Carbodiimide and Isocyanate Hydroboration by a Cyclic Carbodiphosphorane Catalyst.

We report hydroboration of carbodiimide and isocyanate substrates catalyzed by a cyclic carbodiphosphorane catalyst. The cyclic carbodiphosphorane outperformed the other Lewis basic carbon species tested, including other zerovalent carbon compounds, phosphorus ylides, an N-heterocyclic carbene, and an N-heterocyclic olefin. Hydroborations of seven carbodiimides and nine isocyanates were performed at room temperature to form N-boryl formamidine and N-boryl formamide products. Intermolecular competition experiments demonstrated the selective hydroboration of alkyl isocyanates over carbodiimide and ketone substrates. DFT calculations support a proposed mechanism involving activation of pinacolborane by the carbodiphosphorane catalyst, followed by hydride transfer and B-N bond formation.

Ultrasound Evaluation of Primary Alveolar Grafting in Cleft Lip/Palate Treatment: Development of a Novel Sonographic Grading System.

OBJECTIVE: To explore ultrasonographic evaluation of primary alveolar repair in cleft lip/palate patients and develop a grading system to assess outcomes of graft success. DESIGN: Sixteen patients with an average age of 2 years 1 month had sonograms performed at various points in their treatment to determine the feasibility of ultrasound in visualizing alveolar bone defects and changes over time postgrafting. A total of 23 sonograms were performed: 21 at an average of 12 months postoperatively and 2 at an average of 1 month preoperatively. MAIN OUTCOME MEASURES: A 10-point grading system was developed assessing three categories: locations of lateral bone bridging across the cleft, quantification of residual defects with air or fluid channels, and locations of calcification. Three operators graded 10 sonograms to assess interobserver reliability, and the scores were also validated against dental radiographs in patients old enough for radiographic imaging. RESULTS: Linear weighted kappa statistics revealed substantial interobserver agreement for total scores, with an average kappa value of .708. In limited patients with radiographs, a total score of 9/10 correlated with a Chelsea score of 6.5/8 and category A. CONCLUSIONS: Sonographic evaluation, coupled with this novel grading system, shows potential for early assessment of outcomes of graft success when evaluating new techniques of primary alveolar grafting.

Treatment of a giant congenital melanocytic nevus in the adult: review of the current management of giant congenital melanocytic nevus.

Giant congenital melanocytic nevi (GCMNs) create cosmetic disfigurements and pose risk for malignant transformation. Adult GCMN cases are uncommon because most families opt for surgical treatment during childhood. We review the current literature on GCMN and present an interesting case of an adult with a GCMN encompassing the entire back with painful nodules exhibiting gross involvement of his back musculature, without pathologic evidence of malignancy. Surgical management was deferred in childhood because of parental desires to allow the patient to make his own decision, and treatment in adulthood was pursued on the basis of the significant impairment of the patient's quality of life and self-esteem due to the massive size and deforming nature of the nevus. The treatment strategy used for this young adult male patient involved a massive en bloc excision of the GCMN with partial resection of the latissimus dorsi, followed by a 5-week staged reconstructive process using dermal regenerative matrices and split-thickness skin grafting. Because of the shift in GCMN management from early surgical management to more conservative management, we may see an increase in adult cases of GCMN. Thus, it is critical to better understand the controversy surrounding early versus delayed management of GCMN.

Sternal defect reconstruction using a double-barrel vascularized free fibula flap: a case report.

Total and subtotal sternectomy oncological defects can result in large deficits in the chest wall, disrupting the biomechanics of respiration. Reviewing the current literature involving respiratory function and rib motion after sternectomy, autologous rigid reconstruction was determined to provide the optimal reconstructive option. We describe a novel technique for sternal defect reconstruction utilizing a double-barrel, longitudinally oriented, vascularized free fibula flap associated with rib titanium plates fixation. Our reconstructive approach was able to deliver a physiological reconstruction, providing rigid support and protection while allowing articulation with adjacent ribs and preservation of chest wall mechanics.

Emergent SARS-CoV-2 variants: comparative replication dynamics and high sensitivity to thapsigargin.

The struggle to control the COVID-19 pandemic is made challenging by the emergence of virulent SARS-CoV-2 variants. To gain insight into their replication dynamics, emergent Alpha (A), Beta (B) and Delta (D) SARS-CoV-2 variants were assessed for their infection performance in single variant- and co-infections. The effectiveness of thapsigargin (TG), a recently discovered broad-spectrum antiviral, against these variants was also examined. Of the 3 viruses, the D variant exhibited the highest replication rate and was most able to spread to in-contact cells; its replication rate at 24 h post-infection (hpi) based on progeny viral RNA production was over 4 times that of variant A and 9 times more than the B variant. In co-infections, the D variant boosted the replication of its co-infected partners at the expense of its own initial performance. Furthermore, co-infection with AD or AB combination conferred replication synergy where total progeny (RNA) output was greater than the sum of corresponding single-variant infections. All variants were highly sensitive to TG inhibition. A single pre-infection priming dose of TG effectively blocked all single-variant infections and every combination (AB, AD, BD variants) of co-infection at greater than 95% (relative to controls) at 72 hpi. Likewise, TG was effective in inhibiting each variant in active preexisting infection. In conclusion, against the current backdrop of the dominant D variant that could be further complicated by co-infection synergy with new variants, the growing list of viruses susceptible to TG, a promising host-centric antiviral, now includes a spectrum of contemporary SARS-CoV-2 viruses.

