Force-induced tail-autotomy mitochondrial fission and biogenesis of matrix-excluded mitochondrial-derived vesicles for quality control

Mitochondria constantly fuse and divide for mitochondrial inheritance and functions. Here, we identified a distinct type of naturally occurring fission, tail-autotomy fission, wherein a tail-like thin tubule protrudes from the mitochondrial body and disconnects, resembling autotomy. Next, utilizing an optogenetic mitochondria-specific mechanostimulator, we revealed that mechanical tensile force drives tail-autotomy fission. This force-induced fission involves DRP1/MFF and endoplasmic reticulum tubule wrapping. It redistributes mitochondrial DNA, producing mitochondrial fragments with or without mitochondrial DNA for different fates. Moreover, tensile force can decouple outer and inner mitochondrial membranes, pulling out matrix-excluded tubule segments. Subsequent tail-autotomy fission separates the matrix-excluded tubule segments into matrix-excluded mitochondrial-derived vesicles (MDVs) which recruit Parkin and LC3B, indicating the unique role of tail-autotomy fission in segregating only outer membrane components for mitophagy. Sustained force promotes fission and MDV biogenesis more effectively than transient one. Our results uncover a mechanistically and functionally distinct type of fission and unveil the role of tensile forces in modulating fission and MDV biogenesis for quality control, underscoring the heterogeneity of fission and mechanoregulation of mitochondrial dynamics.

Using an ER-specific optogenetic mechanostimulator to understand the mechanosensitivity of the endoplasmic reticulum

The ability of cells to perceive and respond to mechanical cues is essential for numerous biological activities. Emerging evidence indicates important contributions of organelles to cellular mechanosensitivity and mechanotransduction. However, whether and how the endoplasmic reticulum (ER) senses and reacts to mechanical forces remains elusive. To fill the knowledge gap, after developing a light-inducible ER-specific mechanostimulator (LIMER), we identify that mechanostimulation of ER elicits a transient, rapid efflux of Ca2+ from ER in monkey kidney COS-7 cells, which is dependent on the cation channels transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and polycystin-2 (PKD2) in an additive manner. This ER Ca2+ release can be repeatedly stimulated and tuned by varying the intensity and duration of force application. Moreover, ER-specific mechanostimulation inhibits ER-to-Golgi trafficking. Sustained mechanostimuli increase the levels of binding-immunoglobulin protein (BiP) expression and phosphorylated eIF2α, two markers for ER stress. Our results provide direct evidence for ER mechanosensitivity and tight mechanoregulation of ER functions, placing ER as an important player on the intricate map of cellular mechanotransduction.

Experimental Study on Flame Chemical Composition of Coal and Ammonia Gas-Solid Jet in Flat Flame Burner

Ammonia as a fuel to partially or completely replace fossil fuels is one of the effective ways to reduce carbon dioxide, and the research on ammonia coal cocombustion is of great significance. The combustion characteristics of ammonia are very different from those of pulverized coal, resulting in the ignition and emission characteristics of ammonia and pulverized coal gas flow that is different from traditional pulverized coal flame. In this paper, the effect of pulverized coal concentration in coal and ammonia mixed combustion jet on the ignition distance and gas-phase components at different positions of the jet flame were studied experimentally on the flat flame burner, and the conditions of ignition and ignition stability of coal and ammonia gas-solid fuel were expounded. It was found that the ammonia mixed with pulverized coal changed the temperature field of the flat flame burner and therefore the ignition characteristics of the jet were changed. The ignition delay time at the same jet speed was positively correlated with the pulverized coal concentration, but when the pulverized coal concentration continued to decrease, the influence on the ignition delay time gradually became smaller. The composition of coal ammonia gas-solid fuel changed the heat transfer path and share during combustion, and finally, the flame temperature was negatively correlated with the concentration of pulverized coal. Therefore, the reduction of the pulverized coal concentration was conducive to the stable combustion of coal ammonia mixed fuel. When HAB = 100 mm, the conversion rate of fuel N to NOx per unit mass of coal ammonia mixture increased with the increase of pulverized coal concentration. The NOx production amount first increased and then decreased with the increase of pulverized coal concentration, and the amount of N2O and NO2 decreased rapidly with the increase of HAB. The proportion of NOx in NO exceeded 94%, which was conducive to achieving low nitrogen combustion of coal and ammonia gas-solid fuel. In general, the O2 concentration in the ammonia coal jet flame decreased, the flue gas temperature, and NOx and CO generation increased after mixing ammonia, and the optimal pulverized coal concentration in this experiment was 0.41 kgc/kga (mass ratio of pulverized coal to the sum of N2 and NH3).

Interpretable Machine Learning for Predicting Symptomatic Pneumonitis in Locally Advanced Non-Small Cell Lung Cancer Patients Treated with Concurrent Chemoradiotherapy and Immune Checkpoint Inhibitor Consolidation

PURPOSE/OBJECTIVE(S)

The rate of grade 2 and higher pneumonitis has increased with the use of immune checkpoint inhibitors (ICI) following chemoradiotherapy (CRT) for lung cancer, which may alter previously established dose-volume constraints (DVC). In this study, we used an interpretable machine learning model with clinical and dosimetric features to predict grade 2+ pneumonitis and determine DVC associated with pneumonitis for locally advanced non-small cell lung cancer (LA-NSCLC) radiotherapy (RT).

MATERIALS/METHODS

Between October 2017 and December 2021, 223 consecutively treated patients with LANSCLC treated with CRT and ICI were retrospectively reviewed. The dataset was split into training and test sets (n = 144/79). Clinical features included age, sex, smoking status, pack-years, BMI, ECOG PS, COPD, tumor location, delivered dose, RT technique, chemotherapy agent and volume of GTVp/GTVn. A total of 228 dosimetric features from the heart, contralateral/ipsilateral lung and lungs-IGTV were extracted, including the minimum/mean dose to the hottest x% volume (Dx%[Gy]/MOHx%[Gy]; x was 5-95 in 5% increments) and minimum/mean/maximum dose and percent volume receiving at least xGy (VxGy [%]; x was 5-60 in 5Gy increments), as well as the overlapping volume of each structure with PTV and the distance from each structure to GTVp/GTVn. Feature selection was performed using Boruta, followed by collinearity removal based on the variance inflation factor. The explainable boosting machine (EBM) was trained on the selected features. The performance of EBM on the test set was evaluated using the area under the receiver operating characteristic curve (AUC) and compared with that of blackbox (BB) models, including extreme gradient boosting (XGB), random forest (RF), and supporting vector machine (SVM). The global explanation of each feature's contribution to the predictions provided by the EBM was used to determine DVC. Shapley additive explanations (SHAP) were used to explain BB predictions.

RESULTS

Selected features, ranked in order of EBM's overall feature importance, were V25Gy [%] and MOH65%[Gy] in the ipsilateral lung, the maximum dose in the heart, MOH30%[Gy] in the contralateral lung, and BMI. No dosimetric features in the lungs-IGTV were selected. The SHAP values of three BB models showed similar trends to the feature importance of the EBM. The global explanations of the EBM suggested that to mitigate the risk of pneumonitis, the ipsilateral lung should have V25Gy [%] < 36.8% and MOH65%[Gy] < 39.5Gy, and the heart should have D0.03cc [Gy] < 66.0Gy. Furthermore, an increased risk of pneumonitis was indicated with an increase in BMI, and, surprisingly, a decrease in MOH30%[Gy] in the contralateral lung. The EBM showed the best performance for predicting grade 2+ pneumonitis (AUC = 0.739), followed by RF, SVM, and XGB (AUC = 0.735, 0.733, and 0.717).

CONCLUSION

EBM has the potential to predict grade 2+ pneumonitis in LA-NSCLC patients treated with CRT and ICI, while providing guidance on DVC.

Association of Cardiac Dose with Cardiac Events and Survival for Locally Advanced Non-Small Cell Lung Cancer (LA-NSCLC) Treated with Concurrent Chemoradiotherapy (cCRT) in the Era of Immune Checkpoint Inhibitor (ICI) Consolidation

PURPOSE/OBJECTIVE(S)

To assess the association of cardiac dose with post-cCRT cardiac events and survival among patients (pts) with LA-NSCLC after adoption of ICI consolidation, modern radiotherapy (RT) techniques, and data-driven cardiac constraints.

MATERIALS/METHODS

This single-institution, multi-site retrospective study included 335 pts with LA-NSCLC treated with definitive cCRT (60-70 Gy) from October 2017 to December 2021. Pts were evaluated for ICI consolidation. Cardiac dose constraints included heart volume receiving ≥50 Gy (V50) <25% and mean heart dose (MHD) <20 Gy. Heart, left anterior descending artery (LAD), and left ventricle were autocontoured, manually reviewed, and edited. 21 dosimetric parameters (mean dose, max dose, and min dose to the hottest x% volume [Dx%(Gy); x from 5-95 in 5% intervals]) for each were extracted, as well as LAD V15. Baseline cardiovascular disease (bCVD) was defined as heart failure (HF), coronary artery disease, peripheral vascular disease, or cerebrovascular disease. Primary endpoint was post-cCRT major adverse cardiac events (MACE), defined as acute coronary syndrome, HF hospitalization/urgent visit, coronary revascularization, or cardiac death. Secondary endpoints were grade ≥3 cardiac events (CTCAE v5.0), overall survival (OS), cancer specific mortality (CSM), and other cause mortality (OCM). Competing risk regression was used for MACE and grade ≥3 cardiac events, and Cox regression for OS, CSM, and OCM.

