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OBJECTIVE: Fronto-orbital advancement involves removal of the fronto-orbital bandeau. Visualization of the saw blade is lost as it passes through the fronto-orbital-sphenoid junction (FOSJ), placing the temporal lobe at risk of injury. We aim to provide a 3D analysis of the space surrounding this osteotomy to differentiate various types of craniosynostoses. DESIGN: Retrospective cohort. SETTING: Institutional. PATIENTS: Thirty patients with isolated unicoronal synostosis, nonsyndromic bicoronal synostosis, metopic synostosis, Apert syndrome, Crouzon syndrome, and Muenke syndrome. INTERVENTIONS: CT scans conducted between 2 months to 2 years of age were 3D reconstructed to compare craniometrics against normal controls. MAIN OUTCOME MEASURE(S): Craniometrics. RESULTS: The mean bone thickness of the FOSJ at the level of the supraorbital rim was significantly small for the Apert, unicoronal and bicoronal groups. The mean vertical height of the middle cranial fossa from the lesser sphenoid wing was significantly greater in the unicoronal group. The mean vertical height of the tip of the temporal lobe from the lateral sphenoid ridge was greater in the unicoronal, isolated bicoronal, and Apert groups. The mean corneal protrusion beyond the lateral orbital rim was significantly greater in the Apert and unicoronal groups. The mean horizontal depth of the orbit was smallest in the Apert group. The mean vertical distance between the dacryon and the foramen cecum, and the mean volume of temporal lobe beneath the sphenoid shelf were the largest in the Apert group. CONCLUSIONS: Patients with Apert syndrome have the most unfavorable morphology of the anterior and middle cranial fossae.
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Maxillary osteotomies as a component of orthognathic surgery disrupt the normal anatomy and function of the sinus. The osteotomy with advancement of the inferior component of the sinus leaves a bony and mucosal opening in the sinus. Immediately after surgery, nasal drainage is impeded because of intranasal swelling. Acute and chronic maxillary sinusitis would be expected; however, its incidence as an expected complication is not well documented. A systematic review and meta-analysis was completed using PubMed to determine the incidence of sinusitis after maxillary orthognathic surgery. Studies were reviewed by two authors, and incidence data were extracted. Two hundred six articles were identified with 24 meeting the criteria for analysis. The incidence of sinusitis was based on 4213 participants who had undergone orthognathic surgery. Twenty-three studies reported a total number of sinusitis cases, and the results demonstrated a pooled incidence of 3.3% (95% confidence interval: 1.77, 6.06). One study did not report a total number of cases but reported chronic sinusitis survey-duration-based and Lund-Mackay scores. These scores, respectively, worsened from 7.6 to 14.8 and from 1.58 to 2.90 postoperatively. Despite the variability of maxillary surgery, the surgical technique, and the postoperative management, the incidence is low but sinusitis does occur. Prospective studies with validated questionnaires within the context of a specific protocol may further elucidate the causality of sinusitis. Further, patients with sinonasal symptoms postsurgery should be encouraged to consult with an otolaryngologist to ensure prompt treatment.
