Sex Differences in Proximal Thoracic Aortic Disease Pathology: A Call to Action

Introduction/Objective

Sex disparity is reported across all forms of cardiovascular diseases. Only few studies have focused on sex differences in thoracic aortic disease pathology. We aim to identify and understand sex differences in this patient group to bridge the knowledge gap and improve clinicopathologic outcomes.

Methods/Case Report

This is a retrospective analysis of 83 proximal thoracic aortic aneurysm and dissection (TAAD) cases treated at a single quaternary care center in 2019. Chart review was done for demographics. Consensus criteria (Stone JR et al. Cardiovasc Pathol 2015; 24:267-78; Halushka MK et al. Cardiovasc Pathol 2016; 25:247-57) and a scoring system (Waters KM et al. Cardiovasc Pathol 2017; 30:6-11) were used for pathology reporting. Clinical correlation was also made. Pearson’s chi-square test was used for statistical analysis.

Results (if a Case Study enter NA)

83 patients (61 male and 22 female) were retrieved. Overall thoracic aortopathy was higher among males, accounting for 73.4% of individuals with TAAD. In a subgroup analysis, there was no sex difference in dissection, aortic root involvement, and bicuspid aortic valve (p>0.05). Genetic aortopathy was more prevalent in females than males (27.2% vs 9.8%, p=0.04) alongside early age at first aortic event (median age: 31y vs 52y). Histopathologically, females had frequent translamellar mucoid extracellular matrix accumulation (45.4% vs 22.9%, p=0.04), extensive (54.5% vs 27.8%, p=0.02) and severe (59% vs 34.4%, p=0.04) elastic fiber fragmentation, higher band like (9% vs 6.5%, p>0.05) plus extensive (13.6% vs 4.9%, p>0.05) smooth muscle nuclei loss, and extensive (13.6% vs 1.6%, p=0.01) plus dense (4.5% vs 1.6%, p>0.05) laminar medial collapse than males.

Conclusion

In our patient population, females have a lower prevalence of thoracic aortic disease treated with open repair. However, those who develop TAAD harbor a greater burden of wall pathology and probable worse outcomes. We recommend sex-based analysis of all research on thoracic aortic diseases.

The first case of BRG (SMARCA4)/INI Deficient Tracheal Carcinoma: A Case Report and Review of the Literature

Introduction/Objective

Primary tumors of the trachea are rare, they account for less than 0.1% of tumors in humans. In adults, 90% of primary tracheal tumors are malignant, with squamous cell carcinoma and adenoid cystic carcinoma accounting for two-thirds, with other forms occurring less frequently. The BRG (SMARCA4)/INI deficient tumor is a relatively new defined entity which is recently introduced in the WHO Classification of Tumors, 5th edition, 2021. The gene SMARCA4 is located at 19p13. Loss of SMARCA4 has been reported in several aggressive tumors with high- grade undifferentiated rhabdoid morphology but has not been reported in the trachea. Hence, we report the first case of BRG (SMARCA4)/ INI deficient tracheal carcinoma.

Methods/Case Report

We present a 60-year-old male with a history of tobacco abuse, shortness of breath, and a tracheal mass on chest imaging. Bronchoscopy was performed and showed a fleshy friable lesion at the anterior trachea with evidence of blood dripping into the distal airways.

Results (if a Case Study enter NA)

Microscopic examination showed a high grade, poorly differentiated carcinoma with tumor necrosis, high mitotic counts, and marked nuclear pleomorphism. Immunohistochemical stains were performed. The tumor cells were strongly and diffusely positive for CK-7 and weakly positive for synaptophysin, negative for pan-cytokeratin, TTF-1, CK-20, p40, CK5/6, and chromogranin. Then BRG (SMARCA4) and INI 1 (BAR47) were performed and showed negative staining on BRG expression, while INI 1 is intact (nuclear expression). These features are consistent with BRG (SMARCA4)/ INI deficient carcinoma.

Conclusion

BRG (SMARCA4)/ INI deficient carcinoma is a new entity in the trachea, which is very aggressive with a poor prognosis. Targeted therapy or clinical trials may be available as additional cases are diagnosed in the future.

Expression and clinical significance of MMP-9 and P53 in lung cancer

OBJECTIVE

This study aimed to investigate the expression of MMP-9 (matrix metalloproteinases 9) and P53 (tumor suppressor proteins, tumor protein P53) in serum of patients with lung cancer. The relation between the two factors and their clinical pathological features were also explored.