RESULTS

Median age was 68 years, 139 (41%) had bCVD, and 225 (67%) received consolidation ICI. Proton therapy was used in 117 (35%), intensity-modulated RT in 199 (59%), and 3D conformal RT in 19 (6%). Median MHD was 8.7 Gy (IQR 4.6-14.4) and median LAD V15 1.4% (IQR 0-22). Median follow-up was 39.5 months. 35 MACE events occurred; 1- and 2-year cumulative incidence (CI) were 4.2% and 9.5%. No cardiac dosimetric parameter associated with MACE after adjusting for bCVD and age (e.g., MHD sHR 0.98/Gy, 95% CI 0.93-1.03, p = 0.43) or within the following 3 subgroups: no bCVD, photon therapy, and ICI consolidation. 87 grade ≥3 cardiac events occurred; 1- and 2- year CI were 12.6% and 20.4%. Heart dose was not associated with grade ≥3 cardiac events after adjusting for bCVD, ECOG, and BMI (e.g., MHD sHR 1.00/Gy, 95% CI 0.97-1.03, p = 0.85) or within the 3 aforesaid subgroups. 183 OS events occurred, including 125 CSM and 58 OCM events. Multiple cardiac dosimetric parameters associated with worse OS on multivariable analysis (e.g., LAD V15 HR 1.01/%, 95% CI 1.00-1.02, p = 0.003), driven by associations with CSM (LAD V15 HR 1.02/%, p<0.001) but not OCM (LAD V15 HR 1.00/%, p = 0.73). Median OS was worse for LAD V15 ≥10% (22.2 vs 35.1 months, p = 0.004).

CONCLUSION

Among pts with LA-NSCLC treated with cCRT after adoption of ICI consolidation, modern RT techniques, and cardiac constraints, post-cCRT cardiac events were common but showed no association with cardiac dose. Cardiac dose associated with OS, driven by an association with CSM and not OCM, which may not reflect cardiac toxicity.

Multitask AI Models for the Joint Prediction of Overall Survival, Progression-Free Survival, and Death without Progression as a Composite Endpoint for LA-NSCLC Patients Treated with Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

Prior methods model the risk of endpoints separately. Herein, we construct a composite AI model that considers multiple endpoints jointly, including overall survival (OS), progression-free survival (PFS), and death without progression (DWP). Our hypothesis is that the composite model potentially improves predictive performance for patients with locally advanced non-small cell lung cancer (LANSCLC) treated with chemoradiotherapy (CRT).

MATERIALS/METHODS

A total of 335 LANSCLC patients treated with definitive CRT, including all evaluable patients accrued from Oct 2017 to Dec 2021, were randomly split into training/test subsets (n = 234/101). Cardio-pulmonary substructures (CPSs) were autocontoured, manually reviewed, and edited if necessary. A total of 1093 non-independent dosimetric parameters were extracted, including GTVp, GTVn, GTV, PTV, esophagus, lungs minus IGTV, left/right lung, 15 CPSs, and the overlapping volume of each OAR with PTV and the distance from each OAR to GTVp/GTVn. Other clinical parameters included age, consolidation immunotherapy (CI), ECOG score, Charlson comorbidity index, coronary heart disease, histology, PD-L1 expression, and clinical stage (AJCC 8). Within training, censored time-to-event data were imputed based on conditional event distributions derived from Kaplan-Meier estimators for casting survival analysis as a regression problem and training neural additive model (NAM) regressors. Features were selected by LASSO regression for a single endpoint (OS, PFS, DWP) and multi-task (MT) LASSO regression for four separate composite endpoints (OS-PFS, OS-DWP, PFS-DWP, OS-PFS-DWP). The performance of MT NAMs in the test set that jointly predicted the composite endpoints was evaluated using the C-index and compared to that of a single task (ST) NAM that predicted each endpoint separately.

RESULTS

The best testing performance in predicting OS and DWP was attained by the MT NAM that jointly predicted all endpoints (c-index = 0.65, 95% CI 0.58-0.71 for OS; c-index = 0.78, 95% CI 0.69-0.87 for DWP). The best model to predict PFS was also MT between PFS and DWP (c-index = 0.59, 95% CI 0.52-0.65). The c-indices of all ST NAMs were less than 0.56. The best MT NAMs significantly outperformed ST NAMs in predicting OS (p = 0.001) and DWP (p = 0.01) except for PFS (p = 0.32). The best MT NAM in predicting OS and DWP included ECOG score, atria-PTV overlap volume, D75% [Gy] to the left atrium (LA), pulmonary arterial volume, histology (adenocarcinoma), D65% [Gy] to the descending aorta (DA), V10 Gy [%] of the LA and CI in order of overall importance. ECOG score consistently ranked as the most important feature for all four MT NAMs. An increase of ECOG score from 0 to 2 indicated a 6-month earlier risk of mortality and DWP. Atria-PTV overlap volume and D65% [Gy] to the DA were included in all four MT NAMs.

CONCLUSION

MT AI models improved outcome prediction in patients with LANSCLC treated with CRT by jointly learning commonalities between the primary and auxiliary endpoints.

Interpretable Machine Learning Models for Severe Esophagitis Prediction in LA-NSCLC Patients Treated with Chemoradiation Therapy

PURPOSE/OBJECTIVE(S)

Radiation esophagitis is a common adverse event that may occur during chemoradiotherapy (CRT) that can adversely affect survival. This study aimed to develop interpretable machine learning (ML) models to predict grade 3 and higher radiation esophagitis in patients receiving definitive CRT therapy for locally advanced non-small cell lung cancer (LA-NSCLC).

MATERIALS/METHODS

A total of 335 patients with LA-NSCLC who received definitive concurrent CRT at a single institution from 2017 to 2021 were retrospectively identified. Patients with esophagitis were identified and graded according to CTCAE v5.0. For each patient, 31 clinical features and 1093 dose-volume histogram (DVH) parameters from 19 structures were collected. The data was then randomly split into training (n = 233) and testing (n = 102) datasets. Feature selection was performed on the training dataset using the minimum redundancy maximum relevance algorithm to find a set of relevant features while controlling for the redundancy within the selected features, which were then followed by the Boruta algorithm to remove unimportant features and make the ML model more accurate. Synthetic minority oversampling technique was used to handle class-imbalanced datasets by generating synthetic samples for the minority class. Four variants of the Generalized Additive Model (GAM), including Explainable Boosting Machine (EBM), neural GAM (NODE-GAM), eXtreme Gradient Boosting (XGB)-GAM, and Spline, were built with selected features. The models' performance in predicting esophagitis was evaluated using the area under the receiver operating characteristic curve (AUC) in the test dataset. Shape plots were used to interpret the models' output and explain the selected features' contribution to the prediction.

RESULTS

NODE-GAM yielded the highest performance (F1 score = 0.57, accuracy = 0.8, and AUC = 0.837), followed by EBM (F1 score = 0.43, accuracy = 0.8, and AUC = 0.7), Spline (F1 score = 0.42, accuracy = 0.74, and AUC = 0.737), and XGB-GAM (F1 score = 0.42, accuracy = 0.76, and AUC = 0.71). Selected features included D95%[Gy], D90%[Gy], D65%[Gy] and V40Gy [%] for the esophagus, V10Gy [%] for the pulmonary artery, and the distance from GTVn to the ascending aorta. The analysis of the selected features indicated that an increased radiation dose delivered to the esophagus and a shorter distance between the ascending aorta and GTVn were associated with a higher risk of developing esophagitis.

CONCLUSION

Our study demonstrates the feasibility of developing interpretable ML models to predict esophagitis in patients with LA-NSCLC patients treated with CRT. NODE-GAM provided the best accuracy while providing insights into the driving dosimetric factors that could be used to guide optimal RT planning.

Proton Beam Therapy (PBT) Versus Intensity-Modulated Radiotherapy (IMRT) for Locally Advanced Non-Small Cell Lung Cancer (LA-NSCLC) in the Era of Immune Checkpoint Inhibitor (ICI) Consolidation: A Retrospective Cohort Study

PURPOSE/OBJECTIVE(S)

Patients (pts) with LA-NSCLC treated with concurrent chemoradiation (cCRT) and ICI consolidation are at high risk for treatment-related toxicities and subsequent hospitalization. We hypothesized that PBT is associated with a reduction in acute unplanned hospitalizations as compared to IMRT in the era of ICI consolidation.

MATERIALS/METHODS

This single institution, multi-site retrospective study included consecutive pts with LA-NSCLC treated with definitive cCRT with either PBT or IMRT from October 2017 to December 2021. Pts were evaluated for consolidative ICI. Primary endpoint was unplanned treatment-related hospitalization within 90 days of first radiation (RT) treatment. Secondary endpoints included grade 3+ pneumonitis, grade 3+ esophagitis, PFS and OS. Logistic regression was used to assess associations with 90-day hospitalization. Competing risk regression was used for grade 3+ pneumonitis and esophagitis, and Cox regression for PFS and OS.

