276 research outputs found
Unique growth pattern of human mammary epithelial cells induced by polymeric nanoparticles.
Due to their unique properties, engineered nanoparticles (NPs) have found broad use in industry, technology, and medicine, including as a vehicle for drug delivery. However, the understanding of NPs' interaction with different types of mammalian cells lags significantly behind their increasing adoption in drug delivery. In this study, we show unique responses of human epithelial breast cells when exposed to polymeric Eudragit® RS NPs (ENPs) for 1-3 days. Cells displayed dose-dependent increases in metabolic activity and growth, but lower proliferation rates, than control cells, as evidenced in tetrazolium salt (WST-1) and 5-bromo-2'-deoxyuridine (BrdU) assays, respectively. Those effects did not affect cell death or mitochondrial fragmentation. We attribute the increase in metabolic activity and growth of cells culture with ENPs to three factors: (1) high affinity of proteins present in the serum for ENPs, (2) adhesion of ENPs to cells, and (3) activation of proliferation and growth pathways. The proteins and genes responsible for stimulating cell adhesion and growth were identified by mass spectrometry and Microarray analyses. We demonstrate a novel property of ENPs, which act to increase cell metabolic activity and growth and organize epithelial cells in the epithelium as determined by Microarray analysis
A tailored hybrid BODIPY–oligothiophene donor for molecular bulk heterojunction solar cells with improved performances
Fixation of a 5-hexyl-2,2′-bithienyl unit on a conjugated BODIPY donor increases the conversion efficiency of the resulting molecular bulk heterojunction solar cells from 1.30 to 2.20%
The influence of obesity on the outcome of treatment of lumbar disc herniation: analysis of the Spine Patient Outcomes Research Trial (SPORT).
BACKGROUND: Questions remain as to the effect that obesity has on patients managed for symptomatic lumbar disc herniation. The purpose of this study was to determine if obesity affects outcomes following the treatment of symptomatic lumbar disc herniation.
METHODS: An as-treated analysis was performed on patients enrolled in the Spine Patient Outcomes Research Trial for the treatment of lumbar disc herniation. A comparison was made between patients with a body mass index of/m² (nonobese) (n = 854) and those with a body mass index of ≥30 kg/m² (obese) (n = 336). Baseline patient demographic and clinical characteristics were documented. Primary and secondary outcomes were measured at baseline and at regular follow-up time intervals up to four years. The difference in improvement from baseline between operative and nonoperative treatment was determined at each follow-up period for both groups.
RESULTS: At the time of the four-year follow-up evaluation, improvements over baseline in primary outcome measures were significantly less for obese patients as compared with nonobese patients in both the operative treatment group (Short Form-36 physical function, 37.3 compared with 47.7 points [p \u3c 0.001], Short Form-36 bodily pain, 44.2 compared with 50.0 points [p = 0.005], and Oswestry Disability Index, -33.7 compared with -40.1 points [p \u3c 0.001]) and the nonoperative treatment group (Short Form-36 physical function, 23.1 compared with 32.0 points [p \u3c 0.001] and Oswestry Disability Index, -21.4 compared with -26.1 points [p \u3c 0.001]). The one exception was that the change from baseline in terms of the Short Form-36 bodily pain score was statistically similar for obese and nonobese patients in the nonoperative treatment group (30.9 compared with 33.4 points [p = 0.39]). At the time of the four-year follow-up evaluation, when compared with nonobese patients who had been managed operatively, obese patients who had been managed operatively had significantly less improvement in the Sciatica Bothersomeness Index and the Low Back Pain Bothersomeness Index, but had no significant difference in patient satisfaction or self-rated improvement. In the present study, 77.5% of obese patients and 86.9% of nonobese patients who had been managed operatively were working a full or part-time job. No significant differences were observed in the secondary outcome measures between obese and nonobese patients who had been managed nonoperatively. The benefit of surgery over nonoperative treatment was not affected by body mass index.
CONCLUSIONS: Obese patients realized less clinical benefit from both operative and nonoperative treatment of lumbar disc herniation. Surgery provided similar benefit over nonoperative treatment in obese and nonobese patients
Semi-conducteurs Isotropes et Stables pour Cellules solaires Organiques
Date du colloque : 03/2011</p
Duration of symptoms resulting from lumbar disc herniation: effect on treatment outcomes: analysis of the Spine Patient Outcomes Research Trial (SPORT).
BACKGROUND: The purpose of the present study was to determine if the duration of symptoms affects outcomes following the treatment of intervertebral lumbar disc herniation.