PATIENTS AND METHODS

150 patients were selected as the experimental group. They were diagnosed with lung cancer in Shandong Province Chest Hospital from January 2014 to January 2017. Meanwhile, 90 healthy subjects were selected as the control group. The expression levels of MMP-9 and P53 in serum were detected by fluorescence quantitative Real-Time Polymerase Chain Reaction (RT-PCR). The diagnostic value of MMP-9 and P53 in patients with lung cancer was analyzed by receiver operating characteristic curve (ROC). Pearson test was used to analyze the correlation between MMP-9 and P53 in the experimental group. The patients were divided into high expression and low expression groups according to the median of MMP-9 and P53 expressions.

RESULTS

The expressions of MMP-9 and P53 in patients with lung cancer were higher than the normal level (p<0.05). MMP-9 and P53 in serum of the experimental group were closely related to patients' TNM-stage, degree of differentiation, lymph node metastases, smoking history and pattern of organization (p<0.05). The expressions of MMP-9 and P53 were positively correlated (p<0.001).

CONCLUSIONS

The expressions of MMP-9 and P53 played important roles in lung cancer and were closely related to clinicopathology and three-year survival rate. They could provide help for the diagnosis and treatment of clinical lung cancer.

LINC00483 is regulated by IGF2BP1 and participates in the progression of breast cancer

OBJECTIVE

To explore the role of long intergenic non-coding ribonucleic acid 483 (LINC00483) in the development of breast cancer (BC) and its possible mechanism of action.

PATIENTS AND METHODS

LINC00483 expression level in BC tissues and cell lines was detected via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). The association between LINC00483 expression and survival rate of BC patients was analyzed using Kaplan-Meier survival analysis. The binding relation between LINC00483 and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) was verified via RNA immunoprecipitation (RIP) and RNA pull-down assays. The expression of IGF2BP1 in BC patients was determined using qRT-PCR. Moreover, the role of LINC00483 on the proliferative ability of BC cells was detected via cell counting kit-8 (CCK8) and 5-Ethynyl-2'-deoxyuridine (EdU) assays. Whether LINC00483 exerts its effects under the regulation of IGF2BP1 was verified via reversal assay.

RESULTS

The results of qRT-PCR showed that LINC00483 had a significantly high expression in BC tissues and corresponding cell lines, and it rose with the increase in tumor stage, which was higher in patients with metastasis. CCK8/EdU assay revealed that the proliferative ability of MDA-MB-231 and MCF-7 cell lines was enhanced by overexpression of LINC00483. It was confirmed by RIP and pull-down assays that IGF2BP1 could bind to LINC00483, and the expression of LINC00483 was significantly promoted after up-regulation of IGF2BP1. It was found via qRT-PCR that the expression of IGF2BP1 evidently rose in BC patients, which was positively related with the expression level of LINC00483. The results of reversal assay manifested that the function of LINC00483 on cell proliferation was regulated by IGF2BP1.

CONCLUSIONS

LINC00483 has a significantly higher expression in BC tissues than that in para-carcinoma tissues, and its effect of promoting proliferation of BC cells may be regulated by IGF2BP1.

The clinical characteristic of biliary-hyperlipidemic etiologically complex type of acute pancreatitis: a retrospective study from a tertiary center in China

OBJECTIVE

Biliary and hyperlipidemic acute pancreatitis (AP) has become the second most common AP in China. Currently, AP is exclusively diagnosed as biliary or hyperlipidemic AP. However, as suggested by some reports, biliary and hyperlipidemic AP might coexist in a single patient. Moreover, acute lipotoxicity was shown to regulate the severity of biliary AP in the mouse model. Thus, whether these two etiologies coexist in AP patients and potentially worsen the clinical course remains unclear. To elucidate the clinical feature of a new complex type of acute pancreatitis with both biliary and hyperlipidemic etiologies.

PATIENTS AND METHODS

This retrospective study included AP patients who were admitted into our department within 7 days after the onset of the disease. 267 AP patients were enrolled in this study and were classified as BAP (biliary acute pancreatitis, n=153), HLAP (hyperlipidemic acute pancreatitis, n=65) and BHAP (biliary-hyperlipidemic acute pancreatitis, n=49). All the enrolled patients met the classification criteria of biliary etiology, hyperlipidemic etiology, and both etiologies, respectively. BHAP was compared with BAP and HLAP in terms of general information, inflammatory biomarkers, organ dysfunction, disease severity and clinical outcomes.

