASc group, while the proportion of previous diabetes history and history of antiplatelet drugs in the CAS group was higher than that in the CHA₂DS₂-VASc group, and there was no statistical difference in other baseline data. Patients were followed up for (82.8±40.8) months. In CAS risk score group, 225(9.2%) had all-cause death, 186 (7.6%) had thromboembolic events, 81(3.3%) had major bleeding, and 368 (15.0%) had composite endpoint. In CHA₂DS₂-VASc risk score group, 261(9.5%) had all-cause death 209(7.6%) had thromboembolic events, 112(4.1%) had major bleeding, and 424 (15.4%) had composite endpoint. There were no significant differences in the occurrence of all-cause death, thromboembolic events, major bleeding and composite endpoint between anticoagulation in CAS risk score group and anticoagulation in CHA₂DS₂-VASc risk score group (log-rank P =0.643, 0.904, 0.126, 0.599, respectively). Compared with CAS risk score, multivariable Cox proportional hazards regression models showed no significant differences for all-cause death, thromboembolic events, major bleeding and composite endpoint between the two groups with HR(95%CI) 0.95(0.80-1.14), 1.00(0.82-1.22), 0.83(0.62-1.10), 0.96(0.84-1.11), respectively. All P>0.05. Conclusions: There were no significant differences between CAS risk model and CHA₂DS₂-VASc risk score in predicting all-cause death, thromboembolic events, and major bleeding events in Chinese patients with non-valvular atrial fibrillation.

Identification of chitin synthase activator in Aspergillus niger and its application in citric acid fermentation

The biosynthesis of citric acid (CA) using Aspergillus niger as a carrier is influenced by mycelium morphology, which is determined by the expression level of morphology-related genes. As a key component of the fungal cell wall, chitin content has an important effect on morphogenesis, and to investigate the effects of this on fermentation performance, we used RNA interference to knockdown chitin synthase C (CHSC) and chitin synthase activator (CHS3) to obtain the single-gene mutant strains A. niger chs3 and chsC and the double mutant A. niger chs3C. We found that the CA fermentation performance of the two single mutants was significantly better than that of the double mutant. The mutant A. niger chs3-4 exhibited CA production potential compared to that of the parent strain in scale-up fermentation; we determined certain characteristics of CA high-yielding strain fermentation pellets. In addition, when chsC alone was silenced, there was very little change in chs3 mRNA levels, whereas those of chsC were significantly reduced when only chs3 was silenced. As this may be because of a synergistic effect between chsC and chs3, and we speculated that the latent activation target of CHS3 is CHSC, our results confirmed this hypothesis. This study is the first application of a separation and combination silence strategy of chitin synthase and chitin synthase activator in the morphology of A. niger CA fermentation. Furthermore, it provides new insights into the method for the morphological study of A. niger fermentation and the interaction of homologous genes. KEY POINTS: • The function of chitin synthase C (chsC) and chitin synthase activator (chs3) is tightly interrelated. • Mycelial morphology was optimized by knockdown of CHS3, resulting in the overproduction of citric acid. • The separation and combination silence strategies are promising tools for the interaction of homologous housekeeping genes.

Enhancement of the frequency conversion film imaging effect based on a cascade material fusion method

Frequency conversion imaging technology can provide an effective way for infrared detection against the limitations of conventional infrared detectors, such as expense and cooling requirements, but the converted luminescence intensity of frequency conversion materials limits the application of this technology. In this paper, a cascade material (CM) fusion method is proposed to improve the conversion luminous intensity and thus enhance the frequency conversion imaging effect at 1550 nm near infrared (NIR) excitation. First, we derived from the energy level transition mechanism of CM that the CM fusion method can achieve three excitations of substrate materials (SMs). It can improve the conversion luminescence intensity of SM in CM. Then, we experimentally prepared CM and SM films and simultaneously measured the frequency conversion imaging effect of the two films at 1550 nm NIR excitation. It was found that the weight ratio of doped material (DM) to SM affects the imaging enhancement of CM films. Therefore, we compared the imaging grayscale value intensity of CM films with different weight ratios under the same detection conditions. Finally, it was concluded that the best enhancement of frequency conversion imaging was achieved with a DM to SM weight ratio of 0.25 for this mechanism. The enhancement was about 3.11 times compared to SM films.

