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1.
Pretreatment with intravenous fish oil reduces hepatic ischemia reperfusion injury in a murine model
Meredith A. Baker Prathima Nandivada Paul D. Mitchell Gillian L. Fell Amy Pan Lorenzo Anez-Bustillos Duy T. Dao Kathleen M. Gura Vania Nosé Mark Puder 《Surgery》2018,163(5):1035-1039
Background
Ischemia reperfusion injury is a barrier to liver surgery and transplantation, particularly for steatotic livers. The purpose of this study was to determine if pretreatment with a single dose of intravenous fish oil decreases hepatic ischemia reperfusion injury and improves recovery of injured livers.Methods
Sixty adult male C57BL/6 mice received 1?g/kg intravenous fish oil (Omegaven, Fresenius Kabi) or isovolumetric 0.9% NaCl (saline) via tail vein 1 hour before 30 minutes of 70% hepatic ischemia. Animals were killed 4, 8, or 24 hours postreperfusion, and livers were harvested for histologic analysis.Results
Four hours postreperfusion, saline-treated livers demonstrated marked ischemia diffusely around the central veins, while intravenous fish oil–treated livers demonstrated only patchy necrosis with intervening normal parenchyma. Eight hours postreperfusion, all livers demonstrated pale areas of cell loss with surrounding regenerating hepatocytes. Ki67 staining confirmed 14.4/10 high-powered field (95% confidence interval, 3.2–25.6) more regenerating hepatocytes around areas of necrosis in intravenous fish oil–treated livers. Twenty-four hours postreperfusion, all livers demonstrated patchy areas of necrosis, with an 89% (95% confidence interval, 85–92) decrease in the area of necrosis in intravenous fish oil–treated livers.Conclusion
Intravenous fish oil treatment prior to hepatic ischemia reperfusion injury decreased the area of hepatic necrosis and increased hepatocyte regeneration compared to saline treatment in a mouse model. 相似文献2.
Juan C. Duque Marwan Tabbara Laisel Martinez Angela Paez Guillermo Selman Loay H. Salman Omaida C. Velazquez Roberto I. Vazquez-Padron 《Surgery》2018,163(4):866-869
Background
Intimal hyperplasia has been historically associated with improper venous remodeling and stenosis after creation of an arteriovenous fistula. Recently, however, we showed that intimal hyperplasia by itself does not explain the failure of maturation of 2-stage arteriovenous fistulas. We seek to evaluate whether intimal hyperplasia plays a role in the development of focal stenosis of an arteriovenous fistula.Methods
This study compares intimal hyperplasia lesions in stenotic and nearby nonstenotic segments collected from the same arteriovenous fistula. Focal areas of stenosis were detected in the operating room in patients (n?=?14) undergoing the second-stage vein transposition procedure. The entire vein was inspected, and areas of stenosis were visually located with the aid of manual palpation and hemodynamic changes in the vein peripheral and central to the narrowing. Stenotic and nonstenotic segments were documented by photography before tissue collection (14 tissue pairs). Intimal area and thickness, intima-media thickness, and intima to media area ratio were measured in hematoxylin and eosin stained cross-sections followed by pairwise statistical comparisons.Results
The intimal area in stenotic and nonstenotic segments ranged from 1.25 to 11.61?mm2 and 1.29 to 5.81?mm2, respectively. There was no significant difference between these 2 groups (P?=?.26). Maximal intimal thickness (P?=?.22), maximal intima-media thickness (P?=?.13), and intima to media area ratio (P?=?.73) were also similar between both types of segments.Conclusion
This preliminary study indicates that postoperative intimal hyperplasia by itself is not associated with the development of focal venous stenosis in 2-stage fistulas. 相似文献3.
