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BACKGROUND: Bicondylar tibial plateau fractures pose many treatment challenges due to their complex fracture patterns and associated soft tissue compromise. We aim to evaluate outcomes of acute ORIF (aORIF) versus staged ORIF (sORIF) of high energy bicondylar tibial plateau fractures. METHODS: We retrospectively reviewed 186 patients at two high-volume Level I trauma centers. One hundred one patients underwent aORIF and 85 underwent sORIF between 2011 and 2019. Clinical outcomes of interest included operative time, wound dehiscence, superficial and deep infection, nonunion, flap coverage, arthrodesis, and early conversion to arthroplasty. RESULTS: Patients had a median follow up of 12 months (6-98 months). The sORIF group had a higher ISS (p = 0.02) and a higher rate of open fractures (24.7% vs 11.9%, p = 0.03). The groups were statistically similar in other demographics and co-morbidities. Operative time was significantly shorter in the aORIF group (157 vs 213 min., p < 0.001). There was no statistical difference in wound dehiscence, deep infection, flap coverage, nonunion, unplanned reoperation, or post-traumatic arthritis between groups. However, aORIF was associated with a significantly lower rate of superficial infection (p = 0.01), arthroplasty (p = 0.003) and unplanned reoperation (p = 0.005). Subgroup analysis of only the 41C3 fractures showed a lower rate of superficial infections in the aORIF group (p = 0.04). No difference in complications was found between the fracture subgroups. CONCLUSION: We found no increased risk of complications with aORIF compared to sORIF for bicondylar tibial plateau fractures. While not all injuries may be appropriate for aORIF, our results demonstrate the safety of aORIF when patients are properly selected by experienced fracture surgeons. LEVEL OF EVIDENCE: Level III.
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Fracturas de la Tibia , Fracturas de la Meseta Tibial , Humanos , Estudios Retrospectivos , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/métodos , Fracturas de la Tibia/complicaciones , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Resultado del TratamientoRESUMEN
Land use and land cover (LULC) parameters influence the hydrological and ecological processes taking place in a watershed. Understanding the changes in LULC is essential in the planning and development of management strategies for water resources. The purpose of the study was to detect changes in LULC in the Kibwezi watershed in Kenya, using geospatial approaches. Supervised and unsupervised classification techniques using remote sensing (RS) and geographical information system (GIS) were used to process Landsat imagery for 1999, 2009, and 2019 while ERDAS IMAGINE™ 14 and MS Excel software were used to derive change detection, and the Soil and Water Assessment Tool (SWAT) model was used to delineate the watershed using an in-built watershed delineation tool. The watershed was classified into ten major LULC classes, namely cropland (rainfed), cropland (irrigated), cropland (perennial), crop and shrubs/trees, closed shrublands, open shrubland, shrub grasslands, wooded shrublands, riverine woodlands, and built-up land. The results showed that LULC under shrub grassland, urban areas, and crops and shrubs increased drastically by 552.5%, 366.2%, and 357.1% respectively between 1999 and 2019 with an annual increase of 35.55%, 35.38%, and 33.86% per annum. The area under open shrubland and closed shrubland declined by73.7%, and 30.4% annually. These LULC transformations pose a negative impact on the watershed resources. There is therefore a need for proper management of the watershed for sustainable socio-economic development of the Kibwezi area.
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Bosques , Sistemas de Información Geográfica , Kenia , Suelo , Árboles , Monitoreo del Ambiente/métodos , Conservación de los Recursos NaturalesRESUMEN
Achieving health equity for Black people and other people of color in America will be an impossible feat without dismantling racist systems and replacing them with new inclusive systems that create success for everyone. This article highlights activities in Rocky Mount, North Carolina, and the efforts of a community-based nonprofit, OIC, in collaboration with residents, community, and government partners to craft sustainable and replicable solutions.