Research on NCFCP compact broadband NIR detector imaging and energy transfer function

Nonlinear crystal frequency conversion imaging with direct detection by silicon-based detectors is an effective way to break through the limitations for existing near-infrared (NIR) detectors with expensive cost and high noise. In this paper, a broadband NIR detector imaging scheme based on the principle of nonlinear crystal frequency conversion (NCFCP) was proposed. A thin film of nonlinear crystal frequency conversion material (NCFCM) combined with a silicon-based detector was used to form a broadband NIR detector. The theoretically investigated energy transfer function was used as a guidance for experiment. Meanwhile, the relationship between the imaging effect and the energy transfer of the NCFCP-based compact broadband NIR detector in the NIR band was measured experimentally. The accuracy of the theoretical study had been verified by the measured transfer results.

[The relationship between fasting blood glucose level and thromboembolism events in patients with non-valvular atrial fibrillation]

Objective: To explore the relationship between fasting blood glucose level and thromboembolism events in patients with non-valvular atrial fibrillation (NVAF). Methods: This was an observational study based on data from a multicenter, prospective Chinese atrial fibrillation registry cohort, which included 18 703 consecutive patients with atrial fibrillation (AF) in 31 hospitals in Beijing from August 2011 to December 2018. Patients were divided into 5 groups according to status of comorbid diabetes and fasting glucose levels at admission: normal blood glucose (normal glucose group), pre-diabetes group, strict glycemic control group, average glycemic control group and poor glycemic control group. Patients were followed up by telephone or outpatient service every 6 months. The primary follow-up endpoint was thromboembolic events, including ischemic stroke and systemic embolism. The secondary endpoint was the composite endpoint of cardiovascular death and thromboembolic events. Kaplan-Meier survival analysis and multifactorial Cox regression were used to analyze the correlation between fasting glucose levels and endpoint events. Results: The age of 18 703 patients with NVAF was (63.8±12.0) years, and there were 11 503 (61.5%) male patients. There were 11 877 patients (63.5%) in normal blood glucose group, 2 023 patients (10.8%)in pre-diabetes group, 1 131 patients (6.0%) in strict glycemic control group, 811 patients in average glycemic control group and 2 861 patients(4.3%) in poor glycemic control group. Of the 4 803 diabetic patients, 1 131 patients (23.5%) achieved strict glycemic control, of whom 328 (29.0%) were hypoglycemic (fasting blood glucose level<4.4 mmol/L at admission). During a mean follow-up of (51±23) months (up to 82 months), thromboembolic events were reported in 984 patients (5.3%). The survival curve analysis of Kaplan Meier showed that the incidence rates of thromboembolic events in normal glucose group, pre-diabetes group, strict glycemic control group, average glycemic control group and poor glycemic control group were 1.10/100, 1.41/100, 2.09/100, 1.46/100 and 1.71/100 person-years, respectively (χ²=53.0, log-rank P<0.001). The incidence rates of composite endpoint events were 1.86/100, 2.17/100, 4.08/100, 2.58/100, 3.16/100 person-years (χ²=72.3, log-rank P<0.001). The incidence of thromboembolic events and composite endpoint events in the other four groups were higher than that in the normal blood glucose group (P<0.001). Multivariate Cox regression analysis showed that compared with normal glucose group, the risk of thromboembolism increased in pre-diabetes group(HR=1.23, 95%CI 1.00-1.51, P=0.049), strict glycemic control group(HR=1.32, 95%CI 1.06-1.65, P=0.013) and poor glycemic control group(HR=1.26, 95%CI 1.01-1.58, P=0.044). Conclusion: Both high or low fasting glucose may be an independent risk factor for thromboembolic events in patients with NVAF.

Engineering microbial consortia of Elizabethkingia meningoseptica and Escherichia coli strains for the biosynthesis of vitamin K2

Background

The study and application of microbial consortia are topics of interest in the fields of metabolic engineering and synthetic biology. In this study, we report the design and optimisation of Elizabethkingia meningoseptica and Escherichia coli co-culture, which bypass certain limitations found during the molecular modification of E. meningoseptica, such as resistance to many antibiotics and fewer available molecular tools.

