The current role of barbed sutures in fascial closure of ventral hernia repair: a multicenter study using the abdominal core health quality collaborative database.

BACKGROUND: Barbed sutures (BS) have been increasingly used in the last two decades across surgical disciplines but little is known about how widespread their adoption has been in ventral hernia repair (VHR). The aim of this study was to document the use of barbed sutures in VHR in a multicenter database with associated clinical and patient-reported outcomes. METHOD: Prospectively collected data from the Abdominal Core Health Quality Collaborative database was retrospectively reviewed, including all adult patients who underwent VHR with fascial closure from 2020 to 2022. A univariate analysis compared patients with BS against non-barbed sutures (NBS) across the preoperative, intraoperative, and postoperative timeframes including patient-reported outcomes concerning quality of life and pain scores. RESULTS: A total of 4054 patients that underwent ventral hernia repair with BS were compared with 6473 patients with non-barbed sutures (NBS). Overall, BS were used in 86.2% of minimally invasive ventral hernia repairs and about 92.2% of robotic surgery compared to only 9.6% of open procedures. Notable differences existed in patient selection, including a higher BMI (32 vs 30.5; p < 0.001), more incisional hernias (63.3% vs 51.1%; p < 0.001), wider hernias (4 cm vs 3 cm; p < 0.001), and higher ASA score (p < 0.001) in patients with BS. Outcomes in patients with BS included a shorter length of stay (mean days; 1.4 vs 2.4; p < 0.001), less SSI (1.5% vs 3.6%; p < 0.001), while having similar SSO (7.6% vs 7.3%; p = 0.657), readmission (3.0 vs 3.2; p = 0.691), and reoperation (1.5% vs 1.45%; p = 0.855), at a longer operative time (p < 0.001). Hernia-specific questionnaires for quality of life (HerQLes) and pain in patients with BS had a worse preoperative score that was later matched and favorable compared to NBS (p = 0.048). PRO concerning hernia recurrence suggest around 10% at two years of follow-up (p = 0.532). CONCLUSION: Use of barbed sutures in VHR is widespread and highly related to MIS. Outcomes from this multicenter database cannot be reported as superior but suggest that barbed sutures do not have a negative impact on outcomes.

Effect of COVID-19 changes on outcomes and socioeconomic disparities following metabolic and bariatric surgery.

BACKGROUND: We previously showed worse outcomes among lower socioeconomic status (SES) groups following metabolic/bariatric surgery (MBS). In light of healthcare changes in response to COVID-19, this study aims to evaluate post-pandemic MBS outcomes and determine if prior socioeconomic disparities persisted in the post-COVID era. METHODS: A retrospective chart review of patients undergoing primary Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) between 2015 and 2022 was performed. Patients were stratified into pre- and post-COVID groups. Post-COVID cohort was further stratified into high (HT) and low (LT) tier status based on Distressed Communities Index, a geocoded composite measure of SES. Preoperative characteristics and postoperative outcomes were compared between pre- and post-COVID cohorts, as well as between post-COVID HT and LT groups. RESULTS: Of 709 patients, 82.9% were pre-COVID and 17.1% were post-COVID. Post-COVID cohort had greater rate of public insurance (46% vs. 37%, p < 0.001), longer wait time to surgery (mean 358 ± 609.8 days vs 241.9 ± 368.5 days, p = 0.045), and were more likely to undergo RYGB (69% vs. 56%, p = 0.010). Post-COVID patients also had lower risk of any complications on multivariable analysis (OR 0.599, 95% CI 0.372-0.963), had higher follow-up rates at post-discharge (95.8% vs 79.7%, p < 0.005), 6-month (93% vs. 82%, p < 0.001) and 12-month visits (75% vs. 63%, p = 0.005), and lost more weight at 12 months (67% excess weight loss (%EWL) vs. 58%EWL, p = 0.002). Among post-COVID HT and LT cohorts, previously seen disparities in complications were no longer seen. Finally, there were no differences in weight or follow-up rates between post-COVID HT and LT. CONCLUSIONS: Post-COVID changes to MBS care have resulted in improved short-term outcomes and reduced disparities for patients of lower SES. Further studies are needed to identify these positive factors to perpetuate practice patterns that optimize care for patients of all socioeconomic status.

Investigating the Bone Bruise Patterns in Pediatric Patients With Contact and Noncontact Acute Anterior Cruciate Ligament Tears: A Multicenter Study.

