Short telomeres and stem cell exhaustion model Duchenne muscular dystrophy in mdx/mTR mice.

In Duchenne muscular dystrophy (DMD), dystrophin mutation leads to progressive lethal skeletal muscle degeneration. For unknown reasons, dystrophin deficiency does not recapitulate DMD in mice (mdx), which have mild skeletal muscle defects and potent regenerative capacity. We postulated that human DMD progression is a consequence of loss of functional muscle stem cells (MuSC), and the mild mouse mdx phenotype results from greater MuSC reserve fueled by longer telomeres. We report that mdx mice lacking the RNA component of telomerase (mdx/mTR) have shortened telomeres in muscle cells and severe muscular dystrophy that progressively worsens with age. Muscle wasting severity parallels a decline in MuSC regenerative capacity and is ameliorated histologically by transplantation of wild-type MuSC. These data show that DMD progression results, in part, from a cell-autonomous failure of MuSC to maintain the damage-repair cycle initiated by dystrophin deficiency. The essential role of MuSC function has therapeutic implications for DMD.

Long-pulsed neodymium-doped yttrium aluminum garnet for hair reduction in pediatric microtia repair.

Microtia is the term for congenital malformation of the ear in which the external and internal ear are absent or malformed. Surgical reconstruction is a common management approach and occasionally requires hair reduction of the newly constructed auricle. Few studies have investigated lasers for this purpose. We conducted a retrospective chart review of patients seen at a single institution between 2012 and 2021 who underwent laser hair reduction with long-pulsed neodymium-doped yttrium aluminum garnet laser (Nd:YAG). Efficacy ratings were done through review of clinical photographs. Twelve patients were identified with 14 total ears treated. The number of laser treatments varied from 1 to 9 sessions with an average of 5.1 treatments. The majority (8/12) had an "excellent" or "very good" response, one patient had a "good" response, and three were lost to follow-up. Other than pain, there were no side effects documented. Nd:YAG laser was both effective and safe in our pediatric cohort, without any cutaneous side effects in patients with darker skin.

Gender-Affirming Facial Feminization Surgery at a Public, Safety-Net Hospital: A Single-Center Early Experience.

BACKGROUND: Facial feminization surgery (FFS) remains inaccessible to many transgender patients. Zuckerberg San Francisco General Hospital (ZSFG) was among the first public, safety-net hospitals to perform FFS. The purpose of this study is to examine the postoperative outcomes of patients who underwent FFS at ZSFG and describe barriers to providing FFS in a public hospital setting. METHODS: A retrospective review identified patients who underwent FFS at ZSFG. Demographic data, comorbidity profiles, postoperative outcomes, and hospital utilization data were collected from the medical records. FACE-Q modules (scored 0-100) were used to survey patient satisfaction at least 1 year postoperatively. RESULTS: Seventeen patients underwent comprehensive FFS surgery at ZSFG. The median age was 41 years [interquartile range (IQR): 38-55], median body mass index was 26.4 (IQR: 24.1-31.3). Patients underwent a median of 9 procedures, the most common of which included frontal cranioplasty (n=13, 77%), open brow lift (n=13, 77%), rhinoplasty (n=12, 71%), and mandible contouring (n=12, 71%). There were no complications, readmissions, or reoperations within 30 days. Patients reported high satisfaction with the surgical outcome (median: 87, IQR: 87-100), excellent postoperative psychological functioning (median: 100, IQR: 88-100), and low levels of appearance-related distress (median: 3, IQR: 0-35). An estimated 243 operating room hours and 51 inpatient bed days were required to cover all FFS procedures. CONCLUSIONS: Performing FFS in a public, safety-net hospital was associated with zero postoperative complications, few revision procedures, and excellent patient satisfaction. Limited operating room hours and inpatient availability represented barriers to providing FFS in this setting.

Analyzing Linguistic Disparities in Telehealth Care Outcomes at a Multidisciplinary Craniofacial Center.