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Equidad en Salud , Humanos , North CarolinaRESUMEN
Gasification is recognized as a green technology as it can harness energy from biomass in the form of syngas without causing severe environmental impacts, yet producing valuable solid residues that can be utilized in other applications. In this study, the feasibility of co-gasification of woody biomass and food waste in different proportions was investigated using a fixed-bed downdraft gasifier. Subsequently, the capability of biochar derived from gasification of woody biomass in the rehabilitation of soil from tropical secondary forests on degraded land (adinandra belukar) was also explored through a water spinach cultivation study using soil-biochar mixtures of different ratios. Gasification of a 60:40 wood waste-food waste mixture (w/w) produced syngas with the highest lower heating value (LHV) 5.29 MJ/m(3)-approximately 0.4-4.0% higher than gasification of 70:30 or 80:20 mixtures, or pure wood waste. Meanwhile, water spinach cultivated in a 2:1 soil-biochar mixture exhibited the best growth performance in terms of height (a 4-fold increment), weight (a 10-fold increment) and leaf surface area (a 5-fold increment) after 8 weeks of cultivation, owing to the high porosity, surface area, nutrient content and alkalinity of biochar. It is concluded that gasification may be an alternative technology to food waste disposal through co-gasification with woody biomass, and that gasification derived biochar is suitable for use as an amendment for the nutrient-poor, acidic soil of adinandra belukar.
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Alimentos , Bosques , Reciclaje/métodos , Eliminación de Residuos/métodos , Suelo/química , Asia Sudoriental , Biomasa , Carbón Orgánico , Gases , Ipomoea/crecimiento & desarrollo , Singapur , Clima Tropical , Madera/químicaRESUMEN
Grazing affects grasslands worldwide. However, the global patterns and general mechanisms of how grazing affects plant reproductive traits are poorly understood, especially in the context of different climates and grazing duration. We conducted a meta-analysis of 114 independent grazing studies worldwide that measured plant reproductive traits in grasslands. The results showed that the number of tillers of plant increased under grazing. Grazing did not affect the number of reproductive branches of forbs, but significantly reduced the number of reproductive branches of grasses. Grazing increased the number of vegetative branches of all plants and reduced the proportion of reproductive branches. Grazing significantly reduced the number of flowers in forbs. Seed yield in the two plant functional groups was reduced compared with no-grazing. Under grazing, the sexual reproduction of grasses decreased much more substantially than that of forbs. This may be due to biomass allocation pattern of grasses under grazing (i.e., belowground versus aboveground). Under grazing, plants tended to adopt rapid, low-input asexual reproduction rather than long-term, high-risk sexual reproduction. This study represents the first large-scale evaluation of plant reproductive trait responses under grazing and demonstrates that grazing inhibits sexual reproduction and promotes asexual reproduction. The effect of grazing on plant sexual reproduction was influenced by grazing intensity, mean annual precipitation, and grazing duration. These results will assist in the development of sustainable grazing management strategies to improve the balance between human welfare and grassland ecosystem health.
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Ecosistema , Plantas , Humanos , Biomasa , Poaceae/fisiología , Reproducción , Reproducción Asexuada , Herbivoria , PraderaRESUMEN
OBJECTIVE: To determine the outcomes after acute versus staged fixation of complete articular tibial plafond fractures. DESIGN: Retrospective cohort study. SETTING: Single Level 1 Trauma center. PARTICIPANTS: 98 skeletally mature patients with OTA/AO 43C type fractures who underwent definitive fixation with plate and screw constructs and had a minimum 6 months of follow-up. INTERVENTION: Acute open reduction internal fixation (aORIF) versus staged (sORIF) definitive fixation. MAIN OUTCOME MEASUREMENT: Rates of wound dehiscence/necrosis and deep infection. RESULTS: Acute (N = 40) versus staged (N = 58) ORIF groups had comparable rates of vascular disease, renal disease, and substance/nicotine use, but aORIF patients had higher rates of diabetes mellitus (10% vs. 0%, P < 0.001), which correlated with higher American Society of Anaesthesiologist scores (>American Society of Anaesthesiologist 3: 37.5% vs. 13.8%, P = 0.02). Both groups achieved anatomic/good reductions, as determined by postoperative CT scans, at rates greater than 90%; however, the sORIF group required modestly longer operative times to achieve this outcome (aORIF vs. sORIF: 121 vs. 146 minutes, P = 0.02). Postoperatively, both groups had similar rates of wound dehiscence (2.5% vs. 6.9%, P = 0.65), superficial infections (10% vs. 17.2%, P = 0.39), and deep infections (10% vs. 8.6%, P = 0.99). While the injury pattern itself required free flap coverage in 1 patient in each group, unplanned free flap coverage occurred in 10.0% and 10.3% of aORIF and sORIF groups, respectively. Overall, rates of unplanned reoperations, excluding ankle arthrodesis, did not differ between groups (aORIF vs. sORIF:12.5% vs. 25.9%, P = 0.13). CONCLUSIONS: In select patients managed by fellowship-trained orthopaedic traumatologists, acute definitive pilon fixation can produce acceptable outcomes. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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Fracturas de Tobillo , Fracturas de la Tibia , Humanos , Estudios Retrospectivos , Resultado del Tratamiento , Fijación Interna de Fracturas/efectos adversos , Fracturas de la Tibia/diagnóstico por imagen , Fracturas de la Tibia/cirugía , Fracturas de la Tibia/etiología , Fracturas de Tobillo/diagnóstico por imagen , Fracturas de Tobillo/cirugía , Fracturas de Tobillo/etiología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiologíaRESUMEN
STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: To compare early postoperative radiological and clinical outcomes between 2-level minimally invasive (MIS) trans-psoas lateral lumbar interbody fusion (LLIF) and MIS transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spinal stenosis. METHODS: Fifty three consecutive patients undergoing 2-level lumbar interbody fusion from L3-L5 for degenerative lumbar spinal stenosis were enrolled. Twenty four patients underwent LLIF and 29 underwent TLIF. RESULTS: Operative time and length of stay were similar between LLIF and TLIF (272.8 ± 82.4 vs 256.1 ± 59.4 minutes; 5.5 ± 2.8 vs 4.7 ± 3.3 days, P > .05), whereas blood loss was lower for LLIF (229.0 ± 125.6 vs 302.4 ± 97.1mls, P = .026). Neurological deficits were more common in LLIF (9 vs 3, P = .025), whereas persistent deficits were rare for both (1 vs 1, P = 1). For both groups, all patient reported outcomes visual analogue scale (VAS back pain, VAS leg pain, ODI, SF-36 physical) improved from preoperative to 2-years postoperative (P < .05), with both groups showing no significant differences in extent of improvement for any outcome. Lateral lumbar interbody fusion demonstrated superior restoration of disc height (L3-L4: 4.1 ± 2.4 vs 1.2 ± 1.9 mm, P < .001; L4-L5: 4.6 ± 2.4 vs .8 ± 2.8 mm, P < .001), foraminal height (FH) (L3-L4: 3.5 ± 3.6 vs 1.0 ± 3.6 mm, P = .014; L4-L5: 3.0 ± 3.5 vs -.1 ± 4.4 mm, P = .0080), segmental lordosis (4.1 ± 6.4 vs -2.1 ± 8.1°, P = .005), lumbar lordosis (LL) (4.1 ± 7.0 vs -2.3 ± 12.6°, P = .026) and pelvic incidence-lumbar lordosis (PI-LL) mismatch (-4.1 ± 7.0 vs 2.3 ± 12.6°, P = .019) at 2-years follow-up. CONCLUSION: The superior radiological outcomes demonstrated by 2-level trans-psoas LLIF did not translate into difference in clinical outcomes compared to 2-level TLIF at the 2-years follow-up, suggesting both approaches are reasonable for 2-level lumbar interbody fusion in degenerative lumbar spinal stenosis.
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STUDY DESIGN: This was a retrospective review of prospectively collected registry data. OBJECTIVE: The objective of this study was to investigate the effect of smoking on 2 years postoperative functional outcomes, satisfaction, and radiologic fusion in nondiabetic patients undergoing minimally invasive transforaminal lumbar interbody fusion (TLIF) for degenerative spine conditions. SUMMARY OF BACKGROUND DATA: There is conflicting data on the effect of smoking on long-term functional outcomes following lumbar fusion. Moreover, there remains a paucity of literature on the influence of smoking within the field of minimally invasive spine surgery. METHODS: Prospectively collected registry data of nondiabetic patients who underwent primary single-level minimally invasive TLIF in a single institution was reviewed. Patients were stratified based on smoking history. All patients were assessed preoperatively and postoperatively using the Numerical Pain Rating Scale for back pain and leg pain, Oswestry Disability Index, Short-Form 36 Physical and Mental Component Scores. Satisfaction was assessed using the North American Spine Society questionnaire. Radiographic fusion rates were compared. RESULTS: In total, 187 patients were included, of which 162 were nonsmokers, and 25 had a positive smoking history. In our multivariate analysis, smoking history was insignificant in predicting for minimal clinically important difference attainment rates in Physical Component Score and fusion grading outcomes. However, in terms of satisfaction score, positive smoking history remained a significant predictor (odds ratio=4.7, 95% confidence interval: 1.10-20.09, P=0.036). CONCLUSIONS: Nondiabetic patients with a positive smoking history had lower satisfaction scores but comparable functional outcomes and radiologic fusion 2 years after single-level TLIF. Thorough preoperative counseling and smoking cessation advice may help to improve patient satisfaction following minimally invasive spine surgery. LEVEL OF EVIDENCE: Level III-nonrandomized cohort study.
