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BACKGROUND: To assess the clinical outcomes and identify the ideal indication for implementing dorsal distal radioulnar joint (DRUJ) capsular imbrication after triangular fibrocartilage complex (TFCC) repair in cases of DRUJ instability. METHODS: We conducted a retrospective study on patients who underwent arthroscopic TFCC repair between 2016 and 2021. Inclusion criteria comprised a symptomatic ulna fovea sign for over 6 months and dorsal DRUJ subluxation on magnetic resonance imaging. A total of 225 patients were divided into two groups: Group 1 (135 cases) with a negative ballottement test after "Cross-form TFCC repair" (CR) and Group 2 (90 cases) with a positive ballottement test after "Cross-form TFCC repair" and augmented DRUJ stability through dorsal DRUJ capsular imbrication (CR + DCI). Pain visual analog scale score (VAS), grip strength, modified Mayo Wrist Score (MMWS), wrist range of motion (ROM), and patient-reported outcomes (PROMs) were assessed for a minimum of 3 years postoperatively. RESULTS: Both groups showed significant improvements in pain VAS score, grip strength, wrist ROM, MMWS, and PROMs between the preoperative and postoperative periods (all P < 0.05). Recurrent DRUJ instability occurred in 3.7% and 1.1% of patients in the "CR" and "CR + DCI" groups, respectively, with a significant difference. Despite the "CR + DCI" group initially exhibiting inferior ROM compared with the "CR" group, subsequently, no significant difference was noted between them. CONCLUSIONS: Dorsal DRUJ capsular imbrication effectively reduces postoperative DRUJ instability rates, enhances grip strength, and maintains wrist ROM in patients with a positive intra-operative ballottement test after arthroscopic TFCC repair.
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Artroscopia , Instabilidade Articular , Amplitude de Movimento Articular , Fibrocartilagem Triangular , Articulação do Punho , Humanos , Instabilidade Articular/cirurgia , Instabilidade Articular/diagnóstico por imagem , Instabilidade Articular/etiologia , Instabilidade Articular/fisiopatologia , Feminino , Masculino , Estudos Retrospectivos , Artroscopia/métodos , Artroscopia/efeitos adversos , Adulto , Articulação do Punho/cirurgia , Articulação do Punho/diagnóstico por imagem , Articulação do Punho/fisiopatologia , Fibrocartilagem Triangular/cirurgia , Fibrocartilagem Triangular/lesões , Fibrocartilagem Triangular/diagnóstico por imagem , Resultado do Tratamento , Pessoa de Meia-Idade , Adulto Jovem , Força da Mão , Cápsula Articular/cirurgia , Cápsula Articular/diagnóstico por imagem , Medidas de Resultados Relatados pelo PacienteRESUMO
BACKGROUND: Metacarpal shaft fracture is a common type of hand fracture. Numerous studies have explored fixing transverse fractures in the midshaft of the metacarpal bone. However, this section of the metacarpal bone is often susceptible to high-energy injury, resulting in comminuted fracture or bone loss. In such cases, wedge-shaped bone defects can develop in the metacarpal shaft, increasing the difficulty of performing fracture fixation. Notably, the research on this type of fracture fixation is limited. This study compared the abilities of four fixation methods to fix metacarpal shaft fractures with wedge-shaped bone defects. METHODS: In total, 28 artificial metacarpal bones were used. To create wedge-shaped bone defects, an electric saw was used to create metacarpal shaft fractures at the midshaft of each bone. The artificial metacarpal bones were then divided into four groups for fixation. The bones in the first group were fixed with a dorsal locked plate (DP group), those in the second group were fixed with a volar locked plate (VP group), and those in the third group were fixed by combining dorsal and volar locked plates (DP + VP group), and those in the fourth group were fixed with two K-wires (2 K group). Cantilever bending tests were conducted using a material testing machine to measure yielding force and stiffness. The four groups' fixation capabilities were then assessed through analysis of variance and Tukey's test. RESULTS: The DP + VP group (164.1±44.0 N) achieved a significantly higher yielding force relative to the 2 K group (50.7 ± 8.9 N); the DP group (13.6 ± 3.0 N) and VP group (12.3 ± 1.0 N) did not differ significantly in terms of yielding force, with both achieving lower yielding forces relative to the DP + VP group and 2 K group. The DP + VP group (19.8±6.3 N/mm) achieved the highest level of stiffness, and the other three groups did not differ significantly in terms of stiffness (2 K group, 5.4 ± 1.1 N/mm; DP group, 4.0 ± 0.9 N/mm; VP group, 3.9 ± 1.9 N/mm). CONCLUSIONS: The fixation method involving the combined use of dorsal and volar locked plates (DP + VP group) resulted in optimal outcomes with respect to fixing metacarpal shaft fractures with volar wedge bone defects.