Subject(s)
Maxillary Sinusitis , Orthognathic Surgery , Sinusitis , Humans , Prospective Studies , Incidence , Sinusitis/epidemiology , Sinusitis/surgery , Maxillary Sinusitis/epidemiology , Maxillary Sinusitis/etiology , Maxillary Sinusitis/surgery , Osteotomy , Chronic Disease , Endoscopy/methodsABSTRACT
BACKGROUND/PURPOSE: Virtual reality (VR) is emerging as an effective and intuitive surgical planning and 3D visualization tool. Digital surgical planning is the gold standard for planning the placement of implants in maxillofacial prosthetics, but the field lacks a platform exclusively designed to perform the task. Virtual reality planning (VRP) specific for maxillofacial prosthetics offers the clinician improved control of the presurgical planning and the potential to limit the need to adapt other advanced segmentation software. Furthermore, the virtual plan can be directly translated to the patient through custom 3D printed (3DP) surgical guides and visual aids. To the best of our knowledge, this article outlines the development of the world's first virtual reality planning platform and workflow for pre-operatory planning within a VR environment for clinical use specific to facial prosthetics and anaplastology. METHOD: The workflow was applied to managing 2 patients presenting with unilateral total exenteration and severe contracture enucleation, respectively (n=2). A cone-beam CT was acquired for each patient, and their data set was directly imported into the ImmersiveView Surgical Plan VR environment (ImmersiveTouch Inc, Chicago, IL). The clinicians virtually selected appropriately sized craniofacial implants and placed the implants in the desired orientation. Various measurement tools are available to aid in clinical decision-making. The ideal location of craniofacial implants was set according to an orbital and auricular prosthetic reconstruction. The resultant VR plan was exported for 3DP. The patients were evaluated preoperatively and postoperatively using the proposed VRP treatment. The workflow's data accuracy was validated postoperatively by comparing posterative CT data and the proposed VRP. Analysis was performed using Mimics software (Materialise, Leuven, Belgium). RESULT: It takes, on average, 10 minutes to place 4 implants in the virtual reality space. The 3DP files resulting from VRP take ~2 hours to print and are constructed with a biocompatible resin appropriate for clinical use as surgical guides. Our user-friendly VRP workflow allows for an accurate simulation of surgical and nonsurgical procedures with an average displacement in XYZ of 0.6 mm and an SD of 0.3 mm. In addition, VRP is an excellent tool to simulate the craniofacial placement procedure and improves unsupervised self-learning teaching. CONCLUSION: VRP is an exciting tool for training clinicians and students in complex surgical procedures. This study shows the promising applicability and efficiency of VR in clinical planning and management of facial rehabilitation. Patients allowed to interact with VR have been engaged, which would aid their treatment acceptance and patient education. A valuable advantage of surgical simulation is the reduced costs associated with renting instruments, buying implant dummies, and surgical hardware. The authors will explore VR to plan and treat surgical and nonsurgical reconstructive procedures and improve soft tissue manipulation. This study outlines the development of an original platform and workflow for segmentation, preoperative planning, and digital design within a VR environment and the clinical use in reconstructive surgery and anaplastology.
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OBJECTIVES: To assess the effect on the retropalatal airway (RPA), retroglossal airway (RGA), and total airway (TA) volumes and cephalometrics (SNA, SNB, ANB, PP-SN, Occl-SN, N-A, A-TVL, B-TVL) after maxillary advancement orthognathic surgery in patients with unilateral cleft lip/palate (UCL/P) using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The CBCT scans of 30 patients (13 males and 17 females, 17-20 years old) with UCL/P were evaluated at two time points: preoperative (T1) and postoperative (T2). The interval between T1 and T2 ranged from 9-14 weeks, except for two patients in whom the interval was 24 weeks. Intraexaminer reliability was measured with an intraclass correlation coefficient test. A paired t-test was used to compare the airway and cephalometric measurements between T1 and T2, with a P value of .05 being considered significant. RESULTS: From T1 to T2, significant increases were found in the volumes of RPA (from 9574 ± 4573 to 10,472 ± 4767, P = .019), RGA (from 9736 ± 5314 to 11,358 ± 6588, P = .019), and TA (from 19,121 ± 8480 to 21,750 ± 10,078, P = .002). In addition, the RGA (from 385 ± 134 to 427 ± 165, P = .020) and TA (from 730 ± 213 to 772 ± 238, P = .016) sagittal area increased significantly. For minimal cross-sectional area (MCA), only the RPA increased significantly (from 173 ± 115 to 272 ± 129, P = .002). All cephalometric changes were statistically significant between T1 and T2 except for SNB. CONCLUSIONS: Maxillary advancement in patients with UCL/P produces statistically significant increases in the retropalatal (volumetric and MCA), retroglossal (volumetric and sagittal), and total (volumetric and sagittal) airways based on data from CBCT imaging.
