Wt1 transcription factor impairs cardiomyocyte specification and drives a phenotypic switch from myocardium to epicardium.

During development, the heart grows by addition of progenitor cells to the poles of the primordial heart tube. In the zebrafish, Wilms tumor 1 transcription factor a (wt1a) and b (wt1b) genes are expressed in the pericardium, at the venous pole of the heart. From this pericardial layer, the proepicardium emerges. Proepicardial cells are subsequently transferred to the myocardial surface and form the epicardium, covering the myocardium. We found that while wt1a and wt1b expression is maintained in proepicardial cells, it is downregulated in pericardial cells that contributes cardiomyocytes to the developing heart. Sustained wt1b expression in cardiomyocytes reduced chromatin accessibility of specific genomic loci. Strikingly, a subset of wt1a- and wt1b-expressing cardiomyocytes changed their cell-adhesion properties, delaminated from the myocardium and upregulated epicardial gene expression. Thus, wt1a and wt1b act as a break for cardiomyocyte differentiation, and ectopic wt1a and wt1b expression in cardiomyocytes can lead to their transdifferentiation into epicardial-like cells.

Role of Indocyanine Green Angiography in Free Flap Surgery: A Comparative Outcome Analysis of a Single-Center Large Series of 877 Consecutive Free Flaps.

Purpose This study aims to assess and validate the role and cost-effectiveness of indocyanine green angiography (ICGA) in free flap surgery outcomes. A new intraoperative protocol of whole-body surface warming (WBSW) for all free flap surgeries during the strategic "microbreaks" is also described. Methods A retrospective analysis of 877 consecutive free flaps, performed over 12 years, is presented. The results of the ICGA group ( n = 438) were compared with the historical No-ICGA group ( n = 439), and statistical significance was calculated for three crucial flap-related adverse outcomes and cost-effectiveness. ICGA was also used as a tool to show the effect of WBSW on free flaps. Results ICGA showed a notably strong statistical significance in decreasing two outcome parameters, namely, partial flap loss and re-exploration rate. It was also cost-effective. ICGA also demonstrated the positive role of WBSW in increasing flap perfusion. Conclusions Our study shows that the usage of ICGA for intraoperative assessment of flap perfusion can significantly reduce the partial flap loss and re-exploration rate in free flap surgeries in a cost-effective manner. A new protocol of WBSW is also described and recommended to increase flap perfusion in all free flap surgeries.

First Case Report of Breast Implant Associated-Anaplastic Large Cell Lymphoma from India: Are We Ready?

Breast implant associated-anaplastic large cell lymphoma (BIA-ALCL) has become a hot topic in recent plastic surgery and oncology forum. Its cases have been on the rise since its first emergence more than two decades ago. This condition is less known and management guidelines are still evolving. BIA-ALCL was seen recently with a classical presentation in one of our patients, who underwent immediate reconstruction with a macro-textured silicone implant following breast cancer surgery. We want to add the first case report from India to the global information database. There are still unanswered questions in its management, and we wish to highlight the same to make way for further research. With the rise in aesthetic and reconstructive implant surgeries, the knowledge of BIA-ALCL must expand among oncologists, radiologists, and pathologists for early identification and treatment for better patient outcomes.

Suprazygomatic Aponeurotic McLaughlin Myoplasty for Facial Reanimation.

BACKGROUND: Suprazygomatic aponeurotic McLaughlin (SAM) myoplasty technique for facial reanimation is based on the classical McLauglin's lengthening temporalis myoplasty with a series of new modifications. A comprehensive review of previously described other orthodromic temporalis myoplasty techniques is also included to give a succinct comparison. METHODS: Twelve adult patients of facial palsy underwent SAM myoplasty for a period of 4 years. Three had congenital facial palsy, 4 patients had facial palsy secondary to acoustic neuromas, 3 were posttraumatic, and 2 patients had Bell's palsy. RESULTS: Range of modiolus excursion achieved as measured at 3 months postoperatively on reanimation in our patients was 5 mm to 20 mm with an average of 12.6 mm. With SAM myoplasty technique, we were able to achieve excellent result in 4 patients and good results in 8 patients as evaluated with May and Druker scoring system. CONCLUSIONS: Suprazygomatic aponeurotic McLaughlin myoplasty for facial reanimation demonstrates a successful modification of the classical McLaughlin lengthening temporalis myoplasty, making it more customizable, simple, and predictable by taking the level of transection to the temporalis aponeurosis without the need for zygomatic osteotomy. A new classification of orthodromic temporalis myoplasty based on level of transections is also proposed for the first time. Good to excellent outcomes coupled with high patient satisfaction and low morbidity should make this technique popular among the facial reanimation surgeons.