OBJECTIVE: To examine linguistic disparities between English- and Spanish-speaking patients in access to care, satisfaction, and telehealth appointment attendance. DESIGN: Retrospective study recording demographics for non-attendance analysis and conducting phone surveys assessing satisfaction with telehealth. SETTING: Data was collected between March and December 2020 at the UCSF Craniofacial Center (CFC), a multidisciplinary pediatric clinic. Patients: English- and Spanish-speaking patients with a telehealth appointment. Interventions: The CFC offered language-concordant outreach, assistance with the telehealth platform, and interpreters at all telehealth appointments. MAIN OUTCOME MEASURES: Demographics and patient-reported satisfaction with telehealth, barriers, and instruction clarity. RESULTS: Medicaid insurance was the only predictor of non-attendance. Surveys revealed that Spanish-speakers had 12.4 times the odds of lacking access to telehealth technology and 10.7 times the odds of needing help with logging on compared to English-speakers. There were no significant differences in satisfaction outcomes. CONCLUSIONS: We attribute this equity in satisfaction to our language-concordant outreach efforts.

Disparities in Timing of Alveolar Bone Grafting and Dental Reconstruction in Patients With Clefts.

This study sought to identify disparities in the timing of alveolar bone grafting (ABG) surgery and the replacement strategy for missing maxillary lateral incisors for patients with clefts.A retrospective record review identified patients who underwent ABG. Multivariable regression analyzed the independent contribution of each variable.This institutional study was performed at the University of California, San Francisco.Patients who presented under age 12 and underwent secondary ABG between 2012 and 2020 (n = 160).The age at secondary ABG and the recommended dental replacement treatment for each patient, either dental implantation or canine substitution.The average age at ABG was 10.8 ± 2.1 years, 106 (66.3%) patients were not White, and 80 (50.0%) had private insurance. Independent predictors of older age at ABG included an income below $ 50 000 as estimated from ZIP code (ß = 15.0 months, 95% CI, 5.7-24.3, P = .002) and identifying as a race other than White (ß = 10.1 months, 95% CI, 2.1-18.0, P = .01). After ABG, patients were more likely to undergo dental implantation over canine substitution if they were female (odds ratio [OR] = 4.3, 95% CI, 1.3-17.1, P = .02) or had private insurance (OR = 12.5, 95% CI, 2.2-143.2, P = .01).Patients who were low-income or not White experienced delays in ABG, whereas dental implantation was more likely to be recommended for patients with private insurance. Understanding the sources of disparities in dental reconstruction of cleft deformities may reveal opportunities to improve equity.

Satellite cell activation and retention of muscle regenerative potential after long-term denervation.

Irreversible denervation atrophy remains an unsolved clinical problem, and the role of skeletal muscle stem cell (MuSC, satellite cell) depletion in this process is unclear. We investigated the ability of MuSCs to regenerate muscle in the context of denervation. Three to 12 months following sciatic denervation in mice, MuSC number, size, EdU uptake, rate of division, and mitochondrial activity were increased. Following acute myotoxin injury, denervated muscles formed new muscle fibers in situ. MuSCs isolated via flow cytometry from denervated mouse muscle, or from atrophic denervated gluteus maximus muscles of humans with complete spinal cord injuries two decades prior, formed new muscle fibers and reoccupied the anatomic niche after transplantation into uninjured muscle. Our results show unequivocally that, even after prolonged denervation, MuSCs retain intrinsic regenerative potential similar to that of uninjured MuSCs. Treatment of denervation atrophy will require elucidating the non-MuSC environmental changes in muscle that prevent functional regeneration.

Racial and Socioeconomic Disparities in Prompt Craniosynostosis Workup and Treatment.