BACKGROUND: In adults with anterior cruciate ligament (ACL) tears, bone bruises on magnetic resonance imaging (MRI) scans provide insight into the underlying mechanism of injury. There is a paucity of literature that has investigated these relationships in children with ACL tears. PURPOSE: To examine and compare the number and location of bone bruises between contact and noncontact ACL tears in pediatric patients. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Boys ≤14 years and girls ≤12 years of age who underwent primary ACL reconstruction surgery between 2018 and 2022 were identified at 3 separate institutions. Eligibility criteria required detailed documentation of the mechanism of injury and MRI performed within 30 days of the initial ACL tear. Patients with congenital lower extremity abnormalities, concomitant fractures, injuries to the posterolateral corner and/or posterior cruciate ligament, previous ipsilateral knee injuries or surgeries, or closed physes evident on MRI scans were excluded. Patients were stratified into 2 groups based on a contact or noncontact mechanism of injury. Preoperative MRI scans were retrospectively reviewed for the presence of bone bruises in the coronal and sagittal planes using fat-suppressed T2-weighted images and a grid-based mapping technique of the tibiofemoral joint. RESULTS: A total of 109 patients were included, with 76 (69.7%) patients sustaining noncontact injuries and 33 (30.3%) patients sustaining contact injuries. There were no significant differences between the contact and noncontact groups in terms of age (11.8 ± 2.0 vs 12.4 ± 1.3 years; P = .12), male sex (90.9% vs 88.2%; P > .99), time from initial injury to MRI (10.3 ± 8.1 vs 10.4 ± 8.9 days; P = .84), the presence of a concomitant medial meniscus tear (18.2% vs 14.5%; P = .62) or lateral meniscus tear (69.7% vs 52.6%; P = .097), and sport-related injuries (82.9% vs 81.8%; P = .89). No significant differences were observed in the frequency of combined lateral tibiofemoral (lateral femoral condyle + lateral tibial plateau) bone bruises (87.9% contact vs 78.9% noncontact; P = .41) or combined medial tibiofemoral (medial femoral condyle [MFC] + medial tibial plateau) bone bruises (54.5% contact vs 35.5% noncontact; P = .064). Patients with contact ACL tears were significantly more likely to have centrally located MFC bruising (odds ratio, 4.3; 95% CI, 1.6-11; P = .0038) and less likely to have bruising on the anterior aspect of the lateral tibial plateau (odds ratio, 0.27; 95% CI, 0.097-0.76; P = .013). CONCLUSION: Children with contact ACL tears were 4 times more likely to present with centrally located MFC bone bruises on preoperative MRI scans compared with children who sustained noncontact ACL tears. Future studies should investigate the relationship between these bone bruise patterns and the potential risk of articular cartilage damage in pediatric patients with contact ACL tears.

Coexistence of Superconductivity and Antiferromagnetism in Topological Magnet MnBi2Te4 Films.

The interface of two materials can harbor unexpected emergent phenomena. One example is interface-induced superconductivity. In this work, we employ molecular beam epitaxy to grow a series of heterostructures formed by stacking together two nonsuperconducting antiferromagnetic materials, an intrinsic antiferromagnetic topological insulator MnBi2Te4 and an antiferromagnetic iron chalcogenide FeTe. Our electrical transport measurements reveal interface-induced superconductivity in these heterostructures. By performing scanning tunneling microscopy and spectroscopy measurements, we observe a proximity-induced superconducting gap on the top surface of the MnBi2Te4 layer, confirming the coexistence of superconductivity and antiferromagnetism in the MnBi2Te4 layer. Our findings will advance the fundamental inquiries into the topological superconducting phase in hybrid devices and provide a promising platform for the exploration of chiral Majorana physics in MnBi2Te4-based heterostructures.

Engineering Plateau Phase Transition in Quantum Anomalous Hall Multilayers.

The plateau phase transition in quantum anomalous Hall (QAH) insulators corresponds to a quantum state wherein a single magnetic domain gives way to multiple domains and then reconverges back to a single magnetic domain. The layer structure of the sample provides an external knob for adjusting the Chern number C of the QAH insulators. Here, we employ molecular beam epitaxy to grow magnetic topological insulator multilayers and realize the magnetic field-driven plateau phase transition between two QAH states with odd Chern number change ΔC. We find that critical exponents extracted for the plateau phase transitions with ΔC = 1 and ΔC = 3 in QAH insulators are nearly identical. We construct a four-layer Chalker-Coddington network model to understand the consistent critical exponents for the plateau phase transitions with ΔC = 1 and ΔC = 3. This work will motivate further investigations into the critical behaviors of plateau phase transitions with different ΔC in QAH insulators.