Subject(s)
Cleft Lip , Cleft Palate , Male , Female , Humans , Adolescent , Young Adult , Adult , Cleft Lip/diagnostic imaging , Cleft Lip/surgery , Cleft Palate/diagnostic imaging , Cleft Palate/surgery , Reproducibility of Results , Retrospective Studies , Maxilla/diagnostic imaging , Maxilla/surgery , Cone-Beam Computed Tomography/methods , Cephalometry/methodsABSTRACT
Classical orthognathic procedures have long been known to improve the facial esthetic contours and proportions of face by restoring the skeletal foundation, on which the soft-tissue drapes. Distraction osteogenesis was introduced to solve complex skeletal abnormalities in patients with craniofacial conditions that could not be solved by classical orthognathic surgery techniques. The gradual expansion in this group of patients showed not only greater skeletal stability, but the expansion at various tissue planes improved the facial appearance. In this report we review our experience in 22 cases with dentofacial skeletal abnormities for whom we believe achieved aesthetic outcomes could not habe been with classical orthognathic techniques alone. In addition, distraction at the interdental regions allowed for "tailoring" of the osteotomies and for simultaneous expansion at the occlusal level.
Subject(s)
Orthognathic Surgery , Orthognathic Surgical Procedures , Osteogenesis, Distraction , Humans , Osteogenesis, Distraction/methods , Esthetics, Dental , Facial Bones , Orthognathic Surgical Procedures/methodsABSTRACT
OBJECTIVE: The objectives of this study were to assess the oral health status and parental perception of oral health needs of pediatric patients in an urban Craniofacial Center. DESIGN: This research utilized a prospective cross-sectional matched study design. The data was collected prospectively via clinical oral examinations measuring dental caries experience and gingival health status. Parental perception of oral health was assessed through a validated questionnaire. SETTING: The study was conducted at a Pediatric Dentistry Department and Craniofacial Center (CFC) in a large urban American city. PATIENTS/PARTICIPANTS: Participants were recruited and enrolled from a CFC and Pediatric Dental Clinic. MAIN OUTCOME MEASURE(S): The outcome measures were the oral health status and parental perception thereof. RESULTS: CFC patients' caries experience in primary teeth was significantly lower than that of a healthy matched cohort, but statistically similar in permanent teeth. CFC patients had significantly higher unmet dental treatment needs. CFC patients had poor oral hygiene and were shown to have significantly higher plaque levels and worse gingival health than that of a healthy matched cohort. Parental perception of oral health did not show a statistically significantly difference between the two groups. CONCLUSIONS: Patients in our study in an urban CFC were found to have a high unmet dental and poor oral hygiene. Despite the poor oral health status, parents of children with craniofacial anomalies did perceive their oral health as different from a matched cohort of patients without these conditions.
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Virtual reality (VR) and augmented reality (AR) have evolved since their introduction to medicine in the 1990s. More powerful software, the miniaturization of hardware, and greater accessibility and affordability enabled novel applications of such virtual tools in surgical practice. This scoping review aims to conduct a comprehensive analysis of the literature by including all articles between 2018 and 2021 pertaining to VR and AR and their use by plastic and craniofacial surgeons in a clinician-as-user, patient-specific manner. From the initial 1637 articles, 10 were eligible for final review. These discussed a variety of clinical applications: perforator flaps reconstruction, mastectomy reconstruction, lymphovenous anastomosis, metopic craniosynostosis, dermal filler injection, auricular reconstruction, facial vascularized composite allotransplantation, and facial artery mapping. More than half (60%) involved VR/AR use intraoperatively with the remainder (40%) examining preoperative use. The hardware used predominantly comprised HoloLens (40%) and smartphones (40%). In total, 9/10 Studies utilized an AR platform. This review found consensus that VR/AR in plastic and craniomaxillofacial surgery has been used to enhance surgeons' knowledge of patient-specific anatomy and potentially facilitated decreased intraoperative time via preoperative planning. However, further outcome-focused research is required to better establish the usability of this technology in everyday practice.
