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1.
Urology ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38972397

ABSTRACT

OBJECTIVE: To identify risk factors for stenosis and compare management strategies for stenosis etiology and to examine the efficacy of each approach. Patients with classic bladder exstrophy (CBE), a rare genitourinary malformation, may require construction of a continent urinary stoma (CUS) if incontinence persists. Stomal stenosis is a challenging complication as it is common, progressive and recurrent. METHODS: CBE patients who underwent CUS were retrospectively reviewed for risk factors for stenosis including stoma type, prior midline laparotomy number, and umbilicoplasty suture material. Stenosis etiology and management strategies were further reviewed. RESULTS: A total of 260 CBE patients underwent CUS creation. Stenosis developed in 65 patients (25.0%) at a median interval of 1.9 years. Etiology included scar contracture (n=41), keloid (n=17), and hypertrophic scar (n=7). Multifilament suture was the only variable associated with an increased risk of stenosis compared to monofilament suture (p=0.009). Almost all patients required surgical intervention. Most scar contractures underwent stomal incision with success in 100%. Hypertrophic scars and keloids responded best to excision with local tissue rearrangement (66.7%). At last follow-up, all patients achieved success. CONCLUSION: Stomal stenosis is common and challenging for the reconstructive surgeon. Strategies to prevent and effectively manage this are greatly desired. Use of multifilament suture for the umbilicoplasty increased stenosis perhaps from a greater inflammatory response and scarring, while monofilament suture may reduce its incidence. Stomal incision for treating scar contractures, and excision with local tissue rearrangement for hypertrophic scars and keloids may improve successful primary surgical intervention.

2.
Article in English | MEDLINE | ID: mdl-38775428

ABSTRACT

Objective: Nerve scarring after traumatic or iatrogenic exposure can lead to impaired function and pain. Nerve-adjacent biomaterials promoting a regenerative tissue response may help reduce perineural fibrosis. Our prior work suggests that testosterone may promote fibrotic skin scarring, but it is unknown how testosterone alters nerve fibrosis or shifts the response to biomaterials. Approach: Sterilized Lewis rats received either testosterone cypionate (+T) or placebo (-T) biweekly. Fifteen days later, wounds were created over the sciatic nerve and covered with an acellular matrix (AM) or closed via primary closure (PC). At day 42, force gauge testing measured the force required to mobilize the nerve, and wound tissue was analyzed. Results: Nerve mobilization force was greater in +T versus -T wounds (p < 0.01). Nerves tore before gliding in 60% of +T versus 6% of -T rats. Epidermal gap (p < 0.01), scar width (p < 0.01), and cross-sectional scar tissue area (p = 0.02) were greater in +T versus -T rats. +T versus -T rats expressed less Col-3 (p = 0.02) and CD68 (p = 0.02). Nerve mobilization force trended nonsignificantly higher for PC versus AM wounds and for +T versus -T wounds within the AM cohort. Innovation: Testosterone increases nerve tethering in the wound healing milieu, altering repair and immune cell balances. Conclusion: Testosterone significantly increases the force required to mobilize nerves in wound beds and elevates histological markers of scarring, suggesting that testosterone-induced inflammation may increase perineural adhesion. Testosterone may reduce the potential anti-tethering protective effect of AM. Androgen receptor antagonism may represent a therapeutic target to reduce scar-related nerve morbidity.