RESULTS

A total of 316 pts were included: 117 (37%) received PBT and 199 (63%) IMRT. Median age was 68.5 yrs; median RT dose 66.6 Gy (IQR 65.9-70.0). PBT group was older (median 71.1 vs 67.2 yrs, p<0.005) and had a higher Charlson comorbidity index (CCI) (median 4 vs 3, p = 0.02). There was no significant difference in ECOG, smoking pack-years, T stage, N stage, target volume size, or receipt of ICI consolidation (66.7% vs 68.3%, p = 0.76). PBT group had lower mean heart dose (5.9 vs 10.8 Gy, p<0.001), LAD V15 (0 vs 6 %, p = 0.001), mean lung dose (14.7 vs 15.7 Gy, p <0.008) and effective dose to immune circulating cells (median 3.7 vs 4.9 Gy, p<0.001) but not mean esophagus dose. PBT was associated with fewer unplanned 90-day hospitalizations (23.9% vs 34.7%); which persisted on multivariable analysis (OR 0.52, 95% CI 0.30-0.90, p = 0.02) after adjusting for CCI, smoking pack-years, T4 tumors and target volume. Reasons for hospitalization in PBT and IMRT groups included progression (1.7% vs 1.5%), definite/probable toxicity from cCRT (11.1% vs 18.6%), possible toxicity from cCRT (7.7% vs 12.6%) or unrelated to cCRT (3.4% vs 2.0%). There was no significant difference between PBT or IMRT groups in G3+ pneumonitis (1-year 6.0% vs 9.1%, p = 0.49), G3+ esophagitis (1-year 6.0% vs 6.5%, p = 0.71), PFS (median 14.4 vs 15.1 months, p = 0.69), or OS (median 34.2 vs 29.4 months, p = 0.41).

CONCLUSION

Among pts with LA-NSCLC treated with cCRT in the era of ICI consolidation, PBT was associated with fewer acute unplanned hospitalizations compared to IMRT. There was no difference in G3+ pneumonitis, G3+ esophagitis, PFS or OS.

Patterns of Failure, Volume of Disease Progression, and Subsequent Ablative Management in Locally Advanced Non-Small Cell Lung Cancer (LA-NSCLC) Treated with Definitive Chemoradiation and Consolidation Immune Checkpoint Inhibitors (ICI)

PURPOSE/OBJECTIVE(S)

For patients (pts) with LA-NSCLC treated with chemoradiation and consolidation ICI (CRT+ICI), the patterns of failure (POF) and volume of disease progression (PD) are not well characterized. The primary objective of this study was to classify POFs, the frequency of low volume relapse (LVR), and identify pts eligible for further ablative therapy.

MATERIALS/METHODS

We retrospectively identified pts with unresectable stage III NSCLC treated with CRT+ICI between October 2017 and December 2021 at a single institution. Site of first failure was classified as locoregional (LRF), distant (DF), or synchronous LRF + DF. Any LRF was subclassified as in field (IFF; PD within 90% isodose line), marginal (MF; within 50% isodose line) or out of field (OOF; outside of 50% isodose line). LVR was defined as < 3 discrete sites of PD in any number or location of organs. Pts with distant LVR were considered to have oligometastatic relapse. Ablative candidates were defined as pts with < 3 discrete sites of PD amenable to further RT or surgery. Cumulative incidence of PD was calculated with death as a competing risk. Progression free survival (PFS) and overall survival (OS) were calculated from the end of RT and assessed via Kaplan Meier. Multivariable Cox modeling was used to assess correlation of pt characteristics and time-to-event outcomes. Logistic regression was used to predict variables associated with LVR.

RESULTS

A total of 229 pts received CRT+ICI. Median follow up was 39 months and 119 pts experienced PD. Median PFS and OS were 18.4 and 34.5 months, respectively. Of pts with PD, 71 (60%) had DF, 28 (24%) had LRF+DF, and 20 (17%) had LRF. Of pts with any LRF, 28 (57%) had IFF, 10 (21%) had MF, and 10 (21%) had OOF. Estimated 1-year cumulative incidence of LRF, DF, and LRF+DF were 9.3% (95% CI 4.5-16), 39% (95% CI 31-48), and 19% (95% CI 12-27), respectively. A total of 63 (53%) pts had LVR. In pts with LVR, 19 (30%) had isolated thoracic relapse and 44 (69%) had oligometastatic relapse. Most oligometastatic disease was intracranial (22 metastases, 44%). Pts with LVR had a longer median OS vs pts with high volume relapse (37.4 vs 15.2 months, p<0.001). At time of PD, 56 (47%) pts were candidates for further ablative therapies. Subsequent anticancer therapies were local therapy alone (35%), local and systemic therapy (16%), systemic therapy alone (36%), or no therapy (13%). On multivariable analysis, LVR (HR 0.39; 95% CI 0.21-0.73, p = 0.003) and longer receipt of ICI (HR 0.96; 95% CI 0.95-0.98; p<0.001) were associated with improved survival while squamous histology (HR 2.26; 95% CI 1.18-4.32; p = 0.039) was associated with worse survival. Longer receipt of ICI was the only variable predictive for the development of LVR (OR 1.03; 95% CI 1.01-1.05; p = 0.004).

CONCLUSION

This is the largest real-world series reporting POF after CRT+ICI for stage III NSCLC. Approximately half of pts experience LVR and are candidates for further ablative therapy. Further data are needed to define optimal treatment strategies for pts with LVR after CRT+ICI.

Biomimetic Nanofibrillar Hydrogel with Cell-Adaptable Network for Enhancing Cellular Mechanotransduction, Metabolic Energetics, and Bone Regeneration

The natural extracellular matrix, with its heterogeneous structure, provides a stable and dynamic biophysical framework and biochemical signals to guide cellular behaviors. It is challenging but highly desirable to develop a synthetic matrix that emulates the heterogeneous fibrous structure with macroscopic stability and microscopical dynamics and contains inductive biochemical signals. Herein, we introduce a peptide fiber-reinforced hydrogel in which the stiff ß-sheet fiber functions as a multivalent cross-linker to enhance the hydrogel's macroscopic stability. The dynamic imine cross-link between the peptide fiber and polymer network endows the hydrogel with a microscopically dynamic network. The obtained fibrillar nanocomposite hydrogel, with its cell-adaptable dynamic network, enhances cell-matrix and cell-cell interactions and therefore significantly promotes the mechanotransduction, metabolic energetics, and osteogenesis of encapsulated stem cells. Furthermore, the hydrogel can codeliver a fiber-attached inductive drug to further enhance osteogenesis and bone regeneration. We believe that our work provides valuable guidance for the design of cell-adaptive and bioactive biomaterials for therapeutic applications.

[Exploration of clinical pathway-oriented optimal management diagnosis and treatment model for rare diseases]

This study takes Cushing's syndrome, a rare disease, as a model, and adopts the path of "Plan, Do, Check, Action" (PDCA) to explore new methods to optimize the clinical path, can improve the quality and efficiency of diagnosis and treatment of rare diseases. After sorting out the problems existing in the previous diagnosis and treatment mode, our team optimizes the path in various ways and establishes a standard operation procedure (SOP) for the new path. In the evaluation of the optimized mode, 55 patients with Cushing's syndrome were admitted to the Department of Endocrinology, Peking Union Medical College Hospital, including 19 males and 36 females, aged (41.8±14.4) years (6-68 years). The pathway group (28 cases) and the control group (27 cases) were divided according to whether they were included in the new path management at the time of admission, and the effect of path optimization was assessed in terms of time, efficacy, safety and cost. The results showed that compared with the control group, the pathway group had a shorter time of hospitalization in the Department of Endocrinology and critical tests, such as blood cortisol rhythm, low-dose dexamethasone inhibition test, and bilateral inferior petrosal sinus sampling (all P<0.05). There was no significant differences in the decrease of total cortisol after operation, the incidence of postoperative complications, and hospitalization expenses (all P>0.05). The optimized path improves the medical efficiency while ensuring medical quality, safety and no increase in cost. This study proposes PDCA path optimization for complex diseases and establishes SOP process, which provides experience in management optimization for the patient-centered and clinical path-oriented diagnosis and treatment mode of rare diseases.

[Preliminary study on the mechanism underlying the ecological isolation of Oncomelania hupensis populations in Changde City]

OBJECTIVE

To investigate ecological isolation between Oncomelania hupensis snail populations in hilly regions and marshland and lake regions in Yuanjiang valley, Changde City, Hunan Province, and to unravel its underlying mechanisms.