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Fusión Vertebral , Espondilolistesis , Estudios de Cohortes , Humanos , Vértebras Lumbares/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos , Satisfacción del Paciente , Satisfacción Personal , Estudios Retrospectivos , Fumar/efectos adversos , Fusión Vertebral/psicología , Espondilolistesis/cirugía , Resultado del TratamientoRESUMEN
STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: This study aimed to determine the change in cervical sagittal balance following 2-level anterior cervical discectomy and fusion (ACDF) and whether the degree of change was associated with improvement in patient-reported outcomes (PROs). SUMMARY OF BACKGROUND DATA: Sagittal balance in cervical spine surgery has been recognized as an important surgical goal. However, its influence on clinical outcomes following anterior decompressive procedures remains debatable. MATERIALS AND METHODS: Patients who underwent primary 2-level ACDF for cervical spondylotic radiculopathy and/or myelopathy were identified from an institutional spine registry. Radiographic measurements were done preoperatively, postoperatively, and at minimum 24 months follow-up. Measurements comprised segmental lordosis (SL), C2-C7 cervical lordosis (CL), C2-C7 sagittal vertical axis, C7 slope (C7S), T1 slope (T1S) and C7 slope minus cervical lordosis (C7S-CL). Disk heights were measured preoperatively and postoperatively. PROs including the Neck Disability Index, Short Form-36, and Visual Analog Scale for neck pain and arm pain were collected preoperatively and at 24 months postoperatively. RESULTS: In total, 90 patients were included. Mean follow-up was 58.6±22.9 months. Significant improvement in all PROs was achieved at 24 months (P<0.05). SL was -1.2±8.2 degrees preoperatively, increased to 5.2±5.9 degrees postoperatively (P<0.001), and decreased to 1.2±6.2 degrees at follow-up (P=0.005). CL was 8.5±12.5 degrees preoperatively, increased to 10.8±12.4 degrees postoperatively (P=0.018), and maintained at 10.9±11.2 degrees at follow-up (P=0.030). Sagittal vertical axis, C7S, T1S, and C7S-CL did not change significantly. Significant increases in disk heights were achieved postoperatively (P<0.001). Fusion rate was 98.9% at follow-up. PROs were not related to radiologic measurements. Maintaining or increasing CL or SL was not related to a greater degree of improvement in PROs. CONCLUSIONS: Two-level ACDF restored segmental and global CL, but changes in cervical sagittal alignment did not correlate with the magnitude of improvement in PROs. Adequate decompression with solid fusion remains fundamental to achieving good clinical outcomes in patients with degenerative cervical disease.
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Lordosis , Fusión Vertebral , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Discectomía , Humanos , Lordosis/diagnóstico por imagen , Lordosis/cirugía , Medición de Resultados Informados por el Paciente , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To determine the relationship between cervical sagittal balance and adjacent segment degeneration (ASD) development after 3-level anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: ASD is a common complication after ACDF. Previous studies have shown that sagittal imbalance may be associated with ASD development after 1-level or 2-level ACDF. However, these findings may not be generalizable to 3-level procedures. MATERIALS AND METHODS: We reviewed prospectively collected data of 46 patients who underwent 3-level ACDF at a tertiary institution. Lateral cervical radiographs taken preoperatively, postoperatively, and at last follow-up were reviewed for ASD. The mean follow-up duration was 5 years. Radiographic parameters measured were cervical sagittal alignment (CSA), segmental sagittal alignment, T1 slope (T1S), sagittal vertical axis, and T1S-cervical lordosis. RESULTS: ASD was present in 27 (58.7%) patients, but only 1 patient (2.2%) underwent reoperation at 4.8 years. The CSA, sagittal vertical axis, and T1S were similar preoperatively, but the T1S-cervical lordosis was higher in the ASD group (18.28 vs. 9.82, P =0.016). All 4 parameters were similar postoperatively and at last follow-up. The ASD group had a greater change in CSA over the follow-up period (-6.26 vs. -1.47, P =0.05), but they achieved similar sagittal alignment at last follow-up. There was no difference in clinical outcomes between the 2 groups. CONCLUSIONS: Unlike studies on 1-level and 2-level ACDF, this study found that cervical spinal alignment was not associated with ASD development after 3-level ACDF. ASD development also had no impact on clinical outcomes at 2 years. LEVEL OF EVIDENCE: Level III-nonrandomized cohort study.