Richard Teo Josefina C. Farrá Zahra F. Khan Andrea R. Marcadis John I. Lew 《Surgery》2018,163(2):393-396
Background
The importance of intraoperative parathormone “spikes” during parathyroidectomy remains unclear. This study compared patients with and without intraoperative parathormone spikes during parathyroidectomy using the criterion of a?>?50% parathormone and determined the effect of intraoperative parathormone spikes on operative outcome.Methods
We performed a retrospective review of prospectively collected data on 683 patients who underwent parathyroidectomy guided by intraoperative parathormone monitoring. An intraoperative parathormone “spike value” was calculated by subtracting the preincision intraoperative parathormone value from the pre-excision intraoperative parathormone value (SV?=?PE???PI). An intraoperative parathormone spike was defined as having a positive spike value ≥9?pg/mL (≥10th percentile of all spike values).Results
Of 683 patients, 224 (33%) had intraoperative parathormone spikes and a greater rate of multiglandular disease (8% vs. 3%, P?<?0.05) and bilateral neck exploration (10% vs. 5%, P?<?0.05) compared with patients without intraoperative parathormone spikes. Overall, there were no differences between parathyroidectomy patients with and without intraoperative parathormone spikes in terms of operative success (98.2% vs. 98.0%), failure (1.8% vs. 2.0%), or recurrence rates (0.4% vs. 1.3%).Conclusions
Although the presence of intraoperative parathormone spikes may increase suspicion for multiglandular disease, the ability of intraoperative parathormone monitoring to predict operative success after parathyroidectomy is not affected by spikes. 相似文献4.
Andrea R. Marcadis Richard Teo Wenqi Ouyang Josefina C. Farrá John I. Lew 《Surgery》2018,163(3):633-637
Background
The effect of altered parathyroid hormone metabolism in renal insufficiency on intraoperative parathyroid hormone monitoring during parathyroidectomy is not well known. This study evaluates operative outcomes in patients undergoing parathyroidectomy guided by intraoperative parathyroid hormone monitoring for primary hyperparathyroidism with mild and moderate renal insufficiency.Methods
A retrospective review of prospectively collected data in 604 patients with sporadic primary hyperparathyroidism undergoing parathyroidectomy guided by intraoperative parathyroid hormone monitoring was performed. Patients were stratified by stage of chronic kidney disease (CKD); those with overt secondary hyperparathyroidism (CKD stages IV and V) were excluded. Rates of bilateral neck exploration, multiglandular disease, and long-term operative outcomes, including success, failure, and recurrence were compared.Results
Of the 604 patients, 38% (230/604) had normal renal function or stage I CKD, 44% (268/604) had stage II CKD, and 18% (106/604) had stage III CKD. Overall, there were no differences in the rates of bilateral neck exploration or multiglandular disease or in rates of operative success, failure, or recurrence in patients with normal renal function and stages I to III CKD.Conclusion
Parathyroidectomy guided by intraoperative parathyroid hormone monitoring is performed with high operative success uniformly in primary hyperparathyroidism patients with mild and moderate renal insufficiency with outcomes similar to those with normal renal function. 相似文献5.
Tsuyoshi Yokoi Yukihiro Yokoyama Toshio Kokuryo Junpei Yamaguchi Masato Nagino 《Surgery》2018,163(2):270-276
Background
The objective of this study was to elucidate whether the inhibition of Toll-like receptor 4 attenuates liver injury ischemia/reperfusion in the cholestatic liver.Method
Rats were assigned into sham, bile duct ligation, sham ischemia/reperfusion (ischemia/reperfusion after laparotomy), and bile duct ligation ischemia/reperfusion (ischemia/reperfusion after bile duct ligation) groups. In some rats, TAK-242, an inhibitor of Toll-like receptor 4, was administered 15 minutes before ischemia/reperfusion. We measured intrahepatic Toll-like receptor 4 expression, serum hepatic marker expression, liver necrosis, gene expression of inflammation-associated factors, and serum high-mobility group box protein b1 levels.Results
Intrahepatic Toll-like receptor 4 expression was significantly greater in the bile duct ligation group than in the sham group. Toll-like receptor 4 expression was further increased after ischemia/reperfusion in bile duct ligation ischemia/reperfusion groups. The levels of serum hepatic markers were significantly greater in both the sham ischemia/reperfusion and bile duct ligation ischemia/reperfusion groups than in the groups without ischemia/reperfusion. Liver necrosis was greater in the bile duct ligation group than in the sham group and was further increased in the bile duct ligation ischemia/reperfusion group. Genomic expression of inflammation-associated factors was also significantly greater in the bile duct ligation ischemia/reperfusion group than in the sham group. Serum high-mobility groups box protein b1 levels were greater in the bile duct ligation ischemia/reperfusion group than in the sham group (28.1?ng/ml versus 9.2?ng/ml, P?=?.011) and the bile duct ligation group (28.1?ng/ml versus 10.6?ng/ml, P?=?.017). These changes in the bile duct ligation ischemia/reperfusion group were significantly attenuated by preconditioning with TAK242.Conclusions
Toll-like receptor 4 inhibition has a potential to minimize severe injury after ischemia/reperfusion in the cholestatic liver through inhibition of high-mobility groups box protein b1. 相似文献6.