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Placas Ósseas , Fios Ortopédicos , Fixação Interna de Fraturas , Fraturas Ósseas , Ossos Metacarpais , Ossos Metacarpais/lesões , Ossos Metacarpais/cirurgia , Humanos , Fenômenos Biomecânicos , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/cirurgiaRESUMO
STUDY DESIGN: Retrospective comparative study. OBJECTIVE: To investigate the occurrence of neurological complications in patients undergoing thoracic three-column osteotomy (3CO) utilizing an magnetic resonance imaging (MRI)-based classification that assesses spinal cord shape and the presence of cerebrospinal fluid at the curve apex and evaluate its prognostic capacity for postoperative neurological deficits. SUMMARY OF BACKGROUND DATA: Recent advancements in correction techniques have improved outcomes for severe spinal deformity patients undergoing 3CO. A novel MRI-based spinal cord classification system was introduced, but its validation and association with postoperative complications remain unexplored. MATERIALS AND METHODS: Between September 2012 and September 2018, a retrospective analysis was conducted on 158 adult patients with spinal deformities undergoing 3CO. Radiographic parameters were measured. T2-weighted axial MRI was used to describe spinal cord morphology at the apex. Intraoperative neurophysiological monitoring alerts were recorded, and preoperative and postoperative neurological functions were assessed using the Frankel score. Categorical data were compared using the χ 2 or the Fisher exact test. The paired t test was utilized to assess the mean difference between preoperative and postoperative measurements, while the one-way analysis of variance and independent t test were used for comparative analyses among the different spinal cord types. RESULTS: Patients were categorized into three groups: type 1, type 2, and type 3, consisting of 12, 85, and 61 patients. Patients with type 3 morphology exhibited larger Cobb angles of the main curve ( P <0.001). This disparity persisted both postoperatively and during follow-up ( P <0.05). Intraoperative neurophysiological monitoring alerts were triggered in 32 patients (20.3%), with a distribution of one case in type 1, six cases in type 2, and 22 cases in type 3 morphologies ( P <0.001). New neurological deficits were observed in 15 patients (9.5%), with 1, 3, and 11 cases in type 1, 2, and 3 morphologies, respectively. CONCLUSIONS: Patients with type 3 morphology exhibited greater spinal deformity severity, a higher likelihood of preoperative neurological deficits, and an elevated risk of postoperative neurological complications. This underscores the utility of the classification as a tool for predicting postoperative neurological complications in patients undergoing thoracic 3CO. LEVEL OF EVIDENCE: 4.
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Imageamento por Ressonância Magnética , Osteotomia , Complicações Pós-Operatórias , Vértebras Torácicas , Humanos , Feminino , Masculino , Estudos Retrospectivos , Vértebras Torácicas/cirurgia , Vértebras Torácicas/diagnóstico por imagem , Adulto , Osteotomia/métodos , Osteotomia/efeitos adversos , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/diagnóstico por imagem , Adulto Jovem , Doenças do Sistema Nervoso/etiologia , Doenças do Sistema Nervoso/diagnóstico por imagem , Medula Espinal/diagnóstico por imagem , Medula Espinal/cirurgia , IdosoRESUMO
BACKGROUND: A variety of surgical techniques had been developed over the past few decades for treating thumb carpometacarpal joint (CMCJ) osteoarthritis (OA). However, there are currently no accepted consensus on the ideal treatment for thumb CMCJ OA. Arthrodesis was one of the widely popular treatment methods; however, studies have showed that non-union rates were as high as 50%, with higher complications such as osteoarthritis of neighbouring joints and higher revision surgeries required as compared to other surgical methods. Patients with arthrodesis were also reported to have decreased thumb range of motion and loss of opponens function. Currently, there are numerous intraoperative positioning techniques for arthrodesis which could be confusing for young surgeons. With recent developments of fixation plates and better understanding of the wrist anatomy, this retrospective review aimed to evaluate the efficacy of our intraoperative hand-grip positioning method for arthrodesis of thumb CMCJ OA. What are the postoperative functional outcomes of (1) T-hook plates and (2) our intraoperative hand-grip positioning method for Eaton III thumb CMCJ OA arthrodesis by evaluating pain visual analogue scale (VAS) score, Disabilities of the Arm, Shoulder and Hand questionnaires (DASH), Mayo Wrist scores, capability of thumb opposition (Kapandji score), and comparing pre- and postoperative grip and pinch strength? METHODS: Twenty patients with CMCJ OA underwent arthrodesis using our intraoperative hand-grip positioning method and T-hook plates and screws (Acumed, USA). Patients were evaluated preoperatively and at 1, 3, 6 and 12 months postoperatively. Radiologic assessment including fusion evaluation, evaluation of radial and palmar abduction angles was done on hand X-rays. RESULTS: Twenty patients with a minimum follow-up duration of 12 months were included in this study. 