METHODS: An as-treated analysis was performed on patients enrolled in the Spine Patient Outcomes Research Trial (SPORT) for the treatment of intervertebral lumbar disc herniation. Randomized and observational cohorts were combined. A comparison was made between patients who had had symptoms for six months or less (n = 927) and those who had had symptoms for more than six months (n = 265). Primary and secondary outcomes were measured at baseline and at regular follow-up intervals up to four years. The treatment effect for each outcome measure was determined at each follow-up period for the duration of symptoms for both groups.
RESULTS: At all follow-up intervals, the primary outcome measures were significantly worse in patients who had had symptoms for more than six months prior to treatment, regardless of whether the treatment was operative or nonoperative. When the values at the time of the four-year follow-up were compared with the baseline values, patients in the operative treatment group who had had symptoms for six months or less had a greater increase in the bodily pain domain of the Short Form-36 (SF-36) (mean change, 48.3 compared with 41.9; p \u3c 0.001), a greater increase in the physical function domain of the SF-36 (mean change, 47.7 compared with 41.2; p \u3c 0.001), and a greater decrease in the Oswestry Disability Index score (mean change, -41.1 compared with -34.6; p \u3c 0.001) as compared with those who had had symptoms for more than six months (with higher scores indicating less severe symptoms on the SF-36 and indicating more severe symptoms on the Oswestry Disability Index). When the values at the time of the four-year follow-up were compared with the baseline values, patients in the nonoperative treatment group who had had symptoms for six months or less had a greater increase in the bodily pain domain of the SF-36 (mean change, 31.8 compared with 21.4; p \u3c 0.001), a greater increase in the physical function domain of the SF-36 (mean change, 29.5 compared with 22.6; p = 0.015), and a greater decrease in the Oswestry Disability Index score (mean change, -24.9 compared with -18.5; p = 0.006) as compared with those who had had symptoms for more than six months. Differences in treatment effect between the two groups related to the duration of symptoms were not significant.
CONCLUSIONS: Increased symptom duration due to lumbar disc herniation is related to worse outcomes following both operative and nonoperative treatment. The relative increased benefit of surgery compared with nonoperative treatment was not dependent on the duration of the symptoms
Effectiveness of Surgery for Lumbar Stenosis and Degenerative Spondylolisthesis in the Octogenarian Population: Analysis of the Spine Patient Outcomes Research Trial (SPORT) Data.
BACKGROUND: The purpose of this study was to determine whether surgery is an effective option for the treatment of stenosis of the lumbar spine and degenerative spondylolisthesis in the octogenarian population.
METHODS: An as-treated analysis of patients with lumbar stenosis and degenerative spondylolisthesis enrolled in the Spine Patient Outcomes Research Trial (SPORT) was performed. Patients who were at least eighty years of age (n = 105) were compared with those younger than eighty years (n = 1130). Baseline patient and clinical characteristics were noted, and the difference in improvement from baseline between operative and nonoperative treatment was determined for each group at each follow-up time period up to four years.
RESULTS: There were no significant baseline differences in the primary or secondary patient-reported clinical outcome measures between the two patient age groups. Patients at least eighty years of age had higher prevalences of multilevel stenosis, severe stenosis, and asymmetric motor weakness. Patients at least eighty years of age also had higher prevalences of hypertension, heart disease, osteoporosis, and joint problems at baseline, but they had a lower body mass index and lower prevalences of depression and smoking. Fifty-eight of the 105 patients at least eighty years of age and 749 of the 1130 younger patients underwent operative management. There were no differences in the rates of intraoperative or postoperative complications, reoperation, or postoperative mortality between the older and younger groups. Averaged over a four-year follow-up period, operatively treated patients at least eighty years of age had significantly greater improvement in all primary and secondary outcome measures compared with nonoperatively treated patients. The treatment effects in patients at least eighty years of age were similar to those in younger patients for all primary and secondary measures except the SF-36 (Short Form-36) bodily pain domain and the percentage who self-rated their progress as a major improvement, in both of which the treatment effect was significantly smaller.
CONCLUSIONS: Operative treatment of lumbar stenosis and degenerative spondylolisthesis offered a significant benefit over nonoperative treatment in patients at least eighty years of age (p \u3c 0.05). There were no significant increases in the complication and mortality rates following surgery in this patient population compared with younger patients (p \u3e 0.05).
LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence
Does the load-sharing classification predict ligamentous injury, neurological injury, and the need for surgery in patients with thoracolumbar burst fractures?: Clinical article.
OBJECT: The load-sharing score (LSS) of vertebral body comminution is predictive of results after short-segment posterior instrumentation of thoracolumbar burst fractures. Some authors have posited that an LSS \u3e 6 is predictive of neurological injury, ligamentous injury, and the need for surgical intervention. However, the authors of the present study hypothesized that the LSS does not predict ligamentous or neurological injury.
