Development of the Circle of Willis Score (COWS) to help guide decision making during acute tandem occlusion treatment: Preliminary analysis.

BACKGROUND: Acute tandem occlusions (TOs) are challenging to treat. Although acute carotid stenting of the proximal lesion is well tolerated, there are certain situations when the practitioner may be wary of acute stenting (bleeding concerns). OBJECTIVE: The purpose of this study was to retrospectively study patients with tandem occlusions who had re-occlusion of the extracranial ICA and develop a Circle of Willis Score (COWS) to help predict which patients could forego acute stenting. METHODS: This is a retrospective review of TO patients with a persistent proximal occlusion following intervention (either expected or unexpected). Pre intervention CTA and intraoperative DSA were reviewed, and each patient was assigned a score 2 (complete COW), 1a (patent A1-Acomm-A1), 1p (patent Pcomm), or 0 (incomplete COW). Findings from the DSA took precedence over the CTA. Two cohorts were created, the complete COW cohort (COWS 2) versus the incomplete COW cohort (COWS 1a,1p, or 0). Angiographic outcomes were assessed using the mTICI score (2b-3) and clinical outcomes were assessed using discharge mRS (good outcome mRS 0-3). RESULTS: Of 68 TO cases, 12 had persistent proximal occlusions. There were 5/12 (42 %) patients in the complete COW cohort, and 7/12 (58 %) in the incomplete COW cohort (5/12 with scores of 1a/1p and 2/12 with a score of 0). In the complete COW cohort, there were 2 ICA-ICA and 3 ICA-MCA occlusions. In the incomplete COW cohort, there was one ICA-ICA occlusion and 6 ICA-MCA occlusions. LKW-puncture was shorter in the complete COW cohort (208 min vs. 464 min, p = 0.16). Successful reperfusion was higher in the complete COW cohort (100 % vs. 71 %). There was a trend toward better clinical outcomes in the complete COW cohort (80 % vs 29 %, p = 0.079). CONCLUSION: The COWS is a simple score that may help predict a successful clinical outcome without proximal revascularization when concerned about performing an acute carotid stent during TO treatment. Evaluation in larger TO cohort is warranted.

Treatment of intraorbital arteriovenous fistulas with direct puncture: a case series and review of treatments since 1978.

Intraorbital arteriovenous fistulas (IOAVFs) are rare vascular pathologies that may be effectively treated with direct puncture (DP) of the venous supply and may offer a definitive and safe cure when done under ultrasound or stereotactic guidance. Here we present three new cases of DP treatment of IOAVFs, indications for safe use, and their potential complications in comparison to the existing literature on DP and other modalities.Three patients with IOAVFs were treated with DP with ultrasound guidance, stereotactic guidance, and fluoroscopy. Final digital subtraction angiography (DSA) revealed complete cure of IOAVFs. A literature review via PubMed was performed on treatments of IOAVFs since 1978.All three cases of DP resulted in successful cures with 2/3 cases resulting in complications from orbital hematoma formation. 49 total treatments including the cases herein have been documented. DP treatment constituted 5/49, conservative management 17/49, transarterial 8/49, transvenous 18/49, and surgical 3/49. Some cases received more than one mode of treatment. Transarterial and surgical managements were found to have higher complication rates than transvenous and DP.DP is a safe and effective treatment of IOAVFs that can be performed via multiple image guided methods and guarantees a definitive cure. Orbital hematomas are a potential complication of which operators should be aware.

Delayed appearance of basilar trunk small atypical aneurysms in nontraumatic, initially angiogram-negative subarachnoid hemorrhage: A report of three patients.