Results

The octaprenyl pyrophosphate synthase from E. meningoseptica sp. F2 (EmOPPS) was expressed, purified, and identified in the present study. Then, owing to the low vitamin K2 production by E. coli or E. meningoseptica sp. F2 monoculture, we introduced the E. meningoseptica and E. coli co-culture strategy to improve vitamin K2 biosynthesis. We achieved production titres of 32 mg/L by introducing vitamin K2 synthesis-related genes from E. meningoseptica sp. F2 into E. coli, which were approximately three-fold more than the titre achieved with E. meningoseptica sp. F2 monoculture. This study establishes a foundation for further engineering of MK-n (n = 4, 5, 6, 7, 8) in a co-cultivation system of E. meningoseptica and E. coli. Finally, we analysed the surface morphology, esterase activity, and membrane permeability of these microbial consortia using scanning electron microscopy, confocal laser scanning microscopy, and flow cytometry, respectively. The results showed that the co-cultured bacteria were closely linked and that lipase activity and membrane permeability improved, which may be conducive to the exchange of substances between bacteria.

Conclusions

Our results demonstrated that co-culture engineering can be a useful method in the broad field of metabolic engineering of strains with restricted molecular modifications.

The Inverted U-Shaped Association of Caffeine Intake with Serum Uric Acid in U.S. Adults

BACKGROUND AND AIMS

Caffeine is a worldwide popularly consumed constituent in foods that can exert physiological effects. However, previous researches about the relationship between caffeine intake and serum uric acid (SUA) were limited and controversial. Therefore, we sought to investigate that relationship in U.S. adults.

METHODS

In this cross-sectional study, the total sample of 7888 selected participants (3838 males and 4050 females) were identified from the National Health and Nutritional Examination Surveys (NHANES) 2015-2018. All subjects were tested for serum uric acid levels (μmmol/L), and their daily caffeine intakes (mg/d) were obtained by an average of two 24-hour dietary recalls. Multivariate linear regression models were used to evaluate the association between two variables in total subjects and subgroup analyses. Generalized additive models with smooth curve fittings were also performed.

RESULTS

Multivariate regression analyses showed caffeine intake was negatively correlated with SUA after adjustment of other confounders. The subgroup analyses stratified by gender showed the negative correlation of caffeine intake with SUA was statistically significant in males but not in females. Furthermore, we observed a nonlinear inverse association of caffeine intake with SUA (P nonlinear <0.001) in the generalized additive model, followed by an inverted U-shaped curve (inflection point: 60.5mg/d) for all participants. This inverted U-shaped relationship between them could also be found in both genders, individuals aged below 60 years old, overweight (BMI of 25 to 30), and Non-Hispanic White individuals.

CONCLUSIONS

This study indicated that caffeine intake exhibited an inverse correlation with SUA, especially in males. In addition, this inverse relationship was nonlinear, which followed an inverted U-shaped curve.

J-shaped relationship between admission diastolic blood pressure and 2-year cardiovascular mortality in elderly patients with acute coronary syndrome

Objective

To investigate the relationship between admission diastolic blood pressure (DBP) and subsequent cardiovascular and all-cause mortality in elderly patients with acute coronary syndrome (ACS).

Methods

This is a retrospective observational study. Consecutive patients ≥65 years of age admitted for ACS at a 2,300-bed tertiary hospital from December 2012 to July 2019 were included. The association between admission DBP and cardiovascular and all-cause mortality during hospitalization and over the follow-up period among this population were analyzed using multivariate COX regression model. Results were presented according to DBP quartiles: Q1, less than 67 mm Hg; Q2, from 67 to 72 mm Hg; Q3, from 73 to 80 mm Hg; and Q4, above 80 mm Hg.

Results

A total of 6 785 patients were included in this cohort study. Mean (SD) patient age was 74.0 (6.5) years, and 47.6% were women. Mean (SD) follow-up time was 2.54 (1.82) years. A non-linear relation was observed between DBP at admission and cardiovascular and all-cause mortality during hospitalization and over the follow-up period using restricted cubic splines. After adjustment for potential confounders, patients in Q3 or Q2 had lower risk for 2-year cardiovascular death by Cox proportional hazard model compared with patients in Q4 (hazard ratio [HR] 0.66; 95% confidence interval [CI], 0.48–0.90, P=0.010, for Q3 vs Q4; and HR 0.72; 95% CI, 0.53–0.99, P=0.041, for Q2vs Q4), while patients in Q1 had similar risk for cardiovascular death with that of patients in Q4. Meanwhile, when compared with patients in Q1, patients in Q3 had lower risk for 2-year cardiovascular death (HR, 0.72; 95% CI, 0.53–0.97, P=0.033). However, lower or higher admission DBP was not an independent predictor of 2-year all-cause mortality in this population.