RESULTS

BHAP (41 vs. 53) patients were younger than BAP patients. Serum procalcitonin of BHAP patients was higher than BAP and HLAP patients. Serum CRP of BHAP patients was higher than BAP patients. BHAP patients had the highest diagnosis rate of severe acute pancreatitis (SAP) (46.9% vs. 17.6% or 21.5%) compared to BAP and HLAP. Prevalences of persistent respiratory, acute renal, and circulatory failure were highest in BHAP patients (44.9%, 28.6%, 12.2%, respectively). Requirements for mechanical ventilation, renal replacement therapy and vasoactive agents were also highest in BHAP patients (36.7%, 34.7%, 12.2%, respectively). Hospital stay was longer in BHAP patients (33 days) compared with BAP patients (24 days).

CONCLUSIONS

Patients with both biliary and hyperlipidemic etiologies suffer from more severe clinical course of the disease and have worse prognosis than single-etiology BAP or HLAP patients in the early stage of AP (within 7 days). It should be recognized as a new etiological type named biliary-hyperlipidemic acute pancreatitis (BHAP).

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

Correlations of Helicobacter pylori with liver function, inflammatory factors and serum levels of FoxP3 and RORγt in patients with hepatitis B cirrhosis

OBJECTIVE

To investigate the correlations of Helicobacter pylori (HP) with liver function, inflammatory factors and serum levels of forkhead box P3 (FoxP3) and retinoic acid receptor-related orphan receptor gamma-t (RORγt) in patients with hepatitis B cirrhosis (HBC).

PATIENTS AND METHODS

A total of 60 HBC patients were divided into HBC group (n=30) and HP-infected HBC group (HP&HBC group, n=30). QRT-PCR was conducted to determine the messenger ribonucleic acid (mRNA) levels of FoxP3 and RORγt in serum samples. ELISA was applied to measure the levels of relevant inflammatory factors. Besides, immunohistochemical staining was conducted to detect positive expressions of FoxP3 and RORγt in liver tissues of patients in the two groups.

RESULTS

No significant differences in gender, drinking, smoking, diabetes and age were found between HBC group and HP&HBC group (p>0.05). Globulin and albumin levels were comparable between the two groups (p>0.05). Liver function indexes, including ALT, AST and TBIL were higher in HP&HBC group than those in HBC group (p<0.05). The HBV-DNA level was lower in HBC group in comparison with that in HP&HBC group. The interferon-gamma (IFN-γ) level was remarkably higher in HBC group than that in HP&HBC group (p<0.01), and the levels of interleukin (IL)-6, IL-10, IL-17 and transforming growth factor (TGF)-β1 were notably lower in HBC group in comparison with those in HP&HBC group (p<0.01). Additionally, the mRNA levels of FoxP3 and RORγt in HBC group were distinctly lower than those in HP&HBC group (p<0.01). The mRNA levels of FoxP3 and RORγt were positively related to those of IL-6, IL-10, IL-17, and TGF-β1, and negatively associated with IFN-γ level. Immunohistochemical results indicated that positive expression rates of FoxP3 and RORγt in the liver tissues were approximately 50% in HP&HBC group and B. Zhao, Q.-J. Sheng, Y. Qin, X.-L. Wang, H. Zhao, N. Zhaowere 15% in HBC group, and the difference was statistically significant (p<0.05).

CONCLUSIONS

Expression levels of FoxP3 and RORγt in serum and liver tissues are elevated in HP-infected HBC patients, and inflammatory factors are correlated with their expressions, suggesting the aggravated liver damage.