Daniel Saltzman Lance Augustin Arnold Leonard Michael Mertensotto Janet Schottel 《Surgery》2018,163(3):509-514
Background
Immunotherapies for cancer treatment have demonstrated substantial promise even though toxicities and development of tumor resistance limit their effectiveness. A combinatorial approach using immunotherapy with other treatment modalities may decrease side effects while maintaining maximal therapeutic effect. We aimed to determine if bacterial immunotherapy in combination with a chemotherapeutic would be efficacious and less toxic than conventional chemotherapy in an established, preclinical, autochthonous tumor model.Methods
BALB-neuT mice develop autochthonous mammary neoplasms that resemble closely the aggressive Her2-driven cancer found in human patients. Virulence-attenuated S. Typhimurium was used for bacterial immunotherapy. Doxorubicin was the chemotherapeutic agent used at the maximum tolerated dose (5?mg/kg) and low dose (1.25?mg/kg). S. Typhimurium was administered intravenously on day 0 and doxorubicin on days 0, 7, and 14. Experiments concluded on day 35. Mammary pad tumors were measured weekly to ascertain efficacy, and mice were weighed weekly to evaluate toxicity.Results
Mice administered maximum tolerated dose doxorubicin (5?mg/kg) demonstrated a 1.4-fold increase in tumor size by day 35 and showed a nearly 25% weight loss by day 14 revealing severe toxicity. When mice were administered a single dose of S. Typhimurium combined with a low dose of doxorubicin (1.25?mg/kg), tumors increased <3-fold by day 35, and mice showed only 5% weight loss, indicating no clinically relevant toxicity.Conclusion
Bacterial immunotherapy combined with low dose chemotherapy decreased the tumor burden when compared with low dose chemotherapy alone and was less toxic than maximum tolerated dose chemotherapy in an established, autochthonous murine model of breast cancer. 相似文献7.
Xiaoling Jin Teresa A. Zimmers Yanlin Jiang Daniel P. Milgrom Zongxiu Zhang Leonidas G. Koniaris 《Surgery》2018,163(6):1264-1271
Background
Patients with fatty liver have delayed regenerative responses, increased hepatocellular injury, and increased risk for perioperative mortality. Currently, no clinical therapy exists to prevent liver failure or improve regeneration in patients with fatty liver. Previously we demonstrated that obese mice have markedly reduced levels of epidermal growth factor receptor in liver. We sought to identify pharmacologic agents to increase epidermal growth factor receptor expression to improve hepatic regeneration in the setting of fatty liver resection.Methods
Lean (20% calories from fat) and diet-induced obese mice (60% calories from fat) were subjected to 70% or 80% hepatectomy.Results
Using the BaseSpace Correlation Engine of deposited gene arrays we identified agents that increased hepatic epidermal growth factor receptor. Meloxicam was identified as inducing epidermal growth factor receptor expression across species. Meloxicam improved hepatic steatosis in diet-induced obese mice both grossly and histologically. Immunohistochemistry and Western blot analysis demonstrated that meloxicam pretreatment of diet-induced obese mice dramatically increased epidermal growth factor receptor protein expression in hepatocytes. After 70% hepatectomy, meloxicam pretreatment ameliorated liver injury and significantly accelerated mitotic rates of hepatocytes in obese mice. Recovery of liver mass was accelerated in obese mice pretreated with meloxicam (by 26% at 24 hours and 38% at 48 hours, respectively). After 80% hepatectomy, survival was dramatically increased with meloxicam treatment.Conclusion
Low epidermal growth factor receptor expression is a common feature of fatty liver disease. Meloxicam restores epidermal growth factor receptor expression in steatotic hepatocytes. Meloxicam pretreatment may be applied to improve outcome after fatty liver resection or transplantation with steatotic graft. 相似文献8.