BACKGROUND: Repeat angiography will identify vascular pathology in approximately 10% of cases following angiogram-negative subarachnoid hemorrhage (anSAH), but small atypical aneurysms of the basilar artery are very uncommon. OBJECTIVE: To report a case series of delayed appearance of nontraumatic basilar artery small atypical aneurysms. METHODS: IRB approval was obtained for this retrospective case series and patient consent was waived. RESULTS: Herein we report three cases of spontaneous anSAH, all of whom had a negative digital subtraction angiogram (DSA) on admission and all of whom had appearance of a small atypical aneurysms of the upper basilar trunk/apex on follow-up imaging (two during the initial admission and one in a delayed fashion). All three patients were ultimately treated with flow diversion (although one patient underwent attempted coiling that was abandoned due to inability to catheterize the aneurysm). CONCLUSION: This report highlights the importance of a repeat DSA in cases of anSAH as well as the importance of scrutinizing the basilar trunk for these very small atypical aneurysms that may go unnoticed.

Ketamine Boluses Are Associated with a Reduction in Intracranial Pressure and an Increase in Cerebral Perfusion Pressure: A Retrospective Observational Study of Patients with Severe Traumatic Brain Injury.

Background: Increased intracranial pressure (ICP) and hypotension have long been shown to lead to worse outcomes in the severe traumatic brain injury (TBI) population. Adequate sedation is a fundamental principle in TBI care, and ketamine is an attractive option for sedation since it does not commonly cause systemic hypotension, whereas most other sedative medications do. We evaluated the effects of ketamine boluses on both ICP and cerebral perfusion pressure (CPP) in patients with severe TBI and refractory ICP. Methods: We conducted a retrospective review of all patients admitted to the neurointensive care unit at a single tertiary referral center who had a severe traumatic brain injury with indwelling intracranial pressure monitors. We identified those patients with refractory intracranial pressure who received boluses of ketamine. We defined refractory as any sustained ICP greater than 20 mmHg after the patient was adequately sedated, serum Na was at goal, and CO2 was maintained between 35 and 40 mmHg. The primary outcome was a reduction in ICP with a subsequent increase in CPP. Results: The patient cohort consisted of 44 patients with a median age of 30 years and a median presenting Glasgow Coma Scale (GCS) of 5. The median reduction in ICP after administration of a ketamine bolus was -3.5 mmHg (IQR -9 to +1), and the postketamine ICP was significantly different from baseline (p < 0.001). Ketamine boluses led to an increase in CPP by 2 mmHg (IQR -5 to +12), which was also significantly different from baseline (p < 0.001). Conclusion: In this single-institution study of patients with severe traumatic brain injury, ketamine boluses were associated with a reduction in ICP and an increase in CPP. This was a retrospective review of 43 patients and is therefore limited in nature, but further randomized controlled trials should be performed to confirm the findings.

Types and functions of heterogeneity in mycobacteria.

The remarkable ability of Mycobacterium tuberculosis to survive attacks from the host immune response and drug treatment is due to the resilience of a few bacilli rather than a result of survival of the entire population. Maintenance of mycobacterial subpopulations with distinct phenotypic characteristics is key for survival in the face of dynamic and variable stressors encountered during infection. Mycobacterial populations develop a wide range of phenotypes through an innate asymmetric growth pattern and adaptation to fluctuating microenvironments during infection that point to heterogeneity being a vital survival strategy. In this Review, we describe different types of mycobacterial heterogeneity and discuss how heterogeneity is generated and regulated in response to environmental cues. We discuss how this heterogeneity may have a key role in recording memory of their environment at both the single-cell level and the population level to give mycobacterial populations plasticity to withstand complex stressors.

Sources of Geographic Variation in Health Care Spending Among Individuals With Employer Sponsored Insurance.

We use health care claims data from the Health Care Cost Institute to estimate the share of geographic variation in health care spending attributable to person-specific (demand) and place-specific (supply) factors. We exploit patient migration across 112 metropolitan areas between 2012 and 2016. Using an event study approach, we find that moving to an area with 10% higher (lower) spending leads to a 4.2% increase (decrease) in individual medical spending. Our estimate implies that 42% of variation in health care spending among the commercially insured is attributable to place-specific factors. We show that variation in both price and utilization jointly determine the place-specific impact on individual spending. All else equal, we find that moving to an area with 10% higher (lower) prices, on average leads to a 5% increase (decrease) in spending, while moving to an area with 10% higher (lower) utilization leads to a 3.6% increase (decrease).

