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1.
Arch Plast Surg ; 50(4): 361-369, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37564714

RESUMO

The latissimus dorsi (LD) flap is a reliable option for breast reconstruction. This is particularly true in patients with contraindications to abdominally based autologous breast reconstruction. A systematic review of patient satisfaction and health related quality of life following LD breast reconstruction using the BREAST-Q survey was conducted. The scope of the review was to determine the degree of patient satisfaction following the procedure and to examine how patient satisfaction from the pedicled LD flap compares to other breast reconstructive procedures. A literature search on BREAST-Q in LD flap reconstruction was performed. Only articles written in English and in published peer-reviewed journals were included. Studies with less than 20 patients in their sample and those with a follow-up period of less than 1 year were excluded. Five articles representing 331 patients were reviewed, including one case-control study and four retrospective cohort studies. Level of evidence was either III (4) or IV (1). The average age was 53 with average body mass index of 25. Most reconstructions were delayed (67%) and unilateral (88%), and most patients required radiation (79%). The average length of follow-up was 36 months, and the response rate was 75%. Overall, patients who underwent LD flap reconstruction reported favorable outcomes in satisfaction domains and quality of life domains with few complications. A meta-analysis also demonstrated higher satisfaction in LD flap without implants compared with LD flap with implants. Patient-reported outcomes following LD breast reconstruction compare favorably with other techniques of breast reconstruction.

2.
Plast Reconstr Surg Glob Open ; 10(7): e4453, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35923981

RESUMO

Background: Ballistic facial injuries are rare, with most trauma centers reporting 1-20 cases annually. These patients present significant management challenges to reconstructive surgeons, not only due to their rarity but also due to the complex decision-making process that is involved. The aim of this study was to review our experience with the application of craniofacial microsurgery in management of facial gunshot wounds. Methods: A retrospective review of a single-surgeon experience at a level I trauma center from 2011 to 2020 for patients sustaining self-inflicted gunshot wounds to the face requiring microsurgical reconstruction was performed. Outcomes included reconstructive techniques, free flap type and indication, airway evolution, feeding modality, respective timing of interventions, and complications. Results: Between 2012 and 2021, 13 patients presented for microsurgical reconstruction at our institution for gunshot wounds to the face. The majority (90%) of patients were men, and the average age at time of injury was 26. The median from the time of injury to first free flap was 93 days. Thirteen patients represented 23 free flaps. On average, patients underwent a total of two free flaps. The most common microsurgical flap was the fibula flap (14) followed by the radial forearm flap (6). Conclusions: Based on our findings, we describe a novel algorithm for function restoration and aesthetic revisions based on injury location. Underlying principles include avoiding early use of reconstruction plates, establishing occlusion early, and aligning bony segments using external fixation. An algorithmic approach to these injuries can improve outcomes.

3.
Ann Plast Surg ; 88(5 Suppl 5): S403-S409, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35690934

RESUMO

BACKGROUND: Mastectomy skin flap necrosis (MSFN) can significantly impact outcome after immediate breast reconstruction. Several techniques exist to predict MSFN, but these may require additional testing and information, and they are often not available before surgery. We aim to identify whether breast volume, as calculated from preoperative mammography, can be used as a preoperative predictor of MSFN. METHODS: A retrospective chart review from 2010 to 2020 resulted in 378 patients who underwent immediate implant-based breast reconstruction. Complete imaging data were available for 278 patients and 441 reconstructed breasts. Demographic, perioperative, and outcomes data were collected. Measurements from preoperative diagnostic mammograms were used to calculate breast volume. Univariate and multivariate analyses were used to evaluate the association of variables available preoperatively, including breast volume from mammogram and MSFN. Secondary analyses were performed for need for reoperation and loss of reconstruction. RESULTS: On univariate analysis of MSFN development, demographic variables found to be significantly associated with MSFN included body mass index (P = 0.04), diabetes (P = 0.03), and breast volume calculated from routine mammography (P ≤ 0.0001). Average preoperative breast volume via mammography without and with MSFN was 970.6 mL (95% confidence interval [CI], 908.9-1032.3) and 1298.3 mL (95% CI, 1140.0-1456.5) (P < 0.0001), respectively. Statistically significant intraoperative variables for MSFN development included prolonged operative time (P = 0.005), greater initial tissue expander fill volumes (P ≤ 0.001), and prepectoral implant location (P = 0.02). Higher initial tissue expander fill volumes in implant-based reconstructions were associated with increased rates of MSFN, 264.1 mL (95% CI, 247.2-281.0) without MSFN and 349.9 mL (95% CI, 302.0-397.8) in the group with MSFN, respectively (P < 0.001). On multivariate analysis, preoperative imaging volume (P = 0.02) was found to be significant, whereas body mass index and diabetes lost significance (P = 0.40) in association with MSFN. CONCLUSIONS: The results of this study establish an association between larger breast volume on preoperative imaging and development of MSFN. This may be useful as a tool for more appropriate patient selection and guidance in the setting of immediate breast reconstruction.


