[Correlation of hematocrit and cardiovascular events in peritoneal dialysis patients]

Objective: To investigate the correlation between hematocrit (HCT) and cardiovascular events in peritoneal dialysis (PD) patients. Methods: Patients undergoing maintenance PD in the PD center of Guizhou Provincial People's Hospital from March 19, 2012 to July 9, 2020 were included. Demographic, baseline clinical and laboratory data of the patients were collected and patients were followed up until April 8, 2022. The primary endpoint was the first occurrence of a cardiovascular event. According to the tertiles of baseline HCT, the patients were divided into group Q1 (HCT≤26.6%), group Q2 (HCT>26.6%-32.4%), and group Q3 (HCT>32.4%). Laboratory indexes and cardiovascular events were compared among the three groups. Kaplan-Meier survival curve, Cox regression analysis and sensitivity analysis were used to analyze the effect of HCT on cardiovascular outcomes. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of HCT for cardiovascular events in PD patients. Results: A total of 860 PD patients were included, including 494 males (57.4%) and 366 females (42.6%), with a mean age of (41.5±15.0) years. There were 287 cases in group Q1, 289 cases in group Q2, and 284 cases in group Q3, respectively. A total of 265 (30.8%) patients experienced first cardiovascular events during the follow-up period. The incidence of cardiovascular events in groups Q1, Q2 and Q3 was 36.2% (104/287), 34.3% (99/289), and 21.8% (62/284), respectively, with a statistically significant difference (P<0.001). The incidence of cardiovascular events decreased with the increase of HCT. Multivariate Cox proportional hazards regression model analysis showed that decreased HCT was a risk factor for cardiovascular events. Compared with group Q3, the risk of cardiovascular events in group Q1 increased by 50.7% (group Q2: HR=1.444, 95%CI: 1.029-2.028, P=0.034; group Q1: HR=1.570, 95%CI: 1.096-2.250, P=0.014). In the sensitivity analysis, using kidney transplantation as the competition event, the risk of cardiovascular events was lower in group Q3 than that in group Q1 (subdistributional HR=1.413, 95%CI: 1.006-1.990, P=0.046). Kaplan-Meier survival curve showed that compared with the other two groups, the cardiovascular events-free survival rate of patients in group Q1 was significantly lower (log-rank χ2=9.722, P=0.008). ROC analysis showed that the area under the curve (AUC) of HCT for predicting cardiovascular events in PD patients was 0.583 (95%CI: 0.542-0.623, P<0.001), with the sensitivity of 40.6% and the specificity of 75.1%. Conclusion: Low-level HCT is associated with an increased risk of the first cardiovascular event in PD patients.

Cleavage-independent activation of ancient eukaryotic gasdermins and structural mechanisms

Gasdermins (GSDMs) are pore-forming proteins that execute pyroptosis for immune defense. GSDMs are two-domain proteins activated by proteolytic removal of the inhibitory domain. In this work, we report two types of cleavage-independent GSDM activation. First, TrichoGSDM, a pore-forming domain-only protein from the basal metazoan Trichoplax adhaerens, is a disulfides-linked autoinhibited dimer activated by reduction of the disulfides. The cryo-electron microscopy (cryo-EM) structure illustrates the assembly mechanism for the 44-mer TrichoGSDM pore. Second, RCD-1-1 and RCD-1-2, encoded by the polymorphic regulator of cell death-1 (rcd-1) gene in filamentous fungus Neurospora crassa, are also pore-forming domain-only GSDMs. RCD-1-1 and RCD-1-2, when encountering each other, form pores and cause pyroptosis, underlying allorecognition in Neurospora. The cryo-EM structure reveals a pore of 11 RCD-1-1/RCD-1-2 heterodimers and a heterodimerization-triggered pore assembly mechanism. This study shows mechanistic diversities in GSDM activation and indicates versatile functions of GSDMs.

Radiomics-based distinction of small (≤2 cm) hepatocellular carcinoma and precancerous lesions based on unenhanced MRI

AIM

To assess the feasibility of a radiomics model based on unenhanced magnetic resonance imaging (MRI) to differentiate small hepatocellular carcinoma (S-HCC) (≤2 cm) and pre-hepatocellular carcinoma (Pre-HCC).

MATERIALS AND METHODS

One hundred and fourteen histopathologically confirmed 114 hepatic nodules were analysed retrospectively. All patients had undergone MRI before surgery using a 3 T MRI system. Each nodule was segmented on unenhanced MRI sequences (T1-weighted imaging [T1] and T2WI with fat-suppression [FS-T2]). Radiomics features were extracted and the optimal features were selected using the least absolute shrinkage and selection operator (LASSO). The support vector machine (SVM) was used to establish the radiomics model. One abdominal radiologist performed the conventional qualitative analysis for classification of S-HCC and Pre-HCC. The diagnostic performances of the radiomics and radiologist models were evaluated using receiver operating characteristic (ROC) analysis.

RESULT

Radiomics features (n=1,223) were extracted from each sequence and the optimal features were selected from T1, FS-T2, and T1+FS-T2 to construct the radiomics models. The radiomics model based on T1+FS-T2 showed the best performance among the three models, with areas under the ROC curves (AUCs) of 0.95 (95 % confidence interval [CI], 0.875-0.986) and 0.942 (95 % CI, 0.775-0.985), accuracies of 86 % and 88.5 %, sensitivities of 94.12 % and 100 %, and specificities of 85.48 % and 85.19 %, respectively. The radiomics model on FS-T2 showed better performance on a single sequence than that of the T1-based model. The diagnostic performance for the radiomic model was significantly higher than that for the radiologist (AUC = 0.518, p<0.05).