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Background: Facial soft-tissue filler injections are being performed in the United States with increasing popularity.f. Objectives: This study aimed to characterize the observations of The Aesthetic Society members regarding the potential impact of repetitive panfacial fillers on the outcomes of subsequent facelift surgery. Methods: A survey containing closed and open-ended questions was sent to The Aesthetic Society members through email. Results: The response rate was 3.7%. The majority of the respondents (80.8%) believed that less than 60% of their facelift patients had previous repetitive panfacial filler injections. One half (51.9%) reported that a history of panfacial filler injections increased the difficulty of performing facelifts. A large subset (39.7%) of respondents believed that a history of panfacial fillers increased postoperative complication rates, while the remaining either disagreed (28.9%) or were unsure (31.4%). The most common complications following the facelift surgery included undesirable palpability or visibility of filler (32.7%), compromised flap vascularity (15.4%), and decreased longevity of the lifting effect (9.6%). Conclusions: This study identified a potential association with repetitive panfacial filler injections and outcomes following facelift surgery, although the exact effect on postoperative outcomes remains unclear. Large prospectively designed studies are needed to capture objective data comparing facelift patients with a history of repetitive panfacial fillers with those facelift patients who have never had injectables. Given the results of The Aesthetic Society members' survey, the authors encourage careful history-taking to elicit an accurate filler injection record including complications after filler injections, as well as engaging patients in a thorough preoperative discussion regarding the potential of panfacial fillers on the facelift procedure and postoperative outcomes.
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Preoperative surgical planning incorporating computer-aided design and manufacturing is increasingly being utilized today within the fields of craniomaxillofacial, orthopedic, and neurosurgery. Application of these techniques for craniosynostosis reconstruction can include patient-specific anatomic reference models, "normal" reference models or patient-specific cutting/marking guides based on the presurgical plan. The major challenge remains the lack of tangible means to transfer the preoperative plan to the operating table. We propose a simple solution to utilize a digitally designed, 3D-printed "composite model" as a structural template for cranial vault reconstruction. The composite model is generated by merging the abnormal patient cranial anatomy with the "dural surface topography" of an age-matched, sex-matched, and ethnicity-matched normative skull model. We illustrate the applicability of this approach in 2 divergent cases: 22-month-old African American male with sagittal synostosis and 5-month-old White male with metopic synostosis. The aim of this technical report is to describe our application of this computer-aided design and modeling workflow for the creation of practical 3D-printed skulls that can serve as intraoperative frameworks for the correction of craniosynostosis. With success in our first 2 cases, we believe this approach of a composite model is another step in reducing our reliance on subjective guesswork, and the fundamental aspect of the workflow has a wider application within the field of craniofacial surgery for both clinical patient care and education.
Subject(s)
Craniosynostoses , Plastic Surgery Procedures , Humans , Male , Infant , Imaging, Three-Dimensional/methods , Craniosynostoses/diagnostic imaging , Craniosynostoses/surgery , Skull/surgery , Computer-Aided Design , Models, AnatomicABSTRACT
Emergence of highly virulent and multi-drug resistant (MDR) strains of Salmonella in food products significantly impacts public health and demands continuous monitoring for their presence in the food chain. The ability of Salmonella to form biofilms under harsh environmental conditions accompanied by MDR serotypes underscores an important food safety threat. This study aimed to isolate, identify and characterize MDR, biofilm-forming Salmonella from local Indian dairy and meat products (n = 60). All of the 24 isolates of Salmonella produced biofilm and were categorized as strong (16.6%), moderate (58.3%), and weak (25%) biofilm producers. Multiple antimicrobial resistance (MAR) index of all the Salmonella isolates was ≥0.2. The strongest biofilm forming poultry meat isolate, Salmonella SMC25 demonstrated intermediate to complete resistance to 14 of 22 different antibiotics tested. Epifluorescence microscopy showed that biofilm formation initiated as early as 4 h, reaching zenith within 96 h and much denser and robust biofilm is formed on rough stainless steel (SS316) surface compared to smooth glass surface. The results corroborated with increased temporal production of exopolysaccharides (EPS), high cell surface hydrophobicity and upregulation of marker genes vital to biofilm-formation in Salmonella. Significantly, SMC25 was found to adhere and invade mammalian cell lines Caco2 and HepG2, thus posing a serious food safety threat. This study is important in comprehending the prevalence of multidrug resistant, biofilm-forming, invasive strains of foodborne Salmonella in Indian food products and is important for effective risk assessment besides ensuring better food safety and public health.