Vertical Sleeve Gastrectomy Reduces Gut Luminal Deoxycholic Acid Concentrations in Mice.

BACKGROUND: Bariatric surgery alters bile acid metabolism, which contributes to post-operative improvements in metabolic health. However, the mechanisms by which bariatric surgery alters bile acid metabolism are incompletely defined. In particular, the role of the gut microbiome in the effects of bariatric surgery on bile acid metabolism is incompletely understood. Therefore, we sought to define the changes in gut luminal bile acid composition after vertical sleeve gastrectomy (VSG). METHODS: Bile acid profile was determined by UPLC-MS/MS in serum and gut luminal samples from VSG and sham-operated mice. Sham-operated mice were divided into two groups: one was fed ad libitum, while the other was food-restricted to match their body weight to the VSG-operated mice. RESULTS: VSG decreased gut luminal secondary bile acids, which was driven by a decrease in gut luminal deoxycholic acid concentrations and abundance. However, gut luminal cholic acid (precursor for deoxycholic acid) concentration and abundance did not differ between groups. Therefore, the observed decrease in gut luminal deoxycholic acid abundance after VSG was not due to a reduction in substrate availability. CONCLUSION: VSG decreased gut luminal deoxycholic acid abundance independently of body weight, which may be driven by a decrease in gut bacterial bile acid metabolism.

Special Considerations for Advanced Heart Failure Surgeries: Durable Left Ventricular Devices and Heart Transplantation.

Heart transplantation and durable left ventricular assist devices (LVADs) represent two definitive therapies for end-stage heart failure in the modern era. Despite technological advances, both treatment modalities continue to experience unique risks that impact surgical and perioperative decision-making. Here, we review special populations and factors that impact risk in LVAD and heart transplant surgery and examine critical decisions in the management of these patients. As both heart transplantation and the use of durable LVADs as destination therapy continue to increase, these considerations will be of increasing relevance in managing advanced heart failure and improving outcomes.

A Computed Tomography Scan Near Miss of an Intraorbital Wooden Foreign Body.

When intraorbital wooden foreign bodies are missed, the consequences can be devastating. While the gold standard diagnostic imaging is computed tomography (CT), it has low sensitivity. We present a 61-year-old man with a bamboo injury to his right eye. He underwent two CT scans that failed to raise the possibility of intraorbital foreign bodies. Upon additional review, a rectangular-shaped pocket of air was identified in the orbit which was most consistent with wooden foreign bodies based on the clinical history. A combined mid-lid approach followed by a transconjunctival and transcaruncular extension were employed to remove several wooden splinters. Postoperatively, due to recurrent orbital compartment syndrome, he required a second decompression with an inferior rim osteotomy. He had good recovery at 3 months follow-up. Overall, intraorbital wooden foreign bodies are challenging to diagnose due to imaging limitations. Providing a clear history and suspected diagnosis to radiology is critical for diagnosis.

Manquer des corps étrangers intraorbitaires en bois peut avoir des conséquences désastreuses. L'imagerie diagnostique de référence est la tomodensitométrie (TDM) mais sa sensibilité est faible. Nous présentons le cas d'un homme de 61 ans ayant une plaie par morceau de bambou dans son œil droit. Il a bénéficié de deux tomodensitométrie qui n'ont pas réussi à donner l'alarme sur la possibilité de corps étrangers intraorbitaires. Lors d'un réexamen supplémentaire, une poche d'air de forme rectangulaire a été identifiée dans l'orbite; cette poche était très compatible avec des corps étrangers en bois, selon l'histoire clinique. Un abord combiné à mi-paupière, suivi d'une extension transconjonctivale et transcaronculaire, a été employé pour retirer plusieurs échardes en bois. En postopératoire, le patient a nécessité une deuxième décompression avec ostéotomie du bord inférieur en raison d'un syndrome du compartiment orbitaire récidivant. La récupération a été bonne au suivi de trois mois. Globalement, les corps étrangers intraorbitaires en bois sont difficiles à diagnostiquer en raison des limites de l'imagerie. Fournir au radiologue une histoire claire et un diagnostic suspecté est essentiel au diagnostic.

Using Computed Tomography-Based Three-dimensional Modeling and Computer Navigation for Minimally Invasive Core Decompression and Adjuvant Orthobiologic Therapy of Femoral Head Avascular Necrosis.