METHODS

Taoyuan County, Shimen County, Linli County and Lixian County in Changde City were selected as snail sampling sites in hilly regions, and Lixian County, Jinshi City, West Lake Administration District, Hanshou County and Dingcheng District were selected as snail sampling sites in marshland and lake areas. Cytochrome C oxidase 1 (cox 1) gene was amplified in snail samples and sequenced. The genetic sequences of O. hupensis snails were aligned using the software MEGA 11, and the haplotypes of O. hupensis snails were determined using the software DNASP 5.10.01. The phylogenetic tree was generated using Bayesian inference with the software MrBayes 3.2, and analysis of molecular variance (AMOVA) was performed to analyze the source of genetic divergence and estimate the genetic divergence index (F_ST) among snail populations with the software Arlequin 3.5.2.2. The genetic barrier among 11 O. hupensis snail populations was estimated using the Monmonier algorithm of adegenet toolkit in R package. The settings with "land in winter and water in summer" in the Yuanjian River section were divided into two categories according to the upstream and downstream, and the areas with "land in winter and water in summer" in the upstream and downstream were transformed into raster data, and then loaded into the software Fragstats 4 for analysis of landscape indicators. The trends in changes of digital elevation were extracted from the Yuanjiang River section based on the digital elevation model, and made three-dimensional visualization using the R package.

RESULTS

The mitochondrial cox 1 gene were amplified in 165 O. hupensis snais from 11 sampling sites and sequenced, and a total of 152 valid gene sequences were obtained, with 46 haplotypes or 9 populations determined. No haplotype was shared in snails between Taoyuan County and Dingcheng District and Hanshou County along the downstream of the Yuanjiang River. The total area of settings with "land in winter and water in summer" was 617.66 hm² in the upsteram of the Yuanjiang River, which consisted of 473 patches, with each patch measuring 1.31 hm², the largest area index of 0.735 2, the landscape division index of 0.999 9, and the landscape shape index of 45.293 7. The total area of settings with "land in winter and water in summer" was 9 956.92 hm² in the downstream of the Yuanjiang River, which consisted of 771 patches, with each patch measuring 12.91 hm², the largest area index of 97.839 9, the landscape division index of 0.042 7, and the landscape shape index of 7.249 6. The area of settings with "land in winter and water in summer" was much larger in the downstream than that in the upstream of the Yuanjiang River, and the stronger landscape connectivity and non-remarkable alteration of riverbed elevation provided suitable habitats for snail breeding.

CONCLUSIONS

The hydrological and environmental characteristics of the upstream of the Yuanjiang River restrain the breeding and spread of O. hupensis, resulting in ecological isolation between Oncomelania hupensis in Taoyuan County and those in the downstream of Yuanjiang River.

Standardizing image assessment in optical diffraction tomography

Optical diffraction tomography (ODT) has gradually become a popular label-free imaging technique that offers diffraction-limited resolution by mapping an object's three-dimensional (3D) refractive index (RI) distribution. However, there is a lack of comprehensive quantitative image assessment metrics in ODT for studying how various experimental conditions influence image quality, and subsequently optimizing the experimental conditions. In this Letter, we propose to standardize the image assessment in ODT by proposing a set of metrics, including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and structural distinguishability (SD). To test the feasibility of the metrics, we performed experiments on angle-scanning ODT by varying the number of illumination angles, RI contrast of samples, sample feature sizes, and sample types (e.g., standard polystyrene beads and 3D printed structures) and evaluated the RI tomograms with SNR, CNR, and SD. We further quantitatively studied how image quality can be improved, and tested the image assessment metrics on subcellular structures of living cells. We envision the proposed image assessment metrics may greatly benefit end-users for assessing the RI tomograms, as well as experimentalists for optimizing ODT instruments.

A study on serum pro-neurotensin (PNT), furin, and zinc alpha-2-glycoprotein (ZAG) levels in patients with acromegaly

PURPOSE

Acromegaly caused by growth hormone cell adenoma is commonly associated with abnormal glucolipid metabolism, which may result from changes in adipocytokine secretion. This study aims to investigate serum adipokine levels, including pro-neurotensin (PNT), furin, and zinc alpha-2-glycoprotein (ZAG), in acromegalic patients and the correlation between the levels of these three adipokines and GH levels and glucolipid metabolism indices.

METHODS

Sixty-eight acromegalic patients and 121 controls were included, and their clinical data were recorded from electronic medical record system. Serum PNT, furin and ZAG levels were measured by ELISA.

RESULTS

Serum PNT levels in acromegalic patients were significantly higher than controls (66.60 ± 12.36 vs. 46.68 ± 20.54 pg/ml, P < 0.001), and acromegaly was an independent influencing factor of PNT levels (P < 0.001). Moreover, subjects with the highest tertile of PNT levels had a close correlation with acromegaly (OR = 22.200, 95% CI 7.156 ~ 68.875, P < 0.001), even in Model 1 adjusted for gender and age and Model 2 adjusted for gender, age and BMI. Additionally, serum PNT levels were positively correlated with BMI (r = 0.220, P = 0.002) and triglycerides (TGs, r = 0.295, P < 0.001), and TGs were an independent influencing factor of serum PNT levels in acromegalic subjects (P < 0.001). Furthermore, serum PNT levels in obese acromegalic patients were significantly higher than those with normal BMI (P < 0.05). However, serum furin levels were lower in acromegalic patients than controls (0.184 ± 0.036 vs. 0.204 ± 0.061 ng/ml, P < 0.001).

CONCLUSION

This study is the first to demonstrate that acromegalic patients have increased serum PNT levels. Moreover, serum PNT plays a potential role in abnormal lipid metabolism of acromegalic patients.

Bone microarchitecture impairment in prolactinoma patients assessed by HR-pQCT

PURPOSE

Prolactinoma may reduce bone mineral density (BMD) and increase fracture risk, but its influence on bone microarchitecture remains to be elucidated. The purpose of this study is to evaluate bone microarchitecture parameters by high-resolution peripheral quantitative computed tomography (HR-pQCT) in prolactinoma patients.

METHODS

31 prolactinoma patients and 62 age- and sex-matched healthy controls in our center were included, and HR-pQCT was used to evaluate their bone microarchitecture at the radius and tibia. Z-scores for bone microarchitecture parameters were calculated based on previously published reference.

RESULTS

After adjusting for height and weight, prolactinoma patients had lower trabecular (- 0.011 mm, p = 0.005) and cortical thickness (- 0.116 mm, p = 0.008) and cortical area (- 6.0 mm2, p = 0.013) at radius, as well as lower trabecular (- 0.014 mm, p = 0.008) and cortical (- 0.122 mm, p = 0.022) thickness at tibia compared with the controls. Patients with higher prolactin level had more severe bone microarchitecture impairments. After adjusting for prolactin level and age, male patients had lower trabecular volumetric BMD (vBMD), trabecular number, trabecular thickness, and cortical porosity at radius, as well as lower trabecular vBMD, trabecular bone volume fraction, trabecular number, and cortical area, and higher trabecular separation at tibia compared with female patients. Z-score for radius vBMD was correlated with Z-score for areal BMD (aBMD) at lumbar and femoral neck, while Z-score for tibia vBMD was correlated with Z-score for lumbar aBMD, and some patients with vBMD Z-score below - 2.0 had aBMD Z-score within normal range.

CONCLUSION

Peripheral bone microarchitecture was impaired in prolactinoma patients, especially in patients with higher prolactin level. We compared the bone microarchitecture of prolactinoma patients and healthy controls by high-resolution peripheral quantitative computed tomography (HR-pQCT), and found that many bone microarchitecture parameters were impaired among prolactinoma patients. Such impairment was more prominent among patients with higher prolactin level.

[Research progress of circumferential tracheal reconstruction via tissue-engineered trachea]

Tissue engineering, as a new technology, provides a new avenue for the reconstruction of circumferential tracheal defects, which has always been a tremendous challenge for surgeons around the world. Recently, technologies such as decellularization, 3-dimensional printing, electrospinning and cell sheet have significantly enhanced the chondrification. Implantation of epithelial cells or transplantation of epithelial cell sheets also has accelerated the process of epithelialization. And pedicle muscle flap proved to be a reliable strategy for vascularization of tissue-engineered trachea. But it is still a huge challenge to achieve circumferential tracheal functional reconstruction. The key difficulty lies in how to simultaneously realize the functional regeneration of cartilage, blood vessels and epithelial tissues of tissue-engineered trachea. Therefore, how to integrate the above schemes and finally realize segmental tracheal reconstruction needs further research. This article reviews the research progress of repairing circumferential tracheal defects based on tissue engineering technology.

Optogenetic activation of intracellular signaling based on light-inducible protein-protein homo-interactions

Dynamic protein-protein interactions are essential for proper cell functioning. Homo-interaction events—physical interactions between the same type of proteins—represent a pivotal subset of protein-protein interactions that are widely exploited in activating intracellular signaling pathways. Capacities of modulating protein-protein interactions with spatial and temporal resolution are greatly desired to decipher the dynamic nature of signal transduction mechanisms. The emerging optogenetic technology, based on genetically encoded light-sensitive proteins, provides promising opportunities to dissect the highly complex signaling networks with unmatched specificity and spatiotemporal precision. Here we review recent achievements in the development of optogenetic tools enabling light-inducible protein-protein homo-interactions and their applications in optical activation of signaling pathways.