Cyonna Holmes LaShondra Powell Nicholas S. Clarke Michael E. Jessen Matthias Peltz 《Surgery》2018,163(2):436-443
Background
The influence of diabetic therapies on myocardial substrate selection during cardiac surgery is unknown but may be important to ensure optimal surgical outcomes. We hypothesized that metformin and insulin alter myocardial substrate selection during cardiac surgery and may affect reperfusion cardiac function.Methods
Rat hearts (n?=?8 per group) were evaluated under 3 metabolic conditions: normokalemia, cardioplegia, or bypass. Groups were perfused with Krebs-Henseleit buffer in the presence of no additives, metformin, insulin, or both insulin and metformin. Perfusion buffer containing physiologic concentrations of energetic substrates with different carbon-13 (13C) labeling patterns were used to determine substrate oxidation preferences using 13C magnetic resonance spectroscopy and glutamate isotopomer analysis. Rate pressure product and oxygen consumption were measured.Results
Myocardial function was not different between groups. For normokalemia, ketone oxidation was reduced in the presence of insulin and the combination of metformin and insulin reduced fatty acid oxidation. Metformin reduced fatty acid and ketone oxidation during cardioplegia. Fatty acid oxidation was increased in the bypass group compared with all other conditions.Conclusion
Metformin and insulin affect substrate utilization and reduce fatty acid oxidation before reperfusion. These alterations in substrate oxidation did not affect myocardial function in otherwise normal hearts. 相似文献9.
Juan A. Sanchis-Gimeno Susanna Llido David Guede Francisco Martinez-Soriano Jose Ramon Caeiro Esther Blanco-Perez 《The spine journal》2017,17(3):431-434
Background Context
To date, no information about the cortical bone microstructural properties in atlas vertebrae with posterior arch defects has been reported.Purpose
To test if there is an increased cortical bone thickening in atlases with Type A posterior atlas arch defects in an experimental model.Study Design
Micro-computed tomography (CT) study on cadaveric atlas vertebrae.Methods
We analyzed the cortical bone thickness, the cortical volume, and the medullary volume (SkyScan 1172 Bruker micro-CT NV, Kontich, Belgium) in cadaveric dry vertebrae with a Type A atlas arch defect and normal control vertebrae.Results
The micro-CT study revealed significant differences in cortical bone thickness (p=.005), cortical volume (p=.003), and medullary volume (p=.009) values between the normal and the Type A vertebrae.Conclusions
Type A congenital atlas arch defects present a cortical bone thickening that may play a protective role against atlas fractures. 相似文献10.
Tianding Wu Shuangfei Ni Yong Cao Shenghui Liao Jianzhong Hu Chunyue Duan 《The spine journal》2018,18(4):663-673
Background Context
Low back pain (LBP) is more prevalent among postmenopausal women than men. Ovariectomy (OVX) is an established animal model that mimics the estrogen deficiency of postmenopausal women. Little is known about the three-dimensional (3D) morphologic properties of cartilage and subchondral bone changes in the lumbar facet joint (LFJ) of an OVX mouse model.Purpose
The purpose of this study was to characterize the 3D morphologic change of cartilage and subchondral bone in the LFJ of an OVX mouse model.Study Design
Three-dimensional visualization and a histologic study on degenerative changes in cartilage and subchondral bone in the LFJ of an OVX mouse model were conducted.Materials and Methods
Ovariectomy is performed to mimic postmenopausal changes in adult female mice. We present an imaging tool for 3D visualization of the pathologic characteristics of cartilage and subchondral bone changes LFJ degradation using propagation-based phase-contrast computed tomography (PPCT). The samples were further dissected, fixed, and stained for histologic examination.Results
Propagation-based phase-contrast computed tomography imaging provides a 3D visualization of altered cartilage with a simultaneous high detail of the subchondral bone abnormalities in an OVX LFJ model. A quantitative analysis demonstrated that the cartilage volume, the surface area, and thickness were decreased in the OVX group compared with the control group (p<.05). Meanwhile, these decreases were accompanied by an obvious destruction of the subchondral bone surface and a loss of trabecular bone in the OVX group (p<.05). The delineation of the 3D pathologic changes in the PPCT imaging was confirmed by a histopathologic method with Safranin-O staining. Tartrate-resistant acid phosphatase staining revealed an increased number of osteoclasts in the subchondral bone of the OVX mice compared with that of the control group.Conclusions
These results demonstrated that a mouse model of OVX-induced LFJ osteoarthritis (OA)-like changes was successfully established and showed a good resemblance to the human OA pathology. Propagation-based phase-contrast computed tomography has great potential to becomea powerful 3D imaging method to comprehensively characterize LFJ OA and to effectively monitor therapeutics. Moreover, degenerative LFJ possesses a severe morphologic change in the subchondral bone, may be the source of postmenopausal LBP, and has the potential to be a novel therapeutic target for LBP treatment. 相似文献11.