Avascular necrosis of the femoral head is a debilitating condition that can lead to femoral head collapse. Core decompression with adjuvant cellular therapies, such as bone marrow aspirate concentrate, delays disease progression and improves outcomes. However, inconsistent results in the literature may be due to limitations in surgical technique and difficulty in targeting the necrotic lesions. Here, we present a surgical technique utilizing computed tomography-based three-dimensional modeling and instrument tracking to guide the therapy to the center of the lesion. This method minimizes the number of attempts to reach the lesion and confirms the three-dimensional positioning of the instrumentation within the lesion. Our technique may improve the outcomes of core decompression and adjuvant therapy and prevent or delay hip collapse in patients with femoral head avascular necrosis.

Cr-Free Anticorrosive Primers for Marine Propeller Applications.

Marine propellers work under severe service conditions, where they commonly suffer from mechanical, electrochemical, and biological corrosion damage. The major mechanical corrosion involves cavitation, erosion, and impingement corrosion. On the other hand, the major electrochemical corrosion involves galvanic corrosion and electrolysis. As a result, consideration of both desired mechanical and electrochemical properties is necessary when designing a marine propeller coating. In this study, a PVB (polyvinyl butyral) and an epoxy coating were formulated without corrosion inhibitors to investigate the desired coating properties for marine propeller applications. The two coatings were compared with a Cr-containing commercial marine propeller coating to investigate the advantages and disadvantages of using PVB and epoxy for marine propeller coatings. It was found that it is desirable for marine propeller coatings to be flexible to avoid cracking and flaking; to be able to withstand high pH in order to resist cathodic disbondment (electrolysis); to have adequate primer-substrate adhesion; and, ideally, to be able to self-heal when the coating is damaged (cavitation). It was found that the PVB-ZO coating has more desirable properties, and introducing self-healing properties could be one of the options for further optimization in the future.

The evolving roles of Wnt signaling in stem cell proliferation and differentiation, the development of human diseases, and therapeutic opportunities.

The evolutionarily conserved Wnt signaling pathway plays a central role in development and adult tissue homeostasis across species. Wnt proteins are secreted, lipid-modified signaling molecules that activate the canonical (ß-catenin dependent) and non-canonical (ß-catenin independent) Wnt signaling pathways. Cellular behaviors such as proliferation, differentiation, maturation, and proper body-axis specification are carried out by the canonical pathway, which is the best characterized of the known Wnt signaling paths. Wnt signaling has emerged as an important factor in stem cell biology and is known to affect the self-renewal of stem cells in various tissues. This includes but is not limited to embryonic, hematopoietic, mesenchymal, gut, neural, and epidermal stem cells. Wnt signaling has also been implicated in tumor cells that exhibit stem cell-like properties. Wnt signaling is crucial for bone formation and presents a potential target for the development of therapeutics for bone disorders. Not surprisingly, aberrant Wnt signaling is also associated with a wide variety of diseases, including cancer. Mutations of Wnt pathway members in cancer can lead to unchecked cell proliferation, epithelial-mesenchymal transition, and metastasis. Altogether, advances in the understanding of dysregulated Wnt signaling in disease have paved the way for the development of novel therapeutics that target components of the Wnt pathway. Beginning with a brief overview of the mechanisms of canonical and non-canonical Wnt, this review aims to summarize the current knowledge of Wnt signaling in stem cells, aberrations to the Wnt pathway associated with diseases, and novel therapeutics targeting the Wnt pathway in preclinical and clinical studies.

Self-scheduling of Screening Mammograms Using an Online Patient Portal: Initial 8-year Experience at a Multisite Academic Institution.

OBJECTIVE: The goal of this study was to determine patient factors associated with the use of self-scheduling of screening mammograms (SMs) using an online portal. METHODS: All SMs scheduled at our multisite academic institution from January 1, 2015, to December 31, 2022, were included. The frequency of self-scheduling via an online portal was calculated per year. Univariate and multivariate logistic regression models with generalized estimating equation were used to estimate associations between patient characteristics and scheduling format after accounting for correlations between mammograms performed on the same woman. RESULTS: During the study period, 250,369 SMs were performed in 74,860 unique patients (mean age 59 ± 12 years). Of these, 36,200 (14.5%) were self-scheduled via the online portal. Self-scheduling increased each year, from 3.7% in 2015 to 36.9% in 2022. Younger age, non-Black race, being an English speaker, and being from a nondisadvantaged zip code were significant predictors of self-scheduling on univariate and multivariate logistic regression. Age <50 years versus age ≥70 years was the patient characteristic that most strongly predicted the likelihood of self-scheduling (adjusted odds ratio 5.4, 95% confidence interval 5.2-5.6). CONCLUSIONS: Over 8 years (2015-2022), utilization of self-scheduling for screening mammography using an online patient portal increased from 3.7% to 36.9%. Age < 50 years was the patient characteristic that most strongly predicted likelihood of self-scheduling.

