Search

ABSTRACTPink-pigmented facultative methylotrophs of the genera Methylorubrum and Methylobacterium are metabolically versatile bacteria that colonize many diverse environments on earth. Despite their widespread occurrence, the molecular details of how these organisms interact with each other and their environment remain understudied. We analyzed genes encoding N-acylhomoserine lactone (acyl-HSL) quorum sensing signal synthases in the published genomes of these bacteria and determined that the product of the largest family of signal synthases had not been characterized. We identified 3R-OH-5Z-C12:1-HSL as a novel signal produced by these synthases using inverse stable isotopic labeling and structural characterization by mass spectrometry, nuclear magnetic resonance spectroscopy, and chemical synthesis. We show that in the methylotroph Methylobacterium fujisawaense DSM5686, this signal activates its cognate LuxR-family transcription factor and is produced in a positive feedback loop. We also discover that in this strain, quorum sensing negatively regulates swarming motility by activating the expression of a small protein that binds a predicted transcription factor. These results characterize a previously undescribed, yet widespread quorum sensing system used by pink-pigmented facultative methylotrophs, which helps us understand the chemical ecology of these important bacteria.IMPORTANCEBacteria known as pink-pigmented facultative methylotrophs colonize many diverse environments on earth, play an important role in the carbon cycle, and in some cases promote plant growth. However, little is known about how these organisms interact with each other and their environment. In this work, we identify one of the chemical signals commonly used by these bacteria and discover that this signal controls swarming motility in the pink-pigmented facultative methylotroph Methylobacterium fujisawaense DSM5686. This work provides new molecular details about interactions between these important bacteria and will help scientists predict these interactions and the group behaviors they regulate from genomic sequencing information.

Donald Sachs,1 Robyn Capobianco,2 Daniel Cher,2 Timothy Holt,3 Mukund Gundanna,4 Timothy Graven,5 A Nick Shamie,6 John Cummings Jr7 1Center for Spinal Stenosis and Neurologic Care, Lakeland, FL, 2SI-BONE, Inc., San Jose, CA, 3Montgomery Spine Center, Montgomery, AL, 4Brazos Spine, College Station, TX, 5SSM Orthopedics, Wentzville, MO, 6UCLA Spine Center, Santa Monica, CA, 7Community Neurosurgical Care, Indianapolis, IN, USA Background: Sacroiliac joint (SI) pain is an often-overlooked cause of lower-back pain, due in part to a lack of specific findings on radiographs and a symptom profile similar to other back-related disorders. A minimally invasive surgical (MIS) approach to SI joint fusion using a series of triangular, titanium plasma spray-coated implants has shown favorable outcomes in patients with SI joint pain refractory to conservative care. The aim of this study was to provide a multicenter experience of MIS SI joint fusion using a patient-level analysis. Patients and methods: We report a patient-level analysis from 144 patients with a mean of 16 months postoperative follow-up. Demographic information, perioperative measures, complications, and clinical outcomes using a visual analog scale for pain were collected prospectively. Random-effects regression models were used to account for intersite variability. Results: The mean age was 58 years, 71% of patients were female, and 62% had a history of lumbar spinal fusion. Mean (95% confidence interval [CI]) operative time was 73 minutes (25.4–118), blood loss was minimal, and hospital stay was 0.8 days (0.1–1.5). At follow-up, mean (95% CI) visual analog scale pain scores improved by 6.1 points (5.7–6.6). Substantial clinical benefit, defined as a decrease in pain by >2.5 points or a score of 3.5 or less, was achieved in 91.9% of patients (95% CI 83.9%–96.1%), and 96% (95% CI 86.3%–98.8%) of patients indicated they would have the same surgery again. Conclusion: When conservative measures fail to relieve symptoms resulting from degeneration or disruption of the SI joint, MIS SI joint fusion using a series of triangular, porous, titanium plasma spray-coated implants is a safe and effective treatment option. Keywords: minimally invasive surgery, sacroiliac joint, SI joint fusion, arthrodesis, previous spine surgery