Microsurgery Training in Plastic Surgery.

Advances in surgical instruments, magnification technology, perforator dissection techniques, and vascular imaging over the past decades have facilitated exponential growth in the field of microsurgery. With wide application potential including but not limited to limb salvage, breast reconstruction, lymphedema treatment, and sex affirmation surgery, microsurgery represents a critical skill set that powerfully augments the reconstructive armamentarium of plastic surgeons. Accordingly, microsurgical training is now a critical component of the plastic surgery residency education curriculum. Trainees must meet minimum microsurgery case requirements in addition to the core competencies outlined by the Accreditation Council for Graduate Medical Education. Through the use of simulation models, residency programs increasingly incorporate early skills development and assessment in microsurgery in the laboratory. Beyond residency, microsurgery fellowships offer additional exposure and refinement by offering volume, complexity, autonomy, and possible focused specialization. With continued refinement in technology and advances in knowledge, new types of simulation training models will continue to be developed and incorporated into microsurgery training curricula.

The Basics of Integra Dermal Regeneration Template and its Expanding Clinical Applications.

First developed for coverage of burn wounds, Integra (Integra LifeSciences) is a synthetic acellular dermal regeneration template that provides a base for revascularization and neodermal formation. The use of Integra has slowly grown and has now become an important consideration along the reconstructive ladder. This article reviews the basic science of Integra and provides an overview of the many expanding applications based on anatomic location.

Bone Grafts, Bone Substitutes, and Orthobiologics: Applications in Plastic Surgery.

As reconstructive needs often extend past the soft tissue alone, a plastic surgeon must also be well versed in the methods of bony reconstruction. Understanding of the basic science of fracture healing and the biochemical mechanisms of the different bone grafts, bone substitutes, and orthobiologics is essential to selecting among the many different options available to the modern plastic surgeon. This review provides a broad overview of these different options and the specific applications for plastic surgeons based on anatomic location.

Advances in Fetal Surgery: Current and Future Relevance in Plastic Surgery.

Scarless healing has long been the holy grail for plastic surgery. While historically fetal surgery has tempted plastic surgeons with the allure of scarless correction of congenital abnormalities, the risks far outweighed the benefits and these interventions never materialized. Current advances in fetal surgery with minimally invasive fetoscopic surgery have made these early fetal interventions safer, leading to expanding applications. While the plastic surgeon's role is limited as of yet, this article provides a review of the history of fetal surgery and the advances that may become relevant to the future plastic surgeon.

The Evolving Landscape of Gene Therapy in Plastic Surgery.

With the rapid rise of personalized genomic sequencing and clustered regularly interspaced short palindromic repeat (CRISPR) technology, previous gaps in gene therapy are beginning to be bridged, paving the way for increasing clinical applicability. This article aims to provide an overview of the fundamentals of gene therapy and discuss future potential interventions relevant to plastic surgeons. These interventions include enhancing tissue regeneration and healing, as well as modifying disease processes in congenital anomalies. Though clinical applications are still on the horizon, a deeper understanding of these new advances will help plastic surgeons understand the current landscape of gene therapy and stay abreast of future opportunities.

Trends in the Surgical Correction of Gynecomastia.

Gynecomastia refers to the enlargement of the male breast due to a proliferation of ductal, stromal, and/or fatty tissue. Although it is a common condition affecting up to 65% of men, not all cases require surgical intervention. Contemporary surgical techniques in the treatment of gynecomastia have become increasingly less invasive with the advent of liposuction and its variants, including power-assisted and ultrasound-assisted liposuction. These techniques, however, have been largely limited in their inability to address significant skin excess and ptosis. For mild to moderate gynecomastia, newer techniques using arthroscopic morcellation and endoscopic techniques promise to address the fibrous component, while minimizing scar burden by utilizing liposuction incisions. Nevertheless, direct excision through periareolar incisions remains a mainstay in treatment algorithms for its simplicity and avoidance of additional instrumentation. This is particularly true for more severe cases of gynecomastia requiring skin resection. In the most severe cases with significant skin redundancy and ptosis, breast amputation with free nipple grafting remains an effective option. Surgical treatment should be individualized to each patient, combining techniques to provide adequate resection and optimize aesthetic results.

Case series: A novel technique for the treatment of external auditory canal stenosis.

External auditory canal (EAC) stenosis can exist as an isolated problem, as a component of craniofacial disorders, or in association with genetic syndromes. We present five cases and demonstrate the efficacy of a minimally invasive way of opening the EAC, facilitating better hearing, easier office examination, and allowing for other necessary treatments such as ear tube placement or use of a hearing aid. Follow-up ranged from 1 to 19 months, with all patients demonstrating significant improvement. We believe this is a novel surgical approach which is easy to perform, cost effective, and may be applicable to a wide range of patients.