Electrokinetic-enhanced phytoremediation of uranium-contaminated soil using sunflower and Indian mustard.

Electrokinetic-enhanced phytoremediation is an effective technology to decontaminate heavy metal contaminated soil. In this study, we examined the effects of electrokinetic treatments on plant uptake and bioaccumulation of U from soils with various U sources. Redistribution of uranium in soils as affected by planting and electrokinetic treatments was investigated. The soil was spiked with 100 mg kg-1 UO2, UO3, and UO2(NO3)2. After sunflower and Indian mustard grew for 60 days, 1 voltage of direct-current was applied across the soils for 9 days. The results indicated that U uptake in both plants were significantly enhanced by electrokinetic treatments from soil with UO3 and UO2(NO3)2. U was more accumulated in roots than in shoots. Electrokinetic treatments were effective on lowering soil pH near the anode region. Overall, uranium (U) removal efficiency reached 3.4-4.3% from soils with UO3 and uranyl with both plants while that from soil with UO2 was 0.7-0.8%. Electrokinetic remediation treatment significantly enhanced the U removal efficiency (5-6%) from soils with UO3 and uranyl but it was 0.8-1.3% from soil with UO2, indicating significant effects of U species and electrokinetic enhancement on U bioaccumulation. This study implies the potential feasibility of electrokinetic-enhanced phytoremediation of U soils with sunflower and Indian mustard.

How much tumor surgery do early-career orthopaedic oncologists perform?

BACKGROUND: There are few data on the types of procedures orthopaedic oncologists perform in their first years of practice. Because fellowships are graduating fellows each year and the number of tumor patients is limited, defining the practice patterns of early-career orthopaedic oncologists may help diminish early employment discontent and enhance workforce discussions. QUESTIONS/PURPOSES: The aim of the study was to use the objective case log volumes of a cross-section of early career orthopaedic oncologists to describe (1) the number of operations performed annually; (2) the proportion of tumor, trauma, adult reconstruction, and other operations for individual participants, (3) individual practice characteristics that were associated with the number of tumor procedures; and (4) the sources of satisfaction and challenges in each individual's career and surgical practice. METHODS: Fifteen fellowship-trained orthopaedic oncologists out of a potential pool of 33 (45%) in their first 4 years of practice responded to a survey by submitting complete operative case lists for a 2-year period. We recorded the type of procedure and determined associations between the annual number of tumor operations and total operative caseload, years in practice, and some details of individual practice patterns. Each participant completed a survey regarding practice-related sources of stress and satisfaction. A total of 5611 surgical cases were available for review. For the entire cohort, there were 3303 (59%) tumor procedures, 973 (17%) trauma, 890 (16%) adult reconstruction, and 445 (8%) other. RESULTS: The median annual number of total operations was 214 (range, 63-356) and median annual number of tumor operations was 135 (range, 47-216). The median proportion of tumor operations in an individual practice was 56% (range, 43%-94%). The annual number of tumor operations correlated with the total annual number of operations (r = 0.73, p < 0.001). Sources of stress and satisfaction were similar to the general membership of the Musculoskeletal Tumor Society (MSTS), apart from more early-career surgeons regarding case volume as important (29 of 104 [28%] of MSTS versus 11 of 15 [73%] of early-career, p < 0.001). CONCLUSIONS: The typical early-career orthopaedic tumor surgeon had fewer than 60% of his or her operative procedures directly related to the subject of his or her fellowship training in orthopaedic oncology. Overall, the challenges and rewards of clinical practice are similar to oncologic surgeons later in their career. This study is a first step in assessing early practice characteristics and may be of value to the prospective orthopaedic oncologist, fellowship educators, and the society in workforce discussions. Early-career practice patterns have not been previously presented, to our knowledge, for any subspecialty of orthopaedic surgery, and we hope that this study will stimulate similar efforts throughout the field. LEVEL OF EVIDENCE: Level IV, economic and decision analyses. See Guidelines for Authors for a complete description of levels of evidence.

What is the use of imaging before referral to an orthopaedic oncologist? A prospective, multicenter investigation.