Assuntos
Implantes de Mama , Neoplasias da Mama , Mamoplastia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Mamoplastia/métodos , Mastectomia/métodos , Necrose/etiologia , Necrose/cirurgia , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Retalhos Cirúrgicos/cirurgia
4.
Plast Reconstr Surg ; 148(6): 1201-1208, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34644266

RESUMO

BACKGROUND: Increasing amounts of acellular dermal matrix are being used with the adoption of prepectoral breast reconstruction. Postoperative infection remains a challenge in breast reconstruction, and the contribution of acellular dermal matrix type, processing, and sterility assurance level to risk of complications in prepectoral reconstruction is not well studied. METHODS: The authors performed a retrospective review of patients who underwent immediate prepectoral breast reconstruction from February of 2017 to July of 2020. Because of an increase in the rate of infection, the drain protocol was changed and acellular dermal matrix type was switched from AlloDerm (sterility assurance level, 10-3) to DermACELL (sterility assurance level, 10-6) in January of 2019. Demographic and surgical variables were collected, in addition to details regarding development and management of infection. RESULTS: Despite higher rates of direct-to-implant reconstruction and bilateral procedures and increased implant volumes, the rate of infection was significantly lower in patients who received DermACELL instead of AlloDerm [two of 38 (5.3 percent) versus 11 of 41 (26.8 percent); p = 0.014]. Drain duration was slightly longer in the DermACELL group, consistent with the change in drain protocol. Baseline demographic and clinical characteristics remained similar between the two groups. CONCLUSIONS: With increased reliance on large amounts of acellular dermal matrix for prepectoral breast reconstruction, it directly follows that the properties of acellular dermal matrix with respect to incorporation, sterility, and implant support are that much more important to consider. There have been few studies comparing different types of acellular dermal matrix in prepectoral breast reconstruction, and further research is required to determine the contribution of acellular dermal matrix type and processing techniques to development of postoperative infection. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.


Assuntos
Derme Acelular/efeitos adversos , Implante Mamário/efeitos adversos , Terapia de Salvação/métodos , Infecção da Ferida Cirúrgica/terapia , Expansão de Tecido/efeitos adversos , Implante Mamário/instrumentação , Implante Mamário/métodos , Implantes de Mama/efeitos adversos , Neoplasias da Mama/cirurgia , Feminino , Humanos , Mastectomia/efeitos adversos , Pessoa de Meia-Idade , Estudos Retrospectivos , Infecção da Ferida Cirúrgica/etiologia , Expansão de Tecido/instrumentação , Expansão de Tecido/métodos , Dispositivos para Expansão de Tecidos/efeitos adversos
5.
Plast Reconstr Surg Glob Open ; 9(6): e3630, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34150425

RESUMO

BACKGROUND: Insurance coverage for microsurgical lymphatic surgery continues to be sporadic, as the procedures continue to be labeled investigational. The objective of this study was to examine the typical payment patterns of our clinical practice for microsurgical lymphatic procedures. METHODS: We performed a single center, single surgeon retrospective case review for all lymphovenous bypass and vascularized lymph node transfer cases preformed from 2018 to 2020. We then queried the available financial data and calculated total charges, total paid by insurance, total variable cost (cost to the hospital), and the contribution margin (difference between the amount paid and variable cost). Descriptive statistics were then collected for each subgroup for analysis. RESULTS: Financial data were collected on 22 patients with 10 left-sided, 11 right-sided and one bilateral procedure performed. Seven procedures were done prophylactically, and 15 were done for existing lymphedema. An estimated 10 of 22 patients (45%) had Medicare, Medicaid, or Tricare, with the remaining having private insurance. We calculated an average cost of $48,516.73, with average payment of $10,818.68, average variable cost of $5,567.10, for a contribution margin of +$5251.58. CONCLUSIONS: Lymphedema remains a common complication of surgery and a significant cost burden to patients and the healthcare system. Microsurgical procedures offer several advantages over medical therapy. In our practice, we were routinely reimbursed for both prophylactic and therapeutic procedures with positive contribution margins for the hospital and ratios similar to other surgeries. Despite the limitations of a small retrospective review, there is no similar published cost analysis data in the current literature.