100% fusion rate was achieved with only 1 case of complication involving radial sensory nerve neuropathy which was resolved after removal of implant and neurolysis. Significant improvement in pain and Mayo Wrist scores were noted 3 months postoperatively, whilst DASH score exhibited significant improvements after 6 months of follow-up (p < 0.05). Even though there were no significant differences observed between preoperative and postoperative grip strength, pinch strength and Kapandji scores, positive recovery trends were noted for all parameters with these functions surpassing preoperative levels after 12 months of follow-up. Significant improvements on hand X-rays were also noted for both postoperative radial and palmar abduction angles. CONCLUSIONS: There is currently no consensus on the ideal treatment method for thumb CMCJ OA. In this study, we would like to propose a simple intraoperative hand-grip positioning method with T-hook plates for arthrodesis. As seen from our results, our technique was able to provide satisfactory and replicable postoperative results and thus we would like to propose our hand-grip positioning method with T-hook plates fixation for subsequent treatment of patients with Eaton stage III thumb CMCJ OA.
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Articulações Carpometacarpais , Osteoartrite , Humanos , Artrodese/métodos , Articulações Carpometacarpais/cirurgia , Força da Mão , Osteoartrite/diagnóstico por imagem , Osteoartrite/cirurgia , Dor , Amplitude de Movimento Articular , Polegar/cirurgia , Resultado do Tratamento , Estudos RetrospectivosRESUMO
For patients with spinopelvic dissociation (SPD), triangular osteosynthesis is the current method for the fixation of the posterior pelvis. This study aimed to assess the recovery process and radiographic parameters associated with the functional outcomes in patients with SPD treated by triangular osteosynthesis. We collected data from 23 patients with SPD. To investigate the key aspect regarding the functional outcomes of these patients, we measured pre- and post-operative parameters, and a statistical analysis adjusted for age, gender, and time windows was used. The radiographic displacement measurement in the pre-operative period showed that the EQ-5D-5L increased by 2.141 per outlet ratio unit. The EQ-5D-5L increased by 1.359 per inlet ratio unit and 1.804 per outlet ratio during the postoperative period. The EQ-VAS increased significantly only with the inlet ratio in the postoperative period (1.270 per inlet ratio). A vertical reduction in SPD during the surgery can achieve more satisfactory outcomes than a horizontal anatomical reduction, in which the horizontal displacement causes inferior functional outcomes.
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PURPOSE: To evaluate the outcomes of "tent form" triangular fibrocartilage complex (TFCC) repair combined with dorsal distal radioulnar joint (DRUJ) capsule imbrication for posttraumatic chronic DRUJ instability. METHODS: All patients treated with arthroscopic "tent form" TFCC repair and DRUJ capsule imbrication from 2016 to 2019 were retrospectively reviewed. The inclusion criteria were symptomatic chronic DRUJ instability for >6 months and dorsal DRUJ subluxation on magnetic resonance imaging. The Disabilities of the Arm, Shoulder, and Hand score, Patient-Rated Wrist Evaluation, grip strength, Modified Mayo Wrist Score, range of motion, and distal radioulnar joint stability were assessed for a minimum of 2 years postoperatively. RESULTS: Thirty-eight patients were included in the final analysis. The average follow-up duration was 35.6 months (range, 24-48 months). The 24-month postoperative grip strengths and 3-dimensional motions of wrist were not significantly different from that of the nonoperated wrist. Compared with their preoperative status, Disabilities of the Arm, Shoulder, and Hand score, Patient-Rated Wrist Evaluation, and Modified Mayo Wrist Score indicated the significant improvement with P values of .001, .001, and .002, respectively. CONCLUSIONS: In chronic DRUJ instability with a loosening dorsal capsule, "tent form" TFCC transcapsular repair combined with DRUJ capsule imbrication restored the integrity of TFCC and dorsal DRUJ capsule and achieved a promising outcome. We recommend this procedure as an option of treatment for patients with posttraumatic chronic DRUJ instability. LEVEL OF EVIDENCE: IV, case series.