The purpose of this study was to identify racial and socioeconomic disparities in craniosynostosis evaluation and treatment, from referral to surgery. Patients diagnosed with craniosynostosis between 2012 and 2020 at a single center were identified. Chart review was used to collect demographic variables, age at referral to craniofacial care, age at diagnosis, age at surgery, and surgical technique (open versus limited incision). Multivariable linear and logistic regression models with lasso regularization assessed the independent effect of each variable. A total of 298 patients were included. Medicaid insurance was independently associated with a delay in referral of 83 days [95% confidence interval (CI) 4-161, P=0.04]. After referral, patients were diagnosed a median of 21 days later (interquartile range 7-40), though this was significantly prolonged in patients who were not White (ß 23 d, 95% CI 9-38, P=0.002), had coronal synostosis (ß 24 d, 95% CI 2-46, P=0.03), and had multiple suture synostosis (ß 47 d, 95% CI 27-67, P<0.001). Medicaid insurance was also independently associated with diagnosis over 3 months of age (risk ratio 1.3, 95% CI 1.1-1.4, P=0.002) and undergoing surgery over 1 year of age (risk ratio 3.9, 95% CI 1.1-9.4, P=0.04). In conclusion, Medicaid insurance was associated with a 3-month delay in referral to craniofacial specialists and increased risk of diagnosis over 3 months of age, limiting surgical treatment options in this group. Patients with Medicaid also faced a 4-fold greater risk of delayed surgery, which could result in neurodevelopmental sequelae.

Facial Feminization Surgery: Key CT Findings for Preoperative Planning and Postoperative Evaluation.

Facial feminization surgery is an increasingly performed component of gender affirmation surgery for transgender women. Preoperative facial CT is performed to plan the adjustment of the patient's masculine characteristics to feminine and to plan operative navigation around specific readily identifiable anatomic structures. In the upper face, surgery is performed to reduce the prominence of the brow and increase the nasofrontal angle; the radiology report should indicate the frontal sinus and supraorbital foramen anatomy. In the midface, rhinoplasty is performed to increase the nasofrontal and nasolabial angles; the radiology report should indicate the presence of a dorsal hump and septal deviation or spurring. In the lower face, the prominence of the chin and squareness of the jaw are adjusted via genioplasty and mandible contouring, respectively; the radiology report should describe the location and potential anatomic variations of the inferior alveolar nerve and mental foramina as well as the presence of dental abnormalities that directly inform the surgical approach. CT may also be performed if there is clinical suspicion for postoperative complications such as hardware fracture or osteotomy through the supraorbital or mental foramen. Familiarity with these findings will facilitate improved communication between radiologists and surgeons, thereby contributing to the care of transgender women.

Facial Feminization Surgery: Key CT Findings for Preoperative Planning and Postoperative Evaluation.

Facial feminization surgery (FFS) is an increasingly performed component of gender affirmation surgery for transgender women. Preoperative facial CT is performed to plan the adjustment of the patient's masculine characteristics to feminine, and to plan operative navigation around specific readily identifiable anatomic structures. In the upper face, surgery is performed to reduce the prominence of the brow and increase the nasofrontal angle; the radiology report should indicate the frontal sinus and supraorbital foramen anatomy. In the midface, rhinoplasty is performed to increase the nasofrontal and nasolabial angles; the radiology report should indicate presence of a dorsal hump and septal deviation or spurring. In the lower face, prominence of the chin and squareness of the jaw are adjusted via genioplasty and mandible contouring, respectively; the radiology report should describe the location and potential anatomic variations of the inferior alveolar nerve and mental foramina, as well as presence of dental abnormalities that directly inform the surgical approach. CT may also be performed if there is clinical suspicion for postoperative complications such as hardware fraction or osteotomy through the supraorbital or mental foramen. Familiarity with these findings will facilitate improved communication between radiologists and surgeons, thereby contributing to the care of transgender women.

Case Report of Floating-Harbor Syndrome With Bilateral Cleft Lip.

Floating-Harbor syndrome (FHS) is a rare genetic disorder caused by heterozygous mutations in the Snf2-related CREBBP activator protein (SRCAP) gene. The syndrome is characterized by proportional short stature, delayed bone maturation, delayed speech development, and facial dysmorphism. Submucous cleft palate and cleft lip have been reported in FHS, but to our knowledge orofacial clefting in this condition has not been assessed in detail. Here, we report on a case of bilateral cleft lip in a patient with FHS confirmed by exome sequencing.

Recalcitrant Invasive Skin Cancer of the Scalp: Combined Extirpation and Microsurgical Reconstruction Without Cranioplasty.