[Effects of orlistat and metformin on metabolism and gonadal function in overweight or obese patients with polycystic ovary syndrome]

The aim of this study was to assess the effects of orlistat or metformin treatment on lipid and glucose metabolism, and gonadal function in obese/overweight women with polycystic ovary syndrome (PCOS). A total of 39 patients diagnosed with PCOS were randomly (digital table method) divided into orlistat treatment group (20 cases) and metformin treatment group (19 cases). Compared with those before, treatment with either orlistat or metformin significantly reduced body weight, body mass index (BMI), hip circumferences, and serum insulin levels of the PCOS patients both at the end of 3 months and 6 months (P<0.05). No significant differences could be viewed between orlistat and metformin treated subjects. Moreover, orlistat treatment significantly lowered the levels of low-density lipoprotein cholesterol, total cholesterol, fasting blood glucose, and homeostasis model assessment-insulin resistance (HOMA-IR) (P<0.05), while there were no significant changes in above parameters with metformin treatment. The improvement of menstrual cycle was observed after 6-month treatment in both groups (P<0.05). However, changes in polycystic ovarian morphology by ultrasound were only observed in orlistat treated group. In conclusion, orlistat is comparable with metformin in weight loss and improvement of insulin resistance and menstrual cycle, and is superior to metformin in improvement of lipid metabolism in overweight/obese PCOS patients.

Novel AVPR2 mutations and clinical characteristics in 28 Chinese families with congenital nephrogenic diabetes insipidus

AIMS

To investigate genotype and phenotype of congenital nephrogenic diabetes insipidus caused by AVPR2 mutations, which is rare and limitedly studied in Chinese population.

METHODS

88 subjects from 28 families with NDI in a department (Beijing, PUMCH) were screened for AVPR2 mutations. Medical records were retrospectively reviewed and characterized. Genotype and phenotype analysis was performed.

RESULTS

23 AVPR2 mutations were identified, including six novel mutations (p.Y117D, p.W208R, p.L313R, p.S127del, p.V162Sfs*30 and p.G251Pfs*96). The onset-age ranged from 1 week to 3 years. Common presentations were polydipsia and polyuria (100%) and intermittent fever (57%). 21% and 14% of patients had short stature and mental impairment. Urine SG and osmolality were decreased, while serum osmolality and sodium were high. Urological ultrasonography results showed hydronephrosis of the kidney (52%), dilation of the ureter (48%), and thickened bladder wall or increased residual urine (32%), led to intermittent urethral catheterization (7%), cystostomy (11%) and binary nephrostomy (4%). Urological defects were developed in older patients. Genotype and phenotype analysis revealed patients with non-missense mutations had higher levels of serum sodium than missense mutations.

CONCLUSION

In the first and largest case series of NDI caused by AVPR2 mutations in Chinese population, we established genetic profile and characterized clinical data, reporting six novel mutations. Further, we found genotype was associated with phenotype. This knowledge broadens genotype and phenotype spectrum of rare congenital NDI caused by AVPR2 mutations, and provides basis for studying molecular biology of AVPR2.

[Changes in platelet related parameters in obese patients after sleeve gastrectomy]

To compare changes in platelet related parameters in obese patients before and after sleeve gastrectomy (SG), we retrospectively analyzed the clinical data of 31 obese patients who underwent SG in Peking Union Medical College Hospital from December 2012 to September 2020. Results showed that compared with those before surgery, platelet count (PLT) decreased significantly at 2-12 weeks of follow-up (P=0.009), while platelet distribution width (PDW), mean platelet volume (MPV), and large platelet ratio (P-LCR) increased significantly at the same periods of follow-up after operation (P<0.001). However, the levels of PDW, MPV, and P-LCR began to decrease at 16-55 weeks when compared with those at 2-12 weeks of follow-up (P<0.01). PLT was positively correlated with white blood cells and neutrophils at 2-12 weeks of follow-up and positively correlated with high sensitivity C-reactive protein at 16-55 weeks of follow-up after operation (P<0.05).

[Updated key points of Chinese Consensus for the Diagnosis and Treatment of Acromegaly (2021 edition)]

Led by the China Pituitary Adenoma Specialist Council, the Chinese Consensus for the Diagnosis and Treatment of Acromegaly (2021 Edition) is developed combined with the research progress of pituitary growth hormone (GH)-secreting adenoma both at home and abroad, evidence-based evidence of the diagnosis and treatment of acromegaly, and China's national conditions. Based on the guideline for acromegaly (2013 Edition), the new version of consensus emphasizes the importance of multidisciplinary team (MDT) and individual therapy. The criteria for control of acromegaly is discussed. Pathological criteria for the diagnosis of pituitary GH-secreting adenoma is updated. New developments in surgery, drug and radiotherapy are introduced. Meanwhile, the diagnosis and treatment of acromegaly patients concurrent with other particular scenarios, including pregnancy and refractory pituitary GH-secreting adenoma is suggested. This article aims to describe the updated key points of the new version of the consensus, and thus facilitate the clinical implementation of standardized diagnosis and treatment for acromegaly patients.

Light-inducible deformation of mitochondria in live cells

Mitochondria, the powerhouse of the cell, are dynamic organelles that undergo constant morphological changes. Increasing evidence indicates that mitochondria morphologies and functions can be modulated by mechanical cues. However, the mechano-sensing and -responding properties of mitochondria and the relation between mitochondrial morphologies and functions are unclear due to the lack of methods to precisely exert mechano-stimulation on and deform mitochondria inside live cells. Here, we present an optogenetic approach that uses light to induce deformation of mitochondria by recruiting molecular motors to the outer mitochondrial membrane via light-activated protein-protein hetero-dimerization. Mechanical forces generated by motor proteins distort the outer membrane, during which the inner mitochondrial membrane can also be deformed. Moreover, this optical method can achieve subcellular spatial precision and be combined with different optical dimerizers and molecular motors. This method presents a mitochondria-specific mechano-stimulator for studying mitochondria mechanobiology and the interplay between mitochondria shapes and functions.

[Study on the hospitalization cost and its influencing factors of imported malaria patients in Guangxi Zhuang Autonomous Region and Yunnan Province]

OBJECTIVE

To analyze the hospitalization cost and its influencing factors of imported malaria patients in Guangxi Zhuang Autonomous Region and Yunnan Province, so as to provide insights into the evaluation of the economic burden due to imported malaria, and the guiding of malaria control and the rational allocation of medical resources.

METHODS

The data pertaining to the hospitalization costs of imported malaria patients admitted to Shanglin County People's Hospital in Guangxi Zhuang Autonomous Region during the period from January 1 through December 31, 2019, and Tengchong Municipal People's Hospital in Yunnan Province from January 1, 2015 to December 31, 2019, were collected, and the epidemiological data of these imported malaria patients were extracted from the Information Management System for Parasitic Diseases Control and Prevention, China. The composition of the hospitalization expenses was analyzed using a descriptive method. In addition, the factors affecting the hospitalization expenses of imported malaria patients were identified using a univariate analysis and a recursive system model.

RESULTS

A total of 206 imported malaria patients were included in this study, including 194 men (94.17%) and 12 women (5.83%). The mean length of hospital stay was 5.00 days per patient and the median hospitalization expenses were 2 813.07 Yuan per time, in which the expenses for laboratory examinations were the highest (45.31%, 1 274.62/2 813.07). Univariate analysis showed that hospital (z = 5.43, P < 0.01), type of malaria (χ² = 34.86, P < 0.01) and type of payment (χ² = 7.72, P < 0.05) were factors affecting the hospitalization expenses of imported malaria patients. Recursion system modeling revealed that the total effects on hospitalization expenses of imported malaria patients included length of hospital stay (0.78), selection of hospital (0.34), basic medical insurance for urban and rural residents (0.19), new rural cooperative medical care (0.17), Plasmodium falciparum malaria (0.15), gender (0.11) and P. vivax malaria (0.09).

CONCLUSIONS

The hospitalization expenses of imported malaria patients are affected by multiple factors in Guangxi Zhuang Autonomous Region and Yunnan Province, in which the length of hospital stay is the most predominant influencing factor. A reduction in the length of hospital stay is effective to decrease the hospitalization expenses of imported malaria patients.

Ivy Sign in Moyamoya Disease: A Comparative Study of the FLAIR Vascular Hyperintensity Sign Against Contrast-Enhanced MRI

BACKGROUND AND PURPOSE

The ability of the ivy sign on contrast-enhanced T1-weighted MR imaging (CEMR) to reflect cerebral perfusion and postoperative revascularization in Moyamoya disease remains largely unknown. We aimed to compare the capabilities of CEMR and FLAIR.

MATERIALS AND METHODS

CEMR, FLAIR, arterial spin-labeling, and DSA were performed in 44 patients with Moyamoya disease. The ivy sign was scored separately on CEMR and FLAIR using the Alberta Stroke Program Early CT Score. The status of leptomeningeal collaterals was scored on DSA. The postoperative Matsushima grade was evaluated at least 3 months after surgical revascularization.

RESULTS

Scoring of the ivy sign on CEMR showed excellent interrater reliability, and FLAIR vascular hyperintensity showed moderate interrater reliability. Correlation analyses revealed that DSA scores were more consistent with the CEMR-based ivy sign score (r = 0.25, P = .03) than with FLAIR vascular hyperintensity (r = 0.05, P = .65). The CEMR-based ivy sign score was significantly correlated with CBF in late-Suzuki stage Moyamoya disease (t = -2.64, P = .02). The CEMR-based ivy sign score at baseline was significantly correlated with the postoperative Matsushima grade (r = 0.48, P = .03).