CONCLUSION

This study suggested that a radiomics model based on unenhanced MRI may serve as a feasible and non-invasive tool to classify S-HCC and Pre-HCC.

Spatial-temporal trends in leprosy burden and its associations with socioeconomic and physical geographic factors: results from the Global Burden of Disease Study 2019

OBJECTIVES

The purpose of our study was to assess the multiscalar changes in leprosy burden and its associated risk factors over the last three decades.

STUDY DESIGN

We conducted an in-depth examination of leprosy's spatial-temporal trends at multiple geographical scale (global, regional, and national), utilizing information from Global Burden of Disease, Injuries, and Risk Factors Study (GBD 2019).

METHODS

Incidence and the estimated annual percentage change (EAPC) in age-standardized incidence rate (ASIR) of leprosy were determined, with countries categorized based on leprosy incidence changes. We examined socioeconomic and physical geography influences on leprosy incidence via Spearman correlation analysis, using ternary phase diagrams to reveal the synergetic effects on leprosy occurrence.

RESULTS

Globally, incident cases of leprosy decreased by 27.86% from 1990 to 2019, with a reduction in ASIR (EAPC = -2.53), yet trends were not homogeneous across regions. ASIR and EAPC correlated positively with sociodemographic index (SDI), and an ASIR growth appeared in high SDI region (EAPC = 3.07). Leprosy burden was chiefly distributed in Tropical Latin America, Oceania, Central Sub-Saharan Africa, and South Asia. Negative correlations were detected between the incidence of leprosy and factors of SDI, GDP per capita, urban population to total population, and precipitation, whereas the number of refugee population, temperature, and elevation showed opposite positive results.

CONCLUSIONS

Despite a global decline in leprosy over the past three decades, the disparities of disease occurrence at regional and national scales still persisted. Socioeconomic and physical geographic factors posed an obvious influence on the transmission risk of leprosy. The persistence and regional fluctuations of leprosy incidence necessitate the ongoing dynamic and multilayered control strategies worldwide in combating this ancient disease.

Dissecting caspase-2-mediated cell death: from intrinsic PIDDosome activation to chemical modulation

Caspase-2, a highly conserved member of the caspase family, is considered an initiator caspase that triggers apoptosis in response to some cellular stresses. Previous studies suggest that an intracellular multi-protein complex PIDDosome, induced by genotoxic stress, serves as a platform for caspase-2 activation. However, due to caspase-2's inability to process effector caspases, the mechanism underlying caspase-2-mediated cell death upon PIDDosome activation remains unclear. Here we conducted an unbiased genome-wide genetic screen and identified that the Bcl2 family protein BID is required for PIDDosome-induced, caspase-2-mediated apoptosis. PIDDosome-activated caspase-2 directly and functionally processes BID to signal the mitochondrial pathway for apoptosis induction. Additionally, a designed chemical screen identified a compound, HUHS015, that specifically activates caspase-2-mediated apoptosis. HUHS015-stimulated apoptosis also requires BID but is independent of the PIDDosome. Through extensive structure-activity relationship efforts, we identified a derivative with a potency of ~ 60 nmol/L in activating caspase-2-mediated apoptosis. The HUHS015-series of compounds act as efficient agonists that directly target the interdomain linker in caspase-2, representing a new mode of initiator caspase activation. Human and mouse caspase-2 differ in two crucial residues in the linker, rendering a selectivity of the agonists for human caspase-2. The caspase-2 agonists are valuable tools to explore the physiological roles of caspase-2-mediated cell death and a base for developing small-molecule drugs for relevant diseases.

Erratum to: Association between Modifiable Risk Factors and Levels of Blood-Based Biomarkers of Alzheimer's and Related Dementias in the Look AHEAD Cohort

[This corrects the article DOI: 10.14283/jarlife.2024.1.].

Protective Effects of Aspirin Supplemented With Quercetin in L-NAME-Induced Preeclampsia-Like Rats

Aspirin supplemented with quercetin was reported to enhance the therapeutic effects of aspirin in a rat model of preeclampsia. In this study, the underlying mechanisms were further explored. Preeclampsia was induced by L-NAME (50 mg/kg/day) via oral gavage from gestation day (GD)14 to GD19. Aspirin (1.5 mg/kg/day) administration was performed using aspirin mixed with rodent dough from GD0 to GD19. The administration of quercetin (2 mg/kg/day) was performed by intraperitoneal infusion from GD0 to GD19. Protein levels were evaluated using ELISA or Western blot, and microRNA (miRNA) level was evaluated by RT-PCR. Aspirin supplemented with quercetin ameliorated the increase of systolic blood pressure (SBP), proteinuria, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels, and improved the pregnancy outcomes in preeclampsia rats. Aspirin supplemented with quercetin inhibited miR-155 expression in preeclampsia rats. The decreased miR-155 level in placenta further increased the protein level of SOCS1 and inhibited the phosphorylation of p65. In this study, we demonstrated that aspirin supplemented with quercetin enhanced the effects of aspirin for the treatment of preeclampsia.