Audrey H. Choi Michael P. O&#x;Leary Shyambabu Chaurasiya Jianming Lu Sang-In Kim Yuman Fong Nanhai G. Chen 《Surgery》2018,163(2):336-342
Background
Triple-negative breast cancer is an aggressive subtype of breast cancer with high recurrence rate and poor prognosis. Here we describe a novel, genetically engineered parapoxvirus that efficiently kills triple-negative breast cancer.Methods
A novel chimeric parapoxvirus (CF189) was generated via homologous recombination and identified through high-throughput screening. Cytotoxicity was assayed in vitro in 4 triple-negative breast cancer cell lines. Viral replication was examined through standard plaque assay. Orthotopic triple-negative breast cancer xenografts were generated by MDA-MB-468 implantation into the 2nd and 4th mammary fat pads of athymic nude mice and treated with the virus.Results
Chimeric parapoxvirus (CF189) demonstrated dose-dependent cytotoxicity at low multiplicity of infection, with?>?80% cell death 6 days after treatment. Significant reductions in tumor size were observed 2 weeks after intratumoral injection at doses as low as 103 plaque-forming units (PFU) compared with control (P?<?0.01). In addition, abscopal effect (shrinkage of noninjected remote tumors) was clearly demonstrated.Conclusion
Chimeric parapoxvirus (CF189) demonstrated efficient cytotoxicity in vitro and potent antitumor effect in vivo at doses as low as 103 PFU. These are data encouraging of clinical development for this highly potent agent against triple-negative breast cancer. 相似文献12.
13.
Samuel Jang Meagan Mandabach Zviadi Aburjania Courtney J. Balentine Herbert Chen 《Surgery》2018,163(3):638-642
Background
Identifying hospital and provider variation in surgical cost is a potent method for controlling rising healthcare expenditure and delivering cost-effective care. The purpose of this study was to examine the variation of hospital cost by providers for parathyroidectomy in a single academic institution.Methods
We retrospectively evaluated 894 consecutive parathyroidectomies under 8 surgeons in our institution between September 2011 and July 2016. Total duration of stay and cost were evaluated using nonparametric tests. Categorical variables were evaluated with χ2.Results
The median total hospital cost for parathyroidectomy was $4,863.28 (interquartile range: 4,196–5,764), but the median costs per provider varied widely from $4,522.30 to $12,072.87. The median duration of stay was 0 days (IQR: 0–1) and demonstrated a wide variation among providers. Longer duration of practice was associated with lower cost. Despite the variation, only 2% was readmitted after discharge with no patient mortality.Conclusion
We found substantial variation in hospital cost among providers for parathyroidectomy despite practicing in the same academic institution, with some surgeons spending 4 time more for the same operation. Implementing institutional standards of practice could be a method to decrease variation and costs of surgical care. 相似文献14.
