Dermal EZH2 orchestrates dermal differentiation and epidermal proliferation during murine skin development.

Skin development and patterning is dependent on factors that regulate the stepwise differentiation of dermal fibroblasts concomitant with dermal-epidermal reciprocal signaling, two processes that are poorly understood. Here we show that dermal EZH2, the methyltransferase enzyme of the epigenetic Polycomb Repressive Complex 2 (PRC2), is a new coordinator of both these processes. Dermal EZH2 activity is present during dermal fibroblast differentiation and is required for spatially restricting Wnt/ß-catenin signaling to reinforce dermal fibroblast cell fate. Later in development, dermal EZH2 regulates the expression of reticular dermal markers and initiation of secondary hair follicles. Embryos lacking dermal Ezh2 have elevated epidermal proliferation and differentiation that can be rescued by small molecule inhibition of retinoic acid (RA) signaling. Together, our study reveals that dermal EZH2 is acting like a rheostat to control the levels of Wnt/ß-catenin and RA signaling to impact fibroblast differentiation cell autonomously and epidermal keratinocyte development non-cell autonomously, respectively.

Polycomb Repressive Complex 2: a Dimmer Switch of Gene Regulation in Calvarial Bone Development.

PURPOSE OF REVIEW: Epigenetic regulation is a distinct mechanism of gene regulation that functions by modulating chromatin structure and accessibility. Polycomb Repressive Complex 2 (PRC2) is a conserved chromatin regulator that is required in the developing embryo to control the expression of key developmental genes. An emerging feature of PRC2 is that it not only allows for binary ON/OFF states of gene expression but can also modulate gene expression in feed-forward loops to change the outcome of gene regulatory networks. This striking feature of epigenetic modulation has improved our understanding of musculoskeletal development. RECENT FINDINGS: Recent advances in mouse embryos unravel a range of phenotypes that demonstrate the tissue-specific, temporal, and spatial role of PRC2 during organogenesis and cell fate decisions in vivo. Here, we take a detailed view of how PRC2 functions during the development of calvarial bone and skin. Based on the emerging evidence, we propose that PRC2 serves as a "dimmer switch" to modulate gene expression of target genes by altering the expression of activators and inhibitors. This review highlights the findings from contemporary research that allow us to investigate the unique developmental potential of intramembranous calvarial bones.

To Dor or Not to Dor? Heller Myotomy, a Retrospective Study.

Achalasia is a neurodegenerative disorder affecting esophageal sphincter function. Treatment options include non-surgical and surgical approaches, such as Heller myotomy (HM). Combining Dor fundoplication with HM is controversial but may prevent gastroesophageal reflux disease (GERD). This retrospective cohort study aimed to assess whether HM with Dor fundoplication reduces GERD rates and increases dysphagia rates. Eighty patients who underwent HM between January 2018 and August 2023 were included. Sixty-four patients had Dor fundoplication and were matched 4:1 to 16 patients without fundoplication. Records were reviewed for GERD and achalasia symptoms at various postoperative time points. No significant differences in GERD or dysphagia symptoms were found between the two groups at any time point. Similarly, there were no significant differences in chest pain or dysphagia treatment. In conclusion, this study suggests that the addition of Dor fundoplication to HM does not significantly impact postoperative GERD or achalasia-related symptoms.

Bibliometric Analysis of the Top 100 Most Cited Papers in Mohs Surgery.

BACKGROUND: Mohs micrographic surgery is a specialized tissue-sparing technique used to treat skin cancers. OBJECTIVE: By understanding the attributes that make a research paper one of the top 100 cited papers on Mohs surgery, we hope to illuminate seminal research in this field. METHODS AND MATERIALS: The global literature about Mohs surgery published between 1900 and 2023 was searched on the Web of Science. Publication data for all results meeting the search criteria were exported and analyzed. RESULTS: In total, 4,961 publications with 81,405 citations were identified. Dermatologic Surgery was the most cited journal, with 1,073 publications. Papers from the top 100 most cited that were published in the year 2000 or prior had an average of 22.1 citations in the first five years after publication, whereas papers published after 2001 had an average of 56.0 citations in the first five years. CONCLUSION: Analysis of the most cited papers on Mohs surgery demonstrates the influential role of the Dermatological Surgery journal in advancing the field. Noteworthy studies addressing cost, safety, and efficacy have received substantial citations, reflecting their significance within the literature. A trend toward more citation in the first five years after publication over time was identified.

A Case Report of a Rare Hernia: Incarcerated Falciform Ligament Hernia.

Falciform ligament hernias are a rare type of internal hernia that occurs through an abnormal opening in the falciform ligament of the liver. This is the case of a 38-year-old female who presented with a symptomatic enlarging ventral bulge near her umbilicus and was treated with a robotic-assisted laparoscopic falciform hernia repair with mesh. The nonspecific clinical manifestation of a falciform ligament hernia and the low sensitivity of computerized tomography (CT) for these hernias make them hard to diagnose preoperatively. Falciform ligament hernias are mostly attributed to congenital defects, but recently an iatrogenic etiology has also been proposed, given the prior history of laparoscopic surgeries in more recent cases. In our case report, we demonstrate that a robotic-assisted laparoscopic approach is a safe and effective means of correcting this hernia, with an outline of the current literature.