Prediction of Fuhrman grade of renal clear cell carcinoma by multimodal MRI radiomics: a retrospective study

AIM

To explore the value of multimodal magnetic resonance imaging (MRI) radiomics combined with traditional radiologist-defined semantic characteristics and conventional (cMRI) and functional MRI (fMRI) texture features in predicting Fuhrman grade of clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

The data of 89 patients with histopathologically proven ccRCC (low-grade, 54; high-grade, 35) were collected. Texture features were extracted from cMRI (T1- and T2-weighted imaging) and fMRI (Dixon-MRI; blood-oxygen-level dependent [BOLD]-MRI; and susceptibility-weighted imaging [SWI]) images, and the traditional characteristics (TC) were evaluated. Logistic regression analysis was performed to develop models based on TC, cMRI, and fMRI texture features for grading. Receiver operating characteristic (ROC) curve analysis and leave-group-out cross-validation (LGOCV) were performed to test the reliability of combined models.

RESULTS

Two T2-weighted imaging-based, two Dixon_W-based, one Dixon_F-based, one BOLD-based, and three SWI-based texture features, and three TC were extracted for feature selection. TC, cMRI, fMRI, cMRI+fMRI, cMRI+TC, fMRI+TC, and cMRI+fMRI+TC models were constructed. The AUC of the cMRI+fMRI+TC model for differentiating high- from low-grade ccRCC was 0.74, with 81.42% accuracy, 75.93% sensitivity, and 91.43% specificity. The fMRI+TC model exhibited a performance similar to that of the cMRI+fMRI+TC model (p>0.05). The areas under the curve (AUCs) of the fMRI+TC and cMRI+fMRI+TC models were significantly higher than those of the other five models (all p<0.05). For the cMRI+fMRI+TC model, the mean accuracy was 85.40% after 100 LGOCV for the test sets.

CONCLUSION

Multimodal MRI radiomics combined with TC, cMRI, and fMRI texture features may be a reliable quantitative approach for differentiating high-grade ccRCC from low-grade ccRCC.

Association between Modifiable Risk Factors and Levels of Blood-Based Biomarkers of Alzheimer's and Related Dementias in the Look AHEAD Cohort

Background

Emerging evidence suggests that a number of factors can influence blood-based biomarker levels for Alzheimer's disease (AD) and Alzheimer's related dementias (ADRD). We examined the associations that demographic and clinical characteristics have with AD/ADRD blood-based biomarker levels in an observational continuation of a clinical trial cohort of older individuals with type 2 diabetes and overweight or obesity.

Methods

Participants aged 45-76 years were randomized to a 10-year Intensive Lifestyle Intervention (ILI) or a diabetes support and education (DSE) condition. Stored baseline and end of intervention (8-13 years later) plasma samples were analyzed with the Quanterix Simoa HD-X Analyzer. Changes in Aβ42, Aβ40, Aβ42/Aβ40, ptau181, neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) were evaluated in relation to randomization status, demographic, and clinical characteristics.

Results

In a sample of 779 participants from the Look AHEAD cohort, we found significant associations between blood-based biomarkers for AD/ADRD and 15 of 18 demographic (age, gender, race and ethnicity, education) and clinical characteristics (APOE, depression, alcohol use, smoking, body mass index, HbA1c, diabetes duration, diabetes treatment, estimated glomerular filtration rate, hypertension, and history of cardiovascular disease) .

Conclusions

Blood-based biomarkers of AD/ADRD are influenced by common demographic and clinical characteristics. These factors should be considered carefully when interpreting these AD/ADRD blood biomarker values for clinical or research purposes.

V-ATPase recruitment to ER exit sites switches COPII-mediated transport to lysosomal degradation

Endoplasmic reticulum (ER)-phagy is crucial to regulate the function and homeostasis of the ER via lysosomal degradation, but how it is initiated is unclear. Here we discover that Z-AAT, a disease-causing mutant of α1-antitrypsin, induces noncanonical ER-phagy at ER exit sites (ERESs). Accumulation of misfolded Z-AAT at the ERESs impairs coat protein complex II (COPII)-mediated ER-to-Golgi transport and retains V0 subunits that further assemble V-ATPase at the arrested ERESs. V-ATPase subsequently recruits ATG16L1 onto ERESs to mediate in situ lipidation of LC3C. FAM134B-II is then recruited by LC3C via its LIR motif and elicits ER-phagy leading to efficient lysosomal degradation of Z-AAT. Activation of this ER-phagy mediated by the V-ATPase-ATG16L1-LC3C axis (EVAC) is also triggered by blocking ER export. Our findings identify a pathway which switches COPII-mediated transport to lysosomal degradation for ER quality control.

Recognition and maturation of IL-18 by caspase-4 noncanonical inflammasome

The canonical (caspase-1) and noncanonical (comprising caspases 4, 5 and 11; hereafter, caspase-4/5/11) inflammasomes both cleave gasdermin D (GSDMD) to induce pyroptosis1,2. Whereas caspase-1 processes IL-1β and IL-18 for maturation3-6, no cytokine target has been firmly established for lipopolysaccharide-activated caspase-4/5/117-9. Here we show that activated human caspase-4, but not mouse caspase-11, directly and efficiently processes IL-18 in vitro and during bacterial infections. Caspase-4 cleaves the same tetrapeptide site in pro-IL-18 as caspase-1. The crystal structure of the caspase-4-pro-IL-18 complex reveals a two-site (binary) substrate-recognition mechanism; the catalytic pocket engages the tetrapeptide, and a unique exosite that critically recognizes GSDMD10 similarly binds to a specific structure formed jointly by the propeptide and post-cleavage-site sequences in pro-IL-18. This binary recognition is also used by caspase-5 as well as caspase-1 to process pro-IL-18. In caspase-11, a structural deviation around the exosite underlies its inability to target pro-IL-18, which is restored by rationally designed mutations. The structure of pro-IL-18 features autoinhibitory interactions between the propeptide and the post-cleavage-site region, preventing recognition by the IL-18Rα receptor. Cleavage by caspase-1, -4 or -5 induces substantial conformational changes of IL-18 to generate two critical receptor-binding sites. Our study establishes IL-18 as a target of lipopolysaccharide-activated caspase-4/5. The finding is paradigm shifting in the understanding of noncanonical-inflammasome-mediated defences and also the function of IL-18 in immunity and disease.

