Interrater Reliability in the Measurement of Flow Characteristics on Color-Coded Quantitative DSA of Brain AVMs

BACKGROUND AND PURPOSE

Hemodynamic features of brain AVMs may portend increased hemorrhage risk. Previous studies have suggested that MTT is shorter in ruptured AVMs as assessed on quantitative color-coded parametric DSA. This study assesses the interrater reliability of MTT measurements obtained using quantitative color-coded DSA.

MATERIALS AND METHODS

Thirty-five color-coded parametric DSA images of 34 brain AVMs were analyzed by 4 neuroradiologists with experience in interventional neuroradiology. Hemodynamic features assessed included MTT of the AVM and TTP of the dominant feeding artery and draining vein. Agreement among the 4 raters was assessed using the intraclass correlation coefficient.

RESULTS

The interrater reliability among the 4 raters was poor (intraclass correlation coefficient = 0.218; 95% CI, 0.062-0.414; P value = .002) as it related to MTT assessment. When the analysis was limited to cases in which the raters selected the same image to analyze and selected the same primary feeding artery and the same primary draining vein, interrater reliability improved to fair (intraclass correlation coefficient  = 0.564; 95% CI, 0.367-0.717; P < .001).

CONCLUSIONS

Interrater reliability in deriving color-coded parametric DSA measurements such as MTT is poor so minor differences among raters may result in a large variance in MTT and TTP results, partly due to the sensitivity and 2D nature of the technique. Reliability can be improved by defining a standard projection, feeding artery, and draining vein for analysis.

The Effect of Increased Temperatures on Viability, Morphology, Infectivity, and Development of Eimeria tenella

Commonly found in backyard and commercial poultry production, coccidiosis, caused by Eimeria species, presents a self-limiting intestinal infection based on the number of ingested oocysts. Heat stress (HS) is one of the major environmental stressors in poultry, predisposing broiler chickens to immunosuppression and rendering them susceptible to diseases. There are suggestions that HS reduces Eimeria oocyst shedding in chickens; however, the relationship between HS and coccidiosis is not well elucidated. The objective of this study was to investigate the effect of temperature on viability, morphology, infectivity, and development of Eimeria tenella in vitro, and merozoite production and oocyst shedding in vivo. In vitro exposure of sporozoites to 55 C for at least 60 min reduced sporozoites viability as shown by morphological changes and rendering them unable to invade Mardin-Darbi bovine kidney (MDBK) cells. Intracellular development of merozoites was significantly reduced by an increase in 2 C in the optimal temperature of incubation in vitro. Most importantly, the induction of HS in the live chickens caused significantly lower lesion scores, reduced merozoite production, and oocyst shedding, resulting in a much less severe disease outcome.

High Prevalence of Spinal Cord Cavernous Malformations in the Familial Cerebral Cavernous Malformations Type 1 Cohort

BACKGROUND AND PURPOSE

Cavernous malformations occur most often in the brain but can occur in the spinal cord. Small studies of patients with familial cerebral cavernous malformations suggested a prevalence of spinal cord cavernous malformations of 20%-42%. We aimed to review our familial cohort and prospectively estimate the prevalence of spinal cord cavernous malformations.

MATERIALS AND METHODS

We initially reviewed our familial cerebral cavernous malformations cohort for spinal cord cavernous malformations and reviewed clinical spine MR imaging examinations for sequence sensitivity. We then prospectively performed research MR imaging of the spinal cord in 29 patients from the familial cohort to estimate the prevalence.

RESULTS

Gradient-based sequences identified the most spinal cord cavernous malformations on clinical MR images, forming the basis for developing our screening MR imaging. Screening spinal cord MR imaging demonstrated a prevalence of 72.4%, and a positive correlation with patient age and number of cerebral cavernous malformations.

CONCLUSIONS

Spinal cord cavernous malformations occur commonly in the familial cerebral cavernous malformation population. Gradient-based sequences are the most sensitive and should be used when spinal cord cavernous malformations are suspected. This study establishes the prevalence in the familial population at around 70% and supports the idea that this condition is a progressive systemic disease that affects the entire central nervous system.

2D parametric contrast time-density analysis for the prediction of complete aneurysm occlusion at six months' post-flow diversion stent

OBJECTIVE

Indications for the treatment of cerebral aneurysms with flow diversion stents are expanding. The current aneurysm occlusion rate at six months ranges between 60 and 80%. Predictability of complete vs. partial aneurysm occlusion is poorly defined. Here, we evaluate the angiographic contrast time-density as a predictor of aneurysm occlusion rate at six months' post-flow diversion stents.