BACKGROUND: Patients often receive advanced imaging before referral to an orthopaedic oncologist. The few studies that have evaluated the value of these tests have been single-center studies, and there were large discrepancies in the estimated frequencies of unnecessary use of diagnostic tests. QUESTIONS/PURPOSES: (1) Is there regional variation in the use of advanced imaging before referral to an orthopaedic oncologist? (2) Are these prereferral studies helpful to the treating orthopaedic oncologist in making a diagnosis or treatment plan? (3) Are orthopaedic surgeons less likely to order unhelpful studies than other specialties? (4) Are there any tumor or patient characteristics that are associated with the ordering of an unhelpful study? METHODS: We performed an eight-center prospective analysis of patients referred for evaluation by a fellowship-trained orthopaedic oncologist. We recorded patient factors, referral details, advanced imaging performed, and presumptive diagnosis. The treating orthopaedic oncologist determined whether each study was helpful in the diagnosis or treatment of the patient based on objective and subjective criteria used in prior investigations. We analyzed the data using bivariate methods and logistic regression to determine regional variation and risk factors predictive of unhelpful advanced imaging. Of the 371 participants available for analysis, 301 (81%) were referred with an MRI, CT scan, bone scan, ultrasound, or positron emission tomography scan. RESULTS: There were no regional differences in the use of advanced imaging (range of patients presenting with advanced imaging 66%-88% across centers, p = 0.164). One hundred thirteen patients (30%) had at least one unhelpful study; non-MRI advanced imaging was more likely to be unhelpful than MRIs (88 of 129 [68%] non-MRI imaging versus 46 of 263 [17%] MRIs [p < 0.001]). Orthopaedic surgeons were no less likely than nonorthopaedic surgeons to order unhelpful studies before referral to an orthopaedic oncologist (56 of 179 [31%] of patients referred by orthopaedic surgeons versus 35 of 119 [29%] referred by primary care providers and 22 of 73 [30%] referred by nonorthopaedic specialists, p = 0.940). After controlling for potential confounding variables, benign bone lesions had an increased odds of referral with an unhelpful study (59 of 145 [41%] of benign bone tumors versus 54 of 226 [24%] of soft tissue tumors and malignant bone tumors; odds ratio, 2.80; 95% confidence interval, 1.68-4.69, p < 0.001). CONCLUSIONS: We found no evidence that the proportion of patients referred with advanced imaging varied dramatically by region. Studies other than MRI were likely to be considered unhelpful and should not be routinely ordered by referring physicians. Diligent education of orthopaedic surgeons and primary care physicians in the judicious use of advanced imaging in benign bone tumors may help mitigate unnecessary imaging. LEVEL OF EVIDENCE: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Distal femoral osteoarticular allografts: long-term survival, but frequent complications.

BACKGROUND: Complications are frequent with osteoarticular allografts, and their long-term survivorship in the distal femur is unclear. Thus, the benefits of osteoarticular allografting remain controversial. QUESTIONS/PURPOSES: We therefore determined the frequency of complications in osteoarticular allografts of the distal femur relative to their potential long-term survival. METHODS: We retrospectively reviewed 26 patients who had osteoarticular allograft reconstruction of the distal femur after resection of a malignant or aggressive benign tumor of bone. The minimum followup was 15 months (average, 156 months; range, 15-283 months) for all patients and 98 months (average, 191 months; range, 98-283 months) for the surviving patients. RESULTS: At last followup, 16 of the 26 original allografts were still in place. The overall 5-year and 10-year allograft survival rates were 69% and 63%, respectively. The 5-year and 10-year survival rates of the joint surface were 79% and 65%, respectively. Eleven patients retained their original osteoarticular allograft without a resurfacing procedure, and nine had been converted to allograft-prosthetic composites. Five patients were converted to megaprostheses and one had an amputation for local recurrence. At last followup, 25 of 26 patients retained a functional limb. CONCLUSIONS: Osteoarticular allograft reconstructions of the distal femur can provide long term survival and restore function but the risk of complications and their physical and monetary costs for patients are not trivial. Lacking the benefit of improved soft tissue attachments inherent in other anatomic sites, we believe this option is most appropriate for restoring bone stock in young patients with expectations of long-term survival.

Kinetics and Thermodynamics of Uranium (VI) Adsorption onto Humic Acid Derived from Leonardite.