Stefan Maenz Olaf Brinkmann Elke Kunisch Victoria Horbert Francesca Gunnella Sabine Bischoff Harald Schubert Andre Sachse Long Xin Jens Günster Bernhard Illerhaus Klaus D. Jandt Jörg Bossert Raimund W. Kinne Matthias Bungartz 《The spine journal》2017,17(5):709-719
Background Context
Injectable, brushite-forming calcium phosphate cements (CPC) show potential for bone replacement, but they exhibit low mechanical strength. This study tested a CPC reinforced with poly(l-lactide-co-glycolide) acid (PLGA) fibers in a minimally invasive, sheep lumbar vertebroplasty model.Purpose
The study aimed to test the in vivo biocompatibility and osteogenic potential of a PLGA fiber-reinforced, brushite-forming CPC in a sheep large animal model.Study Design/Setting
This is a prospective experimental animal study.Methods
Bone defects (diameter: 5?mm) were placed in aged, osteopenic female sheep, and left empty (L2) or injected with pure CPC (L3) or PLGA fiber-reinforced CPC (L4; fiber diameter: 25?µm; length: 1?mm; 10% [wt/wt]). Three and 9 months postoperation (n=20 each), the structural and functional CPC effects on bone regeneration were documented ex vivo by osteodensitometry, histomorphometry, micro-computed tomography (micro-CT), and biomechanical testing.Results
Addition of PLGA fibers enhanced CPC osteoconductivity and augmented bone formation. This was demonstrated by (1) significantly enhanced structural (bone volume/total volume, shown by micro-CT and histomorphometry; 3 or 9 months) and bone formation parameters (osteoid volume and osteoid surface; 9 months); (2) numerically enhanced bone mineral density (3 and 9 months) and biomechanical compression strength (9 months); and (3) numerically decreased bone erosion (eroded surface; 3 and 9 months).Conclusions
The PLGA fiber-reinforced CPC is highly biocompatible and its PLGA fiber component enhanced bone formation. Also, PLGA fibers improve the mechanical properties of brittle CPC, with potential applicability in load-bearing areas. 相似文献15.
Fábio A. Araújo Ana Martins Nuno Alegrete Laura D. Howe Raquel Lucas 《The spine journal》2017,17(10):1426-1434
Background Context
In each specific habitual standing posture, gravitational forces determine the mechanical setting provided to skeletal structures. Bone quality and resistance to physical stress is highly determined by habitual mechanical stimulation. However, the relationship between bone properties and sagittal posture has never been studied in children.Purpose
This study aimed to investigate the association between bone physical properties and sagittal standing postural patterns in 7-year-old children. We also analyzed the relationship between fat or fat-free mass and postural patterns.Study Design
Cross-sectional evaluation.Patient Sample
This study was performed in a sample of 1,138 girls and 1,260 boys at 7 years of age participating in the Generation XXI study, a population-based cohort of children followed since birth (2005–2006) and recruited in Porto, Portugal.Outcome Measures
Sagittal standing posture was measured through photographs of the sagittal right view of children in the standing position. Three angles were considered to quantify the magnitude of major curves of the spine and an overall balance measure (trunk, lumbar, and sway angles). Postural patterns were identified using latent profile analysis in Mplus.Methods
Weight and height were measured. Total body less head fat or fat-free mass and bone properties were estimated from whole-body dual-energy X-ray absorptiometry scans. The associations of fat or fat-free mass and bone physical properties with postural patterns were jointly estimated in latent profile analysis using multinomial logistic regressions.Results
The identified patterns were labeled as Sway, Flat, and “Neutral to Hyperlordotic” (in girls), and “Sway to Neutral,” Flat, and Hyperlordotic (in boys). In both genders, children in the Flat pattern showed the lowest body mass index, and children with a rounded posture presented the highest: mean differences varying from ?0.86?kg/m2 to 0.60?kg/m2 in girls and from ?0.70?kg/m2 to 0.62?kg/m2 in boys (vs. Sway or “Sway to Neutral”). Fat and fat-free mass were inversely associated with a Flat pattern and positively associated with a rounded posture: odds ratio (OR) of 0.23 per standard deviation (SD) fat and 0.70 per SD fat-free mass for the Flat pattern, and 1.85 (fat) and 1.43 (fat-free) for the Hyperlordotic pattern in boys, with similar findings in girls. The same direction of relationships was observed between bone physical properties and postural patterns. A positive association between bone (especially bone mineral density) and a rounded posture was robust to adjustment for age, height, and body composition (girls: OR=1.79, p=.006 fat-adjusted, OR=2.00, p=.014 fat-free mass adjusted; boys: OR=2.02, p=.002 fat-adjusted, OR=2.42, p<.001 fat-free mass adjusted).Conclusions
In this population-based pediatric setting, there was an inverse association between bone physical properties and a Flat posture. Bone and posture were more strongly positively linked in a rounded posture. Our results support that both bone properties and posture mature in a shared and interrelated mechanical environment, probably modulated by pattern-specific anthropometrics and body composition. 相似文献16.