METHODS

Patients with unruptured cerebral aneurysms proximal to the internal carotid artery terminus treated with single flow diversion stents were included. 2D parametric parenchymal blood flow software (Siemens-Healthineers, Forchheim, Germany) was used to calculate contrast time-density within the aneurysm and in the proximal adjacent internal carotid artery. The area under the curve ratio between the two regions of interests was assessed at baseline and after flow diversion stents deployment. The area under the curve ratio between completely vs. partially occluded aneurysms at six months' follow-up was compared.

RESULTS

Thirty patients with 31 aneurysms were included. Mean aneurysm diameter was 8 mm (range 2-28 mm). Complete occlusion was obtained in 19 aneurysms. Younger patients (P = 0.006) and smaller aneurysms (P = 0.046) presented higher chance of complete obliteration. Incomplete occlusion of the aneurysm was more likely if the area under the curve contrast time-density ratio showed absolute (P = 0.001) and relative percentage (P = 0.001) decrease after flow diversion stents deployment. Area under ROC curve was 0.85.

CONCLUSION

Negative change in the area under the curve ratio indicates less contrast stagnation in the aneurysm and lower chance of occlusion. These data provide a real-time analysis after aneurysm treatment. If validated in larger datasets, this can prompt input to the surgeon to place a second flow diversion stents.

Substrate Supporting Disc Method for Confirmed Detection of Total Coliforms and E. coli in all Foods: Collaborative Study

The Coli Complete® substrate supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with AOAC most probable number (MPN) methods, 966.23 and 966.24. Twenty-nine laboratories participated in this collaborative study in which 6 food types were analyzed. Four food types, raw ground beef, pork sausage, raw liquid milk, and nut meats, were naturally contaminated with coliform bacteria. Two foods, dry egg and fresh frozen vegetables, were seeded with coliforms. Three food types, ground beef, raw liquid milk, and pork sausage, were naturally contaminated with E. coli. Although pork sausage was naturally contaminated, the level was very low (&lt;10/50 g); therefore, additional E. coli were inoculated into 1 lot of this food type. Three food types, nut meats, dry egg, and fresh frozen vegetables, were inoculated with E. coli. For naturally contaminated samples, duplicate determinations were made on 3 separate lots for each food type. For inoculated samples, low, medium, and high contamination levels plus uninoculated control samples were examined in duplicate. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN method. Results were then analyzed for repeatability, reproducibility, and mean log MPN statistical equivalence. Results were statistically equivalent for all total coliform levels in all food types except frozen vegetable and raw nut meat uninoculated control samples and 1 lot of pork sausage where the SSD method produced statistically significant greater numbers. For the E. coli determinations, results were statistically equivalent across all samples and all levels for each food type. The SSD method has been adopted first action by AOAC International for confirmed detection of total coliforms and E. coli in all foods.

Intracranial venous sinus stenosis: hemodynamic assessment with two-dimensional parametric parenchymal blood flow software on digital subtraction angiography

Objective

Intracranial venous sinus stenosis (IVSS) is the most common finding associated with idiopathic intracranial hypertension. A pressure gradient >8–10 mm Hg across the stenosis is considered hemodynamically significant, and typically responds to endovascular stent treatment. Here we assess the venous hemodynamics with two-dimensional (2D) parametric parenchymal blood flow software (Siemens-Healthineers, Forchheim, Germany) and its ability to predict significant IVSS.

Methods

Patients with IVSS treated at our institution between 2013 and 2018 were retrospectively reviewed. Measurements of contrast transit time on DSA were calculated with 2D parametric parenchymal blood flow software. Values were obtained proximally and distally to the stenotic region. Venous Stenosis Index (VSI) was defined as the ratio of the area under the curve (AUC) in the pre-stenotic vessel to the AUC in the post-stenotic vessel. VSI was compared between the stenotic and control groups at baseline, and before and after stent deployment in the stenotic group. The accuracy of VSI was assessed using the non-parametric receiver operating characteristic (ROC) curve.

Results

11 patients with IVSS treated with venous stent deployment were included. Patients in the control group were similar in age, gender, and absence of major comorbidities. VSI in the IVSS group was significantly higher at baseline compared with the control group (1.42 vs 0.97, p=0.01). Area under the ROC was 0.82. After stent deployment, VSI decreased significantly compared with baseline (1.04 vs 1.42, p<0.01).

Conclusion

2D parametric parenchymal blood flow software is a useful tool which can accurately evaluate significant hemodynamic venous stenosis without intracranial catheterization, added radiation exposure, additional contrast injection, and periprocedural risks.

The clinical course of actinic keratosis correlates with underlying molecular mechanisms

BACKGROUND

Actinic keratoses (AKs) are common premalignant skin lesions triggered by excessive ultraviolet exposure. The majority of AKs regress or persist, but some progress to squamous cell carcinomas. Biomarkers associated with their persistence, progression and regression have not been characterized.

OBJECTIVES

We performed skin biopsies in patients with extensive actinic damage to identify biomarkers that correlate with clinical progression and regression of AKs.