3.
J Pediatr Urol ; 2024 Feb 24.
Article in English | MEDLINE | ID: mdl-38433079

ABSTRACT

INTRODUCTION: Classic bladder exstrophy (CBE) is a malformation of the genitourinary system that occurs due to failure of abdominal wall closure. Unlike other malformations of similar incidence, prenatal diagnosis of CBE relies on suggested, rather than formal, diagnostic criteria. OBJECTIVE: This report describes prenatal diagnosis of CBE in the largest single-institutional cohort to date and delineates key sonographic findings and protocols for specialist referral. MATERIALS AND METHODS: A single-institutional database was reviewed for CBE patients born since 2000. Data on screening ultrasound use, gestational age at ultrasound, and abnormal findings were extracted. Where possible, time of prenatal diagnosis (pre- or postnatal and gestational age), ultrasound findings and other imaging data, specialist referral, institution of birth and closure, and outcome of primary closure attempt were compared. RESULTS: Of 557 patients born with CBE between 2000 and 2022, 284 met inclusion criteria and complete data were available for 280 (229 born domestically and 51 born internationally) who were included for analysis. Abnormal sonography suggestive of CBE was present for 48% (n = 134) of patients, for whom absent bladder was the most common abnormal finding (76% [102/134]). Of domestic patients, 46% (n = 106) were diagnosed prenatally at a median gestational age of 22 weeks (inter-quartile range [IQR]: 20-24), and 14% (n = 32) underwent confirmatory fetal magnetic resonance imaging. Of domestic patients with abnormal prenatal findings, 75% (n = 80/106) consulted with maternal-fetal medicine and 58% (n = 62/106) consulted with pediatric urology. On univariate analysis, prenatal diagnosis was positively associated with primary repair at Association for the Bladder Exstrophy Community-recognized centers of excellence (54% vs. 38%, p = 0.02) and negatively associated with osteotomy at primary closure (41% vs 59%, p = 0.003) but not success of primary closure (74% vs. 82%, p = 0.07). DISCUSSION: Rates of prenatal diagnosis in this cohort were similar to previous reports of smaller cohorts. Diagnosis allows for comprehensive pre- and postnatal follow-up with a pediatric urologist, with implications on birth planning and decisions on termination of pregnancy. Because of the previously-reported association between exstrophy and in vitro fertilization, these pregnancies should undergo detailed sonography. Any nonvisualization of the fetal bladder should prompt a detailed exam, and any finding characteristic of bladder exstrophy warrants referral to pediatric urology. CONCLUSIONS: Although CBE is a rare disorder, it is underdiagnosed during pregnancy. Sonographers and obstetricians should be aware of characteristic findings and best practices following diagnosis. Early referral to pediatric urology and maternal-fetal medicine is important for counseling and postnatal planning.

4.
Acta Biomater ; 177: 107-117, 2024 03 15.
Article in English | MEDLINE | ID: mdl-38382830

ABSTRACT

Designing proteins that fold and assemble over different length scales provides a way to tailor the mechanical properties and biological performance of hydrogels. In this study, we designed modular proteins that self-assemble into fibrillar networks and, as a result, form hydrogel materials with novel properties. We incorporated distinct functionalities by connecting separate self-assembling (A block) and cell-binding (B block) domains into single macromolecules. The number of self-assembling domains affects the rigidity of the fibers and the final storage modulus G' of the materials. The mechanical properties of the hydrogels could be tuned over a broad range (G' = 0.1 - 10 kPa), making them suitable for the cultivation and differentiation of multiple cell types, including cortical neurons and human mesenchymal stem cells. Moreover, we confirmed the bioavailability of cell attachment domains in the hydrogels that can be further tailored for specific cell types or other biological applications. Finally, we demonstrate the versatility of the designed proteins for application in biofabrication as 3D scaffolds that support cell growth and guide their function. STATEMENT OF SIGNIFICANCE: Designed proteins that enable the decoupling of biophysical and biochemical properties within the final material could enable modular biomaterial engineering. In this context, we present a designed modular protein platform that integrates self-assembling domains (A blocks) and cell-binding domains (B blocks) within a single biopolymer. The linking of assembly domains and cell-binding domains this way provided independent tuning of mechanical properties and inclusion of biofunctional domains. We demonstrate the use of this platform for biofabrication, including neural cell culture and 3D printing of scaffolds for mesenchymal stem cell culture and differentiation. Overall, this work highlights how informed design of biopolymer sequences can enable the modular design of protein-based hydrogels with independently tunable biophysical and biochemical properties.


Subject(s)
Hydrogels , Mesenchymal Stem Cells , Humans , Hydrogels/chemistry , Proteins/chemistry , Biocompatible Materials/metabolism , Biopolymers , Tissue Engineering
6.
Plast Reconstr Surg ; 2024 Jan 30.
Article in English | MEDLINE | ID: mdl-38289920