Efficacy and safety of the oral Janus kinase 1 inhibitor povorcitinib (INCB054707) in patients with hidradenitis suppurativa in a phase 2, randomized, double-blind, dose-ranging, placebo-controlled study.

BACKGROUND: Janus kinase 1 inhibition may alleviate hidradenitis suppurativa (HS)-associated inflammation and improve symptoms. OBJECTIVE: To assess efficacy and safety of povorcitinib (selective oral Janus kinase 1 inhibitor) in HS. METHODS: This placebo-controlled phase 2 study randomized patients with HS 1:1:1:1 to receive povorcitinib 15, 45, or 75 mg or placebo for 16 weeks. Primary and key secondary end points were mean change from baseline in abscess and inflammatory nodule count and percentage of patients achieving HS Clinical Response at week 16. RESULTS: Of 209 patients randomized (15 mg, n = 52; 45 mg, n = 52; 75 mg, n = 53; placebo, n = 52), 83.3% completed the 16-week treatment. At week 16, povorcitinib significantly reduced abscess and inflammatory nodule count from baseline (least squares mean [SE] change: 15 mg, -5.2 [0.9], P = .0277; 45 mg, -6.9 [0.9], P = .0006; 75 mg, -6.3 [0.9], P = .0021) versus placebo (-2.5 [0.9]). More povorcitinib-treated patients achieved HS Clinical Response at week 16 (15 mg, 48.1%, P = .0445; 45 mg, 44.2%, P = .0998; 75 mg, 45.3%, P = .0829) versus placebo (28.8%). A total of 60.0% and 65.4% of povorcitinib- and placebo-treated patients had adverse events. LIMITATIONS: Baseline lesion counts were mildly imbalanced between groups. CONCLUSION: Povorcitinib demonstrated efficacy in HS, with no evidence of increased incidence of adverse events among doses.

Interferon ɛ restricts Zika virus infection in the female reproductive tract.

Interferon ɛ (IFNɛ) is a unique type I IFN that has been implicated in host defense against sexually transmitted infections. Zika virus (ZIKV), an emerging pathogen, can infect the female reproductive tract (FRT) and cause devastating diseases, particularly in pregnant women. How IFNɛ contributes to protection against ZIKV infection in vivo is unknown. In this study, we show that IFNɛ plays a critical role in host protection against vaginal ZIKV infection in mice. We found that IFNɛ was expressed not only by epithelial cells in the FRT but also by immune and stromal cells at baseline or after exposure to viruses or specific Toll-like receptor (TLR) agonists. IFNɛ-deficient mice exhibited abnormalities in the epithelial border and underlying tissue in the cervicovaginal tract, and these defects were associated with increased susceptibility to vaginal but not subcutaneous ZIKV infection. IFNɛ deficiency resulted in an increase in magnitude, duration, and depth of ZIKV infection in the FRT. Critically, intravaginal administration of recombinant IFNɛ protected Ifnɛ-/- mice and highly susceptible Ifnar1-/- mice against vaginal ZIKV infection, indicating that IFNɛ was sufficient to provide protection even in the absence of signals from other type I IFNs and in an IFNAR1-independent manner. Our findings reveal a potentially critical role for IFNɛ in mediating protection against the transmission of ZIKV in the context of sexual contact.

Three-Dimensional Printing of Models of Patellofemoral Joint Articular Cartilage in Patients With Patella Instability for Observing Joint Congruity.

Three-dimensional (3D) modeling and printing are increasingly used in the field of orthopaedic surgery for both research and patient care. One area where they are particularly helpful is in improving our understanding of the patellofemoral (PF) joint. Heretofore, morphological studies that use 3D models of the PF joint have primarily been based on computed tomography imaging data and thus do not incorporate articular cartilage. Here, we describe a method for creating 3D models of the articular surfaces of the PF joint based on magnetic resonance imaging. Models created using this technique can be used to improve our understanding of the morphology of the articular surfaces of the PF joint and its relationship to joint pathologies. Of particular interest is our finding of articular congruity in printed articular cartilage surfaces of dysplastic PF joints of recurrent patella dislocators.

Impact on Faculty's Own Development When Assessing Student Performance.