6.
Plast Reconstr Surg Glob Open ; 9(6): e3608, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34104615

RESUMO

The deep inferior epigastric perforator flap for breast reconstruction is associated with lengthy operative times that remain an issue for plastic surgeons today. The main objective of this study was to determine if a 2-stage deep inferior epigastric perforator flap reconstruction resulted in a shorter total plastic surgeon operative time compared with an immediate reconstruction. METHODS: A retrospective chart review was conducted on all patients who underwent deep inferior epigastric perforator flap breast reconstruction from February 2013 to July 2020 by the senior author. Patient demographics, medical comorbidities, mastectomy characteristics, expander placement, reconstructive procedures, operative time, and complications were tabulated. RESULTS: The study included a total of 128 patients. For immediate/1-stage flap reconstruction, average operative times for the plastic surgeon were 427.0 minutes for unilateral procedures, and 506.3 minutes for bilateral procedures. For delayed/2-stage reconstruction, average combined plastic surgeon operative times were 351.1 minutes for unilateral expander followed by flap reconstruction (75.9 minutes shorter than immediate unilateral, P = 0.007), and 464.8 minutes for bilateral reconstruction (41.5 minutes shorter than immediate bilateral, P = 0.04). Total patient time under anesthesia was longer for 2-staged bilateral reconstruction (P = 0.0001), but did not differ significantly for unilateral reconstruction. Complications between immediate and delayed groups were not significantly different. CONCLUSIONS: We found that staged reconstruction over 2 procedures resulted in a significant reduction in operative time for the plastic surgeon for both unilateral and bilateral reconstruction. With amenable breast surgeons and patients, the advantages of controlling scheduling and the operating room may encourage plastic surgeons to consider performing free flap reconstruction in a delayed fashion.

7.
Ann Plast Surg ; 86(6S Suppl 5): S510-S516, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34100808

RESUMO

BACKGROUND: Dog bite injuries cause significant preventable patient morbidity and health care expenditure in children. This study aimed to characterize the patient and healthcare burden related to pediatric dog bite injuries at a level 1 trauma center. METHODS: This is a retrospective review of 356 pediatric patients who presented to Virginia Commonwealth University Pediatric Emergency Department between July 2007 and August 2017 after sustaining dog bite injuries. Demographic information, injury details, management, outcomes, and financial information were analyzed. RESULTS: Most pediatric dog bite injuries afflicted male children (55.6%), ages 6 to 12 years (45.7%), by a household dog (36.2%). The most common offending breed was a pit bull or pit bull mix (53.0%). Infants and grade schoolers were more likely to sustain bites to the head/face (P = 0.001). Usual management consisted of primary repair (75.9%), whereas approximately 25% of the patients required advanced reconstructive techniques. Most patients healed uneventfully, but prolonged antibiotics, additional wound care, or procedures were necessary in 8.4% of the patients. Hospital charges per patient averaged US $8830.70 and tended to be higher in the younger age groups. Insurance status was statistically associated with use of conscious sedation, surgical consult placement, and surgical repair. CONCLUSIONS: Although most pediatric dog bite injuries in this study healed uneventfully from primary management in the emergency department, 25% required additional interventions. Furthermore, patient care for these injuries was associated with significant but potentially avoidable personal and financial burden to families. Our data reflect a need for safety education on animal care, behavior, and interaction.