BACKGROUND: Recurrent invasive skin cancer of the scalp and calvarium is a difficult problem for which universally accepted treatment protocols have not been established. The authors present their 10-year experience with treatment of this specific subset of scalp reconstruction patients and present a successful treatment algorithm that is well suited to this patient population. METHODS: The authors retrospectively reviewed all patients of microsurgical scalp reconstruction performed from 2005 to 2015 that involved invasive cutaneous malignancies of the scalp and calvarium. RESULTS: Eleven patients met inclusion criteria. There were 9 squamous cell carcinoma, 1 basal cell carcinoma, and 1 melanoma. Seven received radiation prior to resection, 2 were irradiated postoperatively, and 2 were immunosuppressed. Seven had a history of prior scalp reconstruction. The median scalp defect size was 141 cm. All the patients underwent craniectomy and the median cranial defect size was 71 cm. Cranioplasty was not performed in any patient. There were no intraoperative complications or flap loss. Recipient site complications included hematoma in 1, 1 seroma, 2 cerebral spinal fluid leaks, 3 partial skin graft loss. There was 1 donor site seroma in a patient who had a latissimus dorsi flap. All the patients reported satisfaction with the overall result and none were limited in activities by the existing cranial defect. CONCLUSIONS: This is the largest series published to date that focuses exclusively on management of cutaneous malignancies with intracranial invasion. Wide resection with craniectomy, and reconstruction with microvascular free tissue transfer without cranioplasty provides safe and reliable treatment of recalcitrant invasive scalp skin cancers with low morbidity and without major complications. Pre and postoperative radiation is well tolerated with this approach. The patients in this series were of advanced age and of a lifestyle for which cranioplasty is unnecessary for return to regular activities.

Tumor suppressors: enhancers or suppressors of regeneration?

Tumor suppressors are so named because cancers occur in their absence, but these genes also have important functions in development, metabolism and tissue homeostasis. Here, we discuss known and potential functions of tumor suppressor genes during tissue regeneration, focusing on the evolutionarily conserved tumor suppressors pRb1, p53, Pten and Hippo. We propose that their activity is essential for tissue regeneration. This is in contrast to suggestions that tumor suppression is a trade-off for regenerative capacity. We also hypothesize that certain aspects of tumor suppressor pathways inhibit regenerative processes in mammals, and that transient targeted modification of these pathways could be fruitfully exploited to enhance processes that are important to regenerative medicine.

Bilateral Coronoidectomy by Craniofacial Approach for Hecht Syndrome-Related Trismus.

Hecht Syndrome is an autosomal dominant distal arthrogryposis caused by mutation in the MYH8 locus characterized by trismus and pseudocamptodactyly. Hecht-associated trismus is thought to result from bilateral hyperplasia of the mandibular coronoid processes. Although several interventions to address trismus have been pursued, no consensus exists regarding optimal management. In this report, the authors present a 7-month-old male with Hecht Syndrome referred for management of trismus. By age 2, interincisal opening had progressively decreased from 12 to 5 mm despite physical therapy. Nutrition was limited to liquids, oral hygiene was compromised, and aspiration risk was present. Computed tomography examination revealed enlarged coronoid processes extending medially and superiorly to the zygomatic arches. To release bony impaction of the coronoid processes against the zygoma and to prevent reossification of the temporalis tendon insertion, resection of the enlarged coronoids and distal temporalis muscles as well as placement of Alloderm spacers were performed via an open craniofacial transzygomatic approach. Jaw motion rehabilitation was used following surgery. Two years postoperatively, the patient had no signs of recurrence and good functional stability of jaw excursion. He was able to chew and swallow solid foods, protrude his tongue, use utensils, and perform regular oral hygiene, none of which were possible before surgery. This case demonstrates that open bilateral coronoidectomy can be a successful and durable management option for trismus in patients with Hecht Syndrome. The open transzygomatic approach is safe, has low morbidity, and provides direct access and adequate exposure for coronoid resection, spacer placement, and prevention of temporalis reinsertion.

Simultaneous silencing of multiple RB and p53 pathway members induces cell cycle reentry in intact human pancreatic islets.