Standardization in Quantitative Imaging: A Multicenter Comparison of Radiomic Features from Different Software Packages on Digital Reference Objects and Patient Data Sets

Radiomic features are being increasingly studied for clinical applications. We aimed to assess the agreement among radiomic features when computed by several groups by using different software packages under very tightly controlled conditions, which included standardized feature definitions and common image data sets. Ten sites (9 from the NCI's Quantitative Imaging Network] positron emission tomography–computed tomography working group plus one site from outside that group) participated in this project. Nine common quantitative imaging features were selected for comparison including features that describe morphology, intensity, shape, and texture. The common image data sets were: three 3D digital reference objects (DROs) and 10 patient image scans from the Lung Image Database Consortium data set using a specific lesion in each scan. Each object (DRO or lesion) was accompanied by an already-defined volume of interest, from which the features were calculated. Feature values for each object (DRO or lesion) were reported. The coefficient of variation (CV), expressed as a percentage, was calculated across software packages for each feature on each object. Thirteen sets of results were obtained for the DROs and patient data sets. Five of the 9 features showed excellent agreement with CV < 1%; 1 feature had moderate agreement (CV < 10%), and 3 features had larger variations (CV ≥ 10%) even after attempts at harmonization of feature calculations. This work highlights the value of feature definition standardization as well as the need to further clarify definitions for some features.

Selective optogenetic stimulation of glutamatergic, but not GABAergic, vestibular nuclei neurons induces immediate and reversible postural imbalance in mice

Glutamatergic and GABAergic neurons represent the neural components of the medial vestibular nuclei. We assessed the functional role of glutamatergic and GABAergic neuronal pathways arising from the vestibular nuclei (VN) in the maintenance of gait and balance by optogenetically stimulating the VN in VGluT2-cre and GAD2-cre mice. We demonstrate that glutamatergic, but not GABAergic VN neuronal subpopulation is responsible for immediate and strong posturo-locomotor deficits, comparable to unilateral vestibular deafferentation models. During optogenetic stimulation, the support surface dramatically increased in VN^VGluT2+ mice, and rapidly fell back to baseline after stimulation, whilst it remained unchanged during similar stimulation of VN^GAD2+ mice. This effect persisted when vestibular tactilo kinesthesic plantar inputs were removed. Posturo-locomotor alterations evoked in VN^VGluT2+ animals were still present immediately after stimulation, while they disappeared 1 h later. Overall, these results indicate a fundamental role for VN^VGluT2+ neurons in balance and posturo-locomotor functions, but not for VN^GAD2+ neurons, in this specific context. This new optogenetic approach will be useful to characterize the role of the different VN neuronal populations involved in vestibular physiology and pathophysiology.

Regulation of Osteoclastogenesis and Bone Resorption by miRNAs

Osteoclasts are specialized bone-resorbing cells that contribute to physiological bone development and remodeling in bone metabolism throughout life. Abnormal production and activation of osteoclasts lead to excessive bone resorption in pathological conditions, such as in osteoporosis and in arthritic diseases with bone destruction. Recent epigenetic studies have shed novel insight into the dogma of the regulation of gene expression. microRNAs belong to a category of epigenetic regulators, which post-transcriptionally regulate and silence target gene expression, and thereby control a variety of biological events. In this review, we discuss miRNA biogenesis, the mechanisms utilized by miRNAs, several miRNAs that play important roles in osteoclast differentiation, function, survival and osteoblast-to-osteoclast communication, and their translational potential and challenges in bone biology and skeletal diseases.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

Effect of different CAD/CAM cutting depths on the post-fatigue load-bearing capacity of novel multilayer zirconia restorations

OBJECTIVES

To investigate the post-fatigue load-bearing capacity of restorations milled at various cutting depths in a novel strength- and color-gradient multilayer zirconia CAD/CAM disk.

METHODS

Identical crowns were divided into 4 groups (n = 25 per group): crowns milled at 3 CAD/CAM cutting depths in multilayer zirconia disks as 3 experiment groups and homogeneous zirconia crowns as a control group. The color differences between various cutting depths were measured. In each group, crowns were tilted at 15° and subjected to fatigue loading for various numbers of cycles (0, 10⁶, 2 × 10⁶, 3 × 10⁶ or 4 × 10⁶, n = 5 per subgroup). All surviving crowns were subsequently submitted to a static fracture test to determine load-bearing capacity. The data were analyzed by ANOVA and Weibull distribution analysis. Failure modes were observed with SEM.

RESULTS

For a novel multilayer zirconia, a deeper CAD/CAM cutting depth corresponded to a higher load-bearing capacity but a darker color. After 10⁶ cycles of fatigue loading, there was not a significant reduction in fracture load. However, after 4 × 10⁶ cycles, the load-bearing capacity of all crowns decreased significantly by approximately 50%. For multilayer and homogeneous zirconia materials, similar failure mode and Weibull modulus were identified.