Assuntos
Mordeduras e Picadas , Traumatismos Faciais , Animais , Mordeduras e Picadas/epidemiologia , Mordeduras e Picadas/terapia , Criança , Pré-Escolar , Cães , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Centros de Traumatologia , Virginia/epidemiologia
9.
J Craniofac Surg ; 32(Suppl 3): 1215-1220, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33710046

RESUMO

ABSTRACT: Ian Jackson and Jack Fisher published one of the earliest reports on microsurgical applications for craniofacial patients in 1989. Since that time, applications of craniofacial surgery and microsurgery have significantly expanded and become more refined. However, there remain certain specific clinical problems in cleft and craniofacial surgery in which traditional craniofacial methods provide variable success or suboptimal outcomes. The purpose of the current study is to share our experience using an integrated approach of craniofacial and microsurgical methods to provide optimal surgical solutions to this complex patient population. The authors performed a retrospective review of 17 patients that utilized craniofacial microsurgery in setting of cleft and craniofacial syndromes performed by the senior author from July 2013 to July 2020. 22 free flaps were performed for 17 patients. The patient age at time of flap reconstruction ranged from 10 to 48 years (mean 21.4 years). There were 8 females and 9 males. There was one total flap loss. Based on our collective experience, the authors present a comprehensive algorithm for the role of microsurgical reconstruction in cleft and craniofacial patients. There are several situations in craniofacial surgery which traditional reconstructive methods require numerous operative interventions to achieve suitable outcomes. Craniofacial Microsurgery techniques can bring in new tissue and may prevent the need to manipulate scarred and multiply operated tissues. The craniofacial surgery team should not hesitate to apply microsurgical solutions to these situations for optimal results.


Assuntos
Retalhos de Tecido Biológico , Procedimentos de Cirurgia Plástica , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Microcirurgia , Pessoa de Meia-Idade , Estudos Retrospectivos , Síndrome , Adulto Jovem
10.
J Craniofac Surg ; 32(Suppl 3): 1269-1274, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33710058

RESUMO

ABSTRACT: Surgical treatment for tumors of the skull base remains gross total resection with microscopic negative margins. Sufficient surgical access is paramount to adequate treatment but must be balanced with patient morbidity and protection of vital neurovascular structures. While endoscopic surgery has made transfacial access less common, there are still indications for open transfacial exposure including tumors that involve facial soft tissues, the palate, anterolateral frontal sinus, dural involvement lateral to the mid-pupillary line, tumor recurrence/repeat resection, and/or lack of access to endoscopic equipment or expertise. The authors present a "line-of-sight" algorithm for selection of approach, discuss pre-operative planning, review selected clinical experiences, and discuss the role of microsurgery and prevention of complications.


Assuntos
Neoplasias da Base do Crânio , Algoritmos , Vértebras Cervicais , Humanos , Recidiva Local de Neoplasia , Base do Crânio/cirurgia , Neoplasias da Base do Crânio/cirurgia
12.
J Reconstr Microsurg ; 37(3): 256-262, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33032357

RESUMO

BACKGROUND: The objective of this study is to quantify the prevalence and describe the utilization of an anatomic vascular variant in which the obturator artery (OA) arises from the trunk of the deep inferior epigastric artery (DIEA) in stacked/dual-pedicled autologous breast reconstruction. When this variant is identified preoperatively on computed tomography angiography (CTA), it may be utilized in a "flow-through" fashion to direct antegrade internal mammary artery (IMA) flow into a second free flap to facilitate anastomotic arrangement and optimize perfusion. METHODS: Preoperatively obtained abdomen/pelvis CTA imaging of 121 autologous breast reconstruction patients were retrospectively reviewed for the unilateral or bilateral presence of the OA branch arising from the DIEA (OA variant). The results were analyzed using descriptive statistics. RESULTS: Our analysis revealed the presence of the OA variant in 60 of the 121 (49.6%) breast reconstruction candidates, either unilaterally or bilaterally. Out of these patients, the variant was present unilaterally in 33 (55%) and bilaterally in 27 (45%) patients. Of the unilateral variants, 12 (36.4%) patients demonstrated right-sided laterality, while 21 (63.6%) patients demonstrated left-sided laterality. Clinically, this anatomic variant has been utilized in several cases of autologous breast reconstruction with flap survival in all cases. CONCLUSION: Utilization of this anatomic variant in stacked or dual-pedicled autologous breast reconstruction results in antegrade IMA perfusion of both primary and secondary flaps, as well as improved size match compared with other anastomotic options. Knowledge of the vascular anatomy and variations in the inferior epigastric system is crucial to both preventing complications and optimizing flap planning and outcome.