BACKGROUND: Human pancreatic islet structure poses challenges to investigations that require specific modulation of gene expression. Yet dissociation of islets into individual cells destroys cellular interactions important to islet physiology. Approaches that improve transient targeting of gene expression in intact human islets are needed in order to effectively perturb intracellular pathways to achieve biological effects in the most relevant tissue contexts. RESULTS: Electroporation of intact human cadaveric islets resulted in robust and specific suppression of gene expression. Two genes were simultaneously suppressed by 80% from baseline levels. When multiple (up to 5) genes were simultaneously targeted, effective suppression of 3 of 5 genes occurred. Enzymatic pretreatment of islets was not required. Simultaneous targeting of RB and p53 pathway members resulted in cell cycle reentry as measured by EDU incorporation in 10% of islet nuclei. CONCLUSIONS: At least three genes can be effectively suppressed simultaneously in cultured intact human pancreatic islets without disruption of islet architecture or overt alterations in function. This enabled the effective modulation of two central growth control pathways resulting in the phenotypic outcome of cell cycle reentry in postmitotic islet cells. Transient exposure to multiple siRNAs is an effective approach to modify islets for study with the potential to aid clinical applications.

Acrylated Hyaluronic-Acid Based Hydrogel for the Treatment of Craniofacial Volumetric Muscle Loss.

Current treatment options for craniofacial volumetric muscle loss (VML) have disadvantages and cannot fully restore normal function. Bio-inspired semisynthetic acrylated hyaluronic acid (AcHyA) hydrogel, which fills irregularly shaped defects, resembles an extracellular matrix, and induces a minimal inflammatory response, has shown promise in experimental studies of extremity VML. We therefore sought to study AcHyA hydrogel in the treatment of craniofacial VML. For this, we used a novel model of masseter VML in the rat. Following the creation of a 5 mm × 5 mm injury to the superficial masseter and administration of AcHyA to the wound, masseters were explanted between 2 and 16 weeks postoperatively and were analyzed for evidence of muscle regeneration including fibrosis, defect size, and fiber cross-sectional area (FCSA). At 8 and 16 weeks, masseters treated with AcHyA showed significantly less fibrosis than nonrepaired controls and a smaller decrease in defect size. The mean FCSA among fibers near the defect was significantly greater among hydrogel-repaired than control masseters at 8 weeks, 12 weeks, and 16 weeks. These results show that the hydrogel mitigates the fibrotic healing response and wound contracture. Our findings also suggest that hydrogel-based treatments have potential use as a treatment for the regeneration of craniofacial VML and demonstrate a system for evaluating subsequent iterations of materials in VML injuries.

Melanoma in infants, caused by a gene fusion involving the anaplastic lymphoma kinase (ALK).

We describe the first cases of pediatric melanoma with ALK fusion gene arising within giant congenital melanocytic nevi. Two newborn boys presented with large pigmented nodular plaques and numerous smaller satellite nevi. Additional expansile nodules developed within both nevi and invasive melanomas were diagnosed before 10 months of age in both boys. Oncogenic driver mutations in NRAS and BRAF were absent in both cases. Instead, oncogenic ZEB2::ALK fusion genes were identified in both the nevus and melanoma developing within the nevus. In both cases, tumors were noted by ultrasound in utero, demonstrated significant nodularity at birth, and progressed to melanoma in the first year of life suggesting that congenital nevi with ALK fusion genes may behave more aggressively than those with other mutations. As ALK kinase inhibitors are effective against a range of tumors with similar ALK fusion kinases, identifying ALK fusion genes in congenital melanocytic nevi may provide an opportunity for targeted therapy.

Loss of transcriptional heterogeneity in aged human muscle stem cells.

Age-related loss of muscle mass and function negatively impacts healthspan and lifespan. Satellite cells function as muscle stem cells in muscle maintenance and regeneration by self-renewal, activation, proliferation and differentiation. These processes are perturbed in aging at the stem cell population level, contributing to muscle loss. However, how representation of subpopulations within the human satellite cell pool change during aging remains poorly understood. We previously reported a comprehensive baseline of human satellite cell (Hu-MuSCs) transcriptional activity in muscle homeostasis describing functional heterogenous human satellite cell subpopulations such as CAV1+ Hu-MUSCs. Here, we sequenced additional satellite cells from new healthy donors and performed extended transcriptomic analyses with regard to aging. We found an age-related loss of global transcriptomic heterogeneity and identified new markers (CAV1, CXCL14, GPX3) along with previously described ones (FN1, ITGB1, SPRY1) that are altered during aging in human satellite cells. These findings describe new transcriptomic changes that occur during aging in human satellite cells and provide a foundation for understanding functional impact.