Canonical Wnt signalling regulates epithelial patterning by modulating levels of laminins in zebrafish appendages.

The patterning and morphogenesis of body appendages - such as limbs and fins - is orchestrated by the activities of several developmental pathways. Wnt signalling is essential for the induction of limbs. However, it is unclear whether a canonical Wnt signalling gradient exists and regulates the patterning of epithelium in vertebrate appendages. Using an evolutionarily old appendage - the median fin in zebrafish - as a model, we show that the fin epithelium exhibits graded changes in cellular morphology along the proximo-distal axis. This epithelial pattern is strictly correlated with the gradient of canonical Wnt signalling activity. By combining genetic analyses with cellular imaging, we show that canonical Wnt signalling regulates epithelial cell morphology by modulating the levels of laminins, which are extracellular matrix components. We have unravelled a hitherto unknown mechanism involved in epithelial patterning, which is also conserved in the pectoral fins - evolutionarily recent appendages that are homologous to tetrapod limbs.

Ubiquitin-dependent recruitment of the Bloom syndrome helicase upon replication stress is required to suppress homologous recombination.

Limiting the levels of homologous recombination (HR) that occur at sites of DNA damage is a major role of BLM helicase. However, very little is known about the mechanisms dictating its relocalization to these sites. Here, we demonstrate that the ubiquitin/SUMO-dependent DNA damage response (UbS-DDR), controlled by the E3 ligases RNF8/RNF168, triggers BLM recruitment to sites of replication fork stalling via ubiquitylation in the N-terminal region of BLM and subsequent BLM binding to the ubiquitin-interacting motifs of RAP80. Furthermore, we show that this mechanism of BLM relocalization is essential for BLM's ability to suppress excessive/uncontrolled HR at stalled replication forks. Unexpectedly, we also uncovered a requirement for RNF8-dependent ubiquitylation of BLM and PML for maintaining the integrity of PML-associated nuclear bodies and as a consequence the localization of BLM to these structures. Lastly, we identified a novel role for RAP80 in preventing proteasomal degradation of BLM in unstressed cells. Taken together, these data highlight an important biochemical link between the UbS-DDR and BLM-dependent pathways involved in maintaining genome stability.

Rapidly Resorbable Skin Sutures: Story Retold!

Rapidly resorbable skin sutures have an elaborate use not only in facial surgeries but also in breast, abdomen, and hand wound closure. Its removal may not require trimming, as gentle rubbing with a moisturizing agent makes them fall off easily in 10-14 days postoperatively. This practice has a good acceptance, especially among children, and gives a favorable aesthetic outcome. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the A3 online Instructions to Authors. www.springer.com/00266 .

The potential of R. toruloides mevalonate pathway genes in increasing isoprenoid yields in S. cerevisiae: Evaluation of GGPPS and HMG-CoA reductase.

The enzymes of the mevalonate pathway need to be improved to achieve high yields of isoprenoids in the yeast Saccharomyces cerevisiae. The red yeast Rhodosporidium toruloides produces high levels of carotenoids and may have evolved to carry a naturally high flux of isoprenoids. Enzymes from such yeasts are likely to be promising candidates for improvement. Towards this end, we have systematically investigated the various enzymes of the mevalonate pathway of R. toruloides and custom synthesized, expressed, and evaluated six key enzymes in S. cerevisiae. The two nodal enzymes geranyl pyrophosphate synthase (RtGGPPS) and truncated HMG-CoA reductase (RttHMG) of R. toruloides showed a significant advantage to the cells for isoprenoid production as seen by a visual carotenoid screen. These two were analyzed further, and attempts were also made at further improvement. RtGGPPS was confirmed to be superior to the S. cerevisiae enzyme, as seen from in vitro activity determinations and in vivo production of the heterologous diterpenoid sclareol. Four mutants were created through rational mutagenesis but were unable to improve the activity further. In the case of RttHMG, functional evaluation of the enzyme revealed that it was very unstable despite functioning very well in S. cerevisiae. We succeeded in stabilizing the enzyme through mutation of a conserved serine in the catalytic region, which did not alter the enzyme activity per se. In vivo evaluation of the mutant revealed that it could enable better sclareol yields. Therefore, these two enzymes from the red yeast are excellent candidates for heterologous isoprenoid production.

Does perioperative hydrocortisone or indomethacin improve pancreatoduodenectomy outcomes? A triple arm, randomized placebo-controlled trial.