ABSTRACT

BACKGROUND: The exstrophy-epispadias complex is a spectrum of ventral wall malformations including classic bladder exstrophy (CBE) and cloacal exstrophy (CE). Patients undergo multiple soft-tissues procedures to achieve urinary continence. If unsuccessful bladder neck closure (BNC) is performed, muscle flaps may be used to reinforce BNC or afterwards for fistula reconstruction. In this study, patients reconstructed using a rectus abdominis or gracilis muscle flap were reviewed. METHODS: A retrospective cohort study of exstrophy-epispadias complex patients who underwent BNC and had a muscle fap was performed. Indication for flap use, surgical technique, risks for BNC failure including mucosal violations (MVs) were reviewed. MVs were prior bladder mucosa manipulation for exstrophy closure, repeat closure(s) and bladder neck reconstruction. Success was defined as BNC without fistula development. RESULTS: Thirty-four patients underwent reconstruction. Indications included during BNC (n=13), fistula closure after BNC (n=17), following BNC during open cystolithotomy (n=1) or fistula closure after open cystolithotomy (n=3). A vesicourethral fistula developed most frequently in CBE (88.9%) and vesicoperineal fistula in CE (87.5%). Thirty-three rectus flaps and 3 gracilis flap were used with success achieved in 97.1% and 66.7%, respectively. All 34 patients achieved success and 2 CE patients required a second flap. CONCLUSION: The rectus flap is preferred as it covers the antero-inferior bladder and pelvic floor to prevent urethral, cutaneous, and perineal fistula formation. The gracilis flap only reaches the pelvic floor to prevent urethral and perineal fistula development. Increased MVs, increase the risk of fistula formation and may influence the need for prophylactic flaps.

7.
J Pediatr Urol ; 20(3): 406.e1-406.e7, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38245430

ABSTRACT

PURPOSE: Appropriate perioperative management is crucial in patients undergoing classic bladder exstrophy closure (CBE). Therefore, the authors sought to review their intra and postoperative management of patients with CBE undergoing primary closure and examine the impact of this pathway on patient outcomes. METHOD: A prospectively maintained institutional approved exstrophy-epispadias complex database was reviewed for patients with CBE who had undergone primary closure between 2016 and 2022 and whose closure was performed within one year of age. Electronic medical records for eligible patients were retrospectively reviewed to examine patient demographics, use of pelvic osteotomy, immobilization status, pediatric intensive care unit (PICU) admission and management, perioperative analgesia and sedation, nutritional support, drainage tubes, blood transfusions, antibiotic coverage, hospital length of stay, postoperative complications, and closure failure. RESULTS: A total of 25 patients were identified, 22 with CBE and 3 with variant CBE. Closure was performed at a median age of 84 days with patients ranging in age from 9 to 351 days. All patients underwent osteotomy and immobilization with modified Buck's traction and external fixation for a median duration of 41 days. A suprapubic tube was placed in all patients for a median duration of 46.5 days. All patients underwent PICU admission following closure for a median duration of 8 days. Ventilator support was required in 68 % of patients for a median of 3 days. Epidural analgesia was used in all patients and catheters were maintained for a median duration of 19 days. All patients received a blood transfusion over the course of their admission. Patient-controlled analgesia was used in most patients as an adjunct for a median duration of 38.5 days. Other commonly used analgesic adjuncts included acetaminophen, diazepam, clonidine, and dexmedetomidine. TPN was used in 80 % of patients for a median of 7 days with a return of oral feeding thereafter. Overall, the closure success rate in this cohort of patients was 100 %. DISCUSSION: The outcome of primary bladder closure can have inauspicious consequences that can affect a child's continence for years. The incidence of failed bladder closure can be minimized with the implementation of a detailed plan for immobilization, analgesia, and nutrition guided by an experienced multi-disciplinary team. CONCLUSION: We have identified several guiding principles for perioperative success in exstrophy patients at our center including Buck's traction with external fixation, provision of adequate postoperative analgesia and sedation, aggressive nutritional support, renal and bladder drainage, and robust antibacterial support. Our high success rate in managing this complex pathology demonstrates its validity and use as a pathway to success.


Subject(s)
Bladder Exstrophy , Perioperative Care , Humans , Bladder Exstrophy/surgery , Retrospective Studies , Female , Male , Infant , Perioperative Care/methods , Urologic Surgical Procedures/methods , Treatment Outcome , Infant, Newborn , Critical Pathways
8.
Mol Cell ; 84(2): 234-243.e4, 2024 Jan 18.
Article in English | MEDLINE | ID: mdl-38159566

ABSTRACT

Transcription coactivators are proteins or protein complexes that mediate transcription factor (TF) function. However, they lack DNA-binding capacity, prompting the question of how they engage target loci. Three non-exclusive hypotheses have been posited: coactivators are recruited by complexing with TFs, by binding histones through epigenetic reader domains, or by partitioning into condensates through their extensive intrinsically disordered regions. Using p300 as a prototypical coactivator, we systematically mutated its annotated domains and show by single-molecule tracking in live U2OS cells that coactivator-chromatin binding depends entirely on combinatorial binding of multiple TF-interaction domains. Furthermore, we demonstrate that acetyltransferase activity opposes p300-chromatin association and that the N-terminal TF-interaction domains regulate that activity. Single TF-interaction domains are insufficient for chromatin binding and regulation of catalytic activity, implying a principle that we speculate could broadly apply to eukaryotic gene regulation: a TF must act in coordination with other TFs to recruit coactivator activity.