Humic acid (HA) is well known as an inexpensive and effective adsorbent for heavy metal ions. However, the thermodynamics of uranium (U) adsorption onto HA is not fully understood. This study aimed to understand the kinetics and isotherms of U(VI) adsorption onto HA under different temperatures from acidic water. A leonardite-derived HA was characterized for its ash content, elemental compositions, and acidic functional groups, and used for the removal of U (VI) from acidic aqueous solutions via batch experiments at initial concentrations of 0-100 mg·L-1 at 298, 308 and 318 K. ICP-MS was used to determine the U(VI) concentrations in solutions before and after reacting with the HA. The rate and capacity of HA adsorbing U(VI) increased with the temperature. Adsorption kinetic data was best fitted to the pseudo second-order model. This, together with FTIR spectra, indicated a chemisorption of U(VI) by HA. Equilibrium adsorption data was best fitted to the Langmuir and Temkin models. Thermodynamic parameters such as equilibrium constant (K0), standard Gibbs free energy (ΔG0), standard enthalpy change (ΔH0), and standard entropy change (ΔS0), indicated that U(VI) adsorption onto HA was endothermic and spontaneous. The co-existence of cations (Cu2+, Co2+, Cd2+ and Pb2+) and anions (HPO42- and SO42-) reduced U(VI) adsorption. The high propensity and capacity of leonardite-derived HA adsorbing U(VI) suggests that it has the potential for cost-effective removal of U(VI) from acidic contaminated waters.

Aging Promotes Sirtuin 3-Dependent Cartilage Superoxide Dismutase 2 Acetylation and Osteoarthritis.

OBJECTIVE: To quantify functional age-related changes in the cartilage antioxidant network in order to discover novel mediators of cartilage oxidative stress and osteoarthritis (OA) pathophysiology. METHODS: We evaluated histopathologic changes of knee OA in 10-, 20-, and 30-month-old male F344BN rats and analyzed cartilage oxidation according to the ratio of reduced to oxidized glutathione. Antioxidant gene expression and protein abundance were analyzed by quantitative reverse transcription-polymerase chain reaction and selected reaction-monitoring mass spectrometry, respectively. Superoxide dismutase 2 (SOD2) activity and acetylation were analyzed by colorimetric enzyme assays and Western blotting, respectively. We examined human OA cartilage to evaluate the clinical relevance of SOD2 acetylation, and we tested age-related changes in the mitochondrial deacetylase sirtuin 3 (SIRT-3) in rats and mice. RESULTS: Cartilage oxidation and OA severity in F344BN rats increased with age and were associated with an increase in SOD2 expression and protein abundance. However, SOD2-specific activity decreased with age due to elevated posttranslational lysine acetylation. Consistent with these findings, SIRT-3 levels decreased substantially with age, and treatment with SIRT-3 increased SOD2 activity in an age-dependent manner. SOD2 was also acetylated in human OA cartilage, and activity was increased with SIRT-3 treatment. Moreover, in C57BL/6J mice, cartilage SIRT-3 expression decreased with age, and whole-body deletion of SIRT-3 accelerated the development of knee OA. CONCLUSION: Our results show that SIRT-3 mediates age-related changes in cartilage redox regulation and protects against early-stage OA. These findings suggest that mitochondrial acetylation promotes OA and that restoration of SIRT-3 in aging cartilage may improve cartilage resistance to oxidative stress by rescuing acetylation-dependent inhibition of SOD2 activity.

Chondroblastoma of the distal phalanx.

Chondroblastoma is a rare, benign primary bone tumor that usually occurs at the epiphysis of long bones. The authors present an example of the diagnosis and successful treatment of this neoplasm in an exceedingly rare location in the distal phalanx. Clinical and radiographic outcomes after 68 months of follow-up are presented. A 15-year-old, right hand-dominant, boy developed painful swelling of the right ring finger. Radiographs revealed a radiolucent lesion of the distal phalanx with expansile remodeling of the bone. An excisional biopsy was performed with curettage and bone grafting of the lesion. The diagnosis of chondroblastoma was made based on pathologic evaluation of the biopsy specimen. Sixty-six months after surgical treatment, the patient was free of recurrence and metastatic disease with excellent clinical and functional outcomes. To the authors' knowledge, this represents only the second reported case of chondroblastoma of the distal phalanx. The diagnosis of chondroblastoma in this rare location was made by pathologic review of the resection specimen. It is imperative to confirm the diagnosis of any resected bone specimen even when the concern for an aggressive or malignant lesion is low. A tumor presenting in an unusual location may require a change in treatment or surveillance.