RESUMO
The semicircular canals of the mammalian inner ear are derived from epithelial pouches in which epithelial cells in the central region of each pouch undergo resorption, leaving behind the region at the rim to form a tube-shaped canal. Lack of proliferation at the rim and/or over-clearing of epithelial cells in the center of the pouch can obliterate canal formation. Otic-specific knockout of bone morphogenetic protein 2 (Bmp2) results in absence of all three semicircular canals; however, the common crus and ampullae housing the sensory tissue (crista) are intact. The lack of Bmp2 causes Ntn1 (which encodes netrin 1), which is required for canal resorption, to be ectopically expressed at the canal rim. Ectopic Ntn1 results in reduction of Dlx5 and Lmo4, which are required for rim formation. These phenotypes can be partially rescued by removing one allele of Ntn1 in the Bmp2 mutants, indicating that Bmp2 normally negatively regulates Ntn1 for canal formation. Additionally, non-resorption of the canal pouch in Ntn1-/- mutants is partially rescued by removing one allele of Bmp2 Thus, reciprocal inhibition between Bmp2 and netrin 1 is involved in canal formation of the vestibule.
Assuntos
Proteína Morfogenética Óssea 2/genética , Regulação da Expressão Gênica no Desenvolvimento , Netrina-1/genética , Canais Semicirculares/embriologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Alelos , Animais , Proteína Morfogenética Óssea 2/metabolismo , Linhagem da Célula , Proliferação de Células , Fatores de Transcrição Forkhead/metabolismo , Perfilação da Expressão Gênica , Genótipo , Proteínas de Homeodomínio/metabolismo , Proteínas com Domínio LIM/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Proteínas do Tecido Nervoso/metabolismo , Netrina-1/metabolismo , Fenótipo , Ligação Proteica , Domínios Proteicos , Vestíbulo do Labirinto/embriologiaRESUMO
BACKGROUND: The debate of whether to centralize hepato-pancreato-biliary surgery has been ongoing. The principal objective was to compare outcomes of a community pancreatic surgical program with those of high-volume academic centers. METHODS: The current pancreatic surgical study occurred in an environment where (1) a certified abdominal transplant surgeon performed all surgeries; (2) complementary quality enhancement programs had been developed; (3) the hospital's trauma center had been verified; and (4) the hospital's surgical training had been accredited. Pancreatic surgical outcomes at high-volume academic centers were obtained through PubMed literature searches. Articles were selected if they described diverse surgical procedures. Two-tailed Fisher exact and mid-P tests were used to perform 2 × 2 contingency analyses. RESULTS: The study patients consisted of 64 consecutive pancreatic surgical patients. The study patients had a similar pancreaticoduodenectomy proportion (59.4%) when compared to literature patients (66.8%; P = 0.227). The study patients also had a similar distal pancreatectomy proportion (25.0%) when compared to literature patients (31.9%; P = 0.276). The study patients had a significantly higher American Society of Anesthesiologists physical status ≥ 3 proportion (100%) than literature patients (28.1%; P < 0.001). The 90-day study mortality proportion (0%) was similar to the literature proportion (2.3%; P = 0.397). The study postoperative pancreatic fistula proportion was lower (3.2%), when compared to the literature proportion (18.4%; P < 0.001; risk ratio = 5.8). The study patients had a lower reoperation proportion (3.1%) than the literature proportion (8.7%; mid-P = 0.051; risk ratio = 2.8). The study patients had a lower surgical site infection proportion (3.1%) than those in the literature (21.1%; P < 0.001; risk ratio = 6.8). The study patients had equivalent delayed gastric emptying (15.6%) when compared to literature patients (10.6%; P = 0.216). The study patients had decreased Clavien-Dindo grades III-IV complications (10.9%) compared to the literature patients (21.8%; mid-P = 0.018). Lastly, the study patients had a similar readmission proportion (20.3%) compared to literature patients (18.4%; P = 0.732). CONCLUSION: Despite pancreatic surgical patients having greater preoperative medical comorbidities, the current community study outcomes were comparable to or better than high-volume academic center results.
Assuntos
Robótica , Centros de Traumatologia , Humanos , Hospitais de EnsinoRESUMO
The goal of the present work was to perform a systematic review of the literature of the past 10 years regarding dynamic and static fixation of the distal tibiofibular syndesmosis to determine any clinical differences between the 2 procedures. A literature search of the PubMed MEDLINE database was conducted to identify relevant studies related to distal tibiofibular syndesmosis. Studies before January 1, 2007, were excluded to limit the project to the recent literature. Clinical outcomes, device removal rates, time to weightbearing after the initial procedure, and the cost effectiveness of each device were explored. In these 26 studies, 350 patients were treated using a dynamic technique and 845 were treated using a static technique. The weighted American Orthopedic Foot and Ankle Score was 91.70 (standard error [SE] 1.87) for dynamic fixation patients and the weighted average was 86.48 (SE 2.17) for static fixation patients (pâ¯=â¯.068). A secondary procedure to remove the fixation device was performed in 7.7% of dynamic fixation patients and in 39.4% of static fixation patients when studies with 100% device removal were excluded (p < .0001). The mean time to weightbearing was 5.96 (SE 0.72) weeks for patients who underwent dynamic fixation and 10.45 (SE 0.99) weeks for those who had static fixation (pâ¯=â¯.0002). The cost for dynamic fixation was found to be less than that for static fixation when secondary procedures for device removal were considered. Based on similar clinical functional scores, lower secondary procedure rates, faster time to full weightbearing, and lower costs to patients, dynamic fixation of the distal tibiofibular syndesmosis may be a superior option compared with static fixation.