CONCLUSIONS

Restorations can be milled at various CAD/CAM cutting depths in a novel multilayer zirconia disk depending on the durability and esthetic requirements. The load-bearing capacity of multilayer restorations degraded significantly after 4 × 10⁶ cycles of fatigue loading, but not after 10⁶ cycles.

CLINICAL SIGNIFICANCE

For a novel multilayer zirconia disk, a posterior restoration can be milled from the middle or bottom of the disk to improve its load-bearing capacity. For an anterior restoration, to meet the esthetic requirements, milling the entire thickness of a multilayer disk is recommended.

Mitochondrial Behavior in Axon Degeneration and Regeneration

Mitochondria are organelles responsible for bioenergetic metabolism, calcium homeostasis, and signal transmission essential for neurons due to their high energy consumption. Accumulating evidence has demonstrated that mitochondria play a key role in axon degeneration and regeneration under physiological and pathological conditions. Mitochondrial dysfunction occurs at an early stage of axon degeneration and involves oxidative stress, energy deficiency, imbalance of mitochondrial dynamics, defects in mitochondrial transport, and mitophagy dysregulation. The restoration of these defective mitochondria by enhancing mitochondrial transport, clearance of reactive oxidative species (ROS), and improving bioenergetic can greatly contribute to axon regeneration. In this paper, we focus on the biological behavior of axonal mitochondria in aging, injury (e.g., traumatic brain and spinal cord injury), and neurodegenerative diseases (Alzheimer's disease, AD; Parkinson's disease, PD; Amyotrophic lateral sclerosis, ALS) and consider the role of mitochondria in axon regeneration. We also compare the behavior of mitochondria in different diseases and outline novel therapeutic strategies for addressing abnormal mitochondrial biological behavior to promote axonal regeneration in neurological diseases and injuries.

A88 PATIENT AND PHYSICIAN PERSPECTIVE OF TELE-HEALTH IN GASTROENTEROLOGY

Background

Given the social distancing measures employed to reduce the transmission of SARS-CoV-2, tele-health has rapidly expanded and is now routinely used in new patient encounters and in follow up appointments across Canada.

Aims

To determine the patient and physician perspective towards tele-health in a gastroenterology outpatient setting.

Methods

An anonymous voluntary online survey was distributed to patients who had previously undergone at least one tele-health visit in a tertiary care gastroenterology outpatient setting. A separate online survey was distributed to gastroenterologists practising across Canada.

Results

A total of 181 patients from British Columbia (59.8% female) completed the survey. The tele-health appointment was the first visit for 21.8% of patients. Appointments occurred by phone call alone (61.4%) or by video and audio software (38.6%) and started within 5 minutes of the scheduled time in 75% of visits. Patient satisfaction with the tele-health visit was high (8.54 on a scale of 0–10; 0 completely dissatisfied, 10 extremely satisfied; IQR 8–10). Most patients did not perceive a difference in likelihood of compliance compared to a non-tele-health visit (90.6%), were not concerned about the lack of physical exam during a tele-health visit (82.4%) and did not with-hold information they would have revealed in person (88.7%). After the COVID-19 pandemic, some patients would prefer tele-heath visits (39.2%), whereas others would prefer in office visits (28.5%) and the remainder were indifferent (32.3%). Post-pandemic, most patients would prefer tele-health for follow up visits (68.4%), over tele-health for all possible visits (27.9%) or no tele-health visits (3.8%).

A total of 25 Canadian gastroenterologists (28.0% female; 60% academic practice, 40% community practice) completed a separate survey. Regarding the lack of physical exam in tele-health, 44% of physicians believed this did not affect the quality of their assessment, whereas some physicians believed it had either minimally (48%) or greatly (8%) impaired the quality of their assessment. Almost all physicians (96%) perceived that patients either appreciate tele-health as much as or more than in office visits.

Post-pandemic, most physicians (96%) supported a hybrid model of both tele-health and in office visits. Appointments for follow up of benign endoscopic pathology results (96%), follow up visits (92%), consultations prior to endoscopy (76%) were deemed to be most appropriate for tele-health. Follow up of malignant pathology results (24%) and consultations for new patients (32%) were thought to be less appropriate for tele-health visits.

Conclusions

Patient and physician satisfaction with tele-health in a Canadian outpatient gastroenterology setting is high. Most patients and physicians wish for tele-health to remain available in the post-pandemic setting.

