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Abstract: Increasing nitrogen (N) deposition due to anthropogenic activities has become a significant global change threat to N-poor terrestrial ecosystems. We compared bacterial growth and nutrients limiting bacterial growth in one of the longest running experiments on increasing N-deposition to a temperate forest, the Chronic Nitrogen Amendment Study at Harvard Forest, USA. Soil samples were collected in fall 2009 from the organic and mineral horizons of plots treated annually since 1988 with 0 (unfertilized), 50 (low N) or 150 (high N) kg N ha−1 as NH4NO3. In the organic horizon, bacterial growth (leucine incorporation) decreased by 5 times in the high N plots compared to the unfertilized treatment, while no decrease was observed in the mineral horizon. Bacterial growth in all soils was primarily limited by lack of carbon (C), although adding only C (as glucose) resulted in only a minor increase in bacterial growth in the unfertilized soil compared to adding C in combination with N. The bacterial growth induced by adding only C increased with higher level of N fertilization, up to 7–8 times the level without any C addition in the high N treatment, suggesting increased availability of N for the bacteria with increasing N addition. [Copyright &y& Elsevier]

Objective: Because of limited medical and surgical options for patients with end-stage congestive heart failure, we expanded the criteria for surgical ventricular remodeling to include patients with multiterritory myocardial infarction, a group historically considered high-risk candidates. We present our series of patients with multiterritory myocardial infarction who underwent surgical ventricular remodeling and propose a new patient population who may benefit from this procedure. Methods: Data were analyzed for 51 consecutive patients undergoing surgical ventricular remodeling from January 2002 to June 2004, with 100% follow-up. Three left ventricular vascular territories were defined: anteroapicoseptal (left anterior descending), lateral (circumflex), and inferior (right coronary artery). Infarction was assessed with magnetic resonance imaging and intraoperative findings. Results: Multiterritory myocardial infarction was found in 64.7% of patients (33/51) undergoing surgical ventricular remodeling. Mean age was 61.6 ± 11.1 years (range 40-81 years). Sixty-one percent (20/33) demonstrated evidence of myocardial infarction in all three territories. Five patients underwent concomitant mitral valve repair or replacement. Operative mortality was 6.1% (2/33) and did not differ from that of patients with single-territory infarction (11.1%, P = .61). Surgical ventricular remodeling significantly improved left ventricular volumes and ejection fraction in patients with multiterritory myocardial infarction. Three patients required assist device implantation, and 2 patients required defibrillator placement. Sixty-nine percent of patients in preoperative New York Heart Association functional class III or IV (22/32) had improvement to class I or II at follow-up (P < .01). Cox regression analysis discriminated a preoperative left ventricular end-systolic volume index greater than 100 mL/m2 as a significant risk factor for mortality (odds ratio 12.1, 95% confidence interval 1.27-114.51, P = .03). Thirty-month survival of patients with multiterritory myocardial infarction (73.5% ± 8.3%) did not differ statistically from that of patients with single-territory infarction (n = 18). Conclusion: Surgical ventricular remodeling improves cardiac function and New York Heart Association functional status in patients with multiterritory myocardial infarction. Our initial results are promising and should prompt further studies to confirm our results and potentially expand the surgical ventricular remodeling inclusion criteria to include patients with multiterritory myocardial infarction. [Copyright &y& Elsevier]

Background: Hepatitis C is associated with increased adverse events following surgery. The goals of this study were therefore to evaluate postoperative outcomes in patients with hepatitis C following ankle arthrodesis., Materials and Methods: A review of Medicare patients was performed to identify patients who underwent ankle arthrodesis. Patients were then divided into those with a preoperative history of hepatitis C and those who did not and were matched using propensity scores. Outcomes of interest were analyzed using multivariate logistic regression., Results: A diagnosis of hepatitis C was associated with a significantly increased risk of myocardial infarction, emergency department visits, and readmission within 90 days following surgery. In addition, hepatitis C is associated with an increased length of stay, cost of hospitalization, and total hospital charge., Conclusions: A diagnosis of hepatitis C was associated with a significant increase in hospital resource utilization during the initial inpatient stay and the immediate post-discharge period. Level of Evidence: III., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Summary of Background: Multiple sclerosis (MS) is a chronic inflammatory disease that can cause physical and neurological dysfunction. Patients with MS are living longer and undergoing more