Subject(s)
Transcription Factors , Transcription, Genetic , Transcription Factors/genetics , Transcription Factors/metabolism , Gene Expression Regulation , Histones/metabolism , Chromatin/genetics
9.
J Pediatr Surg ; 58(12): 2308-2312, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37777362

ABSTRACT

PURPOSE: Staged pelvic osteotomy has been shown in the past to be an effective tool in the closure of the extreme pubic diastasis of cloacal exstrophy. The authors sought to compare orthopedic complications between non-staged pelvic osteotomies and staged pelvic osteotomies in cloacal exstrophy. METHODS: A prospectively maintained exstrophy-epispadias complex database of 1510 patients was reviewed for cloacal exstrophy bladder closure events performed with osteotomy at the authors' institution. Bladder closure failure was defined as any fascial dehiscence, bladder prolapse, or vesicocutaneous fistula within one year of closure. There was a total of 172 cloacal exstrophy and cloacal exstrophy variant patients within the database and only closures at the authors' institution were included. RESULTS: 64 closure events fitting the inclusion criteria were identified in 61 unique patients. Staged osteotomy was performed in 42 closure events and non-staged in 22 closures. Complications occurred in 46/64 closure events, with 16 grade III/IV complications. There were no associations between staged osteotomy and overall complication or grade III/IV complications (p = 0.6344 and p = 0.1286, respectively). Of the 46 total complications, 12 were orthopedic complications with 6 complications being grade III/IV. Staged osteotomy closure events experienced 10/42 orthopedic complications while non-staged osteotomy closures experienced 2/22 orthopedic complications, however this did not reach significance (p = 0.1519). Of the 64 closure events, 57 resulted in successful closure with 6 failures and one closure with planned cystectomy. CONCLUSION: This study confirms, in a larger series, superior outcomes when using staged pelvic osteotomy in cloacal exstrophy bladder closure. Staged osteotomy was shown to be a safe alternative to non-staged osteotomy that can decrease the risk of closure failure in this group. Staged pelvic osteotomy should be considered in all patients undergoing cloacal exstrophy bladder closure. TYPE OF STUDY: Treatment study. LEVEL OF EVIDENCE: Level III.


Subject(s)
Bladder Exstrophy , Epispadias , Humans , Bladder Exstrophy/surgery , Epispadias/surgery , Urologic Surgical Procedures/methods , Osteotomy/methods , Cystectomy , Retrospective Studies , Treatment Outcome
10.
Plast Reconstr Surg ; 2023 Jul 18.
Article in English | MEDLINE | ID: mdl-37467112

ABSTRACT

BACKGROUND: Poor outcomes in functional recovery following upper extremity transplantation are largely due to denervation-induced muscle atrophy that occurs during the prolonged period of nerve regeneration. Growth hormone (GH) has well-established trophic effects on neurons, myocytes, and Schwann cells and represents a promising therapeutic approach to address this challenge. This study sought to confirm the positive effects of GH treatment on nerve regeneration and functional recovery and to evaluate the effects of GH treatment on the immune response in the setting of vascularized composite allotransplantation. METHODS: Rats underwent orthotopic forelimb transplantation across a full MHC-mismatch and received either porcine-derived growth hormone or no treatment (n=18 per group). Functional recovery was measured using electrically-stimulated grip strength testing. Animals were monitored for clinical and subclinical signs of rejection. RESULTS: Neuromuscular junction reinnervation and grip strength were improved in GH-treated animals (p=0.005; p=0.08). No statistically significant differences were seen in muscle atrophy, degree of myelination, axon diameter, and axon counts between groups. The rates of clinical and histological rejection did not significantly differ among groups. CONCLUSIONS: Our findings alleviate concern for increased risk of transplant rejection during GH therapy and therefore support the translation of growth hormone as a therapeutic method to promote improved functional recovery in upper extremity transplantation.