Funding Agencies

Gastrointestinal Research Institute, Vancouver, British Columbia

A83 IMPACT OF TELEHEALTH ON MEDICATION ADHERENCE IN GASTROENTEROLOGY CHRONIC DISEASE MANAGEMENT

Background

With the COVID-19 pandemic, the demand and availability of telehealth in outpatient care has increased. Although use of telehealth has been studied and validated for various medical specialties, relatively few studies have looked at its role in gastroenterology despite burden of chronic diseases such as inflammatory bowel disease (IBD).

Aims

To assess effectiveness of telehealth medicine in gastroenterology by comparing medication adherence rate for patients seen with telehealth and traditional in-person appointment for various GI conditions.

Methods

Retrospective chart analysis of patients seen in outpatient gastroenterology clinic was performed to identify patients who were given prescription to fill either through telehealth or in-person appointment. By using provincial pharmacy database, we determined the prescription fill rate.

Results

A total of 241 patients were identified who were provided prescriptions during visit with their gastroenterologists. 128 patients were seen through in-person visit during pre-pandemic period. 113 patients were seen through telehealth appointment during COVID pandemic.

The mean age of patients in telehealth cohort was 42 years (57% male). On average patients had 10 prior visits with their gastroenterologists before index appointment, used for adherence assessment. 92% of patients were seen in follow-up, while 8% were seen in initial consultation. The majority of the patients in the telehealth cohort had IBD (89%), while the remaining 11% had various diagnoses, including functional GI disorder, gastroesophageal reflux disease, viral hepatitis, or hepatobiliary disorders. Biologic therapy was the most commonly prescribed medication (66.4%). 45 patients were provided either new medication or dose change, and 68 patients had prescription refill to continue their current medications. It took a mean of 18 days (SD = 16.2) for patients to fill their prescriptions.

Prescription fill rate for patients seen through telehealth and in-person visit were 98.2% and 89.1% (P = 0.004) respectively. Patients seen through telehealth were 6.8 times more likely to fill their prescriptions compared to the in-person counterparts (OR 6.82, CI 1.51 – 30.68, P = 0.004). When we compared adherence rate while excluding biologic therapies, the prescription fill rate was 94.7% in telehealth group and 81.4% in in-person group (OR 4.11, CI 0.88 – 19.27, P = 0.056). Due to high level of adherence, statistical analysis comparing adherent and non-adherent groups was performed but yielded insignificant results.

Conclusions

Medication adherence rate for patients seen through telehealth was higher compared to patients seen through in-patient visit in this study. Telehealth is a viable alternative for outpatient care especially for patients with chronic GI conditions such as IBD.

Funding Agencies

None

Adipsin promotes bone marrow adiposity by priming mesenchymal stem cells

Background

Marrow adipose tissue (MAT) has been shown to be vital for regulating metabolism and maintaining skeletal homeostasis in the bone marrow (BM) niche. As a reflection of BM remodeling, MAT is highly responsive to nutrient fluctuations, hormonal changes, and metabolic disturbances such as obesity and diabetes mellitus. Expansion of MAT has also been strongly associated with bone loss in mice and humans. However, the regulation of BM plasticity remains poorly understood, as does the mechanism that links changes in marrow adiposity with bone remodeling.

Methods

We studied deletion of Adipsin, and its downstream effector, C3, in C57BL/6 mice as well as the bone-protected PPARγ constitutive deacetylation 2KR mice to assess BM plasticity. The mice were challenged with thiazolidinedione treatment, calorie restriction, or aging to induce bone loss and MAT expansion. Analysis of bone mineral density and marrow adiposity was performed using a μCT scanner and by RNA analysis to assess adipocyte and osteoblast markers. For in vitro studies, primary bone marrow stromal cells were isolated and subjected to osteoblastogenic or adipogenic differentiation or chemical treatment followed by morphological and molecular analyses. Clinical data was obtained from samples of a previous clinical trial of fasting and high-calorie diet in healthy human volunteers.

Results

We show that Adipsin is the most upregulated adipokine during MAT expansion in mice and humans in a PPARγ acetylation-dependent manner. Genetic ablation of Adipsin in mice specifically inhibited MAT expansion but not peripheral adipose depots, and improved bone mass during calorie restriction, thiazolidinedione treatment, and aging. These effects were mediated through its downstream effector, complement component C3, to prime common progenitor cells toward adipogenesis rather than osteoblastogenesis through inhibiting Wnt/β-catenin signaling.