Assuntos
Mamoplastia , Retalho Perfurante , Abdome , Artérias Epigástricas/diagnóstico por imagem , Artérias Epigástricas/cirurgia , Humanos , Pelve , Prevalência , Estudos Retrospectivos
13.
J Craniofac Surg ; 32(5): e457-e459, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33273200

RESUMO

ABSTRACT: Large vascular malformations (VMs) pose several difficult clinical challenges to the plastic surgeon. Traditionally surgical dissection was labor-intensive and required a significant amount of time and technique. The advent of more advanced vessel sealing devices has resulted in easier vascular and lymphatic control during resection surgery. The authors present 2 cases of large VMs resected using newer energy devices. First, an infant who was born with a large neck AVM that was acutely bleeding requiring immediate control. The authors utilized the Impact Ligasure device to perform a subtotal resection, stabilize the patient, and returned for definitive resection in the future. In the second case, an adult male with a large complex tongue/lip AVM, presented for elective resection. He underwent staged sclerotherapy, followed by resection using the Harmonic Scalpel. The use of vessel sealing devices allows for a safe and efficient resection for a previously difficult surgery.


Assuntos
Pescoço , Malformações Vasculares , Adulto , Cabeça , Humanos , Lactente , Masculino , Pescoço/cirurgia , Escleroterapia , Instrumentos Cirúrgicos , Malformações Vasculares/diagnóstico por imagem , Malformações Vasculares/cirurgia
14.
Ann Plast Surg ; 81(1): 106-112, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29762453

RESUMO

BACKGROUND: Pediatric dog bite injuries account for 1% of emergency department visits per year and represent an underrecognized and underreported public health problem. Reconstructive surgery is frequently utilized, and in the most extreme injuries, microvascular replantation may be considered. We sought to systematically review the available literature on microvascular replantation after facial dog bite injuries in children, with particular attention to perioperative morbidity and long-term follow-up. METHODS: We reviewed a case of microvascular replantation after a facial dog bite injury in a child from our own institution and conducted a systematic literature search to identify other similar reports. Clinical variables were collected from the reported cases, and descriptive statistics were calculated. A management algorithm was developed from the reviewed published experience. RESULTS: We report the youngest child to date in the literature to undergo replantation after a facial dog bite injury. Nineteen other cases were found involving children aged 18 months to 17 years, with follow-up ranging from 2 weeks to 28 years. Anastomosis techniques varied considerably and included both an artery and vein in only 9 (47%) of 19 cases. Venous congestion was nearly universal, and multimodal techniques were used until native venous outflow was reestablished. Blood transfusion was common, but intensive care unit utilization was not frequently reported. Long-term outcomes were excellent, with growth of the replanted part and recovery of function; however, minor revision procedures were common. CONCLUSIONS: Microvascular replantation following facial dog bite amputation injuries in the pediatric population is the ultimate step in the reconstructive ladder. Strong consideration should be given to microvascular exploration with involvement of large or whole segments of the lip, nose, or ear; however, parents should be counseled extensively regarding the known morbidity of replantation surgery. With meticulous surgical technique and careful postoperative care, replantation after facial dog bite amputation injuries may successfully achieve dramatic and lasting results for pediatric patients.


Assuntos
Amputação Traumática/cirurgia , Mordeduras e Picadas/cirurgia , Traumatismos Faciais/cirurgia , Reimplante/métodos , Adolescente , Algoritmos , Amputação Traumática/etiologia , Animais , Mordeduras e Picadas/complicações , Criança , Pré-Escolar , Cães , Traumatismos Faciais/etiologia , Feminino , Humanos , Masculino , Procedimentos de Cirurgia Plástica/métodos , Lesões dos Tecidos Moles/cirurgia , Cicatrização
15.
Ann Plast Surg ; 80(6S Suppl 6): S421-S425, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29668509