Subject(s)
Meat Products , Salmonella typhimurium , Animals , Humans , Poultry , Caco-2 Cells , Biofilms , Anti-Bacterial Agents/pharmacology , Meat , Food Microbiology , MammalsABSTRACT
BACKGROUND: The fibula flap is the workhorse for mandibular reconstruction, but fibula bone width is not ideal to match mandibular height. In this study, in situ widening of the fibula with distraction osteogenesis before transfer is evaluated as a solution. The authors present a proof of concept of this technique with a patient series, including one patient who has undergone subsequent orthognathic surgery of the reconstructed mandible. METHODS: A retrospective review of patients undergoing the authors' technique was performed. A longitudinal fibula osteotomy was made in situ and distraction was performed in the leg to widen the fibula. After distraction and consolidation periods, flaps were osteotomized and transferred to the mandible. RESULTS: This technique was applied to three patients (ages 9, 11, and 13 years) with Pruzansky III mandibular hypoplasia at the authors' institution over 15 years. In all cases, bony union was achieved. Mean surgical follow-up was 5 years. No significant morbidity occurred at the donor sites. Partial flap resorption was observed a number of years postoperatively in one patient. Temporomandibular joint ankylosis developed in one patient after closed treatment of an unrelated mandible fracture. A sinus tract developed in one patient, requiring débridement of a partial flap necrosis. One patient had orthognathic surgery, including osteotomy of the fibula. CONCLUSIONS: In situ fibula distraction osteogenesis is a novel technique to prelaminate a fibula flap before transfer to the mandible. This method allows for the reconstruction of challenging mandibular defects without compromising bone height, pedicle length, or the ability to perform orthognathic surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.
Subject(s)
Mandibular Reconstruction , Osteogenesis, Distraction , Plastic Surgery Procedures , Humans , Fibula/surgery , Osteogenesis, Distraction/methods , Surgical Flaps/surgery , Mandible/surgery , Mandible/abnormalities , Retrospective Studies , Bone Transplantation/methods , Plastic Surgery Procedures/methodsABSTRACT
Background: The aim of the study was to compare the effect of two different regimens of milrinone in pediatric patients with pulmonary artery hypertension (PAH) undergoing corrective procedure. Materials and Methods: This randomized prospective study included 100 pediatric patients undergoing corrective cardiac surgeries. Group E: Milrinone was started as infusion 0.5 µg/kg/min without a loading dose after induction of anesthesia and continued as infusion 0.5-0.75 µg/kg/min in the pediatric cardiac surgical intensive care unit (PSICU). Group L: Milrinone was started as a loading dose 50 µg/kg over 10 min before weaning from cardiopulmonary bypass (CPB) followed by infusion 0.5-0.75 µg/kg/min in the PSICU. We compared heart rate, mean arterial blood pressure, central venous pressure, cardiac index (CI), mean pulmonary arterial pressure (MPAP), serum lactate level, urine output, vasoactive inotropic score, mechanical ventilation duration, and intensive care unit (ICU)- and hospital length of stay between the groups. Results: There was an increase in mean arterial blood pressure, CI, and urine output in Group E compared to Group L (P < 0.05). MPAP, serum lactate level, and requirement of inotropes and vasopressors were lower in Group E compared to Group L (P < 0.05). Mechanical ventilation duration, ICU, and hospital length of stay were shorter in Group E than Group L (P < 0.05). Conclusions: Early use of milrinone in patients with PAH undergoing corrective cardiac surgeries improved CI and mean arterial pressure, decreased MPAP, improved urine output, decreased serum lactate level, and decreased requirement of inotropes and vasopressors after weaning from CPB compared to the milrinone bolus group.