11.
J Pediatr Surg ; 58(12): 2313-2318, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37302866

ABSTRACT

BACKGROUND: Cloacal exstrophy (CE) is rare and challenging to reconstruct. In the majority of CE patients voided continence cannot be achieved and so patients often undergo bladder neck closure (BNC). Prior mucosal violations (MVs), a surgical event when the bladder mucosa was opened or closed, significantly predicted failed BNC in classic bladder exstrophy with an increased likelihood of failure after 3 or more MVs. The aim of this study was to assess predictors for failed BNC in CE. METHODS: CE patients who underwent BNC were reviewed for risk factors for failure including osteotomy use, successful primary closure, and number of MVs. Chi-squared and Fisher's exact tests were used for comparing baseline characteristics and surgical details. RESULTS: Thirty-five patients underwent BNC. Eleven patients (31.4%) failed BNC including a vesicoperineal fistula in nine, vesicourethral and vesicocutaneous fistula in one each. The fistula rate in patients with 2 or more MVs was 47.4% (p = 0.0252). Two patients subsequently developed a vesicocutaneous fistula after undergoing repeated cystolithotomies. A rectus abdominis or gracilis muscle flap were used to close the fistula in 11 and 2 patients, respectively. CONCLUSIONS: MVs have a greater impact in CE with an increased risk of failed BNC after 2 MVs. CE patients are most likely to develop a vesicoperineal fistula while a vesicocutaneous fistula is more likely after repeat cystolithotomy. A prophylactic muscle flap should be considered at time of BNC in patients with 2 or more MVs. LEVELS OF EVIDENCE: Prognosis Study, Level III.


Subject(s)
Bladder Exstrophy , Cutaneous Fistula , Humans , Urinary Bladder/surgery , Bladder Exstrophy/surgery , Urologic Surgical Procedures , Urination , Retrospective Studies
12.
bioRxiv ; 2023 May 18.
Article in English | MEDLINE | ID: mdl-37292840

ABSTRACT

Transcription coactivators are proteins or protein complexes that mediate transcription factor (TF) function. However, they lack DNA binding capacity, prompting the question of how they engage target loci. Three non-exclusive hypotheses have been posited: coactivators are recruited by complexing with TFs, by binding histones through epigenetic reader domains, or by partitioning into phase-separated compartments through their extensive intrinsically disordered regions (IDRs). Using p300 as a prototypical coactivator, we systematically mutated its annotated domains and show by single-molecule tracking in live cells that coactivator-chromatin binding depends entirely on combinatorial binding of multiple TF-interaction domains. Furthermore, we demonstrate that acetyltransferase activity negatively impacts p300-chromatin association and that the N-terminal TF-interaction domains regulate that activity. Single TF-interaction domains are insufficient for both chromatin binding and regulation of catalytic activity, implying a principle that could broadly inform eukaryotic gene regulation: a TF must act in coordination with other TFs to recruit coactivator activity.

13.
J Pediatr Urol ; 19(5): 564.e1-564.e7, 2023 10.
Article in English | MEDLINE | ID: mdl-37244839

ABSTRACT

INTRODUCTION: Bladder capacity (BC) is an important metric in the management of patients with classic bladder exstrophy (CBE). BC is frequently used to determine eligibility for surgical continence procedures, such as bladder neck reconstruction (BNR), and is associated with the likelihood of achieving urinary continence. OBJECTIVE: To use readily available parameters to develop a nomogram that could be used by patients and pediatric urologists to predict BC in patients with CBE. STUDY DESIGN: An institutional database of CBE patients was reviewed for those who have undergone annual gravity cystogram 6 months after bladder closure. Candidate clinical predictors were used to model BC. Linear mixed effects models with random intercept and slope were used to construct models predicting log transformed BC and were compared with adjusted R2, Akaike Information Criterion (AIC), and cross-validated mean square error (MSE). Final model evaluated via K-fold cross-validation. Analyses were performed using R version 3.5.3 and the prediction tool was developed with ShinyR. RESULTS: In total, 369 patients (107 female, 262 male) with CBE had at least one BC measurement after bladder closure. Patients had a median of 3 annual measurements (range 1-10). The final nomogram includes outcome of primary closure, sex, log-transformed age at successful closure, time from successful closure, and interaction between outcome of primary closure and log-transformed age at successful closure as the fixed effects with random effect for patient and random slope for time since successful closure (Extended Summary). DISCUSSION: Using readily accessible patient and disease related information, the bladder capacity nomogram in this study provides a more accurate prediction of bladder capacity ahead of continence procedures when compared to the age-based Koff equation estimates. A multi-center study using this web-based CBE bladder growth nomogram (https://exstrophybladdergrowth.shinyapps.io/be_app/) will be needed for widespread application. CONCLUSION: Bladder capacity in those with CBE, while known to be influenced by a broad swath of intrinsic and extrinsic factors, may be modeled by the sex, outcome of primary bladder closure, age at successful bladder closure and age at evaluation.