METHODS: The prospectively collected spinal cord injury database from a single institution was queried for thoracolumbar burst fractures. Study inclusion criteria were acute (\u3c 24 hours) burst fractures between T-10 and L-2 with preoperative CT and MRI. Flexion-distraction injuries and pathological fractures were excluded. Four experienced spine surgeons determined the LSS and posterior ligamentous complex (PLC) integrity. Neurological status was assessed from a review of the medical records.
RESULTS: Forty-four patients were included in the study. There were 4 patients for whom all observers assigned an LSS \u3e 6, recommending operative treatment. Eleven patients had LSSs ≤ 6 across all observers, suggesting that nonoperative treatment would be appropriate. There was moderate interobserver agreement (0.43) for the overall LSS and fair agreement (0.24) for an LSS \u3e 6. Correlations between the LSS and the PLC score averaged 0.18 across all observers (range -0.02 to 0.34, p value range 0.02-0.89). Correlations between the LSS and the American Spinal Injury Association motor score averaged -0.12 across all observers (range -0.25 to -0.03, p value range 0.1-0.87). Correlations describing the relationship between an LSS \u3e 6 and the treating physician\u27s decision to operate averaged 0.17 across all observers (range 0.11-0.24, p value range 0.12-0.47).
CONCLUSIONS: The LSS does not uniformly correlate with the PLC injury, neurological status, or empirical clinical decision making. The LSSs of only one observer correlated significantly with PLC injury. There were no significant correlations between the LSS as determined by any observer and neurological status or clinical decision making
Anatomical relationships of the anterior blood vessels to the lower lumbar intervertebral discs: analysis based on magnetic resonance imaging of patients in the prone position.
BACKGROUND: Intra-abdominal vascular injuries are rare during posterior lumbar spinal surgery, but they can result in major morbidity or mortality when they do occur. We are aware of no prior studies that have used prone patient positioning during magnetic resonance imaging for the purpose of characterizing the retroperitoneal iliac vasculature with respect to the intervertebral disc. The purpose of this study was to define the vascular anatomy adjacent to the lower lumbar spine with use of supine and prone magnetic resonance imaging.
METHODS: A prospective observational study included thirty patients without spinal abnormality who underwent supine and prone magnetic resonance imaging without abdominal compression. The spinal levels of the aortic bifurcation and confluence of the common iliac veins were identified. The proximity of the anterior iliac vessels to the anterior and posterior aspects of the anulus fibrosus in sagittal and coronal planes was measured by two observers, and interobserver reliability was calculated.
RESULTS: The aortic bifurcation and confluence of the common iliac veins were most commonly at the level of the L4 vertebral body and migrated cranially with prone positioning. The common iliac vessels were closer to the anterior aspect of the intervertebral disc and to the midline at L4-L5 as compared with L5-S1, consistent with the bifurcation at the L4 vertebral body. Prone positioning resulted in greater distances between the disc and iliac vessels at L4-L5 and L5-S1 by an average of 3 mm. The position of the anterior aspect of the anulus with respect to each iliac vessel demonstrated substantial variation between subjects. The intraclass correlation coefficient for measurement of vessel position exceeded 0.9, demonstrating excellent interobserver reliability.
CONCLUSIONS: This study confirmed the L4 level of the aortic bifurcation and iliac vein coalescence but also demonstrated substantial mobility of the great vessels with positioning. Supine magnetic resonance imaging will underestimate the proximity of the vessels to the intervertebral disc. Large interindividual variation in the location of vasculature was noted, emphasizing the importance of careful study of the location of the retroperitoneal vessels on a case-by-case basis.
CLINICAL RELEVANCE: Anatomic relationships between vessels and intervertebral discs on supine magnetic resonance imaging may differ from relationships during surgery with the patient in a prone position
Circularly polarized luminescence from helically chiral N,N,O,O-boron-chelated dipyrromethenes
Helically chiral N,N,O,O-boron chelated dipyrromethenes showed solution-phase circularly polarized luminescence (CPL) in the red region of the visible spectrum (λem(max) from 621 to 663 nm). The parent dipyrromethene is desymmetrised through O chelation of boron by the 3,5-ortho-phenolic substituents, inducing a helical chirality in the fluorophore. The combination of high luminescence dissymmetry factors (|glum| up to 4.7 ×10−3) and fluorescence quantum yields (ΦF up to 0.73) gave exceptionally efficient circularly polarized red emission from these simple small organic fluorophores, enabling future application in CPL-based bioimaging
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