Comparing different methods of indexing commercial health care prices.

OBJECTIVE: To compare different methods of indexing health care service prices for the commercially insured population across geographic markets. DATA SOURCES: Health Care Cost Institute commercial claims data from 2012 to 2016. STUDY DESIGN: We compare price indices computed using methods with differing levels of computational intensity: weighted-average versus regression-based methods. We separately compute indices of the prices paid for set of common inpatient and set of common outpatient services in different markets across the United States using each type of method. We subsequently examined the variation of and correlations between the resulting index values. DATA COLLECTION/EXTRACTION METHODS: We computed health care service price indices separately using samples of inpatient and outpatient facility claims from 2012 to 2016 across 112 Core-Based Statistical Areas. Within each category of services, claims were limited to members under the age of 65 with employer-sponsored insurance. Both samples were limited to a common set of services that made up nearly 80 percent of the service use in the full sample every year. PRINCIPAL FINDINGS: We found that the methods studied produced highly correlated price indices (r > .94) with similar distributions across years for both inpatient and outpatient services. CONCLUSIONS: Our findings suggest that weighted-average methods, which are much less computationally intensive, will generate results similar to regression-based methods.

Efficient inhibition of RNA self-primed extension by addition of competing 3'-capture DNA-improved RNA synthesis by T7 RNA polymerase.

In vitro synthesized RNA is used widely in studies of RNA biology, biotechnology and RNA therapeutics. However, in vitro synthesized RNA often contains impurities, such as RNAs with lengths shorter and longer than the expected runoff RNA. We have recently confirmed that longer RNA products are formed predominantly via cis self-primed extension, in which released runoff RNA folds back on itself to prime its own RNA-templated extension. In the current work, we demonstrate that addition of a DNA oligonucleotide (capture DNA) that is complementary to the 3' end of the expected runoff RNA effectively prevents self-primed extension, even under conditions commonly used for high RNA yields. Moreover, the presence of this competing capture DNA during 'high yield' transcription, leads to an increase in the yield of expected runoff RNA by suppressing the formation of undesired longer RNA byproducts.

Re-evaluating the Weekend Effect on SAH: A Nationwide Analysis of the Association Between Mortality and Weekend Admission.

OBJECTIVE: Multiple studies have shown worse outcomes in patients admitted for medical and surgical conditions on the weekend. However, past literature analyzing this "weekend effect" on subarachnoid hemorrhage (SAH) found no significant increase in mortality. This study utilizes more recent data to re-evaluate the association between weekend admission and mortality of patients hospitalized for SAH. METHODS: This retrospective cohort study queried the SAH patients in the Nationwide Inpatient Sample (NIS) database who were discharged from 2006 through 2014 during the weekend. RESULTS: Of the 54,703 admissions for SAH identified during the study period, 14,821 (27.1%) occurred over the weekend. Patients admitted over the weekend had a mean age of 59.2 years and were most likely to be female (59.6%), to be white (62.9%), located in the south region of the USA (40.1%), and be admitted to a teaching hospital (74.4%). When compared directly to weekday admissions, patients admitted over the weekend had higher odds of in-hospital mortality (odds ratio 1.07; confidence interval 95%, 1.02-1.12). There was no significant difference shown in the rate patients get surgical clipping versus endovascular coiling (p = 0.28) or the amount of time between admission to procedure for clipping (p = 0.473) or coiling (p = 0.255) on the weekend versus a weekday. CONCLUSION: Based on our findings, the likelihood of the in-hospital mortality was higher for patients admitted over the weekend. However, the characteristics of the study, primarily observational, prevent us arriving at an accurate conclusion about why this occurs; hence, we believe it is an important starting point to consider for future research.

Trends of the neurosurgical economy in the United States.