Conclusions

Adipsin promotes new adipocyte formation and affects skeletal remodeling in the BM niche. Our study reveals a novel mechanism whereby the BM sustains its own plasticity through paracrine and endocrine actions of a unique adipokine.

Funding

This work was supported by the National Institutes of Health T32DK007328 (NA), F31DK124926 (NA), R01DK121140 (JCL), R01AR068970 (BZ), R01AR071463 (BZ), R01DK112943 (LQ), R24DK092759 (CJR), and P01HL087123 (LQ).

MiR-33a inhibits the adipogenic differentiation of ovine adipose-derived stromal vascular fraction cells by targeting SIRT6

Adipose tissue is important for the regulation of energy balance through its metabolic, cellular, and endocrine functions. Furthermore, the excessive storage of subcutaneous fat can seriously affect the health and carcass traits of domestic animals. Stromal vascular fraction (SVF) cell adipogenic differentiation increases the number of differentiated adipocytes and plays a role in lipid deposition. The adipogenic differentiation of SVF cells is regulated by various factors, including microRNAs and cytokines. Sirt6 and miR-33a are known to be involved in metabolism and adipogenesis, respectively; however, their effects on the adipogenic differentiation of ovine SVF cells were previously unknown. Thus, the aim of this study was to investigate this. The results showed that SIRT6 is a binding target for miR-33a. Moreover, overexpression or inhibition of miR-33a was found to change the expression of SIRT6 messenger RNA and protein. Furthermore, modulating SIRT6 altered the expression of adipogenic marker genes. In addition, miR-33a and SIRT6 were found to play opposing roles in adipogenesis. Specifically, we demonstrated that miR-33a is involved in the negative regulation of ovine SVF cell adipogenic differentiation by inhibiting the expression of SIRT6. These findings reveal a key role for miR-33a and SIRT6 in adipogenesis, which will enrich our understanding of the regulatory factors associated with SVF cell adipogenic differentiation and provide a basis for further study on this process.

Def6 regulates endogenous type-I interferon responses in osteoblasts and suppresses osteogenesis

Bone remodeling involves a balance between bone resorption and formation. The mechanisms underlying bone remodeling are not well understood. DEF6 is recently identified as a novel loci associated with bone mineral density. However, it is unclear how Def6 impacts bone remodeling. We identify Def6 as a novel osteoblastic regulator that suppresses osteoblastogenesis and bone formation. Def6 deficiency enhances both bone resorption and osteogenesis. The enhanced bone resorption in Def6-/- mice dominates, leading to osteoporosis. Mechanistically, Def6 inhibits the differentiation of both osteoclasts and osteoblasts via a common mechanism through endogenous type-I IFN-mediated feedback inhibition. RNAseq analysis shows expression of a group of IFN stimulated genes (ISGs) during osteoblastogenesis. Furthermore, we found that Def6 is a key upstream regulator of IFNβ and ISG expression in osteoblasts. Collectively, our results identify a novel immunoregulatory function of Def6 in bone remodeling, and shed insights into the interaction between immune system and bone.

The colonic macrophage transcription factor RBP-J orchestrates intestinal immunity against bacterial pathogens

Macrophages play pleiotropic roles in maintaining the balance between immune tolerance and inflammatory responses in the gut. Here, we identified transcription factor RBP-J as a crucial regulator of colonic macrophage–mediated immune responses against the enteric pathogen Citrobacter rodentium. In the immune response phase, RBP-J promoted pathogen clearance by enhancing intestinal macrophage-elicited Th17 cell immune responses, which was achieved by maintenance of C/EBPβ-dependent IL-6 production by overcoming miRNA-17∼92–mediated suppressive effects. RBP-J deficiency–associated phenotypes could be genetically corrected by further deleting miRNA-17∼92 in macrophages. In the late phase, noneradicated pathogens in RBP-J KO mice recruited abundant IL-1β–expressing CD64⁺Ly6C⁺ colonic macrophages and thereby promoted persistence of ILC3-derived IL-22 to compensate for the impaired innate and adaptive immune responses, leading to ultimate clearance of pathogens. These results demonstrated that colonic macrophage–intrinsic RBP-J dynamically orchestrates intestinal immunity against pathogen infections by interfacing with key immune cells of T and innate lymphoid cell lineages.