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OBJECTIVE: To evaluate rates of complications in patients with bilateral femur fractures treated with intramedullary nailing (IMN) during either 1 single procedure or 2 separate procedures. DESIGN: A multicenter retrospective review of patients sustaining bilateral femur fractures, treated with IMN in single or 2-stage procedure, from 1998 to 2018 was performed at 10 Level-1 trauma centers. SETTING: Ten Level-1 trauma centers. PATIENTS/PARTICIPANTS: Two hundred forty-six patients with bilateral femur fractures. INTERVENTIONS: Intramedullary nailing. MAIN OUTCOME MEASURES: Incidence of complications. RESULTS: A total of 246 patients were included, with 188 single-stage and 58 two-stage patients. Gender, age, injury severity score, abbreviated injury score, secondary injuries, Glasgow coma scale, and proportion of open fractures were similar between both groups. Acute respiratory distress syndrome (ARDS) occurred at higher rates in the 2-stage group (13.8% vs. 5.9%; P value = 0.05). When further adjusted for age, gender, injury severity score, abbreviated injury score, Glasgow coma scale, and admission lactate, the single-stage group had a 78% reduced risk for ARDS. In-hospital mortality was higher in the single-stage cohort (2.7% compared with 0%), although this did not meet statistical significance (P = 0.22). CONCLUSIONS: This is the largest multicenter study to date evaluating the outcomes between single- and 2-stage IMN fixation for bilateral femoral shaft fractures. Single-stage bilateral femur IMN may decrease rates of ARDS in polytrauma patients who are able to undergo simultaneous definitive fixation. However, a future prospective study with standardized protocols in place will be required to discern whether single- versus 2-stage fixation has an effect on mortality and to identify those individuals at risk. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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Fracturas del Fémur , Fijación Intramedular de Fracturas , Fracturas del Fémur/diagnóstico por imagen , Fracturas del Fémur/cirugía , Fémur , Fijación Intramedular de Fracturas/efectos adversos , Humanos , Estudios Prospectivos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
INTRODUCTION: The purpose of our study was to evaluate the factors that influence the timing of definitive fixation in the management of bilateral femoral shaft fractures and the outcomes for patients with these injuries. METHODS: Patients with bilateral femur fractures treated between 1998 to 2019 at ten level-1 trauma centers were retrospectively reviewed. Patients were grouped into early or delayed fixation, which was defined as definitive fixation of both femurs within or greater than 24 hours from injury, respectively. Statistical analysis included reversed logistic odds regression to predict which variable(s) was most likely to determine timing to definitive fixation. The outcomes included age, sex, high-volume institution, ISS, GCS, admission lactate, and admission base deficit. RESULTS: Three hundred twenty-eight patients were included; 164 patients were included in the early fixation group and 164 patients in the delayed fixation group. Patients managed with delayed fixation had a higher Injury Severity Score (26.8 vs 22.4; p<0.01), higher admission lactate (4.4 and 3.0; p<0.01), and a lower Glasgow Coma Scale (10.7 vs 13; p<0.01). High-volume institution was the most reliable influencer for time to definitive fixation, successfully determining 78.6% of patients, followed by admission lactate, 64.4%. When all variables were evaluated in conjunction, high-volume institution remained the strongest contributor (X2 statistic: institution: 45.6, ISS: 8.83, lactate: 6.77, GCS: 0.94). CONCLUSION: In this study, high-volume institution was the strongest predictor of timing to definitive fixation in patients with bilateral femur fractures. This study demonstrates an opportunity to create a standardized care pathway for patients with these injuries. LEVEL OF EVIDENCE: Level III.