Effects of Bacillus pumilus on growth performance, serum indexes and muscle development-related gene expression of weanling Jintang black goat

Antibiotic misuse has been a severe problem in animal husbandry. It is meaningful to replace antibiotics with Bacillus, as feed additives are indeed a research hotspot. Bacillus pumilus plays a certain role in promoting the growth performance and immunological indicators of animals. There are few reports about the function of goat-derived B. pumilus in animals until now. This study aimed to investigate the effects of B. pumilus fsznc-09 on growth performance and immune function of Jintang black goats. B. pumilus-treated group was fed with 1 ml freeze-dried agent of B. pumilus fsznc-09 at a concentration of 109 cfu/ml every 2 days. The growth performance, serum biochemical indexes, the expressions of muscle development and metabolism related genes of Jintang black goats were measured after 30 days. The results showed that the average daily gain and average daily feed intake were significantly increased, and feed conversion ratio was significantly decreased. The activities of total superoxide dismutase, alkaline phosphatase, immunoglobulin G and interferon-γ in serum of goats were significantly increased. However, the activity of malondialdehyde in serum was significantly decreased. The diameters and areas in longissimus dorsi fibre and gluteus fibre of goats were significantly decreased, while the densities in gluteus fibre of goats were significantly increased. The expressions of FAS, LPL, PPAR-γ, CAT, MYOD1, MYOG, MYF5 and MyHCI in longissimus dorsi and gluteus of goats were significantly improved. The expressions of TGFβ1, SREBP-1, MyHCIIb and MyHCIIx in longissimus dorsi and gluteus of goats were significantly increased. The expressions of FN1 in longissimus dorsi and MyHCIIa in gluteus of goats were significantly decreased. In conclusion, B. pumilus fsznc-09 can effectively improve the growth performance, immunological indicators and the expressions of muscle development and metabolism related genes of Jintang black goat.

[Safety and efficacy of yellow zebra guide wire exchange system in the treatment of complete upper digestive stenosis]

To investigate the efficacy and safety of yellow zebra guide wire exchange system in the treatment of complete upper digestive stenosis. To analyze the success rate and adverse events, a retrospective analysis was conducted on patients with complete digestive stenosis in Zhongda Hospital Affiliated to Southeast University from May 2019 to April 2023 and the First Affiliated Hospital of Nanjing Medical University from August 2011 to March 2015. A total of 41 patients were included, including 25 males and 16 females, aged (65±12) years (28-94 years). Among them, 40 patients were successfully inserted with yellow zebra guide wire and underwent endoscopic treatment using the outer tube replacement with hard steel wire, with 97.6% (40/41) effective rate. Eleven patients (27.5%) were accompanied by varying degrees of retrosternal pain, without complications such as bleeding or perforation.

[Efficacy analysis of surgical combined with postoperative adjuvant therapy for T3 gallbladder carcinoma: a multicenter retrospective study]

Objective: To explore the clinical value of adjuvant therapy in patients with T3 gallbladder cancer (GBC) who have undergone R0 resection. Methods: Clinical and pathological data from 415 patients with T3 GBC who underwent surgical treatment in 7 tertiary centers in China from January 2013 to December 2018 were collected,including 251 males and 164 females,aged (61±11)years (range: 26 to 88 years). Depending on whether to receive adjuvant therapy after radical resection,the patients were divided into the radical resection group alone (group A,n=358) and the radical resection combined with the postoperative adjuvant therapy group (group B,n=57). The general data of the two groups were matched 1∶1 by propensity score matching method,and the caliper value was 0.02.Clinicopathological characteristics,overall survival and disease-free survival of the two groups were compared.The Cox regression model was used for multivariate analysis,and patients with at least one or more independent risk factors were classified as high-risk clinicopathological subtypes. Subgroup analysis was performed to assess the clinical value of adjuvant therapy after radical resection in patients with high-risk clinicopathological subtypes. Results: After the matching,there were 42 patients in each of the two groups. The incidence of gallbladder cancer and the number of dissected lymph nodes in group B after cholecystectomy were higher than those in group A (χ2=9.224,2.570,both P<0.05). There were no significant differences in overall survival rate and disease-free survival rate between the two groups before and after matching (all P>0.05). The results of the univariate and multivariate analysis showed that CA19-9>39 U/ml,nerve invasion,tumor location (liver side or bilateral),TNM stage ⅢB to ⅣB ,poorly differentiated tumor were independent prognostic factors of overall survival and disease-free survival of patients with T3 stage gallbladder cancer (all P<0.05).Three hundred and twenty-nine patients(79.3%) had high-risk clinicopathological subtypes,and the median survival time after curative resection with and without adjuvant therapy was 17 months and 34 months respectively,and the 3-year and 5-year overall survival rates were respectively 40.0%,21.3% and 46.0%,46.0% (χ2=4.042,P=0.044);the median disease-free survival time was 9 months and 13 months,and the 3-year and 5-year disease-free survival rates were 23.4%,13.6% and 30.2%,18.2% (χ2=0.992,P=0.319). Conclusions: Postoperative adjuvant therapy following radical surgery did not yield significant improvements in the overall survival and disease-free survival rates of patients diagnosed with T3 gallbladder cancer. However, it demonstrated a significant extension in the overall survival rate for patients presenting high-risk clinicopathological subtypes.