INTRODUCTION: Assessing learner performance is a primary focus within simulation-based education in order to prepare students with the knowledge and skills they will need going forward in their careers. In order to properly conduct these assessments of learner performance, faculty must be adequately trained on the scenario, expectations, assessment measures, and debriefing. During Operation Bushmaster, a five-day "deployment" for learners, faculty assess students as they rotate through different leadership roles. The faculty development includes online and in-person training that provides them with an understanding of the scenario; what learners know; the framework used at USU to guide curriculum, development, and assessment; how to assess learners; and how to provide feedback to learners. Research has examined the value of receiving assessment and feedback from a student perspective, but the impact of being the assessor and giving feedback has not been researched from the faculty point of view. The purpose of this study, therefore, was to examine the impact of assessing students in simulation scenarios on faculty's own development as an educator and leader. MATERIALS AND METHODS: Through a phenomenological qualitative study, we explored participants' lived experiences as faculty at Operation Bushmaster. Eighteen faculty from a variety of medical specialties and military ranks volunteered to participate. Participants were interviewed in-person using a semi-structured interview. Analyses included individually reading through each transcript; then individually coding and taking notes of terms and phrases used by participants; codes were compiled and organized into categories, which became the themes of our study. RESULTS: The interviews demonstrated the following themes in which providers who serve as faculty of Operation Bushmaster believe they gain from the experience: (1) The experience helps to reground their own thinking; (2) acting as faculty during simulation-based education helps them remain up-to-date on necessary skills; and (3) working with students helps faculty continually develop as an educator and a leader. CONCLUSIONS: This work describes how even when faculty are brought in for learner assessment, they are taking away lessons and experiences that aid in their own development as an educator as well as a leader. Acting as an assessing faculty for students may allow faculty to reground their own thinking, remain up-to-date on necessary skills, and continually develop their skills as an educator and leader. These findings suggest that some faculty involved in simulation events may also gain knowledge, skills, and experiences that can help with their own development even when the focus is on learners.

Scrambler Therapy for Patients With Complex Regional Pain Syndrome: A Case Series.

Complex regional pain syndrome is a chronic debilitating pain disorder that is difficult to manage, in part due to its heterogeneous clinical presentation and lack of clearly defined pathophysiology. Patients usually require a multidisciplinary approach to treatment, which can entail pharmacotherapy, physical therapy, behavioral therapy, and interventional pain procedures, such as sympathetic nerve blocks, spinal cord stimulation, and dorsal root ganglion stimulation. However, many patients continue to experience pain refractory to these multimodal strategies. Scrambler therapy (ST) is a noninvasive method of neuromodulation that is applied through cutaneous electrodes, and can alleviate chronic neuropathic pain by stimulating C-fibers and replacing endogenous pain signals with synthetic non-nociceptive signals. Although the use of ST has been reported for several types of refractory central and peripheral neuropathic pain, there is a paucity of data regarding the use of ST for complex regional pain syndrome. We present two patients with complex regional pain syndrome of the right lower extremity, who each underwent ST and experienced significant pain relief and improvement in function and quality of life.

Long noncoding RNA (lncRNA) H19: An essential developmental regulator with expanding roles in cancer, stem cell differentiation, and metabolic diseases.

Recent advances in deep sequencing technologies have revealed that, while less than 2% of the human genome is transcribed into mRNA for protein synthesis, over 80% of the genome is transcribed, leading to the production of large amounts of noncoding RNAs (ncRNAs). It has been shown that ncRNAs, especially long non-coding RNAs (lncRNAs), may play crucial regulatory roles in gene expression. As one of the first isolated and reported lncRNAs, H19 has gained much attention due to its essential roles in regulating many physiological and/or pathological processes including embryogenesis, development, tumorigenesis, osteogenesis, and metabolism. Mechanistically, H19 mediates diverse regulatory functions by serving as competing endogenous RNAs (CeRNAs), Igf2/H19 imprinted tandem gene, modular scaffold, cooperating with H19 antisense, and acting directly with other mRNAs or lncRNAs. Here, we summarized the current understanding of H19 in embryogenesis and development, cancer development and progression, mesenchymal stem cell lineage-specific differentiation, and metabolic diseases. We discussed the potential regulatory mechanisms underlying H19's functions in those processes although more in-depth studies are warranted to delineate the exact molecular, cellular, epigenetic, and genomic regulatory mechanisms underlying the physiological and pathological roles of H19. Ultimately, these lines of investigation may lead to the development of novel therapeutics for human diseases by exploiting H19 functions.