RESUMO

BACKGROUND: The perforator anatomy of the tensor fascia lata (TFL) flap has been studied using cadaver dissection; however, exact descriptions of location, size, and origin of perforator vessels using preoperative imaging modalities remain limited. The aims of this study are to describe TFL perforator anatomy using high-resolution computed tomography angiography (CTA) and to correlate these findings with landmarks for the anterolateral thigh flap to facilitate flap planning. METHODS: We identified 33 patients who previously underwent bilateral lower extremity CTAs for preoperative planning of free-flap reconstruction. The images were retrospectively reviewed, and the TFL perforator number, size, type, location, and overall pedicle origin and length were recorded. RESULTS: Thirty-three patients and 59 thighs were included in the study. There was an average of 2.5 perforators per TFL. All perforators arose from the ascending branch of the lateral circumflex femoral artery with an average pedicle length of 8.3 cm (range, 6.0-11.2 cm). Sixty-six percent of perforators were septocutaneous and 34% were musculocutaneous. The average perforator size as measured on CTA was 3 mm. The average perforator location was 10.1 cm inferior and 8.5 cm lateral to the line drawn from the anterior superior iliac spine to the superolateral patella. CONCLUSIONS: To our knowledge, this is the first study to characterize the vascular anatomy of the TFL perforator flap using high-resolution CTA and correlate this with well-established landmarks used in the planning for other thigh-based flaps. We believe data will facilitate flap design and dissection; potentially shortening operating room times, limiting exploratory incisions used to confirm the presence of thigh based perforators, and improving overall outcomes for patients.


Assuntos
Angiografia por Tomografia Computadorizada , Retalhos de Tecido Biológico/irrigação sanguínea , Músculo Esquelético/irrigação sanguínea , Retalho Perfurante/irrigação sanguínea , Procedimentos de Cirurgia Plástica , Cuidados Pré-Operatórios , Coxa da Perna/irrigação sanguínea , Adulto , Fascia Lata , Humanos , Masculino , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/transplante , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos , Coxa da Perna/diagnóstico por imagem , Coxa da Perna/cirurgia
16.
J Craniofac Surg ; 28(2): 489-491, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28033194

RESUMO

Total parenteral nutrition (TPN) can be a lifesaving intervention for premature neonates and it is often delivered through peripheral access in this unique population. However, extravasation and tissue damage can result. Current literature lacks strong evidence regarding the treatment and reconstruction of such injuries in this age group. The authors present a patient with a 30-week gestational age premature newborn whom suffered an extravasation injury with peripherally administered TPN leading to full thickness skin and soft tissue necrosis of the dorsum of the right hand. This was serially debrided and ultimately repaired using Apligraf (Graftskin, Living Skin Equivalent, LSE; Organogenesis Inc, Canton, MA), which rapidly facilitated secondary healing.


Assuntos
Colágeno , Procedimentos Cirúrgicos Dermatológicos/métodos , Nutrição Parenteral Total/efeitos adversos , Pele Artificial , Lesões dos Tecidos Moles/cirurgia , Feminino , Humanos , Recém-Nascido , Lesões dos Tecidos Moles/etiologia , Cicatrização
17.
J Biol Chem ; 287(37): 31280-97, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-22815488

RESUMO

Thyroid hormone receptor (TR) is a member of the nuclear receptor superfamily that shuttles between the cytosol and nucleus. The fine balance between nuclear import and export of TR has emerged as a critical control point for modulating thyroid hormone-responsive gene expression; however, sequence motifs of TR that mediate shuttling are not fully defined. Here, we characterized multiple signals that direct TR shuttling. Along with the known nuclear localization signal in the hinge domain, we identified a novel nuclear localization signal in the A/B domain of thyroid hormone receptor α1 that is absent in thyroid hormone receptor ß1 and inactive in the oncoprotein v-ErbA. Our prior studies showed that thyroid hormone receptor α1 exits the nucleus through two pathways, one dependent on the export factor CRM1 and the other CRM1-independent. Here, we identified three novel CRM1-independent nuclear export signal (NES) motifs in the ligand-binding domain as follows: a highly conserved NES in helix 12 (NES-H12) and two additional NES sequences spanning helix 3 and helix 6, respectively. Mutations predicted to disrupt the α-helical structure resulted in a significant decrease in NES-H12 activity. The high degree of conservation of helix 12 suggests that this region may function as a key NES in other nuclear receptors. Furthermore, our mutagenesis studies on NES-H12 suggest that altered shuttling of thyroid hormone receptor ß1 may be a contributing factor in resistance to thyroid hormone syndrome. Taken together, our findings provide a detailed mechanistic understanding of the multiple signals that work together to regulate TR shuttling and transcriptional activity, and they provide important insights into nuclear receptor function in general.