Subject(s)
Bladder Exstrophy , Humans , Male , Child , Female , Bladder Exstrophy/surgery , Urinary Bladder/surgery , Treatment Outcome , Retrospective Studies , Urologic Surgical Procedures/methods
14.
J Pediatr Urol ; 19(4): 372.e1-372.e7, 2023 08.
Article in English | MEDLINE | ID: mdl-37149474

ABSTRACT

INTRODUCTION: Restoration of genitourinary anatomy with functional urinary continence is the reconstruction aim is the exstrophy-epispadias complex (EEC). In patients who do not achieve urinary continence or those who are not a candidate for bladder neck reconstruction (BNR), bladder neck closure (BNC) is considered. Interposing layers including human acellular dermis (HAD) and pedicled adipose tissue are routinely placed between the transected bladder neck and distal urethral stump to reinforce the BNC and minimize failure due to fistula development from the bladder. OBJECTIVE: The aim of this study was to review classic bladder exstrophy (CBE) patients who underwent BNC to identify predictors of BNC failure. Specifically, we hypothesize that increased operations on the bladder urothelium leads to a higher rate of urinary fistula. STUDY DESIGN: CBE patients who underwent BNC were reviewed for predictors of failed BNC which was defined as bladder fistula development. Predictors included prior osteotomy, interposing tissue layer use and number of previous bladder mucosal violations (MV). A MV was defined as a procedure when the bladder mucosa was opened or closed for: exstrophy closure(s), BNR, augmentation cystoplasty or ureteral re-implantation. Predictors were evaluated using multivariate logistic regression. RESULTS: A total of 192 patients underwent BNC of which 23 failed. Patients were more likely to develop a fistula with a wider pubic diastasis at time of primary exstrophy closure (4.4 vs 4.0 cm, p=0.0016), have failed exstrophy closure (p=0.0084), or have 3 or more MVs before BNC (p=0.0002). Kaplan-Meier analysis of fistula-free survival after BNC, demonstrated an increased fistula rate with additional MVs (p=0.0004, Figure 1). MVs remained significant on multivariate logistic regression analysis with a per-violation odds ratio of 5.1 (p<0.0001). Of the 23 failed BNC's, 16 were surgically closed including 9 using a pedicled rectus abdominis muscle flap which was secured to the bladder and pelvic floor. CONCLUSION: This study conceptualized MVs and their role in bladder viability. Increased MVs confer an increased risk of failed BNC. When considering BNC, CBE patients with 3 or more prior MVs may benefit from a pedicled muscle flap, in addition to HAD and pedicled adipose tissue, to prevent fistula development by providing wellvascularized coverage to further reinforce the BNC.


Subject(s)
Bladder Exstrophy , Urinary Bladder , Humans , Bladder Exstrophy/surgery , Treatment Outcome , Urinary Bladder/surgery , Urologic Surgical Procedures/methods
15.
Biochem Soc Trans ; 51(2): 557-569, 2023 04 26.
Article in English | MEDLINE | ID: mdl-36876879

ABSTRACT

How molecules interact governs how they move. Single-molecule tracking (SMT) thus provides a unique window into the dynamic interactions of biomolecules within live cells. Using transcription regulation as a case study, we describe how SMT works, what it can tell us about molecular biology, and how it has changed our perspective on the inner workings of the nucleus. We also describe what SMT cannot yet tell us and how new technical advances seek to overcome its limitations. This ongoing progress will be imperative to address outstanding questions about how dynamic molecular machines function in live cells.