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ABSTRACT: Prenatal diagnosis of cleft lip and palate as well as other craniofacial differences is now possible with a significant level of accuracy due to sonographic and other evaluations. Thus, prospective parents have the opportunity to be informed ahead of time about these conditions making them better prepared to deal with their child after birth. The role of the plastic surgeon and other craniofacial team members in prenatal consultations is becoming increasingly important and well accepted. Therefore, any additional publication reviewing the topic from different angles and specifically from the parents' perspective is a welcome addition to our understanding of the parents' points of view and enables the team to most effectively assist them as they cope with the new diagnosis.This review describes details about our Craniofacial Center's efforts over 24âyears. Our focus has always been on providing support through face-to-face multidisciplinary consultations with prospective parents as well as offering education to the public and referring sources, such as obstetricians and sonographers through direct communications, newsletters, and our website for timely referrals. As an additional service, the authors have organized a group of volunteer parents of children who are patients of the Center to share their short long-term experiences.
Subject(s)
Cleft Lip , Cleft Palate , Chicago , Child , Cleft Lip/diagnostic imaging , Cleft Palate/diagnostic imaging , Counseling , Female , Humans , Pregnancy , Prenatal Diagnosis , Prospective Studies , Review Literature as TopicABSTRACT
LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Describe the evolution of three-dimensional computer-aided reconstruction and its current applications in craniofacial surgery. 2. Recapitulate virtual surgical planning, or computer-assisted surgical simulation, workflow in craniofacial surgery. 3. Summarize the principles of computer-aided design techniques, such as mirror-imaging and postoperative verification of results. 4. Report the capabilities of computer-aided manufacturing, such as rapid prototyping of three-dimensional models and patient-specific custom implants. 5. Evaluate the advantages and disadvantages of using three-dimensional technology in craniofacial surgery. 6. Critique evidence on advanced three-dimensional technology in craniofacial surgery and identify opportunities for future investigation. SUMMARY: Increasingly used in craniofacial surgery, virtual surgical planning is applied to analyze and simulate surgical interventions. Computer-aided design and manufacturing generates models, cutting guides, and custom implants for use in craniofacial surgery. Three-dimensional computer-aided reconstruction may improve results, increase safety, enhance efficiency, augment surgical education, and aid surgeons' ability to execute complex craniofacial operations. Subtopics include image analysis, surgical planning, virtual simulation, custom guides, model or implant generation, and verification of results. Clinical settings for the use of modern three-dimensional technologies include acquired and congenital conditions in both the acute and the elective settings. The aim of these techniques is to achieve superior functional and aesthetic outcomes compared to conventional surgery. Surgeons should understand this evolving technology, its indications, limitations, and future direction to use it optimally for patient care. This article summarizes advanced three-dimensional techniques in craniofacial surgery with cases highlighting clinical concepts.
Subject(s)
Computer-Aided Design , Maxillofacial Injuries/surgery , Maxillofacial Prosthesis Implantation/methods , Prosthesis Design/methods , Skull/surgery , Humans , Imaging, Three-Dimensional , Maxillofacial Injuries/diagnostic imaging , Models, Anatomic , Patient Care Planning , Printing, Three-Dimensional , Skull/diagnostic imaging , Tomography, X-Ray ComputedABSTRACT
Sepsis and autoimmune diseases remain major causes of morbidity and mortality. The last decade has seen a new appreciation of platelets in host defense, in both immunity and thrombosis. Platelets are first responders in the blood to microbes or non-microbial antigens. The role of platelets in physiologic immunity is counterbalanced by their role in pathology, for example, microvascular thrombosis. Platelets encounter microbes and antigens via both innate and adaptive immune processes; platelets also help to shape the subsequent adaptive response. FcγRIIA is a receptor for immune complexes opsonized by IgG or pentraxins, and expressed in humans by platelets, granulocytes, monocytes and macrophages. With consideration of the roles of IgG and Fc receptors, the host response to microbes and autoantigens can be called adaptive immunothrombosis. Here we review newer developments involving platelet FcγRIIA in humans and humanized mice in immunity and thrombosis, with special attention to heparin-induced thrombocytopenia, systemic lupus erythematosus, and bacterial sepsis. Human genetic diversity in platelet receptors and the utility of humanized mouse models are highlighted.