CONCLUSIONS

In this study, CEMR outperformed FLAIR in capturing the ivy sign in Moyamoya disease. In addition, the CEMR-based ivy sign score provided adequate information on hemodynamic status and postoperative neovascularization. The current study suggested that CEMR could be considered as an alternative to FLAIR in future studies investigating leptomeningeal collaterals in Moyamoya disease.

Association of Frailty Status with Risk of Fall among Middle-Aged and Older Adults in China: A Nationally Representative Cohort Study

OBJECTIVES

To investigate the association between frailty status and risk of fall among middle-aged and older Chinese people.

DESIGN

A nationally representative prospective cohort study.

SETTING AND PARTICIPANTS

The study included 13,877 community-dwelling participants aged 45 years and above from the China Health and Retirement Longitudinal Study.

METHODS

Frailty status was identified by the frailty index of health deficit accumulation. 34 variables at baseline were selected to calculate the frailty index. We excluded participants with incomplete information in construction of the frailty index at baseline. Falls were measured based on the respondents' self-report. We used a logistic regression model to estimate the associations between the frailty status and risk of fall, and subgroup analyses and sensitivity analyses were further conducted.

RESULTS

Of 13,877 participants, 2310 (16.6%) had falls during the observation period. 9027 (65.0%) participants were classified as robust, 4019 (29.0%) participants were classified as pre-frail, and 831 (6.0%) participants were classified as frail. Our results indicated per 0.01 increment in the frailty index was significantly associated with an increased risk of fall among middle-aged and older participants (OR: 1.52, 95%CI: 1.45-1.60). Such association was stronger when frailty was presented as a categorical variable, with an OR of 1.75 (95%CI: 1.59-1.93) for pre-frail and 3.04 (95%CI: 2.60-3.56) for frail. The area under the curve of the logistic model was 0.612 (95%CI: 0.600-0.625). Each 0.01 increment of the frailty index was association with a higher risk of fall among middle-aged (45-59years) participants (OR: 1.44, 95%CI: 1.29-1.60) than among older (≥60 years) participants (OR: 1.28, 95%CI: 1.16-1.41) at baseline (p=0.015 for interaction).

CONCLUSION

Frailty was significantly associated with an increased risk of fall among community-dwelling middle-aged and older people in China. It is necessary to screen and recognize frailty status to prevent falls among middle-aged and older adults.

Triggers of stress cardiomyopathy and their association with clinical outcomes

Background

Stress cardiomyopathy can be a result of physical stress, emotional stress, or both. Whether the type of trigger affects clinical outcomes is not well studied.

Purpose

The objectives of this study were to identify the prevalence of emotional and physical stressors and to assess differences in patient characteristics and mortality based on the type of trigger.

Methods

We conducted a retrospective review of 523 consecutive patients who presented to our institution from 2006 to 2016. All patients presented with acute coronary syndrome. Triggers for stress cardiomyopathy were abstracted from reviewing patients' medical records. Patients were categorized into those with 1) physical trigger, 2) emotional trigger, 3) both physical and emotional trigger, or 4) no known trigger. Baseline characteristics and clinical outcomes were reported.

Results

Among 523 patients with stress cardiomyopathy, 151 (28.9%) had a physical trigger, 189 (36.1%) had an emotional trigger, 30 (5.7%) had both physical and emotional triggers, and 153 (29.3%) had no known triggers identified. Men comprised the higher proportion of patients with physical triggers. Comorbidities including diabetes, pulmonary disease, chronic kidney disease and hypothyroidism were more prevalent among patients with physical triggers. Compared to patients with no obvious triggers, patients with a physical trigger had a much higher mortality rate (hazard ratio 2.0, 95% CI 1.2–3.3, p=0.007), whereas patients with an emotional trigger had significantly lower mortality (hazard ratio 0.40, 95% CI 0.21–0.89, p=0.007).

Conclusion

Different triggers for stress cardiomyopathy is associated with different baseline characteristics and clinical outcomes. Overall survival is worst in the group with an identified physical trigger.

Figure 1

Funding Acknowledgement

Type of funding source: None

Optical Activation of TrkB Signaling

Brain-derived neurotrophic factor, via activation of tropomyosin receptor kinase B (TrkB), plays a critical role in neuronal proliferation, differentiation, survival, and death. Dysregulation of TrkB signaling is implicated in neurodegenerative disorders and cancers. Precise activation of TrkB signaling with spatial and temporal resolution is greatly desired to study the dynamic nature of TrkB signaling and its role in related diseases. Here we develop different optogenetic approaches that use light to activate TrkB signaling. Utilizing the photosensitive protein Arabidopsis thaliana cryptochrome 2, the light-inducible homo-interaction of the intracellular domain of TrkB in the cytosol or on the plasma membrane is able to induce the activation of downstream MAPK/ERK and PI3K/Akt signaling as well as the neurite outgrowth of PC12 cells. Moreover, we prove that such strategies are generalizable to other optical homo-dimerizers by demonstrating the optical TrkB activation based on the light-oxygen-voltage domain of aureochrome 1 from Vaucheria frigida. The results open up new possibilities of many other optical platforms to activate TrkB signaling to fulfill customized needs. By comparing all the different strategies, we find that the cryptochrome 2-integrated approach to achieve light-induced cell membrane recruitment and homo-interaction of intracellular domain of TrkB is most efficient in activating TrkB signaling. The optogenetic strategies presented are promising tools to investigate brain-derived neurotrophic factor/TrkB signaling with tight spatial and temporal control.

[Etiology and clinical features of primary adrenal insufficiency]

Objective: To summarize the etiology of primary adrenal insufficiency (PAI) and analyze its clinical features. Methods: A retrospective analysis was performed in the Department of Endocrinology, Peking Union Medical College Hospital from October 1981 to June 2019. Patients with PAI as the first symptom were enrolled. The etiology of PAI was analyzed and the clinical characteristics was also summarized. Results: A total of 131 patients with PAI were enrolled, including 87 males and 44 females (57 adolescents, and 74 adults). The age ranged from 0 to 73 years. The primary cause of PAI in adolescents was genetic defects (52.6%, 30/57), in which congenital adrenal dysplasia caused by DAX1 gene deficiency accounted for 50.0% (15/30), followed by autoimmunity (22.8%, 13/57). The primary cause of adult PAI was infection (58.1%, 43/74), of which tuberculosis accounted for the majority (93.0%, 40/43), and autoimmune adrenalitis accounted for 19.0% (14/74). Compared with the tuberculosis group, female patients were more common, and the onset age was younger, the plasma cortisol, serum sodium, fasting blood glucose, creatinine and aldosterone were lower (all P<0.05), and serum potassium and renin levels were higher in the autoimmune adrenalitis group (both P<0.05). Conclusions: In the current study, the proportion of PAI caused by infection in the adult group was higher than that in the adolescent group. The most common cause of adult PAI was tuberculosis infection. The most common cause of childhood PAI was genetic defects. Autoimmune damage to the adrenal glands may be more severe than tuberculosis infection.

KLF8 promotes cancer stem cell-like phenotypes in osteosarcoma through miR-429-SOX2 signaling

Krüppel-like factor 8 (KLF8) regulates critical gene transcription associated with different types of cancer. A novel paradigm in tumor biology suggests that the initiation and progression of osteosarcoma (OS) are driven by osteosarcoma stem cell-like cells (OSCs), but the role and underlying mechanisms of KLF8 in OSCs are poorly elucidated. In this study, an obviously increased level of KLF8 is shown in 9 out of 10 primary OS tissues and is associated with the poor progression-free interval. Significantly, KLF8 expression in CD133+ OSCs is higher than that in CD133- counterparts. By knocking down KLF8 in CD133+ OSCs, we show that si-KLF8-OSCs can hardly form compact spheres. In the meantime, infection with si-KLF8 in CD133+ OSCs results in the downregulation of OCT4 and SOX2; increased adriamycin (ADM) sensitivity; and decreased tumorigenic potential in vivo. Mechanisms study demonstrates that KLF8 directly binds the miR-429 promoter region and regulates its expression transcriptionally. Furthermore, we indicate that miR-429 directly targets SOX2 to mediate cancer stem cell-like features in CD133+ OSCs. In the clinic, miR-429 levels are negatively associated with KLF8 levels in OS, suggesting that an elevated KLF8/miR-429 ratio may have clinical value as a predictive biomarker. In conclusion, targeting the KLF8-miR-429-SOX2 signaling pathway may provide an effective therapeutic approach to suppress the initiation and progression of OS.

Nrf2-ARE signaling pathway regulates the expressions of A1R and ENT1 in the brain of epileptic rats

OBJECTIVE

To explore the behavioral changes and the expressions of the A1 receptor (A1R) and balanced nucleoside transporter-1 (ENT1) in the brain of epileptic rats after activating the NF-E2-related factor 2 (Nrf2)-ARE signaling pathway.

MATERIALS AND METHODS

Adult male Sprague-Dawley (SD) rats were randomly divided into normal control group, epilepsy group, and t-butylhydroquinone (tBHQ) group, with 10 rats in each group. Lithium-pilocarpine induced epilepsy model in rats was established. The first epileptic latency and seizure frequency within 1 hour were observed in each group using the Racine scoring system. HE (Hematoxylin and Eosin) staining was used to observe the pathological lesions in the brain tissue of each group. The expressions of A1R, ENT1, and relative genes in Nrf2-ARE pathway in rat hippocampus was detected by immunohistochemistry and Western blot.