Backgrounds/Aims: This trial evaluated whether anti-inflammatory agents hydrocortisone (H) and indomethacin (I) could reduce major complications after pancreatoduodenectomy (PD). Methods: Between June 2018 and June 2020, 105 patients undergoing PD with > 40% of acini on the intraoperative frozen section were randomized into three groups (35 patients per group): 1) intravenous H 100 mg 8 hourly, 2) rectal I suppository 100 mg 12 hourly, and 3) placebo (P) from postoperative day (POD) 0-2. Participants, investigators, and outcome assessors were blinded. The primary outcome was major complications (Clavien-Dindo grades 3-5). Secondary outcomes were overall complications (Clavien-Dindo grades 1-5), Clinically relevant postoperative pancreatic fistula (CR-POPF), delayed gastric emptying (DGE), postpancreatectomy hemorrhage (PPH), surgical site infections (SSI), length of stay, POD-3 serum amylase, readmission rate, and mortality. Results: Major complications were comparable (8.6%, 5.7%, and 8.6% in groups H, I, and P, respectively). However, overall complications were significantly lower in group H than in group P (45.7% vs. 80.0%, p = 0.006). CR-POPF (14.3% vs. 25.7%, p = 0.371), PPH (8.6% vs. 14.3%, p = 0.710), DGE (8.6% vs. 22.9%, p = 0.188), and SSI (14.3% vs. 25.7%, p = 0.371) were comparable between groups H and P. Major complications and overall complications in group I were 5.7% and 60.0%, respectively, which were comparable to those in groups P and H. CR-POPF rates in groups H, I, and P were 14.3%, 17.1%, and 25.7%, respectively, which was comparable. Conclusions: H and I did not decrease major complications in PD.

Cox7a1 controls skeletal muscle physiology and heart regeneration through complex IV dimerization.

The oxidative phosphorylation (OXPHOS) system is intricately organized, with respiratory complexes forming super-assembled quaternary structures whose assembly mechanisms and physiological roles remain under investigation. Cox7a2l, also known as Scaf1, facilitates complex III and complex IV (CIII-CIV) super-assembly, enhancing energetic efficiency in various species. We examined the role of Cox7a1, another Cox7a family member, in supercomplex assembly and muscle physiology. Zebrafish lacking Cox7a1 exhibited reduced CIV2 formation, metabolic alterations, and non-pathological muscle performance decline. Additionally, cox7a1-/- hearts displayed a pro-regenerative metabolic profile, impacting cardiac regenerative response. The distinct phenotypic effects of cox7a1-/- and cox7a2l-/- underscore the diverse metabolic and physiological consequences of impaired supercomplex formation, emphasizing the significance of Cox7a1 in muscle maturation within the OXPHOS system.

Transcriptomic data meta-analysis reveals common and injury model specific gene expression changes in the regenerating zebrafish heart.

Zebrafish have the capacity to fully regenerate the heart after an injury, which lies in sharp contrast to the irreversible loss of cardiomyocytes after a myocardial infarction in humans. Transcriptomics analysis has contributed to dissect underlying signaling pathways and gene regulatory networks in the zebrafish heart regeneration process. This process has been studied in response to different types of injuries namely: ventricular resection, ventricular cryoinjury, and genetic ablation of cardiomyocytes. However, there exists no database to compare injury specific and core cardiac regeneration responses. Here, we present a meta-analysis of transcriptomic data of regenerating zebrafish hearts in response to these three injury models at 7 days post injury (7dpi). We reanalyzed 36 samples and analyzed the differentially expressed genes (DEG) followed by downstream Gene Ontology Biological Processes (GO:BP) analysis. We found that the three injury models share a common core of DEG encompassing genes involved in cell proliferation, the Wnt signaling pathway and genes that are enriched in fibroblasts. We also found injury-specific gene signatures for resection and genetic ablation, and to a lower extent the cryoinjury model. Finally, we present our data in a user-friendly web interface that displays gene expression signatures across different injury types and highlights the importance to consider injury-specific gene regulatory networks when interpreting the results related to cardiac regeneration in the zebrafish. The analysis is freely available at: https://mybinder.org/v2/gh/MercaderLabAnatomy/PUB_Botos_et_al_2022_shinyapp_binder/HEAD?urlpath=shiny/bus-dashboard/ .

A randomized trial to compare the analgesic effect of pecto-intercostal fascial plane block with erector spinae plane block after mid-sternotomy incision for cardiac surgery.