BACKGROUND: The objective of this study was to identify the neurosurgical MS-DRGs highest national bills and to analyze economic, demographic, and patient outcome trends. METHODS: This retrospective cohort study used the Nationwide Inpatient Sample (NIS) database to achieve the results. All MS-DRG codes for the years 2014 were ranked based on total aggregate charges. The highest ranked relevant to neurosurgery were identified and retrospectively reviewed to 2008. The data was analyzed by Z-test. RESULTS: In 2014, NIS reported the MS-DRG with the highest national bill of $22,894,340,928 was "Spinal Fusion Except Cervical without MCC," which also had the largest rise over the cohort period, increasing from $15,853,679,222 in 2008 (p < .001). It was also the MS-DRG with the highest incidence, totaling 1,443,112 discharges and increasing from 190,692 in 2008 to 214,100 in 2014 (p < .10). "Craniotomy with major Device Implant/Acute Complex CNS Procedure w/MCC or Chemo Implant" had the longest length of stay (LOS) with a mean patient stay of 12.9 days. This MS-DRG also had the oldest patient population mean age of 57.5 years old. "Craniotomy & Endovascular Intracranial Procedures with MCC" had the most in-hospital deaths totaling 28,707 increasing significantly from 3602 in 2008 to 4410 in 2014 (p < .05). CONCLUSIONS: "Spinal fusion except cervical without MCC," had the highest national bill in the USA over the period of the cohort. Healthcare organizations can benefit from awareness of this information by using it to establish the most efficient healthcare investments and preparing a health-care roadmap for the following decades.

Development of an ideal observer that incorporates nuisance parameters and processes list-mode data.

Observer models were developed to process data in list-mode format in order to perform binary discrimination tasks for use in an arms-control-treaty context. Data used in this study was generated using GEANT4 Monte Carlo simulations for photons using custom models of plutonium inspection objects and a radiation imaging system. Observer model performance was evaluated and presented using the area under the receiver operating characteristic curve. The ideal observer was studied under both signal-known-exactly conditions and in the presence of unknowns such as object orientation and absolute count-rate variability; when these additional sources of randomness were present, their incorporation into the observer yielded superior performance.

Collagen adsorption and structure on polymer surfaces observed by atomic force microscopy.

The structure and adsorption patterns of type I and type III collagen were imaged on various polymer substrates with atomic force microscopy. Type I collagen had higher adsorption on polystyrene than on a series of polymethacrylates and formed a network of tightly, interwoven strands. Upon adsorption to different polymethacrylates, with varying side chain lengths, the collagen molecules formed long, branching fibrils. Types I and III collagen had different adsorption patterns, in some cases, on the identical substrate material. For example, instead of forming a tightly packed network, type III forms long, branching fibers on the polystyrene surface. On other materials, such as poly(n-butyl methacrylate), the two types of collagen showed similar adsorption pattern and structure. Adsorbed collagen was also imaged on various blends of polystyrene and polymethacrylates to determine how the polymer surface chemical structure and surface topography mediates protein adsorption.

Surface structures and properties of polystyrene/poly(methyl methacrylate) blends and copolymers.

Sum frequency generation (SFG) vibrational spectroscopy has been applied to study the molecular surface structures of polystyrene (PS)/poly(methyl methacrylate) (PMMA) blends and the copolymer between PS and PMMA (PS-co-PMMA) in air, supplemented by atomic force microscopy (AFM) and contact angle goniometer. Both the blend and the copolymer have equal weight amounts of the two components. SFG results show that both components, PS and PMMA, can segregate to the surface of the blend and the copolymer before annealing, although PMMA has a slightly higher surface tension. Upon annealing both SFG results and contact angle measurements indicate that the PS segregates to the surface of the PS/PMMA blend more but no change occurs on the PS-co-PMMA surface. AFM images show that the copolymer surface is flat but the 1:1 PS/PMMA blend has a rougher surface with island like domains present. The annealing effect on the blend surface morphology has also been investigated. We collected amide SFG signals from interfacial fibrinogen molecules at the copolymer or blend/protein solution interfaces as a function of time. Different time-dependent SFG signal changes have been observed, showing that different surfaces of the blend and the copolymer mediate fibrinogen adsorption behavior differently.