Conclusion

Among patients aged ≥65 years admitted for ACS, there is a J-curve relationship between supine admission DBP and risk for 2-year cardiovascular death, with a nadir at 73–80 mm Hg.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): the Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding Support Study population and selectionAdjusted multivariate COX regression

[Safety and effectiveness of left atrial appendage occlusion in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis]

Objective: To evaluate the safety and effectiveness of left atrial appendage occlusion (LAAO) in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis. Methods: Six patients with AF and end-stage renal disease(ESRD)on long term hemodialysis who underwent LAAO from March 2017 to March 2021 in Beijing Anzhen Hospital were enrolled. Baseline characteristics such as age, sex, types of arrhythmia, stroke and bleeding score, and continuous dialysis time were collected. Four patients underwent LAAO, two patients underwent the combined procedure of catheter ablation and LAAO. Perioperative treatment and serious complications were recorded. Transesophageal echocardiography was repeated at 45 days and 60 days after the procedure. Telephone follow-up was conducted at 3, 6 and 12 months after the procedure, and every 6 months thereafter. Thromboembolism and major bleeding events and survival were evaluated. Results: The average age was (66.7±17.0) years old, and 5 were male (5/6). There were 4 patients with paroxysmal AF (4/6), and 2 patients with persistent AF (2/6). The mean CHA₂DS₂-VASc score was (4.8±1.5), and the HAS-BLED score was (3.5±1.4). The duration of hemodialysis was 2.6 (1.1, 8.3) years. Successfully Watchman implantation was achieved in all patients. There were no severe perioperative complications, and no device related thrombosis or leaks were observed by transesophageal echocardiography. During a mean of 22.0 (12.0, 32.0) months follow-up, there was no thromboembolism or major bleeding events. A total of 2 patients died, one from sudden cardiac death, and another one from heart failure. Conclusions: LAAO may be a safe and effective therapeutic option for prevention of thromboembolism in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis, further studies with larger patient cohort are needed to confirm our results.

Probiotic and prebiotic interventions for non-alcoholic fatty liver disease: a systematic review and network meta-analysis

Many studies have associated altered intestinal bacterial communities and non-alcoholic fatty liver disease, but the putative effects are inconclusive. The purpose of this network meta-analysis (NMA) was to evaluate the effects of probiotics, prebiotics, and synbiotics on non-alcoholic fatty liver disease through randomised intervention trials. Literature searches were performed until March 2020. For each outcome, a random NMA was performed, the surface under the cumulative ranking curve (SUCRA) was determined. A total of 22 randomised trials comparing prebiotic, probiotic, and synbiotic treatments included 1301 participants. Considering all seven results (aspartate aminotransferase, alanine aminotransferase, body mass index, weight, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol) together, the highest SUCRA values are probiotics (94%), synbiotics (61%) and prebiotics (56%), respectively. NMA results provide evidence that probiotics, prebiotics, and synbiotics can alleviate non-alcoholic fatty liver disease. However, due to the lack of high-quality randomised trials, this research also has some limitations.

[Clinical analysis of left atrial appendage occlusion for stroke prevention in elderly patients with atrial fibrillation]