Assuntos
Instabilidade Articular , Fibrocartilagem Triangular , Traumatismos do Punho , Artroscopia/efeitos adversos , Humanos , Cápsula Articular/cirurgia , Instabilidade Articular/etiologia , Instabilidade Articular/cirurgia , Estudos Retrospectivos , Resultado do Tratamento , Fibrocartilagem Triangular/cirurgia , Traumatismos do Punho/cirurgia , Articulação do Punho/cirurgiaRESUMO
BACKGROUND: Chondrosarcoma, a cartilage matrix producing tumor, is the second most commonly observed primary bone tumor after osteosarcoma, accounting for 15% of all chest wall malignancies. We herein report the case of a patient with chondrosarcoma of the sternum and our management of the chest wall defects that presented following radical tumor resection. CASE SUMMARY: A 31-year-old patient presented to our hospital with dull pain and a protruding mass overlying the chest for 3 mo. The presence of nocturnal pain and mass size progression was reported, as were overhead arm elevation-related limitations. Computed tomography showed a focal osteoblastic mass in the sternum with bony exostosis and adjacent soft tissue calcification. Positron emission tomography-computed tomography revealed hypermetabolic activity with a mass located over the upper sternum. Magnetic resonance imaging showed a focal ill-defined bony mass of the sternum with cortical destruction and periosteal reaction. Preoperative biopsy showed a consistent result with chondrosarcoma with immunohistochemical positivity for S100 and focal positivity for IDH-1. The grade II chondrosarcoma diagnosis was confirmed by postoperative pathology. The patient underwent radical tumor resection and chest wall reconstruction with a locking plate and cement spacer. The patient was discharged 1 wk after surgery without any complications. At the 1-year follow-up, there was no local recurrence on imaging. The functional scores, including Constant Score, Nottingham Clavicle Score, and Oxford Shoulder Score, showed the absence of pain in the performance of daily activities or substantial functional disabilities. CONCLUSION: The diagnosis of chondrosarcoma must be considered when chest wall tumors are encountered. The surgical reconstructive materials, with a locking plate and cement spacer, used in our study are cost-effective and readily-available for the sternum defect.
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BACKGROUND: Electroacupuncture (EA) alleviates chronic pain and acute postoperative pain after several surgical procedures. However, whether EA facilitates postoperative functional recovery after arthroscopic surgery has yet to be determined. This study investigated the short-term effect of EA on a rehabilitation course after arthroscopic triangular fibrocartilage complex (TFCC) repair. METHODS: Forty-two patients undergoing arthroscopic TFCC repair were randomised to an EA group (n = 19) or control group (n = 23). In the EA group, patients received EA treatment and standard active rehabilitation for 4 weeks. In the control group, patients received standard active rehabilitation for 4 weeks. At the end of the treatment and at the follow-up visit 4 weeks after the treatment, Disabilities of the Arm, Shoulder, and Hand (DASH) scores, wrist range of motion (ROM), handgrip strength, and key pinch strength were collected and analysed. RESULTS: The EA group improved significantly than the control group in terms of DASH scores, all wrist motion arcs, and key pinch strength (P < 0.05) at the end of the 4-week treatment and the follow-up visit another 4 weeks later. CONCLUSION: Patients treated with 4 weeks of EA after the arthroscopic TFCC repair had better wrist ROM and DASH scores than patients of control group.