Roger H. Kim Rebecca K. Viscusi Ashley N. Collier Marie A. Hunsinger Mohsen M. Shabahang George M. Fuhrman James R. Korndorffer 《Surgery》2018,163(4):901-905
Background
The VARK model categorizes learners by preferences for 4 modalities: visual, aural, read/write, and kinesthetic. Previous single-institution studies found that VARK preferences are associated with academic performance. This multi-institutional study was conducted to test the hypothesis that the VARK learning preferences of residents differ from the general population and that they are associated with performance on the American Board of Surgery In-Training Examination (ABSITE).Methods
The VARK inventory was administered to residents at 5 general surgery programs. The distribution of the VARK preferences of residents was compared with the general population. ABSITE results were analyzed for associations with VARK preferences. χ2, Analysis of variance, and multiple linear regression were used for statistical analysis.Results
A total of 132 residents completed the VARK inventory. The distribution of the VARK preferences of residents was different than the general population (P?<?.001). The number of aural responses on the VARK inventory was an independent predictor of ABSITE percentile rank (P?=?.03), percent of questions correct (P?=?.01), and standard score (P?=?.01).Conclusion
This study represents the first multi-institutional study to examine VARK preferences among surgery residents. The distribution of preferences among residents was different than that of the general population. Residents with a greater number of aural responses on VARK had greater ABSITE scores. The VARK model may have potential to improve learning efficiency among residents. 相似文献17.
Dong-Ho Lee Jae Hwan Cho Choon Sung Lee Chang Ju Hwang Sung Hoon Choi Chul Gie Hong 《The spine journal》2018,18(6):1099-1105
Background Context
Conventional anterior decompression surgery for cervical myelopathy, including anterior corpectomy and fusion, is technically demanding and is known to be associated with a higher incidence of surgery-related complications, including cerebrospinal fluid (CSF) leakage, neurologic deterioration, and graft failure compared with posterior surgery.Purpose
We introduce a novel anterior decompression technique (vertebral body sliding osteotomy [VBSO]) for cervical myelopathy caused by ossification of posterior longitudinal ligament (OPLL) and evaluate the efficacy and safety of this procedure.Study Design
This is a case series for novel surgical technique.Patient Sample
Fourteen patients (M:F=11:3, mean age 56.9±10) with cervical myelopathy caused by OPLL who underwent VBSO by a single surgeon were included.Outcome Measures
The surgical outcome was evaluated according to the Japanese Orthopaedic Association score for cervical myelopathy (C-JOA score), and the recovery rate of the C-JOA score was calculated. Patients were also evaluated radiographically with plain and dynamic cervical spine radiographs and pre- and postoperative computed tomography images.Methods
Fourteen patients were followed up for more than 24 months, and operation time, estimated blood loss, neurologic outcomes, and surgery-related complications were investigated. Radiological measurements were also performed to analyze the following parameters: (1) canal-occupying ratio and postoperative canal widening, and (2) pre- and postoperative sagittal alignment.Results
The mean recovery rate of C-JOA score at the final follow-up was 68.65±17.8%. There were no perioperative complications, including neurologic deterioration, vertebral artery injury, esophageal injury, graft dislodgement, and CSF leaks, after surgery except for pseudarthrosis in one case. An average spinal canal compromised ratio by OPLL decreased from 61.5±8.1% preoperatively to 16.5±11.2% postoperatively. An average postoperative canal widening was 5.15±1.39?mm, and improvement of cervical alignment was observed in all patients, with average recovery angle of 7.3±6.1° postoperatively.Conclusions
The VBSO allows sufficient decompression of spinal cord and provides excellent neurologic outcomes. Because surgeons do not need to manipulate the OPLL mass directly, this technique could significantly decrease surgery-related complications. Furthermore, as VBSO is based on the multilevel discectomy and fusion technique, it would be more helpful to restore a physiological lordosis. 相似文献18.