Computing Geographical Networks Generated by Air-Mass Movement

As air masses move within the troposphere, they transport a multitude of components including gases and particles such as pollen and microorganisms. These movements generate atmospheric highways that connect geographic areas at distant, local, and global scales that particles can ride depending on their aerodynamic properties and their reaction to environmental conditions. In this article we present an approach and an accompanying web application called tropolink for measuring the extent to which distant locations are potentially connected by air-mass movement. This approach is based on the computation of trajectories of air masses with the HYSPLIT atmospheric transport and dispersion model, and on the computation of connection frequencies, called connectivities, in the purpose of building trajectory-based geographical networks. It is illustrated for different spatial and temporal scales with three case studies related to plant epidemiology. The web application that we designed allows the user to easily perform intensive computation and mobilize massive archived gridded meteorological data to build weighted directed networks. The analysis of such networks allowed us for example, to describe the potential of invasion of a migratory pest beyond its actual distribution. Our approach could also be used to compute geographical networks generated by air-mass movement for diverse application domains, for example, to assess long-term risk of spread from persistent or recurrent sources of pollutants, including wildfire smoke.

Auto-Correction for Inaccurate Auto-Segmentation of Abdominal MRI by Combining Deep Learning and Active Contour Method

PURPOSE/OBJECTIVE(S)

Fast and accurate auto-segmentation is crucial during the magnetic resonance-guided adaptive radiation therapy (MRgART). Deep learning auto-segmentation (DLAS) approaches do not always result in clinically acceptable contours, especially for complex abdominal organs. We have previously reported that the inaccurate DLAS for bowels can be refined using deep learning (DL) and/or active contour method (ACM). This study aims to develop an automatic contour correction (ACC) tool by combining DL and ACM techniques to correct for inaccurate DLAS of pancreas and stomach on MRI.

MATERIALS/METHODS

The ACC technique consisted of ACM and DL based on UNet system. The ACM utilizes the probability maps generated from DLAS models to establish 2D parameter maps and to initialize contour evolution, thus not requiring initial parameter adjustments. The Organ specific DL-UNet models were trained for pancreas and stomach contours obtained from a research DLAS tool on abdominal MRIs acquired during routine MRgART from a 1.5T MR-Linac using either turbo field-echo or balanced turbo field-echo sequences. The training dataset contained MR slices along with DLAS and ground truth contours from 54 abdominal MRL sets, and 540 additional augmented sets created by shifting and rotating. DLAS contours were classified based on the expected editing effort into the acceptable, minor edit, or major edit category using an in-house developed classification model. Performance of the obtained ACC models were tested on an independent dataset of 11 sets of abdominal MRIs.

RESULTS

For pancreas, the DL-UNet model improved 17% (26/153) and 2% (2/95) of the minor and major edits' slices of the testing dataset, respectively, to acceptable and 39% (37/95) of the major edit slices improved to minor edits. The ACM model improved 3% (4/153) of the minor edit slices to acceptable and the 36% (34/95) of the major slices to minor edits. Using the ACC technique with DL and ACM combined, the percentage of acceptable contours increased from 10% (29/277) to 24% (66/277), and minor edits from 55% (153/277) to 61% (170/277), while the percentage of the major edit slices reduced from 35% (95/277) to 15% (41/277). For stomach, the DL model improved 8% (29/366) of the minor edit slices to acceptable and 50% (16/32) of the major edit slices to minor edit slices. The ACM resulted in 2% (6/366) of minor edit slices to acceptable and 41% (13/32) of major edit slices to minor category. Combining both the DL and ACM, the overall percentage of acceptable stomach contours grew from 13% (58/456) to 22% (101/456) and the percentage of major edit slices reduced from 7% (32/456) to 2% (11/456).

CONCLUSION

The ACC method combining both DL and ACM models can substantially improve the quality of inaccurate DLAS contours of pancreas and stomach in a fully automated and fast manner, minimizing the subsequent manual editing time required for MRgART.

Clinical Usability-Oriented Automatic Contour Quality Evaluation for Deep Learning Auto-Segmentation

PURPOSE/OBJECTIVE(S)

Various auto-segmentations, including deep learning auto-segmentation (DLAS), are being increasingly adopted in radiotherapy. A common method to evaluate quality of auto-segmented contours uses thresholds of various quantitative metrics (e.g., dice similarity coefficient (DSC), mean distance to agreement (MDA), etc.) that are often averaged over all contour slices. This method fails to detect contour errors on individual slices, thus, does not reflect the current clinical practice (slice-by-slice evaluation) and the clinical usability (e.g., expected contour editing time). In addition, the use of multi-metrics is generally not easy to interpret. This work aims to develop a novel contour quality classification (CQC) model to evaluate auto-segmented contours based on their clinical applicability.