To evaluate the efficacy and safety of left atrial appendage occlusion (LAAO) in patients with atrial fibrillation (AF) over 75 years. A total of 82 patients with AF who underwent LAAO successfully in Beijing Anzhen Hospital from March 2014 to March 2019 were divided into two groups according to age: the elderly group (aged>75 years) and the young group (aged ≤75 years). Risk of perioperative complications and incidence of ischemic stroke and major bleeding during follow-up were retrospectively analyzed. The results showed that there were no significant differences in procedure-related ischemic stroke(0 vs.1.6%,P=0.768) and major bleeding (0 vs.1.6%,P=0.768) during perioperative period between the two groups. No complications as death or pericardial tamponade occurred in the two group. During a (25.9±15.9) months period of followed up, ischemic stroke event rate was 3.6/100 person-years in the elderly group and 4.9/100 person-years in the young group, respectively. Major bleeding event rate was 2.5/100 person-years in the elderly group and 0/100 person-years in the young group, respectively. Compared with the expected ones, the relative risk reduction (RRR) of stroke in the elderly group was more profound than that in the young group (32.0% vs. 25.0%), while the risk of major bleeding in the young group was significantly lower than that in the elderly group (RRR 100% vs. 56.9%). Therefore, LAAO might be suitable for stroke prevention in the elderly AF patients.

MiRNA-15a-3p inhibits the metastasis of hepatocellular carcinoma by interacting with HMOX1

OBJECTIVE

To uncover the relationship between microRNA-15a-3p (miRNA-15a-3p) level and clinical features of hepatocellular carcinoma (HCC), and to explore the influence of miRNA-15a-3p on metastasis of HCC cells.

PATIENTS AND METHODS

HCC and paracancerous tissues were surgically resected from 44 HCC patients. Their clinical data and follow-up files were recorded. Differential expressions of miRNA-15a-3p in HCC samples were determined. The relationship between miRNA-15a-3p level and clinical features of HCC patients was analyzed. Changes in proliferative, migratory and invasive potentials in Huh7 and HepG2 cells overexpressing miRNA-15a-3p were examined. The downstream gene of miRNA-15a-3p and its involvement in HCC development were finally explored.

RESULTS

MiRNA-15a-3p was downregulated in HCC tissues. High metastasis rate and poor prognosis were observed in HCC patients expressing a low level of miRNA-15a-3p. Overexpression of miRNA-15a-3p attenuated proliferative, migratory and invasive potentials in HCC. Protein levels of HMOX1, CD31, c-Myc, MMP-2 and MMP-9 were downregulated in HCC cells after overexpression of miRNA-15a-3p. HMOX1 was the downstream gene of miRNA-15a-3p, which was upregulated in HCC samples. Highly expressed HMOX1 was unfavorable to the prognosis in HCC. Overexpression of HMOX1 abolished the regulatory effects of miRNA-15a-3p on HCC cell phenotypes.

CONCLUSIONS

MiRNA-15a-3p is closely linked to lymphatic metastasis, distant metastasis and poor prognosis in HCC. It inhibits the malignant development of HCC by interacting with HMOX1.

[Causes of death and influencing factors of atrial fibrillation patients undergoing anticoagulation therapy]

Objective: To investigate the causes of death and predictors in patients with nonvalvular atrial fibrillation (AF) undergoing anticoagulation therapy. Methods: Consecutive anticoagulated nonvalvular AF patients were recruited from the China Atrial Fibrillation Registry (China-AF) Study from August 2011 to December 2018. After exclusion of patients with hypertrophic cardiomyopathy, dilated cardiomyopathy, or loss of follow-up within 1 year, 2 248 patients were included in this analysis. Enrolled patients were followed up were followed up for 3 and 6 months, and then every 6 months. The primary endpoint was death, including cardiovascular death, non-cardiovascular death and undetermined death. The patients were divided into survival group and death group according to the survival status after follow-up. Clinical information such as age and sex was collected. Cox proportional hazards regression was performed to identify associated risk factors for all-cause mortality, and Fine-Gray competing risk model was used to identify associated risk factors for cardiovascular mortality. Results: A total of 2 248 patients with atrial fibrillation receiving anticoagulant therapy died over a mean follow-up of (42±24) months, mean age was (67±10) years old and 41.1% (923/2 248) patients were female. The mortality rate was 2.8 deaths per 100 patient-years. The most common cause of death was cardiovascular deaths, accounted for 55.0% (120/218). Worsening heart failure was the most common cause of cardiovascular deaths (18.3% (40/218)), followed by bleeding events (12.9% (28/218)) and ischemic stroke (8.7% (19/218)). Multivariate Cox regression analysis showed that age (HR = 1.05, 95%CI 1.04-1.07, P<0.001), anemia (HR = 1.81, 95%CI 1.02-3.18, P = 0.041), heart failure (HR=2.40, 95%CI 1.75-3.30, P<0.001), ischemic stroke/transient ischemic attack (TIA)(HR = 1.59, 95%CI 1.21-2.13, P = 0.001) and myocardial infarction (HR = 2.93, 95%CI 1.79-4.81, P<0.001) were independently associated with all-cause death. Fine-Gray competing risk model showed that age (HR=1.05, 95%CI 1.02-1.08, P<0.001), heart failure (HR=2.81, 95%CI 1.79-4.39, P<0.001), ischemic stroke/TIA (HR=1.50, 95%CI 1.02-2.22, P=0.041) and myocardial infarction (HR=3.31, 95%CI 1.72-6.37, P<0.001) were independently associated with cardiovascular death. Conclusions: In anticoagulated nonvalvular AF patients, ischemic stroke represents only a small subset of deaths, whereas worsening heart failure is the most common cause of cardiovascular deaths. Heart failure, ischemic stroke/TIA, and myocardial infarction are associated with increased mortality.