RESULTS

Compared with rats in epileptic group, the first seizure latency was prolonged and the seizure frequency decreased in tBHQ group (p<0.05). The degree of brain lesions in tHBQ group was lighter than that of epilepsy group. ENT1 expression in rat hippocampus of epileptic group was significantly upregulated than that of normal control group and tBHQ group. Besides, the protein levels of A1R, Nrf2, HO-1, and ARE in rat hippocampus of epilepsy group markedly decreased compared with those of normal control group. However, protein expressions of A1R, Nrf2, HO-1, and ARE proteins in rat hippocampus of tBHQ group were markedly upregulated.

CONCLUSIONS

Activation of the Nrf2-ARE signaling pathway can reduce the pathological damage of rat hippocampal neurons, prolong the latency of seizures, and reduce the degree of epileptic seizure in rats.

[Severe acute pancreatitis with iatrogenic duodenal fistula: cause and minimal invasive treatment]

Objective: To investigate the causes and treatment of severe acute pancreatitis (SAP) with iatrogenic duodenal fistula. Methods: The clinical data of the SAP patients with duodenal fistula treated in the Severe Acute Pancreatitis Center of Sir Run Run Shaw Hospital from May 2015 to May 2018 was analyzed retrospectively. Results: A total of 11 patients were enrolled, among which 5 cases of duodenal fistula were caused by iatrogenic injury, including 2 cases of puncture injury, 2 cases of nutritional tube injury and 1 case of drainage tube injury. For patients with poor infection control after conservative treatment, laparoscopic assisted debridement through the right retroperitoneal approach was performed. Treatment of two patients failed for liver failure and the remaining patients were cured. Conclusions: Iatrogenic injury is one of the causes of duodenal fistula in patients with severe pancreatitis. Laparoscopic assisted debridement through the right retroperitoneal approach is an effective treatment for duodenal fistula.

[Effectiveness of vaginal high uterosacral ligament suspension for treatment of recurrent pelvic organ prolapse]

Objective: To evaluate the indications and clinic outcomes of vaginal high uterosacral ligament suspension (HUS) for treatment of recurrent advanced pelvic organ prolapse (POP). Methods: This retrospective study analyzed 42 women with recurrent advanced POP who were referred to Fourth Medical Center of PLA General Hospital and underwent transvaginal HUS between November 2005 and January 2018. Primary surgeries included 30 vaginal colporrhaphy, 5 Manchester operation, 5 transvaginal mesh repair,2 sacrospinous ligament fixation.The median time for recurrence from primary pelvic floor repair surgery was 9 months, including 14 cases (33%, 14/42) ≤3 months (median time was 2 months) and 25 cases (67%, 28/42) longer than 3 months (median time was 18 months).The rate of recurrent prolapse in stage Ⅲ or Ⅳ was 79% (33 cases), 45% (19 cases) and 17%(7 cases) in anterior, apical and posterior compartment respectively. Results: Transvaginal high bilateral uterosacral ligaments were identified and used for successful vaginal vault suspension after vaginal hysterectomy and residual cervical resection in all 42 consecutive patients. The cases of transvaginal mesh used in anterior wall and posterior wall were 25 (60%, 25/42) and 3 (7%, 3/42) respectively. There was no major intra- and postoperative complications,such as ureter and other pelvic organ injury. The median time of follow-up was 5.3 years after transvaginal HUS. The points of pelvic organ prolapse quantification system reduced significantly and point C improved from +0.3 cm to -8.2 cm after reoperation (P<0.01). The objective cure rate were 100% (42/42) both in apex and posterior compartment,while 93% (39/42) in anterior compartment. None had reoperation or pessary usage for recurrence of prolapse. Conclusion: Transvaginal HUS with vaginal wall repair could be as a safety, cost-effective, minimal traumatic and durable procedure for recurrent POP in the most of cases.

Magnetic resonance spectroscopy may serve as a presurgical predictor of somatostatin analog therapy response in patients with growth hormone-secreting pituitary macroadenomas

PURPOSE

Somatostatin analogs (SSAs) are considered one of the most effective medical treatments for patients with growth hormone-secreting pituitary adenomas (GH-PAs). The postoperative electron microscopy (EM) pathological subtype and SSTR2 expression in the tumor are the most established predictors of patient response to SSA therapy. The aim of this study was to evaluate how will magnetic resonance spectroscopy (MRS) measurements before surgery predict the EM pathological subtypes and SSTR2 expression of tumors, and thereby serve as an indicator for the therapeutic sensitivity to SSAs of patients with GH-PAs.

METHODS

Eighteen patients with GH pituitary macroadenomas who underwent transsphenoidal surgery were included in this retrospective study. The preoperative MRS data and T2 signal intensity were obtained from patients by 1.5 T MR spectroscopy of the sellar mass. The EM pathological subtypes of tumors were determined after surgery through examination of cell granulations. The expressions of somatostatin receptor 2 (SSTR2), SSTR5, P21, P27, and Ki-67 were evaluated by immunohistochemistry.

RESULTS

The MRS parameters that were found to significantly predict the EM pathological subtypes of tumors, as calculated by the receiver operating characteristic curve, were the choline (Ch) value at 3140.5 MR units (sensitivity 69.2%, specificity 100%) and the choline/creatine (Ch/Cr) ratio at 1.27 (sensitivity 92.3%, specificity 100%). Further, the Ch/Cr ratio, but not other MRS data, was shown to negatively correlate with the expression of SSTR2 (P = 0.02). The Ch/Cr ratio was also found to positively correlate with the Ki-67 value (P < 0.05) and T2 signal (P < 0.05), but not with other factors that were examined in this study. Moreover, the Ch/Cr ratio could predict the EM pathological subtypes of tumors with an accuracy of 83.3% (5/6) for patients with an isointense T2 signal.

CONCLUSION

The Ch/Cr ratio by MRS could effectively predict the tumor subtype and was significantly correlated with the expression of SSTR2, which was consistent with other predictors. It was also able to distinguish the patients with isointense T2 signals. Our results provide a potentially new and non-invasive method to predict the response to SSAs in patients with GH pituitary macroadenomas.

Developing a diagnostic understanding of GERD phenotypes through the analysis of levels of mucosal injury, immune activation, and psychological comorbidity

Patients with gastroesophageal reflux disease (GERD) can present with typical or atypical symptoms. The aim of this study is to explore the underlying physiological and psychological mechanisms that lead to different symptomatic manifestations of GERD. A total of 238 patients diagnosed with GERD underwent gastroscopy, 24 h multichannel intraluminal impedance-pH (MII-pH) monitoring, and psychological assessment with questionnaires. Patient symptoms were used to classify GERD into phenotypes of typical reflux syndrome (TRS, n = 87), reflux chest pain syndrome (RCS, n = 98), and extraesophageal syndromes (EES, n = 53). 38 healthy volunteers served as controls. Reflux parameters and baseline impedance values (BIVs) were acquired from MII-pH monitoring results. A subset of subjects were biopsied from the lower esophagus; certain immune cells were stained with immunohistochemistry. BIVs in GERD patients (TRS, RCS, and EES) were significantly lower than in healthy controls and TRS patients exhibited the lowest BIVs (all P < 0.01). This indicated that the extent of mucosal injury differed across groups. TRS patients had higher acid exposure time (AET) compared to RCS, EES and controls (all P < 0.05). RCS patients had more intraepithelial T lymphocyte (IEL) and mast cell (MC) infiltration, and higher psychometric scores compared to TRS patients and controls (all P < 0.05), suggesting a possible stress-related esophageal hypersensitivity basis. TRS patients are characterized by acid reflux and correlated mucosal injury, which explains their typical reflux symptoms. RCS patients exhibit less acid-related injury but possible psychological stress-related esophageal hypersensitivity, which could be the main cause of their esophageal pain.

[Clinical management of 110 cases of polypropylene mesh and sling exposure after reconstructive pelvic floor surgery]

Objective: To explore the clinical management and outcomes of polypropylene mesh and sling exposure after reconstructive pelvic surgery (RPS) . Methods: A total of 110 cases of mesh and sling exposure after RPS were analyzed, who admitted between Jan. 2002 and Oct. 2017 in First Affiliated Hospital of PLA General Hospital, in which 3 cases were referred from other hospitals. Mesh and sling exposures were identified in the outpatient clinic and categorized and managed according to International Continence Society and International Urogynecology Association (ICS-IUGA) classification about category, time and site (CTS) of mesh complication. Outpatient management included observation, topical estrogen use and mesh removal. Management in hospital included surgical removal of exposed mesh and repair of the resulting defects under the anesthesia. Seventy-four cases were managed in the outpatient setting, and 36 cases required inpatient management. Follow-up was consecutively performed from 1 month to 10 years. Objective outcome included the surgeon's assessment of the healing state of the vaginal mucosa. Subjective outcome was evaluated with patient global impression of improvement questionnaire (PGI-I) . Results: One hundred and ten patients with mesh exposure were classified according to the different RPS underwent. There were 95 cases from transvaginal mesh surgery, 5 cases from anti-stress urinary incontinence sling surgery, and 10 cases from sacrocolpopxy. The outpatient group healed at an average of (3.0±1.8) months. Of the 36 patients who required inpatient management, 21 cases healed completely at an average of 7 days after one surgery. The remaining 8 cases required either two or three times surgeries or conservative management. In the outpatient group, the PGI-I scale very much better was found in 65 cases (87.8%) and much better in 9 cases (12.2%) . In the inpatient surgery group, the scale was very much better in 30 cases (83.3%) , and much better in 6 cases (16.7%) . Conclusions: Among patients with mesh exposure after mesh-augmented RPS, 2/3 of patients with a CTS classification 1-3 could be managed in the office, and remaining 1/3 with CTS classification 4-6 need operation under anesthesia in hospital. If the mesh and sling exposure could be scientifically classified, according to the size, site and accompany symptoms, as well as pain, most of the mesh complications after explosure could be resolved. Using the pelvic floor repair and polypropylene mesh sling, the majority of the patients could get a better outcome, without affecting the effect of the original operation.