Bret H. Clough Eoin P. McNeill Daniel Palmer Ulf Krause Thomas J. Bartosh Christopher D. Chaput Carl A. Gregory 《The spine journal》2017,17(3):418-430
Background Context
Spine pain and the disability associated with it are epidemic in the United States. According to the National Center for Health Statistics, more than 650,000 spinal fusion surgeries are performed annually in the United States, and yet there is a failure rate of 15%–40% when standard methods employing current commercial bone substitutes are used. Autologous bone graft is the gold standard in terms of fusion success, but the morbidity associated with the procedure and the limitations in the availability of sufficient material have limited its use in the majority of cases. A freely available and immunologically compatible bone mimetic with the properties of live tissue is likely to substantially improve the outcome of spine fusion procedures without the disadvantages of autologous bone graft.Purpose
This study aimed to compare a live human bone tissue analog with autologous bone grafting in an immunocompromised rat model of posterolateral fusion.Design/Setting
This is an in vitro and in vivo preclinical study of a novel human stem cell–derived construct for efficacy in posterolateral lumbar spine fusion.Methods
Osteogenically enhanced human mesenchymal stem cells (OEhMSCs) were generated by exposure to conditions that activate the early stages of osteogenesis. Immunologic characteristics of OEhMSCs were evaluated in vitro. The secreted extracellular matrix from OEhMSCs was deposited on a clinical-grade gelatin sponge, resulting in bioconditioned gelatin sponge (BGS). Bioconditioned gelatin sponge was used alone, with live OEhMSCs (BGS+OEhMSCs), or with whole human bone marrow (BGS+hBM). Efficacy for spine fusion was determined by an institutionally approved animal model using 53 nude rats.Results
Bioconditioned gelatin sponge with live OEhMSCs did not cause cytotoxicity when incubated with immunologically mismatched lymphocytes, and OEhMSCs inhibited lymphocyte expansion in mixed lymphocyte assays. Bioconditioned gelatin sponge with live OEhMSC and BGS+hBM constructs induced profound bone growth at fusion sites in vivo, with a comparable rate of fusion with syngeneic bone graft (negative [0 of 10], BGS alone [0 of 10], bone graft [7 of 10], BGS+OEhMSC [10 of 15], and BGS+hBM [8 of 8]).Conclusions
Collectively, these studies demonstrate that BGS+OEhMSC constructs possess low immunogenicity and drive vertebral fusion with efficiency matching syngeneic bone graft in rodents. We also demonstrate that BGS serves as a promising scaffold for spine fusion when combined with hBM. 相似文献19.
Rodrigo Mondragon-Lozano Camilo Ríos Ernesto Roldan-Valadez Guillermo J. Cruz Maria G. Olayo Roberto Olayo Hermelinda Salgado-Ceballos Juan Morales Marisela Mendez-Armenta Laura Alvarez-Mejia Omar Fabela Axayacatl Morales-Guadarrama Stephanie Sánchez-Torres Araceli Diaz-Ruiz 《The spine journal》2017,17(4):562-573
Background Context
Traumatic spinal cord injury (SCI) causes irreversible damage with loss of motor, sensory, and autonomic functions. Currently, there is not an effective treatment to restore the lost neurologic functions.Purpose
Injection of polypyrrole-iodine(PPy-I) particle suspension is proposed as a therapeutic strategy.Study Design
This is an in vivo animal study.Methods
This study evaluates the use of such particles in rats after SCI by examining spared nervous tissue and the Basso, Beattie, and Bresnahan (BBB) scale to evaluate the functional outcome. Diffusive magnetic resonance imaging (MRI) was employed to measure the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) as non-invasive biomarkers of damage after SCI.Results
Fractional anisotropy decreased, whereas ADC increased in all groups after the lesion. There were significant differences in FA when compared with the SCI-PPy-I group versus the SCI group (p<.05). Significant positive correlations between BBB and FA (r2=0.449, p<.05) and between FA and preserved tissue (r2=0.395, p<.05) were observed, whereas significant negative associations between BBB and ADC (r2=0.367, p<.05) and between ADC and preserved tissue (r2=0.421, p<.05) were observed.Conclusions
The results suggested that PPy-I is neuroprotective as it decreased the amount of damaged tissue while improving the motor function. Non-invasive MRI proved to be useful in the characterization of SCI and recovery. 相似文献20.
Vivek Palepu Melvin D. Helgeson Michael Molyneaux-Francis Srinidhi Nagaraja 《The spine journal》2018,18(2):321-329