Subject(s)
Blood Platelets , Thrombosis , Animals , Mice , Mice, Transgenic , Platelet Activation , Receptors, IgGABSTRACT
ABSTRACT: Management of residual clefts of the alveolus and maxilla requires the coordinated effort of multiple members of the craniofacial team including surgeon, orthodontist, and when teeth are hypoplastic or absent, the prosthodontist to achieve complete habilitation. Such cooperation among specialists begins early in the patient's life and continues through completion of care.Although numerous publications on this topic exist, few present definitive multidisciplinary reconstructive outcomes with longterm results. In this review paper, the authors present our comprehensive, multidisciplinary protocols, experience, and techniques as they have evolved with over 35âyears of practice at our Craniofacial Center.Details of our updated protocols for each intervention and procedure, including our current thoughts on appropriate timing, follow up and advantages from the incorporation of current technologies are discussed. Close cooperation among specialists at all stages of care, the use of evolving technology, and adherence to, and modification where indicated, of time honored team protocols enables us to consistently achieve successful functional and esthetic outcomes, while minimizing complications.
Subject(s)
Cleft Palate , Plastic Surgery Procedures , Cleft Palate/surgery , Esthetics, Dental , Humans , Maxilla/surgeryABSTRACT
BACKGROUND: Immune complexes (ICs) bind to and activate platelets via FcγRIIA, causing patients to experience thrombocytopenia, as well as an increased risk of forming occlusive thrombi. Although platelets have been shown to mediate IC-induced pathologies, the mechanisms involved have yet to be fully elucidated. We identified that apoptosis signal-regulating kinase 1 (ASK1) is present in both human and mouse platelets and potentiates many platelet functions. OBJECTIVES: Here we set out to study ASK1's role in regulating IC-mediated platelet functions in vitro and IC-induced pathologies using an in vivo mouse model. METHODS: Using human platelets treated with an ASK1-specific inhibitor and platelets from FCGR2A/Ask1-/- transgenic mice, we examined various platelet functions induced by model ICs in vitro and in vivo. RESULTS: We found that ASK1 was activated in human platelets following cross-linking of FcγRIIA using either anti-hCD9 or IV.3 + goat-anti-mouse. Although genetic deletion or inhibition of ASK1 significantly attenuated anti-CD9-induced platelet aggregation, activation of the canonical FcγRIIA signaling targets Syk and PLCγ2 was unaffected. We further found that anti-mCD9-induced cPla2 phosphorylation and TxA2 generation is delayed in Ask1 null transgenic mouse platelets leading to diminished δ-granule secretion. In vivo, absence of Ask1 protected FCGR2A transgenic mice from thrombocytopenia, thrombosis, and systemic shock following injection of anti-mCD9. In whole blood microfluidics, platelet adhesion and thrombus formation on fibrinogen was enhanced by Ask1. CONCLUSIONS: These findings suggest that ASK1 inhibition may be a potential target for the treatment of IC-induced shock and other immune-mediated thrombotic disorders.
Subject(s)
Thrombocytopenia , Thrombosis , Animals , Apoptosis , Blood Platelets , Humans , MAP Kinase Kinase Kinase 5/genetics , Mice , Platelet Activation , Platelet Aggregation , Thrombocytopenia/genetics , Thrombosis/geneticsABSTRACT
The existence of mitogen activated protein kinases (MAPKs) in platelets has been known for more than 20 years. Since that time hundreds of reports have been published describing the conditions that cause MAPK activation in platelets and their role in regulating diverse platelet functions from the molecular to physiological level. However, this cacophony of reports, with inconsistent and sometimes contradictory findings, has muddied the waters leading to great confusion. Since the last review of platelet MAPKs was published more than a decade ago, there have been more than 50 reports, including the description of novel knockout mouse models, that have furthered our knowledge. Therefore, we undertook an extensive literature review to delineate what is known about platelet MAPKs. We specifically discuss what is currently known about how MAPKs are activated and what signaling cascades they regulate in platelets incorporating recent findings from knockout mouse models. In addition, we will discuss the role each MAPK plays in regulating distinct platelet functions. In doing so, we hope to clarify the role for MAPKs and identify knowledge gaps in this field that await future researchers. In addition, we discuss the limitations of current studies with a particular focus on the off-target effects of commonly used MAPK inhibitors. We conclude with a look at the clinical utility of MAPK inhibitors as potential antithrombotic therapies with an analysis of current clinical trial data.