Opioid-free Pain Management after Cleft Lip Repair.

Background: Side effects of opioid pain management after surgical repair of cleft lips are numerous and affect postoperative course. We compared opioid versus opioid-free pain management regimens for infants who underwent cleft lip repair to evaluate the impact on postoperative recovery. Methods: Cleft lip repairs at our institution from December 2016 to February 2021 were retrospectively reviewed, comparing patients who received opioids to patients receiving a nonopioid pain control regimen. Data collected include length of stay, oral morphine equivalents (OME) received on day of surgery (DOS)/postoperative day (POD) 1, time to and volume of first oral feed, and Face/Legs/Activity/Cry/Consolability (FLACC) scores. Results: Seventy-three infants were included (47 opioid and 26 nonopioid). The opioid group received average 1.75 mg OME on DOS and 1.04 mg OME on POD1. Average DOS FLACC scores were similar between groups [1.57 ±â€…1.18 nonopioid versus 1.76 ±â€…0.94 (SD) opioid; P = 0.46]. Average POD1 FLACC scores were significantly lower for the nonopioid group (0.73 ±â€…1.05 versus 1.35 ±â€…1.06; P = 0.022). Median time to first PO (min) was similar [178 (interquartile range [IQR] 66-411) opioid versus 147 (IQR 93-351) nonopioid; P = 0.65]. Median volume of first feed (mL) was twice as high for the nonopioid group [90 (IQR 58-120) versus 45 (IQR 30-60); P = 0.003]. Conclusions: Nonopioid postoperative pain management was more effective than opioids for pain management in infants after cleft lip repair, as evidenced by FLACC scores and increased volume of the first oral feed.

Superior Long-term Appearance of Strip Craniectomy Compared with Cranial Vault Reconstruction in Metopic Craniosynostosis.

BACKGROUND: Strip craniectomy with orthotic helmet therapy (SCOT) is an increasingly supported treatment for metopic craniosynostosis, although the long-term efficacy of deformity correction remains poorly defined. We compared the longterm outcomes of SCOT versus open cranial vault reconstruction (OCVR). METHODS: Patients who underwent OCVR or SCOT for isolated metopic synostosis with at least 3 years of follow-up were identified at our institution. Anthropometric measurements were used to assess baseline severity and postoperative skull morphology. Independent laypersons and craniofacial surgeons rated the appearance of each patient's 3D photographs, compared to normal controls. RESULTS: Thirty-five patients were included (15 SCOT and 20 OCVR), with similar follow-up between groups (SCOT 7.9 ± 3.2 years, OCVR 9.2 ± 4.1 years). Baseline severity and postoperative anthropometric measurements were equivalent. Independent adolescent raters reported that the forehead, eye, and overall appearance of SCOT patients was better than OCVR patients (P < 0.05, all comparisons). Craniofacial surgeons assigned Whitaker class I to a greater proportion of SCOT patients with moderate-to-severe synostosis (72.2 ± 5.6%) compared with OCVR patients with the same severity (33.3 ± 9.2%, P = 0.02). Parents of children who underwent SCOT reported equivalent satisfaction with the results of surgery (100% versus 95%, P > 0.99), and were no more likely to report bullying (7% versus 15%, P = 0.82). CONCLUSIONS: SCOT was associated with superior long-term appearance and perioperative outcomes compared with OCVR. These findings suggest that SCOT should be the treatment of choice for patients with a timely diagnosis of metopic craniosynostosis.

Purification and preservation of satellite cells from human skeletal muscle.

Regeneration and repair of skeletal muscle is driven by tissue-specific progenitor cells called satellite cells, which occupy a minority of the cells in the muscle. This protocol provides researchers with techniques to efficiently isolate and purify functional satellite cells from human muscle tissue. The proven techniques described here enable the preparation of purified and minimally altered satellite cells for in vitro and in vivo experimentation and for potential clinical applications. For complete details on the use and execution of this protocol, please refer to Barruet et al. (2020) and Garcia et al. (2018).