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Artroscopia/reabilitação , Eletroacupuntura/métodos , Fibrocartilagem Triangular/lesões , Fibrocartilagem Triangular/cirurgia , Adulto , Artroscopia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Método Simples-Cego , Fatores de Tempo , Resultado do Tratamento , Fibrocartilagem Triangular/fisiopatologia , Adulto JovemRESUMO
BACKGROUND: The treatment of mallet fracture using hook plate fixation was first introduced in 2007 and has subsequently shown excellent outcomes. Common complications, such as nail deformity and screw loosening, have also been reported. Very few studies have focused on these common complications or their prevention. In this study, we present the clinical outcomes and complications of our case series and describe the pitfalls and detailed solution of surgical tips to avoid common complications related to this procedure. METHODS: The retrospective case series of 16 patients with mallet fractures who underwent open reduction and hook plate fixation in our hospital from 2015 to 2020 were retrospectively reviewed. Data on extension lag, range-of-motion (ROM) of the distal interphalangeal joint (DIP) joint, the Disabilities of the Arm, Shoulder, and Hand (DASH) score, and surgical complications were collected and analysed. The clinical outcome was graded according to the Crawford mallet finger criteria. RESULTS: Sixteen patients were included in our analysis. The median DIP extension lag was 0° (range, 0° to 30°) and the median active DIP flexion angle was 60° (range, 40° to 90°). The median DASH score was 0 (range, 0-11.3). Fourteen patients with good and excellent results were satisfied with this treatment. The Complication rate in our patient series was 18%. Common complications reported in articles included wound necrosis, extension lag, nail deformity, and plate loosening. CONCLUSIONS: Despite the fact that the treatment of mallet fracture with hook plate fixation has satisfactory functional outcomes, pitfalls, including iatrogenic nail germinal matrix injury, unnecessary soft tissue dissection, and insufficient screw purchase, were still reported. To avoid complications, we suggest modifications of the skin incision, soft tissue dissection, and screw position.
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Falanges dos Dedos da Mão , Placas Ósseas , Fixação Interna de Fraturas/efeitos adversos , Humanos , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Surgical treatment is necessary for scaphoid nonunion. Open surgery with a combined volar and dorsal approach is thought to have poor functional outcomes and a prolonged recovery course. However, the detailed recovery course for this approach is rarely reported. The aim of this study was to investigate the recovery course and radiographic outcome for patients with scaphoid nonunion who underwent a combined volar bone grafting and dorsal antegrade headless screw approach. MATERIAL AND METHODS: Eighteen patients with scaphoid nonunion who underwent combined volar bone grafting and dorsal antegrade headless screw fixation were enrolled in this retrospective study. Preoperative and serial postoperative wrist functional and radiographic outcomes were collected and analysed. RESULTS: All 18 patients achieved bone union at a mean time of 14.3 weeks. Compared to the preoperative status, the grip strength, wrist motion arc, and Mayo Wrist score were improved significantly 6 months after surgery, whilst the Disabilities of the Arm, Shoulder, and Hand (DASH) score did not recover until 12 months after surgery. Significant improvements were found in all scaphoid radiographic parameters. CONCLUSION: The surgical outcomes for scaphoid nonunion treated with a combined volar bone grafting and dorsal antegrade headless screw achieved a high union rate, with great wrist functional and radiographic outcomes. The earliest recovered wrist functional parameters were grip strength, motion arc, Mayo Wrist score and finally the DASH score at postoperative 6 months and 12 months, respectively.
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Parafusos Ósseos , Transplante Ósseo/métodos , Fraturas não Consolidadas/fisiopatologia , Fraturas não Consolidadas/cirurgia , Procedimentos Ortopédicos/métodos , Recuperação de Função Fisiológica , Osso Escafoide/lesões , Osso Escafoide/cirurgia , Punho/fisiopatologia , Adulto , Feminino , Fraturas não Consolidadas/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Osso Escafoide/diagnóstico por imagem , Fatores de Tempo , Resultado do Tratamento , Punho/diagnóstico por imagem , Adulto JovemRESUMO
OBJECTIVE: Chronic osteomyelitis (COM) can induce systemic inflammation, and systemic inflammation may be associated with suicide tendency. However, no studies have investigated the correlation between COM and suicide tendency. METHODS: The aim of this population-based study was to determine the epidemiology of fatal/non-fatal suicide among COM patients. Subjects with at least two outpatient visits or one course of inpatient care diagnosed with COM were recruited into a COM cohort. The control/COM subject ratio was approximately 4:1 matched by age, sex, major depression coding and index year (COM patients). Subjects with suicide attempts before COM diagnosis and subjects aged <20 years were excluded. RESULTS: COM patients had 1.93 (95% confidence interval [CI]: 1.11-3.36) times the risk of fatal/non-fatal suicide as control subjects. Considering death as the competing event of fatal/non-fatal suicide, COM patients had 1.76 (95% CI: 1.03-3.01) times the risk of fatal/non-fatal suicide (competing risk regression model). The effect of COM on fatal/non-fatal suicide was more prominent among diabetic patients. COM severity also correlated with the risk of fatal/non-fatal suicide. CONCLUSIONS: More attention must be paid to suicide tendency among COM patients.