Physics-informed machine learning: case studies for weather and climate modelling

Machine learning (ML) provides novel and powerful ways of accurately and efficiently recognizing complex patterns, emulating nonlinear dynamics, and predicting the spatio-temporal evolution of weather and climate processes. Off-the-shelf ML models, however, do not necessarily obey the fundamental governing laws of physical systems, nor do they generalize well to scenarios on which they have not been trained. We survey systematic approaches to incorporating physics and domain knowledge into ML models and distill these approaches into broad categories. Through 10 case studies, we show how these approaches have been used successfully for emulating, downscaling, and forecasting weather and climate processes. The accomplishments of these studies include greater physical consistency, reduced training time, improved data efficiency, and better generalization. Finally, we synthesize the lessons learned and identify scientific, diagnostic, computational, and resource challenges for developing truly robust and reliable physics-informed ML models for weather and climate processes. This article is part of the theme issue 'Machine learning for weather and climate modelling'.

[Current status and quality analysis of interventional therapy for patients with atrial fibrillation in China]

Objective: To define the current status and analyze the medical quality of interventional therapy for patients with atrial fibrillation (AF) in China. Methods: This survey was performed in all seven large regions of China, one to three regional major medical centers were selected from each region. Medical records of patients underwent interventional therapy for AF in the year 2017 were randomly inspected. CHA2DS2-VASc score, prescribed anticoagulant after ablation, indication of left atrial appendage occlusion (LAAO), and complications in the medical records were analyzed. Results: A total of 10 800 AF catheter ablations and 447 LAAOs were performed in 17 regional medical centers in 2017. There were 10/17 centers performing AF catheter ablation<500 cases and 7/17 centers performing LAAO<20 cases. A total of 1 347 cases of catheter ablation and 160 cases of LAAO were selected for further analysis. Among all selected cases, 15.8% (238/1 505) non-valvar AF cases recorded CHA2DS2-VASc scores. The anticoagulation rate after AF catheter ablation was 98.6% (1 328/1 347), anticoagulation rate was higher than 90% in 16 out of 17 centers. The complication and severe complication rates of AF catheter ablation were 0.9% (12/1 347) and 0.4% (5/1 347), respectively. The differences of complication and severe complication rates in AF catheter ablation were similar between centers performing<500 cases and centers performing ≥500 cases (0.5% (2/413) vs. 1.1% (10/934), P>0.05; 0.5% (2/413) vs. 0.3% (3/934), P>0.05). The coincidence rate of LAAO indication was 81.3% (130/160), and the rate was higher in center performing ≥20 cases than in centers performing<20 cases (84.8% (106/125) vs. 68.6% (24/35), P<0.05). The complication and severe complication rates of LAAO were 3.1% (5/160) and 1.9% (3/160). The rate of complications in LAAO was higher in center performing<20 cases than in centers performing ≥20 cases (8.6% (3/35) vs. 1.6% (2/125), P<0.05), and there was no significant difference in severe complication rate (5.7% (2/35) vs. 0.8% (1/125), P>0.05). Conclusions: Interventional therapy for AF in China is generally standardized and safe. The overall incidence of complications post AF interventional ablation is low, the anticoagulation rate after AF catheter ablation is high, and the adherence rate of LAAO indication is fair. The indicators mentioned above vary widely among centers.