Subject(s)
Gene Expression Regulation , Single Molecule Imaging
16.
Urology ; 176: 150-155, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36944401

ABSTRACT

OBJECTIVE: To report the technique and outcomes of tissue expansion (TE) for generating additional penile skin for urethroplasty and/or skin coverage during primary or redo hypospadias repair in penoscrotal transposition (PST) patients with a proximal hypospadias. METHODS: Proximal hypospadias and PST patients with a lack of penile skin, congenitally or after failed repair, who underwent TE assisted reconstruction were reviewed. TE were placed under the penile shaft and expanded skin was used for tubularized incised plate repair. Success was defined as urethral advancement to the corona or more distal with tension free skin coverage. RESULTS: A total of 24 patients underwent reconstruction including 16 as part of primary repair and for redo repairs in 8. Nine patients experienced expander extrusion and posturethroplasty complications occurred in 43.8% of primary repairs and 75.0% of redo repairs; a urethrocutaneous fistula was most common (n = 8). Overall, success was achieved in 87.5% of patients with postoperative meatal locations almost all coronal (45.8%) or glanular (50.0%). CONCLUSION: Proximal hypospadias reconstruction is challenging, and complications are not infrequent. TE is a useful alternative for complex patients with a skin paucity such that cutaneous coverage would be difficult following urethroplasty. Although the complication rate was 43.8% for primary repair, TE generated sufficient residual skin for success after additional reconstruction. For redo repair early use is most beneficial as there is more expandable skin. The pseudocapsules provide vascularized coverage to reinforce the urethra while there is sufficient skin to minimize the need for a skin graft for penile coverage.


Subject(s)
Hypospadias , Male , Humans , Infant , Hypospadias/surgery , Tissue Expansion Devices , Treatment Outcome , Urethra/surgery , Urologic Surgical Procedures, Male/methods
17.
Pediatr Surg Int ; 39(1): 138, 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36820882

ABSTRACT

PURPOSE: Circumcision is one of the most frequently performed surgical procedures. Complications are infrequent, including bleeding, though can be significant such as shaft skin excision. The aim of this study was to identify mechanism of injury and reconstructive techniques for skin excision using a full thickness skin graft (FTSG) or with the novel application of tissue expanders (TE). METHODS: Patients who underwent penile reconstruction following shaft skin excision from an overzealous circumcision were retrospectively reviewed. The penis was covered using a FTSG, harvested from the groin/hip, or using TE, with expanders placed in residual shaft skin. RESULTS: Twelve patients experienced significant skin loss (range 65-95%) including 2 with partial glans loss. Ten were reconstructed using a FTSG and 2 with TE. Injury was most frequently from a Mogen clamp (n = 9), or from a Gomco clamp, Plastibell device, and electrocautery burns. Six FTSG patients experienced complications with lymphedema (n = 3) most common. CONCLUSION: Shaft skin excision is a devastating complication with risk greatest from Mogen clamp use. TE is preferred as this avoids donor site morbidity which reassures parents but requires sufficient residual skin that can be expanded. Both techniques effectively provide soft tissue coverage with acceptable appearance and long-term function.


Subject(s)
Circumcision, Male , Plastic Surgery Procedures , Male , Humans , Retrospective Studies , Penis/surgery , Circumcision, Male/methods , Skin Transplantation/methods
18.
ACS Appl Bio Mater ; 6(2): 591-602, 2023 02 20.
Article in English | MEDLINE | ID: mdl-36626688

ABSTRACT

Diagnostic medical imaging utilizes magnetic resonance (MR) to provide anatomical, functional, and molecular information in a single scan. Nanoparticles are often labeled with Gd(III) complexes to amplify the MR signal of contrast agents (CAs) with large payloads and high proton relaxation efficiencies (relaxivity, r1). This study examined the MR performance of two structurally unique cages, AaLS-13 and OP, labeled with Gd(III). The cages have characteristics relevant for the development of theranostic platforms, including (i) well-defined structure, symmetry, and size; (ii) the amenability to extensive engineering; (iii) the adjustable loading of therapeutically relevant cargo molecules; (iv) high physical stability; and (v) facile manufacturing by microbial fermentation. The resulting conjugates showed significantly enhanced proton relaxivity (r1 = 11-18 mM-1 s-1 at 1.4 T) compared to the Gd(III) complex alone (r1 = 4 mM-1 s-1). Serum phantom images revealed 107% and 57% contrast enhancements for Gd(III)-labeled AaLS-13 and OP cages, respectively. Moreover, proton nuclear magnetic relaxation dispersion (1H NMRD) profiles showed maximum relaxivity values of 50 mM-1 s-1. Best-fit analyses of the 1H NMRD profiles attributed the high relaxivity of the Gd(III)-labeled cages to the slow molecular tumbling of the conjugates and restricted local motion of the conjugated Gd(III) complex.