Introduction: Most cardiac surgeries are performed through a median sternotomy, of which 49% of these patients experience severe pain at rest postoperatively and up to 78% on coughing and deep breathing. Regional thoracic wall blocks targeting thoracic nerve roots improve the analgesia quality and limit opioid use. Truncal blocks through the posterior approach can often be cumbersome in patients with multiple lines and catheters. Pecto-Intercostal Fascial Plane Block (PIFB) can be a convenient alternative for achieving comparable analgesia. Material and methods: The patients were randomly assigned to receive either an ultrasound-guided Pecto-Intercostal Fascial Plane Block (PIFB) or Erector Spinae Plane Block (ESPB). The outcomes measured and compared postoperative pain scores at rest and on deep breathing at 2, 6, 12, 24 h, total opioid (fentanyl) consumption in the postoperative period, time to rescue analgesia and total rescue analgesic doses required, between the two groups. Results: Data from 30 patients were analysed. Post-operative pain scores at rest and during deep breathing were found to be comparable in both groups. The total opioid consumed, time to rescue analgesia and total doses of rescue analgesia was not found to be statistically different in the two groups. Conclusions: PIFB was found to be comparable to ESPB in alleviating post-operative pain in patients who underwent cardiac surgeries through sternotomy. And it/PIFB can be a quicker alternative to posterior truncal blocks since it can be safely given in a supine position with an ultrasound.

Mode of Mechanical Ventilation in a Case of Venolymphatic Malformation: Spontaneous-Saves, Positive-Precludes.

Mediastinal venolymphatic malformations (VLM) are rare tumours, with very few reported cases in the literature. Arising often from the anterior mediastinum, VLM manifests symptoms based on invaded surrounding structures. Masses from the anterior and superior mediastinum pose an anaesthetic challenge for airway and hemodynamic management. A 7-month-old male child presented with a progressively growing mass over the left anterior chest wall for one month, about 4x4 cm, with diffuse margins and now expanded to involve the root of the neck and into the axilla. The patient was free from any apparent systemic illness. The breathing difficulty worsened in the past week with noisy respiration associated with feeding difficulty and hence sought medical admission to the paediatrics emergency unit. In conclusion, such huge mediastinal masses are managed better under spontaneous ventilation with an adequate surgical depth of anaesthesia to maintain appropriate respiratory compliance and necessitate lower peak inspiratory pressure. Given rare cases reported in the literature, similar topics would help choose the modus of ventilation and their safe management.

Incidence of postoperative pulmonary congestion as diagnosed by lung ultrasound in surgeries performed under general anaesthesia: A prospective, observational study.

Background and Aims: Administering liberal fluid raises concerns about pulmonary congestion postoperatively. Bedside ultrasonography is a valuable tool for the early detection of pulmonary congestion. In this study, we have used it to ascertain the impact of the duration of surgery and intraoperative fluid volume on the causation of pulmonary congestion. Our objective was to determine the incidence of pulmonary congestion as diagnosed by lung ultrasound in patients undergoing general anaesthesia with varied fluid administration. Methods: Seventy participants of American Society of Anesthesiologists physical status I and II, aged between 18 and 60 years, undergoing elective extrathoracic surgeries of over 3 h under general anaesthesia were included. Preoperative lung ultrasound was carried out in all patients, and a postoperative lung ultrasound was carried out at 1 h after extubation. The appearance of three or more "B"-lines was considered positive for lung congestion. Results: Significant differences (P < 0.001) were found in the duration of surgery and the appearance of B-lines in the postoperative period. Participants who developed B lines received, on average, 150% more fluid (1148.16 ± 291.79 ml) than those who did not (591.29 ± 398.42 ml) (P = 0.0240). Net fluid balance was also significantly different in patients who developed B lines (P = 0.0014). None of the patients developed symptoms of lung congestion postoperatively. Conclusion: Long duration of surgery under general anaesthesia (>3 h) with the administration of large volumes of intraoperative fluid and a large net fluid balance are associated with lung congestion as diagnosed by lung ultrasound.

Transillumination and Point-of-Care Ultrasonography to Delineate Tracheal Deviation for Challenging Tracheostomy: A Case Report.

Tracheostomy is indicated for varied reasons and is a relatively safe procedure that can be done with both open and percutaneous methods. However, the procedure is often challenging in cases of distorted neck anatomy. Neck swellings often push the trachea laterally or shield it. Even some gross intrathoracic pathology may shift the trachea from the typical trajectory making it challenging to delineate the course of the trachea. A bedside point-of-care technique having a visual aid that can guide the performer thus appears beneficiary. Fiber-optic assistance for correct puncture and confirmation is known, and light-based techniques have been used for tracheostomies. As fiberscopes are not infrequent in tertiary and even secondary care hospitals, transillumination from a flexible bronchoscope can identify the altered course of the trachea, much like a navigation system, and systematically aid the performer in steering away from the obstacles. We present two cases in two scenarios with tracheal deviation who underwent either open or percutaneous tracheostomy with point-of-care ultrasound and transillumination to delineate the course of the trachea and facilitate difficult tracheostomies safely.