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Osteomielite , Idoso , Doença Crônica , Estudos de Coortes , Humanos , Incidência , Osteomielite/epidemiologia , Medição de Risco , Fatores de RiscoRESUMO
Pseudomonas nitroreducens TX1 is of special interest because of its ability to utilize 0.05% to 20% octylphenol polyethoxylates (OPEOn) as a sole source of carbon. In this study, a library containing 30,000 Tn5-insertion mutants of the wild-type strain TX1 was constructed and screened for OPEOn utilization, and 93 mutants were found to be unable to grow on OPEOn In total, 42 separate disrupted genes were identified, and the proteins encoded by the genes were then classified into various categories, namely, information storage and processing (14.3%), cellular processes and signaling (28.6%), metabolism (35.7%), and unknown proteins (21.4%). The individual deletion of genes encoding isocitrate lyase (aceA), malate synthase (aceB), and glycolate dehydrogenase (glcE) was carried out, and the requirement for aceA and aceB but not glcE confirmed the role of the glyoxylate cycle in OPEOn degradation. Furthermore, acetaldehyde dehydrogenase and acetyl-coenzyme A (acetyl-CoA) synthetase activity levels were 13.2- and 2.1-fold higher in TX1 cells grown on OPEOn than in TX1 cells grown on succinate, respectively. Growth of the various mutants on different carbon sources was tested, and based on these findings, a mechanism involving exoscission to liberate acetaldehyde from the end of the OPEOn chain during degradation is proposed for the breakdown of OPEOn IMPORTANCE: Octylphenol polyethoxylates belong to the alkylphenol polyethoxylate (APEOn) nonionic surfactant family. Evidence based on the analysis of intermediate metabolites suggested that the primary biodegradation of APEOn can be achieved by two possible pathways for the stepwise removal of the C2 ethoxylate units from the end of the chain. However, direct evidence for these hypotheses is still lacking. In this study, we described the use of transposon mutagenesis to identify genes critical to the catabolism of OPEOn by P. nitroreducens TX1. The exoscission of the ethoxylate chain leading to the liberation of acetaldehyde is proposed. Isocitrate lyase and malate synthase in glyoxylate cycle are required in the catabolism of ethoxylated surfactants. Our findings also provide many gene candidates that may help elucidate the mechanisms in stress responses to ethoxylated surfactants by bacteria.
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Elementos de DNA Transponíveis , Mutagênese Insercional , Fenóis/metabolismo , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/genética , Acetaldeído/metabolismo , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Aldeído Oxirredutases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Deleção de Genes , Isocitrato Liase/genética , Isocitrato Liase/metabolismo , Malato Sintase/genética , Malato Sintase/metabolismo , Pseudomonas/metabolismo , Ácido Succínico/metabolismo , Tensoativos/metabolismoRESUMO
Biological information generated by high-throughput technology has made systems approach feasible for many biological problems. By this approach, optimization of metabolic pathway has been successfully applied in the amino acid production. However, in this technique, gene modifications of metabolic control architecture as well as enzyme expression levels are coupled and result in a mixed integer nonlinear programming problem. Furthermore, the stoichiometric complexity of metabolic pathway, along with strong nonlinear behaviour of the regulatory kinetic models, directs a highly rugged contour in the whole optimization problem. There may exist local optimal solutions wherein the same level of production through different flux distributions compared with global optimum. The purpose of this work is to develop a novel stochastic optimization approach-information guided genetic algorithm (IGA) to discover the local optima with different levels of modification of the regulatory loop and production rates. The novelties of this work include the information theory, local search, and clustering analysis to discover the local optima which have physical meaning among the qualified solutions.