Vaccine-Associated Maintenance of Epithelial Integrity Correlated With Protection Against Virus Entry

To identify the mechanisms by which human immunodeficiency virus type 1 (HIV-1) might penetrate the epithelial barrier during sexual transmission to women and the mechanisms of vaccine-associated protection against entry, we characterized early epithelial responses to vaginal inoculation of simian immunodeficiency virus strain mac251 (SIVmac251) in naive or SIVmac239Δnef-vaccinated rhesus macaques. Vaginal inoculation induced an early stress response in the cervicovaginal epithelium, which was associated with impaired epithelial integrity, damaged barrier function, and virus and bacterial translocation. In vaccinated animals, early stress responses were suppressed, and the maintenance of epithelial barrier integrity correlated with prevention of virus entry. These vaccine-protective effects were associated with a previously described mucosal system for locally producing and concentrating trimeric gp41 antibodies at the mucosal interface and with formation of SIV-specific immune complexes that block the stress responses via binding to the epithelial receptor FCGR2B and subsequent inhibitory signaling. Thus, blocking virus entry may be one protective mechanism by which locally concentrated non-neutralizing Ab might prevent HIV sexual transmission to women.

Optical Activation of TrkA Signaling

Nerve growth factor/tropomyosin receptor kinase A (NGF/TrkA) signaling plays a key role in neuronal development, function, survival, and growth. The pathway is implicated in neurodegenerative disorders including Alzheimer's disease, chronic pain, inflammation, and cancer. NGF binds the extracellular domain of TrkA, leading to the activation of the receptor's intracellular kinase domain. As TrkA signaling is highly dynamic, mechanistic studies would benefit from a tool with high spatial and temporal resolution. Here we present the design and evaluation of four strategies for light-inducible activation of TrkA in the absence of NGF. Our strategies involve the light-sensitive protein Arabidopsis cryptochrome 2 and its binding partner CIB1. We demonstrate successful recapitulation of native NGF/TrkA functions by optical induction of plasma membrane recruitment and homo-interaction of the intracellular domain of TrkA. This approach activates PI3K/AKT and Raf/ERK signaling pathways, promotes neurite growth in PC12 cells, and supports survival of dorsal root ganglion neurons in the absence of NGF. This ability to activate TrkA using light bestows high spatial and temporal resolution for investigating NGF/TrkA signaling.

Appropriate dose of Lactobacillus buchneri supplement improves intestinal microbiota and prevents diarrhoea in weaning Rex rabbits

This study examined the effects on intestinal microbiota and diarrhoea of Lactobacillus buchneri supplementation to the diet of weaning Rex rabbits. To this end, rabbits were treated with L. buchneri at two different doses (LC: 104 cfu/g diet and HC: 105 cfu/g diet) for 4 weeks. PCR-DGGE was used to determine the diversity of the intestinal microbiota, while real-time PCR permitted the detection of individual bacterial species. ELISA and real-time PCR allowed the identification of numerous cytokines in the intestinal tissues. Zonula occludens-1, polymeric immunoglobulin receptor and immunoglobulin A genes were examined to evaluate intestinal barriers. Results showed that the biodiversity of the intestinal microbiota of weaning Rex rabbits improved in the whole tract of the treated groups. The abundance of most detected bacterial species was highly increased in the duodenum, jejunum and ileum after L. buchneri administration. The species abundance in the HC group was more increased than in the LC group when compared to the control. Although the abundance of Enterobacteriaceae exhibited a different pattern, Escherichia coli was inhibited in all treatment groups. Toll-like receptor (TLR)2 and TLR4 genes were down-regulated in all intestinal tissues as the microbiota changed. In the LC group, the secretion of the inflammatory cytokine tumour necrosis factor-α was reduced, the gene expression of the anti-inflammatory cytokine interleukin (IL)-4 was up-regulated and the expression of intestinal-barrier-related genes was enhanced. Conversely, IL-4 expression was increased and the expression of other tested genes did not change in the HC group. The beneficial effects of LC were greater than those of HC or the control in terms of improving the daily weight gain and survival rate of weaning Rex rabbits and reducing their diarrhoea rate. Therefore, 104 cfu/g L. buchneri treatment improved the microbiota of weaning Rex rabbits and prevented diarrhoea in these animals.

Vaccine-modified NF-kB and GR signaling in cervicovaginal epithelium correlates with protection

Cervicovaginal epithelium plays a critical role in determining the outcome of virus transmission in the female reproductive tract (FRT) by initiating or suppressing transmission-facilitating mucosal immune responses in naïve and SIVmac239Δnef-vaccinated animals, respectively. In this study, we examined the very early responses of cervical epithelium within 24 h after vaginal exposure to SIV in naive and SIVmac239Δnef-vaccinated rhesus macaques. Using both ex vivo and in vivo experimental systems, we found that vaginal exposure to SIV rapidly induces a broad spectrum of pro-inflammatory responses in the epithelium associated with a reciprocal regulation of NF-kB and glucocorticoid receptor (GR) signaling pathways. Conversely, maintenance of high-level GR expression and suppression of NF-kB expression in the epithelium were associated with an immunologically quiescent state in the FRT mucosa and protection against vaginal challenge in SIVmac239Δnef-vaccinated animals. We show that the immunologically quiescent state is induced by FCGR2B-immune complexes interactions that modify the reciprocal regulation of NF-kB and GR signaling pathways. Our results suggest that targeting the balance of NF-kB and GR signaling in early cervicovaginal epithelium responses could moderate mucosal inflammation and target cell availability after vaginal infection, thereby providing a complementary approach to current prevention strategies.

[Retroperitoneal laparoscopic debridement therapy for infected severe acute pancreatitis]

Objective: To investigate the feasibility and availability of retroperitoneal laparoscopic debridement therapy for patients with infected severe acute pancreatitis. Methods: Clinical data of 6 patients with severe acute pancreatitis who underwent retroperitoneal laparoscopic necrotic tissue debridement therapy in the Severe Acute Pancreatitis Center of Sir Run Run Hospital between August 2014 and October 2015 was retrospectively analyzed. The laparoscopic instruments and sponge forceps were used to remove necrotic tissue under retroperitoneal space, and double-cavity drainage tube was left for continuous washing. The perioperative indicators were collected and analyzed. Results: Two of six patients underwent two surgeries, and the others underwent one surgery, with an average operation time of (220.0±58.3) minutes and a mean hospital stay time of 62.6 days (35-117 days). One patient underwent re-operation after 33 days because of intraperitoneal hemorrhage, and another patient suffered pancreatic pseudocyst after the surgery, but no one died in hospital. Conclusion: Retroperitoneal laparoscopic debridement therapy is an additional choice for patients with infected severe acute pancreatitis, especially for those who had limited necrosis under retroperitoneal space. Furthermore, the therapy is in line with the concept of minimally invasive surgery and enhanced recovery after surgery.

Revealing the Cell-Material Interface with Nanometer Resolution by Focused Ion Beam/Scanning Electron Microscopy

The interface between cells and nonbiological surfaces regulates cell attachment, chronic tissue responses, and ultimately the success of medical implants or biosensors. Clinical and laboratory studies show that topological features of the surface profoundly influence cellular responses; for example, titanium surfaces with nano- and microtopographical structures enhance osteoblast attachment and host-implant integration as compared to a smooth surface. To understand how cells and tissues respond to different topographical features, it is of critical importance to directly visualize the cell-material interface at the relevant nanometer length scale. Here, we present a method for in situ examination of the cell-to-material interface at any desired location, based on focused ion beam milling and scanning electron microscopy imaging to resolve the cell membrane-to-material interface with 10 nm resolution. By examining how cell membranes interact with topographical features such as nanoscale protrusions or invaginations, we discovered that the cell membrane readily deforms inward and wraps around protruding structures, but hardly deforms outward to contour invaginating structures. This asymmetric membrane response (inward vs outward deformation) causes the cleft width between the cell membrane and the nanostructure surface to vary by more than an order of magnitude. Our results suggest that surface topology is a crucial consideration for the development of medical implants or biosensors whose performances are strongly influenced by the cell-to-material interface. We anticipate that the method can be used to explore the direct interaction of cells/tissue with medical devices such as metal implants in the future.