orthopedic procedures, but the risk of patients with MS undergoing posterior lumbar fusion (PLF) has not been studied in literature before., Objective: This study aims to (1) analyze the rates of postoperative complications of MS patients undergoing primary PLF and (2) analyze the economic burden associated with these surgeries in the MS population compared with patients without MS., Methods: A retrospective review of the Medicare database was conducted on all patients who underwent PLF and/or posterior lumbar interbody fusion between the years of 2006 and 2013. Cases involving same-day anterior or revision procedures and patients with a history of spine, infection, and trauma, or neoplasm were excluded from the study. Demographics, comorbidities, 90-day postoperative complications, cost, and length of stay were calculated. All outcomes of interest were analyzed using multivariate logistic regression, adjusting for age, sex, and comorbidity burden. Significance was defined as P-value <0.05., Results: There were 2363 patients with MS and 23,569 matched controlled patients. We found a significant increase in the risk of sepsis [odds ratio (OR)=1.85, P=0.034], urinary tract infection (OR=1.89, P<0.001), deep vein thrombosis (OR=1.4, P=0.044), 90-day emergency room visit (OR=1.14, P=0.027), and 90-day readmissions (OR=1.20, P=0.011) compared with patients without a history of MS. Patients with MS also incurred $4379 extra in total hospital charge, a $1679 increase in the cost of hospitalization, and an increase in length of stay (4.05 vs. 3.61, P<0.001)., Conclusions: A diagnosis of MS is associated with a significant increase in postoperative complications and higher costs after hospitalization. It is imperative for physicians to understand the risk factors of patients undergoing PLF and/or posterior lumbar interbody fusion with MS to better counsel them about postoperative complications before surgery., Level of Evidence: Level III., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Obese patients undergoing orthopedic procedure have been reported to have higher rates of postoperative complications, but the published associations have numerous confounders. This study aims to evaluate the independent effect of obesity on postoperative complications and hospital utilization following ankle arthrodesis. A database review of a Medicare database was performed on patients less than 85 years old who underwent ankle arthrodesis between 2005 and 2014. Patient cohorts were defined using International Classification of Diseases-9 coding for body mass index (BMI)-obese (30-40 kg/m 2 ), and morbidly obese (>40 kg/m 2 ). Normal BMI patients were defined as those without the respect codes for obesity (30-40 kg/m 2 ), morbidly obese (>40 kg/m 2 ), or underweight (<19 kg/m 2 ). All groups were propensity score matched by demographics and comorbidities. Outcomes of interest included 90-day major and minor medical complications, and hospital burden. Morbid obesity was associated with an increased risk of acute kidney injury (4.4% vs 2.4%, OR 1.94, 95% CI 1.37-2.74, p < .001), urinary tract infection (5.2% vs 3.2%, OR 1.66, 95% CI 1.21-2.25, p = .001), readmission (13.6% vs 10.8%, OR 1.33, 95% CI 1.10-1.61, p = .003), and overall minor complications (16.0% vs 11.8%, OR 1.44, 95% CI 1.19-1.74, p < .001) compared to normal BMI patients, and an increased risk for acute kidney injury (4.4% vs 1.9%, OR 2.25, 95% CI 1.32-3.97, p = .003) compared to obese patients. Obesity was not associated with increased medical complications (p > .05). While morbid obesity was associated with an increase in the postoperative complications, obesity was not associated with any increase in postoperative complications following ankle arthrodesis., (Copyright © 2021 the American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Predicting survival in myxoid liposarcoma (MLS) patients is very challenging given its propensity to metastasize and the controversial role of adjuvant therapy. The purpose of this study was to develop a machine-learning algorithm for the prediction of survival at five years for patients with MLS and externally validate it using our institutional cohort., Methods: Two databases, the surveillance, epidemiology, and end results program (SEER) database and an institutional database, were used in this study. Five machine learning models were created based on the SEER database and performance was rated using the TRIPOD criteria. The model that performed best on the SEER data was again tested on our institutional database., Results: The net-elastic penalized logistic regression model was the best according to our performance indicators. This model had an area under the curve (AUC) of 0.85 when compared to the SEER testing data and an AUC of 0.76 when tested against institutional database. An application to use this calculator is available at https://sorg-apps.shinyapps.io/myxoid&#95;liposarcoma/., Conclusion: MLS is a soft-tissue sarcoma with adjunct treatment options that are, in part, decided by prognostic survival. We developed the first machine-learning predictive algorithm specifically for MLS using the SEER registry that retained performance during external validation with institutional data., (© 2021 Wiley Periodicals LLC.)