Assuntos
Sinais de Localização Nuclear/metabolismo , Receptores alfa dos Hormônios Tireóideos/metabolismo , Receptores beta dos Hormônios Tireóideos/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Motivos de Aminoácidos , Animais , Células HeLa , Humanos , Mutação , Sinais de Localização Nuclear/genética , Proteínas Oncogênicas v-erbA/genética , Proteínas Oncogênicas v-erbA/metabolismo , Estrutura Terciária de Proteína , Ratos , Receptores alfa dos Hormônios Tireóideos/genética , Receptores beta dos Hormônios Tireóideos/genética
18.
Med Sci Sports Exerc ; 41(3): 682-7, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19204580

RESUMO

UNLABELLED: Ratings of perceived exertion (RPE) were developed to provide a subjective estimation of exercise intensity during exercise but are also used to produce exercise intensities and to report the intensity of completed exercise sessions. PURPOSE: To determine the relationship between RPE assessed before, during, and after trials of RPE-based self-regulated aerobic exercise. METHODS: Twenty-six participants (10 males and 16 females) were tested for aerobic fitness. Participants completed three 30-min trials of treadmill exercise at a self-selected intensity corresponding to verbal prescriptions of light, moderate, and vigorous. Participants were instructed to adjust treadmill speed every 5 min to maintain the prescribed intensity. RPE using the OMNI picture system was taken immediately before, every 5 min during, immediately after, and 15 min after exercise. RESULTS: Treadmill speed increased during the moderate trial, and HR increased during all trials (P < 0.05). Predicted RPE and session RPE were higher than the average RPE for all sessions (P < 0.05) but not different than RPE values obtained at the end of the 30-min trials (P > 0.05). CONCLUSIONS: Findings suggest that predicted and session RPE are well matched to the exertion associated with the finishing minute of exercise sessions but are poorly matched to the majority of the exercise session. In-task RPE values tend to drift throughout exercise despite little or no change in treadmill speed and instructions to self-regulate exercise intensity. These findings indicate that RPE may be linked to exercise duration during self-regulated exercise. Additionally, session RPE ratings taken after exercise tend to reflect the close of exercise rather than the exertion associated with the exercise session as a whole.


Assuntos
Teste de Esforço/métodos , Esforço Físico/fisiologia , Adulto , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Resistência Física/fisiologia
19.
J Sports Sci ; 27(5): 509-16, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19204846

RESUMO

In this study, we assessed how ungraded jogging and graded walking at the same rating of perceived exertion (RPE) affect heart rate and oxygen consumption ([Vdot]O(2)). Twenty untrained participants completed a treadmill test to determine peak [Vdot]O(2) (mean = 40.3 +/- 6.3 ml . kg(-1) . min(-1)). Participants completed separate 30-min trials of moderate exercise (RPE of 13 on the Borg 6-20 scale) in random order on the treadmill: graded walking and ungraded jogging. Treadmill speed or grade was adjusted throughout the trial by the experimenter based on participant responses to maintain an RPE of 13. The jogging trial produced a significantly higher heart rate (161 +/- 18 vs. 142 +/- 24 beats . min(-1)) and [Vdot]O(2) (7.4 +/- 1.8 vs. 5.8 +/- 1.5 METs) (P < 0.01) than the walking trial. Treadmill grade decreased significantly during the walking trial (11.1 +/- 2.3% to 10.0 +/- 2.2%; P < 0.01), but treadmill speed did not change significantly during the jogging trial (5.2 +/- 1.0 miles . h(-1) to 5.0 +/- 0.9 miles . h(-1)) (P > 0.05), in an effort to maintain constant RPE. These findings provide evidence that similar perceptions of effort during graded walking and ungraded jogging do not produce similar cardiovascular and metabolic responses. The results indicate that, for a given prescribed perceived effort, jogging provides a greater stimulus for fitness benefits and caloric expenditure.


Assuntos
Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Corrida Moderada/fisiologia , Consumo de Oxigênio/fisiologia , Caminhada/fisiologia , Adulto , Exercício Físico/psicologia , Teste de Esforço , Feminino , Humanos , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Adulto Jovem
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