MATERIALS/METHODS

The CQC method was designed to classify a contour on a slice into acceptable, minor edit or major edit category, based on the expected editing effort/time. Organ-specific supervised ensemble tree classification models were trained to relate the slice-based quality category with the combination of seven commonly used calculatable quantitative metrics (i.e., DSC, MDA, Hausdorff 95% distance, surface DSC, added path length (APL), slice area and relative APL). The proposed method was demonstrated by training CQC models using DLAS contours of five abdominal organs (i.e., pancreas, duodenum, stomach, and small and large bowels) from 50 MRI sets and evaluating on 20 MRI and 9 CT testing sets. These test datasets were labelled by six individual observers and the consensus labels were generated through majority vote method. The model performance was evaluated using accuracy (acc), and risk rate (RR, the percentage of unacceptable slices mislabeled as acceptable) and compared with inter-observer variation and baseline threshold-based method.

RESULTS

Compared to the majority vote labels, the obtained CQC models achieved a mean accuracy of 95.8% ([94.5%-99.1%]) and 94.3% ([90.6%-96.9%]), and the mean RR of 0.8% ([0.3%-1.3%]) and 0.7% ([0%-1.1%]) for the MRI and CT testing sets, respectively. The CQC performance was comparable to the inter-observer variation and significantly higher than those from the threshold-based method with single or multiple metrics. The execution time on a typical abdominal dataset (e.g., 70 slices) took less than 3 seconds. Table 1 CQC models performance for different organs CONCLUSION: The proposed CQC model can classify the quality of a contour slice with high accuracy. This slice-based single-output evaluation method better reflects the current clinical practice and may be used to evaluate/compare performance of DLAS on any image modality, facilitating its clinical implementation and quality assurance.

Organ Specific Deep Learning-Based Correction of Inaccurate Auto-Segmentation on Abdominal MRI

PURPOSE/OBJECTIVE(S)

Deep learning-based automatic segmentation (DLAS) techniques offer limited success for abdominal organs on MRI, requiring substantial editing time. We have previously developed a deep learning based automatic contour correction (ACC) technique that can correct for inaccurate DLAS contours of bowels on MRI, reducing the manual editing time in MR-guided online adaptive radiation therapy (MRgART). This study aims to develop deep learning-based ACC models for pancreas and duodenum that are particularly difficult to contour either manually or with DLAS.

MATERIALS/METHODS

Dense UNet, a deep learning algorithm that combines UNet with dense blocks, was trained to create ACC models. Organ-specific models were trained for pancreas and duodenum contours obtained from a research DLAS tool on MRIs from a 1.5T MR-Linac. The training dataset contained MRI slices paired with DLAS contours from 54 abdominal MRL sets along with ground truth contours and 540 additional augmented sets created by shifting, rotating, and scaling each organ along with the contours and varying the noise and bias field for each patient set. Each DLAS contour was classified into the acceptable (no additional edits required), minor edit (only simple edits required), or major edit category based on the expected editing effort determined using a contour classification model developed in a separate study. The ACC models were trained for the slices requiring minor edit and major edit separately. Performance of the obtained models were tested using an independent 11 MRI sets in term of the change of contour category based on the contour classification model.

RESULTS

After applying the duodenum ACC model to the testing datasets, 16% (27/165) and 5% (8/178) of the minor and major edits' slices, respectively, improved to acceptable and 31% (54/178) of the major edit slices improved to minor edits. Furthermore, the total percentage of acceptable contours grew from 10% (36/378) to 19% (71/378) and the percentage of the major edit slices reduced from 47% (178/378) to 30% (115/378). After applying the pancreas ACC model to the testing datasets, 32% (47/143) and 1% (1/96) of the minor and major edits' slices, respectively, improved to acceptable and 49% (47/96) of the major edit slices improved to minor edit slices. Furthermore, the total percentage of acceptable contours grew from 14% (38/277) to 31% (86/277) and the percentage of major edit slices reduced from 35% (96/277) to 17% (48/277).

CONCLUSION

Deep learning based automatic contour corrections can substantially improve inaccurate DLAS contours of pancreas and duodenum on MRI that would otherwise require time-consuming edits, resulting in less manual intervention and increased efficiency during MRgART.

Frequency-Dependent Squeezed Vacuum Source for the Advanced Virgo Gravitational-Wave Detector

In this Letter, we present the design and performance of the frequency-dependent squeezed vacuum source that will be used for the broadband quantum noise reduction of the Advanced Virgo Plus gravitational-wave detector in the upcoming observation run. The frequency-dependent squeezed field is generated by a phase rotation of a frequency-independent squeezed state through a 285 m long, high-finesse, near-detuned optical resonator. With about 8.5 dB of generated squeezing, up to 5.6 dB of quantum noise suppression has been measured at high frequency while close to the filter cavity resonance frequency, the intracavity losses limit this value to about 2 dB. Frequency-dependent squeezing is produced with a rotation frequency stability of about 6 Hz rms, which is maintained over the long term. The achieved results fulfill the frequency dependent squeezed vacuum source requirements for Advanced Virgo Plus. With the current squeezing source, considering also the estimated squeezing degradation induced by the interferometer, we expect a reduction of the quantum shot noise and radiation pressure noise of up to 4.5 dB and 2 dB, respectively.