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Fracturas del Fémur , Traumatismo Múltiple , Fracturas del Fémur/diagnóstico por imagen , Fracturas del Fémur/cirugía , Fémur , Humanos , Puntaje de Gravedad del Traumatismo , Estudios Retrospectivos , Centros TraumatológicosRESUMEN
BACKGROUND AND PURPOSE: Intraoperative monitoring of the motor pathways is a routine procedure for ensuring the integrity of descending motor tracts during spinal surgery. Intraoperative motor evoked potential improvement (MEPI) may be associated with a better postsurgical outcome in cervical spondylotic myelopathy (CSM). To compare the efficacy of two cortical stimulation parameters in eliciting MEPI intraoperatively during CSM surgery. METHODS: We studied 69 patients who underwent decompression surgery for CSM over a 9-month period using either 5 (Group 1) or 9 (Group 2) stimuli. MEPI was defined as the increase in the amplitude of MEPs from baseline at the end of CSM surgery just prior to skin closure. RESULTS: An MEPI of 100% from baseline was observed in 10 patients (53%) in Group 1 and 36 patients (72%) in Group 2. Comparisons of the baseline mean MEP amplitudes of muscles bilaterally between Groups 1 and 2 did not reveal any significant differences. Supramaximal stimulation showed that a significantly higher mean intensity was required for Group 1 than for Group 2. CONCLUSIONS: MEPI is observed in a much larger proportion of cervical decompression surgery cases than previously thought. Intraoperative MEPI with longer-train cortical stimulation may reflect adequacy of decompression and provide additional guidance for the surgical procedure.
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In the crystal structure of the complex between the soluble extracellular domain of tissue factor (sTF) and active-site-inhibited VIIa, residues 91 and 92 in the Pro(79)-Pro(92) loop of sTF interact with the catalytic domain of VIIa. It is not known, however, whether this loop has a role in allosteric activation of VIIa. Time-resolved fluorescence anisotropy measurements of probes covalently bound to sTF mutants E84C and T121C show that binding uninhibited Factor VIIa affects segmental motions in sTF. Glu(84) resides in the Pro(79)-Pro(92) loop, and Thr(121) resides in the turn between the first and second antiparallel beta-strands of the sTF subdomain that interacts with the Gla and EGF1 domains of VIIa; neither Glu(84) nor Thr(121) makes direct contact with VIIa. Probes bound to T121C report limited segmental flexibility in free sTF, which is lost after VIIa binding. Probes bound to E84C report substantial segmental flexibility in the Pro(79)-Pro(92) loop in free sTF, which is greatly reduced after VIIa binding. Thus, VIIa binding reduces dynamic motions in sTF. In particular, the decrease in the Pro(79)-Pro(92) loop motions indicates that loop entropy has a role in the thermodynamics of the protein-protein interactions involved in allosteric control of VIIa activation.
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Factor VIIa/química , Factor VIIa/metabolismo , Tromboplastina/química , Tromboplastina/metabolismo , Polarización de Fluorescencia , Humanos , Modelos Químicos , Modelos Estadísticos , Mutación , Naftalenosulfonatos , Unión Proteica , Conformación Proteica , Espectrometría de Fluorescencia , Termodinámica , Tromboplastina/genéticaRESUMEN
E. coli Integration host factor (IHF) condenses the bacterial nucleoid by wrapping DNA. Previously, we showed that DNA flexibility compensates for structural characteristics of the four consensus recognition elements associated with specific binding (Aeling et al., J. Biol. Chem. 281, 39236-39248, 2006). If elements are missing, high-affinity binding occurs only if DNA deformation energy is low. In contrast, if all elements are present, net binding energy is unaffected by deformation energy. We tested two hypotheses for this observation: in complexes containing all elements, (1) stiff DNA sequences are less bent upon binding IHF than flexible ones; or (2) DNA sequences with differing flexibility have interactions with IHF that compensate for unfavorable deformation energy. Time-resolved Förster resonance energy transfer (FRET) shows that global topologies are indistinguishable for three complexes with oligonucleotides of different flexibility. However, pressure perturbation shows that the volume change upon binding is smaller with increasing flexibility. We interpret these results in the context of Record and coworker's model for IHF binding (J. Mol. Biol. 310, 379-401, 2001). We propose that the volume changes reflect differences in hydration that arise from structural variation at IHF-DNA interfaces while the resulting energetic compensation maintains the same net binding energy.