Subject(s)
Nanoparticles , Protons , Contrast Media/chemistry , Gadolinium/chemistry , Magnetic Resonance Imaging/methods
19.
Neural Regen Res ; 18(6): 1229-1234, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36453398

ABSTRACT

Peripheral nerve injuries remain a challenging problem in need of better treatment strategies. Despite best efforts at surgical reconstruction and postoperative rehabilitation, patients are often left with persistent, debilitating motor and sensory deficits. There are currently no therapeutic strategies proven to enhance the regenerative process in humans. A clinical need exists for the development of technologies to promote nerve regeneration and improve functional outcomes. Recent advances in the fields of tissue engineering and nanotechnology have enabled biomaterial scaffolds to modulate the host response to tissue repair through tailored mechanical, chemical, and conductive cues. New bioengineered approaches have enabled targeted, sustained delivery of protein therapeutics with the capacity to unlock the clinical potential of a myriad of neurotrophic growth factors that have demonstrated promise in enhancing regenerative outcomes. As such, further exploration of combinatory strategies leveraging these technological advances may offer a pathway towards clinically translatable solutions to advance the care of patients with peripheral nerve injuries. This review first presents the various emerging bioengineering strategies that can be applied for the management of nerve gap injuries. We cover the rationale and limitations for their use as an alternative to autografts, focusing on the approaches to increase the number of regenerating axons crossing the repair site, and facilitating their growth towards the distal stump. We also discuss the emerging growth factor-based therapeutic strategies designed to improve functional outcomes in a multimodal fashion, by accelerating axonal growth, improving the distal regenerative environment, and preventing end-organs atrophy.

20.
J Pediatr Urol ; 19(1): 37.e1-37.e7, 2023 02.
Article in English | MEDLINE | ID: mdl-36369236

ABSTRACT

INTRODUCTION: In patients with classic bladder exstrophy (CBE), posterior urethral strictures after primary bladder closure can be difficult to manage and therefore necessitate alternative techniques in reconstruction of the proximal urethra. There is a paucity of literature describing treatment and management of posterior urethral stricture arising after repair of classic bladder exstrophy. OBJECTIVE: To describe the technique of a bladder neck reconstruction (BNR) with a modified Tanagho anterior detrusor flap in the treatment of posterior urethral stricture arising after repair of classic bladder exstrophy. PATIENTS AND METHODS: A prospectively maintained, IRB-approved database of 1401 exstrophy-epispadias patients was reviewed for patients who underwent bladder neck or proximal urethral reconstruction with modified Tanagho flap for proximal urethral stricture disease from the time period of 1975-2021. A total of 5 patients (1 female and 4 males) with classic bladder exstrophy who underwent proximal urethral reconstruction with modified Tanagho flap were identified. Of these 5 patients, the 1 female patient was treated for ongoing incontinence, not posterior urethral stricture, and was thus excluded from this report. Outcomes measured included post operative bladder capacity, post-operative continence status, upper urinary tract status, and stricture recurrence. RESULTS: Four male patients with CBE were treated for posterior urethral strictures and are reviewed here. Three patients underwent successful primary closure (1 via modern staged repair of exstrophy (MSRE) and 2 via complete primary repair of exstrophy (CPRE)), and 1 patient (MSRE) required repeat closure at the time of stricture repair. Mean age at BNR Tanagho flap was 3.8 (range 2.3-5.0) years. All patients remained stricture free with post-operative urinary incontinence; 2 patients underwent subsequent elective bladder neck transection to achieve continence. Mean follow up 9.9 (range 2.1-15.6) years. DISCUSSION: All 4 patients had excellent long term success rates, comparable to results reported in several adult studies utilizing a modified Tanagho flap in women with post-traumatic bladder neck contractures. In addition, our technique described here shares similarities with both the originally described Tanagho flap as well as with a dorsal onlay graft urethroplasty. CONCLUSION: In this limited series, modified Tanagho flap reconstruction is effective in treating posterior urethral stricture disease in CBE. This technique adds a valuable adjunct to the armamentarium of surgical options for this difficult to manage condition.


Subject(s)
Bladder Exstrophy , Urethral Stricture , Urinary Incontinence , Adult , Humans , Male , Female , Child, Preschool , Bladder Exstrophy/surgery , Urethral Stricture/etiology , Urethral Stricture/surgery , Urinary Bladder/surgery , Urinary Incontinence/surgery , Urologic Surgical Procedures/methods , Constriction, Pathologic , Retrospective Studies , Treatment Outcome
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