[Characteristics of Guyton's exaggerated forced duction test (FDT) and torsional FDT in congenital superior oblique palsy]

Objective: To investigate the characteristics of Guyton's exaggerated forced duction test (FDT) and torsional FDT in patients with congenital superior oblique palsy (CSOP) and their correlation with clinical features. Methods: This cross-sectional study included single-eye CSOP patients and intermittent exotropia (IXT) patients scheduled for strabismus correction surgery at Tianjin Eye Hospital from September 2021 to March 2022. Prior to surgery, measurements of fovea-disc angle (FDA) and maximum cross-sectional area of the superior oblique muscle (max-CSA) were obtained in both eyes of the patients. The Guyton's exaggerated FDT and torsional FDT were performed intraoperatively to assess the degree of superior oblique muscle relaxation. The characteristics of the two FDT tests and their correlation with vertical strabismus angle, FDA, and max-CSA were analyzed. Statistical analyses were conducted using t-test, ANOVA, Tukey's test, Mann-Whitney U test, and chi-square test. Results: A total of 42 patients (84 eyes) were included in the study, including 19 IXT patients (38 eyes) and 23 CSOP patients (46 eyes, 23 eyes with palsy and 23 eyes without palsy). There were no statistically significant differences in gender composition or age between the IXT and CSOP patients (all P>0.05). The degrees of superior oblique muscle relaxation measured by the Guyton's exaggerated FDT were (-2.52±1.20), (-0.35±0.71), and (-0.03±0.16) for the palsy eye, non-palsy eye, and IXT eyes, respectively, showing significant differences (F=88.10, P<0.001). The torsional FDT measurements yielded external rotation angles of 48.70°±9.67°, 37.39°±5.40°, and 38.95°±2.88° for the palsy eye, non-palsy eye, and IXT eyes, respectively, showing significant differences (F=16.67, P<0.001). There was no statistically significant difference in internal rotation angles (F=2.36, P=0.100). The FDA values were-12.11°±7.42° for IXT patients and-19.02°±4.95° for CSOP patients, while the max-CSA values for the palsy eye and non-palsy eye of CSOP patients were (7.59±4.69) mm² and (11.63±3.64) mm², respectively, all showing significant differences (all P<0.001). The degree of superior oblique muscle tendon relaxation assessed by the Guyton's exaggerated FDT was negatively correlated with the external rotation angle measured by the torsional FDT (r=-0.64, P=0.001). They were positively correlated with max-CSA (r=0.45, P=0.030) and negatively correlated with max-CSA (r=-0.52, P=0.011). However, there was no correlation with vertical and rotational strabismus angle (r=-0.12, P=0.579; r=0.33, P=0.126) and FDA (r=-0.02, P=0.921; r=-0.23, P=0.309). Conclusions: Guyton's exaggerated FDT and torsional FDT can both assess the degree of superior oblique muscle relaxation in patients with CSOP. Furthermore, these two tests are correlated with changes in superior oblique muscle morphology. However, FDT cannot reflect the degree of vertical and rotational strabismus in patients.

Daytime Sleepiness Is Associated with Lower Cognitive Scores: The Look AHEAD Study

Background

Daytime sleepiness is common in older adults and may result from poor nighttime sleep due to sleep disordered breathing, fragmented sleep, or other sleep disorders. Daytime sleepiness may be associated with cognition in older adults.

Objectives

We investigated the association between self-reported daytime sleepiness and cognitive function in the Look AHEAD clinical trial.

Design

Observational follow-up of a randomized clinical trial of an intensive lifestyle intervention.

Setting

Clinic.

Participants

Participants (n=1,778) aged 45-76 years at baseline with type 2 diabetes and overweight or obesity.

Interventions

Participants were randomized to an intensive lifestyle intervention for weight loss or a control condition of diabetes support and education.

Measurements

Participants provided self-reported levels of daytime sleepiness at baseline and years 12-13. Cognitive function was assessed with a neurocognitive battery at years 12-13 and 18-20.

Results

Participants who reported having frequent daytime sleepiness (often or always) performed significantly worse than others on the cognitive composite (-0.35; p-value=0.014) after controlling for covariates. When stratified by intervention arm, participants assigned to the intensive lifestyle intervention who reported often/always having daytime sleepiness performed worse on Digit Symbol Coding (-0.63; p-value=0.05) and Trail Making Part-B (-0.56; p-value=0.02) after controlling for covariates. Statistical interactions revealed associations between daytime sleepiness and the following covariates: race and ethnicity, APOE ε4 carrier status, baseline history of cardiovascular disease, and depression.

Conclusions

Daytime sleepiness over ~13 years predicted poorer cognitive performance in older individuals who, by virtue of having diabetes and overweight/obesity, are at high risk for sleep disorders and cognitive impairment.

Resilience in adolescence during the COVID-19 crisis in Canada

BACKGROUND

The COVID-19 pandemic constitutes a social crisis that will have long-term health consequences for much of the global population, especially for adolescents. Adolescents are triply affected as they: 1) are experiencing its immediate, direct effects, 2) will carry forward health habits they develop now into adulthood, and 3) as future parents, will shape the early life health of the next generation. It is therefore imperative to assess how the pandemic is influencing adolescent wellbeing, identify sources of resilience, and outline strategies for attenuating its negative impacts.

METHODS

We report the results of longitudinal analyses of qualitative data from 28 focus group discussions (FGDs) with 39 Canadian adolescents and of cross-sectional analyses of survey data from 482 Canadian adolescents gathered between September 2020 and August 2021. FGD participants and survey respondents reported on their: socio-demographic characteristics; mental health and wellbeing before and during the pandemic; pre- and during-pandemic health behaviours; experiences living through a crisis; current perceptions of their school, work, social, media, and governmental environments; and ideas about pandemic coping and mutual aid. We plotted themes emerging from FGDs along a pandemic timeline, noting socio-demographic variations. Following assessment for internal reliability and dimension reduction, quantitative health/wellbeing indicators were analyzed as functions of composite socio-demographic, health-behavioural, and health-environmental indicators.