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ADN/química , Proteínas de Escherichia coli/química , Factores de Integración del Huésped/química , Sitios de Unión , Ensayo de Cambio de Movilidad Electroforética , Transferencia Resonante de Energía de Fluorescencia , Presión Hidrostática , Modelos Moleculares , Conformación de Ácido Nucleico , Unión Proteica , Cloruro de Sodio/químicaRESUMEN
The series of complexes [XRu(CO)(L-L)(L')2][PF6] (X = H, TFA, Cl; L-L = 2,2'-bipyridyl, 1,10-phenanthroline, 5-amino-1,10-phenanthroline and 4,4'-dicarboxylic-2,2'-bipyridyl; L'2 = 2PPh3, Ph2 PC2H4PPh2, Ph2PCHâCHPPh2) have been synthesized from the starting complex K[Ru(CO)3(TFA)3] (TFA = CF3CO2) by first reacting with the phosphine ligand, followed by reaction with the L-L and anion exchange with NaPF6. In the case of L-L = phenanthroline and L'2 = 2PPh3, the neutral complex Ru(Ph3P)(CO)(1,10-phenanthroline)( TFA)2 is also obtained and its solid state structure is reported. Solid state structures are also reported for the cationic complexes where L-L = phenanthroline, L2 = 2PPh3 and X = Cl and for L-L = 2,2'-bipyridyl, L2 = 2PPh3 and X = H. All the complexes were characterized in solution by a combination of 1H and 31P NMR, IR, mass spectrometry and elemental analyses. The purpose of the project was to synthesize a series of complexes that exhibit a range of excited-state lifetimes and that have large Stokes shifts, high quantum yields and high intrinsic polarizations associated with their metal-to-ligand charge-transfer (MLCT) emissions. To a large degree these goals have been realized in that excited-state lifetimes in the range of 100 ns to over 1 µs are observed. The lifetimes are sensitive to both solvent and the presence of oxygen. The measured quantum yields and intrinsic anisotropies are higher than for previously reported Ru(II) complexes. Interestingly, the neutral complex with one phosphine ligand shows no MLCT emission. Under the conditions of synthesis some of the initially formed complexes with X = TFA are converted to the corresponding hydrides or in the presence of chlorinated solvents to the corresponding chlorides, testifying to the lability of the TFA Ligand. The compounds show multiple reduction potentials which are chemically and electrochemically reversible in a few cases as examined by cyclic voltammetry. The relationships between the observed photophysical properties of the complexes and the nature of the ligands on the Ru(II) is discussed.
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Both neointimal hyperplasia and inward remodeling contribute to restenosis and lumen loss. Nogo-B has been recently described as an inhibitor of vascular injury and neointimal hyperplasia. To determine whether Nogo-B expression may be a mediator of inward remodeling, we examine the localization of expression of Nogo-B in an in vivo model that examines both neointimal hyperplasia and inward remodeling. The rabbit carotid artery was subjected to balloon injury, outflow branch ligation to reduce flow, or both balloon injury and reduction in flow. In balloon injury-induced neointimal hyperplasia Nogo-B expression was reduced in the intima and media but stimulated in the adventitia. In low flow-induced inward remodeling medial Nogo-B expression was not reduced and adventitial Nogo-B expression was not stimulated. Low flow significantly augmented balloon injury-induced neointimal hyperplasia and was accompanied by reduced intimal and medial Nogo-B expression, and increased adventitial Nogo-B expression in both smooth muscle cells and macrophages. Low flow-induced inward remodeling is not associated with changes in medial Nogo-B expression and is distinct from injury-induced neointimal hyperplasia. Pharmacological strategies to inhibit neointimal hyperplasia and restenosis using normal flow models may only partially account for lumen loss and therefore may not accurately predict responses in patients with extensive outflow disease.
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Arterias Carótidas/patología , Estenosis Carotídea/patología , Proteínas de la Mielina/análisis , Túnica Íntima/patología , Túnica Media/patología , Animales , Apoptosis , Biomarcadores/análisis , Velocidad del Flujo Sanguíneo , Arterias Carótidas/química , Arterias Carótidas/fisiopatología , Arterias Carótidas/cirugía , Estenosis Carotídea/metabolismo , Estenosis Carotídea/fisiopatología , Cateterismo , Proliferación Celular , Tejido Conectivo/metabolismo , Tejido Conectivo/patología , Modelos Animales de Enfermedad , Hiperplasia , Ligadura , Masculino , Proteínas Nogo , Conejos , Estrés Mecánico , Resistencia a la Tracción , Túnica Íntima/química , Túnica Media/químicaRESUMEN
CONTEXT: Adolescence is the time which is crucial for the overall development of a person both mentally and physically. In this period, along with academic intelligence, emotional intelligence (EI) also plays an equal or strong role in student life. AIMS: This study was to assess EI, parental bonding, and their association among adolescents in high schools under Sarjapur PHC area. SUBJECTS AND METHODS: This was a cross-sectional study conducted among high school students under Sarjapur PHC area. The EI was assessed using EI scale which measured self-awareness, self-regulation, motivation, empathy, and social skills. The parental bonding instrument was utilized to determine the parental styles of both the parents and was interpreted in terms of care and protection as neglectful parenting, affectionless control, optimal parenting, and affectionate control. RESULTS: A total of 300 adolescents were interviewed. It was seen that most of them had low EI in self-awareness, i.e., 92 (30.7%), motivation 99 (33%), and social skills 101 (33.7%). It was also observed that most of them had high EI in self-regulation, i.e., 98 (32.7%) and moderately high EI in empathy 117 (39%). The study group perceived that 147 (49%) of the fathers and 109 (36.3%) of the mothers had affectionless control. CONCLUSION: Along with poor parenting, most of the respondents also have low EI in self-awareness, motivation, and social skills which has to be addressed for the future of the country.