Charles GT Ledonio,1 David W Polly Jr,1 Marc F Swiontkowski,1 John T Cummings Jr2 1Department of Orthopaedic Surgery, University of Minnesota, Twin Cities, MN, 2Community Neurosurgical Care, Indianapolis, IN, USA Background: The mainstay of sacroiliac joint disruption/degenerative sacroiliitis therapy has been nonoperative management. This nonoperative management often includes a regimen of physical therapy, chiropractic treatment, therapeutic injections, and possibly radiofrequency ablation at the discretion of the treating physician. When these clinical treatments fail, sacroiliac joint fusion has been recommended as the standard treatment. Open and minimally invasive (MIS) surgical techniques are typical procedures. This study aims to compare the perioperative measures and Oswestry Disability Index (ODI) outcomes associated with each of these techniques. Methods: A comparative retrospective chart review of patients with sacroiliac joint fusion and a minimum of 1 year of follow-up was performed. Perioperative measures and ODI scores were compared using the Fisher's exact test and two nonparametric tests, ie, the Mann–Whitney U test and the Wilcoxon signed-rank test. The results are presented as percent or median with range, as appropriate. Results: Forty-nine patients from two institutions underwent sacroiliac joint fusion between 2006 and 2012. Ten patients were excluded because of incomplete data, leaving 39 evaluable patients, of whom 22 underwent open and 17 underwent MIS sacroiliac joint fusion. The MIS group was significantly older (median age 66 [39–82] years) than the open group (median age 51 [34–74] years). Surgical time and hospital stay were significantly shorter in the MIS group than in the open group. Preoperative ODI was significantly greater in the open group (median 64 [44–78]) than in the MIS group (median 53 [14–84]). Postoperative improvement in ODI was statistically significant within and between groups, with MIS resulting in greater improvement. Conclusion: The open and MIS sacroiliac joint fusion techniques resulted in statistically and clinically significant improvement for patients with degenerative sacroiliitis refractory to nonoperative management. However, the number of patients reaching the minimal clinically important difference and those showing overall improvement were greater in the MIS group. Keywords: sacroiliac joint, arthrodesis, sacroiliac joint disruption, degenerative sacroiliitis

Stacey J Ackerman,1 David W Polly Jr,2 Tyler Knight,3 Karen Schneider,4 Tim Holt,5 John Cummings Jr6 1Covance Market Access Services Inc., San Diego, CA, USA; 2University of Minnesota, Orthopaedic Surgery, Minneapolis, MN, USA; 3Covance Market Access Services Inc., Gaithersburg, MD, USA; 4Covance Market Access Services Inc., Sydney, Australia; 5Montgomery Spine Center, Orthopedic Surgery, Montgomery, AL, USA; 6Community Health Network, Neurosurgery, Indianapolis, IN, USA Introduction: Low back pain is common and treatment costly with substantial lost productivity and lost wages in the working-age population. Chronic low back pain originating in the sacroiliac (SI) joint (15%–30% of cases) is commonly treated with nonoperative care, but new minimally invasive surgery (MIS) options are also effective in treating SI joint disruption. We assessed whether the higher initial MIS SI joint fusion procedure costs were offset by decreased nonoperative care costs from a US commercial payer perspective. Methods: An economic model compared the costs of treating SI joint disruption with either MIS SI joint fusion or continued nonoperative care. Nonoperative care costs (diagnostic testing, treatment, follow-up, and retail pharmacy pain medication) were from a retrospective study of Truven Health MarketScan® data. MIS fusion costs were based on the Premier's Perspective™ Comparative Database and professional fees on 2012 Medicare payment for Current Procedural Terminology code 27280. Results: The cumulative 3-year (base-case analysis) and 5-year (sensitivity analysis) differentials in commercial insurance payments (cost of nonoperative care minus cost of MIS) were $14,545 and $6,137 per patient, respectively (2012 US dollars). Cost neutrality was achieved at 6 years; MIS costs accrued largely in year 1 whereas nonoperative care costs accrued over time with 92% of up front MIS procedure costs offset by year 5. For patients with lumbar spinal fusion, cost neutrality was achieved in year 1. Conclusion: Cost offsets from new interventions for chronic conditions such as MIS SI joint fusion accrue over time. Higher initial procedure costs for MIS were largely offset by decreased nonoperative care costs over a 5-year time horizon. Optimizing effective resource use in both nonoperative and operative patients will facilitate cost-effective health care delivery. The impact of SI joint disruption on direct and indirect costs to commercial insurers, health plan beneficiaries, and employers warrants further consideration. Keywords: epidural injection, iFuse, economic model, sacroiliac joint fusion, sacroiliac joint pain, insurance

I. Introduction A. Summary Conclusions B. Nomenclature--Sales and Exchanges C. The Negative Connotations of Circularity D. The Positive Roles of Circularity E. Substitution of Setoffs for Circular Cash Flows F. [...]

Advances in US agriculture provide an extraordinary example of the successful development and application of science and technology. Two percent of the population feeds the whole country, and, even so, [...]

The article talks about the Tax Reform Act of 1986 in the U.S. and the difference between it and the 2017 tax reforms. Topics discussed include Andrew W. Mellon, the former Secretary of the Treasury for the U.S.; the federal taxation under the presidency of Ronald Reagan; and the role of U.S. Congress' Finance Committee Chair Bob Packwood in the 1986 reform. Also mentioned is former U.S. President Barack Obama and taxation under his administration.