RESULTS

Our mixed methods analyses indicate that adolescents faced considerable mental and physical health challenges due to the pandemic, and were generally in poorer health than expected in non-crisis times. Nevertheless, some participants showed significantly better outcomes than others, specifically those who: got more exercise; slept better; were food secure; had clearer routines; spent more time in nature, deep in-person social relationships, and leisure; and spent less time on social media.

CONCLUSIONS

Support for youth during times of crisis is essential to future population health because adolescence is a period in the life course which shapes the health behaviours, socio-economic capacities, and neurophysiology of these future parents/carers and leaders. Efforts to promote resilience in adolescents should leverage the factors identified above: helping them find structure and senses of purpose through strong social connections, well-supported work and leisure environments, and opportunities to engage with nature.

[High-fat intake alleviates lung injury induced by Paragonimus proliferus infection in rats through up-regulating CYP 4A1 expression in lung tissues]

OBJECTIVE

To explore the improvements of high-fat intake on lung injury induced by Paragonimus proliferus infection in rats, and to preliminarily explore the mechanisms underlying the role of cytochrome P450 4A1 (CYP 4A1) in the improve ments.

METHODS

SD rats were randomly assigned into three groups, including the normal control group (n = 10), the infection and normal diet group (n = 12) and the infection and high-fat diet group (n = 12). Rats in the normal control group were fed with normal diet and without any other treatments, and animals in the infection and normal diet group were subcutaneously injected with 8 excysted metacercariae of P. proliferus via the abdominal wall, followed by feeding with normal diet, while rats in the infection and high-fat diet group were subcutaneously injected with 8 excysted metacercariae of P. proliferus via the abdominal wall, followed by feeding with high-fat diet. All rats were sacrificed 28 weeks post-infection, and serum samples and lung specimens were collected. Following hematoxylin-eosin (HE) staining of rat lung specimens, the rat lung injury was observed under an optical microscope, and alveolitis was evaluated using semi-quantitative scoring. Serum interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) levels were measured using enzyme-linked immunosorbent assay (ELISA), and the cytochrome P450 4A1 (CYP 4A1) expression was quantified in rat lung specimens at transcriptional and translational levels using quantitative real-time PCR (qPCR) and Western blotting assays.

RESULTS

Alveolar wall thickening, edema and inflammatory cell infiltration were alleviated 28 weeks post-infection with P. proliferus in rats in the infection and high-fat diet group relative to the infection and normal diet group, and no alveolar consolidation was seen in the infection and high-fat diet group. The semi-quantitative score of alveolitis was significantly higher in the infection and normal diet group [(2.200 ± 0.289) points] than in the normal control group [(0.300 ± 0.083) points] and the infection and high-fat diet group [(1.300 ± 0.475) points] (both P values < 0.05), and higher serum IL-1β [(151.586 ± 20.492)] pg/mL and TNF-α levels [(180.207 ± 23.379) pg/mL] were detected in the infection and normal diet group than in the normal control group [IL-1β: (103.226 ± 3.366) pg/mL; TNF-α: (144.807 ± 1.348) pg/mL] and the infection and high-fat diet group [IL-1β: (110.131 ± 12.946) pg/mL; TNF-α: (131.764 ± 27.831) pg/mL] (all P values < 0.05). In addition, lower CYP 4A1 mRNA (3.00 ± 0.81) and protein expression (0.40 ± 0.02) was quantified in lung specimens in the infection and normal diet group than in the normal control group [(5.03 ± 2.05) and (0.84 ± 0.14)] and the infection and high-fat diet group [(11.19 ± 3.51) and (0.68 ± 0.18)] (all P values < 0.05).

CONCLUSIONS

High-fat intake may alleviate lung injuries caused by P. proliferus infection in rats through up-regulating CYP 4A1 expression in lung tissues at both translational and transcriptional levels.

Structural mechanisms for regulation of GSDMB pore-forming activity

Cytotoxic lymphocyte-derived granzyme A (GZMA) cleaves GSDMB, a gasdermin-family pore-forming protein1,2, to trigger target cell pyroptosis3. GSDMB and the charter gasdermin family member GSDMD4,5 have been inconsistently reported to be degraded by the Shigella flexneri ubiquitin-ligase virulence factor IpaH7.8 (refs. 6,7). Whether and how IpaH7.8 targets both gasdermins is undefined, and the pyroptosis function of GSDMB has even been questioned recently6,8. Here we report the crystal structure of the IpaH7.8-GSDMB complex, which shows how IpaH7.8 recognizes the GSDMB pore-forming domain. We clarify that IpaH7.8 targets human (but not mouse) GSDMD through a similar mechanism. The structure of full-length GSDMB suggests stronger autoinhibition than in other gasdermins9,10. GSDMB has multiple splicing isoforms that are equally targeted by IpaH7.8 but exhibit contrasting pyroptotic activities. Presence of exon 6 in the isoforms dictates the pore-forming, pyroptotic activity in GSDMB. We determine the cryo-electron microscopy structure of the 27-fold-symmetric GSDMB pore and depict conformational changes that drive pore formation. The structure uncovers an essential role for exon-6-derived elements in pore assembly, explaining pyroptosis deficiency in the non-canonical splicing isoform used in recent studies6,8. Different cancer cell lines have markedly different isoform compositions, correlating with the onset and extent of pyroptosis following GZMA stimulation. Our study illustrates fine regulation of GSDMB pore-forming activity by pathogenic bacteria and mRNA splicing and defines the underlying structural mechanisms.