Subject(s)
Blood Platelets , Mitogen-Activated Protein Kinases , Animals , Blood Platelets/metabolism , Hemostasis , Mice , Mice, Knockout , Signal TransductionABSTRACT
Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase kinase kinase (MAPKKK) that regulates activation of the c-Jun N-terminal kinase (JNK)- and p38-stress response pathways leading to apoptosis in nucleated cells. We have previously shown that ASK1 is expressed in platelets and regulates agonist-induced platelet activation and thrombosis. However, the mechanism by which platelet agonists cause activation of ASK1 is unknown. Here, we show that in platelets agonist-induced activation of p38 is exclusively dependent on ASK1. Both thrombin and collagen were able to activate ASK1/p38. Activation of ASK1/p38 was strongly dependent on thromboxane A2 (TxA2) and ADP. Agonist-induced ASK1 activation is blocked by inhibition of phospholipase C (PLC) ß/γ activity or by chelating intracellular Ca2+. Furthermore, treatment of platelets with thapsigargin or Ca2+ ionophore robustly induced ASK1/p38 activation. In addition, calcium and integrin-binding protein 1 (CIB1), a Ca2+-dependent negative regulator of ASK1, associates with ASK1 in resting platelets and is dissociated upon platelet activation by thrombin. Dissociation of CIB1 corresponds with ASK1 binding to tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6) and the autophosphorylation of ASK1 Thr838 within the catalytic domain results in full activation of ASK1. Furthermore, genetic ablation of Cib1 in mice augments agonist-induced Ask1/p38 activation. Together our results suggest that in resting platelets ASK1 is bound to CIB1 at low Ca2+ concentrations. Agonist-induced platelet activation causes an increase in intracellular Ca2+ concentration that leads to the dissociation of CIB1 from ASK1, allowing for proper dimerization through ASK1 N-terminal coiled-coil (NCC) domains.
Subject(s)
Blood Platelets/metabolism , Calcium-Binding Proteins/metabolism , MAP Kinase Kinase Kinase 5/metabolism , Platelet Activation/physiology , p38 Mitogen-Activated Protein Kinases/metabolism , Animals , Blood Platelets/cytology , Calcium/metabolism , Female , Healthy Volunteers , Humans , Male , Mice , Mice, Inbred C57BL , Protein BindingABSTRACT
Incorporation of Spirulina in milk as thermally dried powder has the disadvantages of non-uniform distribution with undesirable odor and flavor. Through homogenization (200 ± 10 bar), complete dispersion of fresh Spirulina biomass (7% w/w) in milk was achieved and thereafter a carotenoid enriched probiotic yogurt was developed. Confocal microscopy revealed porous Spirulina-milk protein matrix integrated with smaller fat globules in the yogurt. Spirulina led to a 29.56% increase in Lactobacillus acidophilus count, a 20% reduction in fermentation time and a total probiotic count of 1.2 × 107 CFU mL-1. The protein, total chlorophyll, total carotenoid and ß-carotene content (on dry w/w basis) were 3.58 ± 0.08 g 100 g-1, 0.407 ± 0.018 mg g-1, 0.235 ± 0.016 mg g-1 and 13.28 ± 0.08 µg g-1, respectively. During storage (18 days at 6-8 °C), the L. acidophilus count reached 8.83 ± 0.11 log CFU mL-1 with 103.03% increase in the viability by day three and the yogurt retained 71.5% carotenoids. The probiotc Spirulina yogurt was found to be acceptable to consumers as evaluated by affective consumer test.