RESUMEN
IMPORTANCE: Glaucoma represents a major public health challenge in an aging population. The Tanjong Pagar Eye Study reported the prevalence and risk factors of glaucoma in a Singapore Chinese population in 1997, which established the higher rates of blindness in this population. OBJECTIVES: To determine the prevalence and associated risk factors for glaucoma among Chinese adults in Singapore and to compare the results with those of the 1997 study. DESIGN, SETTING, AND PARTICIPANTS: In a population-based survey of 4605 eligible individuals, we selected 3353 Chinese adults 40 years or older from the southwestern part of Singapore. Participants underwent examination at a single tertiary care research institute from February 9, 2009, through December 19, 2011. EXPOSURES: All participants underwent slitlamp ophthalmic examination, applanation tonometry, measurement of central corneal thickness, gonioscopy, and a dilated fundus examination. MAIN OUTCOMES AND MEASURES: Glaucoma as defined by the International Society of Geographical and Epidemiological Ophthalmology guidelines and age-standardized prevalence estimates computed as per the 2010 Singapore Chinese census. Blindness was defined as logMAR visual acuity of 1.00 (Snellen equivalent, 20/200 or worse). RESULTS: Of the 3353 respondents, 134 (4.0%) had glaucoma, including primary open-angle glaucoma (POAG) in 57 (1.7%), primary angle-closure glaucoma (PACG) in 49 (1.5%), and secondary glaucoma in 28 (0.8%). The age-standardized prevalence (95% CI) of glaucoma was 3.2% (2.7%-3.9%); POAG, 1.4% (1.1%-1.9%); and PACG, 1.2% (0.9%-1.6%). In a multivariate model, POAG was associated with being older and male and having a higher intraocular pressure. Of the 134 participants with glaucoma, 114 (85.1%; 95% CI, 78.1%-90.1%) were not aware of their diagnosis. Prevalence (95% CI) of blindness caused by secondary glaucoma was 14.3% (5.7%-31.5%), followed by 10.2% (4.4%-21.8%) for PACG and 8.8% (3.8%-18.9%) for POAG. We could not identify a difference in the prevalence of glaucoma compared with the 3.2% reported in 1997 (difference, -0.04%; 95% CI, -1.2 to 1.2; P = .97). CONCLUSIONS AND RELEVANCE: The prevalence of glaucoma among Singapore Chinese likely ranges from 2.7% to 3.9%, with secondary glaucoma being the most visually debilitating type. We could not identify a difference compared with previous studies approximately 12 years earlier. We report a high proportion of previously undiagnosed disease, suggesting the need to increase public awareness of this potentially blinding condition.
Asunto(s)
Pueblo Asiatico/etnología , Glaucoma/clasificación , Glaucoma/etnología , Población Urbana/estadística & datos numéricos , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Glaucoma/diagnóstico , Gonioscopía , Humanos , Presión Intraocular , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Distribución por Sexo , Singapur/epidemiología , Encuestas y Cuestionarios , Tonometría Ocular , Agudeza Visual/fisiologíaRESUMEN
Cardiocutaneous fistulas arising from pledgets used in the closure of resected left ventricular aneurysms are rare but have serious implications. The case histories of four patients, each managed in a somewhat different manner, are presented. From this experience we recommend an aggressive approach to remove the infected pledgets once scar formation is complete and before erosion of the pledgets into the left ventricular cavity can occur.