METHODS

This was an observational study of a cohort of patients with extensive actinic damage. AKs were mapped on a clear plastic template in 26 patients at months 3, 6, 9 and 11. Biopsies were taken from randomly selected, predetermined AKs and were evaluated for p53, E-cadherin, Snail, Slug and Twist. The study is registered at Clinicaltrials.gov: NCT00027976.

RESULTS

p53 exhibited greater expression in clinically apparent AKs (histological score 2·89 ± 1·45) than in regressed AKs (0·75 ± 0·96); P < 0·01. There was also significantly less membrane E-cadherin, the lack of which is a marker of epithelial-mesenchymal transition, in clinically apparent AKs (1·89 ± 1·81) than in sun-exposed skin (3·07 ± 1·75); P < 0·005. The E-cadherin transcription repressors Snail, Slug and Twist were increased in AKs compared with sun-exposed skin. A limitation of the study is that measurement of histological biomarkers was not a primary end point. In addition, patients were allowed to apply sunscreens.

CONCLUSIONS

At the molecular level, loss of E-cadherin and an increase in p53 are linked to the dynamic interplay between the persistence, progression and regression of AKs. What's already known about this topic? Actinic keratoses (AKs) are common dysplastic epidermal lesions that result from chronic and excessive ultraviolet exposure. Biomarkers associated with progression and regression of AK have not been characterized. What does this study add? Decreased E-cadherin and increased p53, Snail, Slug and Twist (E-cadherin transcription factors) were associated with progression from AK to nonmelanoma skin cancer. What is the translational message? Strategies targeting these molecules may be effective in reversing rising skin cancer rates. E-cadherin, p53, Snail, Slug and Twist are potential biomarkers that may be used to assess the efficacy of existing chemopreventive agents.

Measurements of Nonsinglet Moments of the Nucleon Structure Functions and Comparison to Predictions from Lattice QCD for Q^{2}=4 GeV^{2}

We present extractions of the nucleon nonsinglet moments utilizing new precision data on the deuteron F_{2} structure function at large Bjorken-x determined via the Rosenbluth separation technique at Jefferson Lab Experimental Hall C. These new data are combined with a complementary set of data on the proton previously measured in Hall C at similar kinematics and world datasets on the proton and deuteron at lower x measured at SLAC and CERN. The new Jefferson Lab data provide coverage of the upper third of the x range, crucial for precision determination of the higher moments. In contrast to previous extractions, these moments have been corrected for nuclear effects in the deuteron using a new global fit to the deuteron and proton data. The obtained experimental moments represent an order of magnitude improvement in precision over previous extractions using high x data. Moreover, recent exciting developments in lattice QCD calculations provide a first ever comparison of these new experimental results with calculations of moments carried out at the physical pion mass, as well as a new approach that first calculates the quark distributions directly before determining moments.

Aplidin (plitidepsin) is a novel anti-myeloma agent with potent anti-resorptive activity mediated by direct effects on osteoclasts

Despite recent progress in its treatment, Multiple Myeloma (MM) remains incurable and its associated bone disease persists even after complete remission. Thus, identification of new therapeutic agents that simultaneously suppress MM growth and protect bone is an unmet need. Herein, we examined the effects of Aplidin, a novel anti-cancer marine-derived compound, on MM and bone cells. In vitro, Aplidin potently inhibited MM cell growth and induced apoptosis, effects that were enhanced by dexamethasone (Dex) and bortezomib (Btz). Aplidin modestly reduced osteocyte/osteoblast viability and decreased osteoblast mineralization, effects that were enhanced by Dex and partially prevented by Btz. Further, Aplidin markedly decreased osteoclast precursor numbers and differentiation, and reduced mature osteoclast number and resorption activity. Moreover, Aplidin reduced Dex-induced osteoclast differentiation and further decreased osteoclast number when combined with Btz. Lastly, Aplidin alone, or suboptimal doses of Aplidin combined with Dex or Btz, decreased tumor growth and bone resorption in ex vivo bone organ cultures that reproduce the 3D-organization and the cellular diversity of the MM/bone marrow niche. These results demonstrate that Aplidin has potent anti-myeloma and anti-resorptive properties, and enhances proteasome inhibitors blockade of MM growth and bone destruction.

Spectroscopic Investigation of the Effect of Microstructure and Energetic Offset on the Nature of Interfacial Charge Transfer States in Polymer: Fullerene Blends

Despite performance improvements of organic photovoltaics, the mechanism of photoinduced electron–hole separation at organic donor–acceptor interfaces remains poorly understood. Inconclusive experimental and theoretical results have produced contradictory models for electron–hole separation in which the role of interfacial charge-transfer (CT) states is unclear, with one model identifying them as limiting separation and another as readily dissociating. Here, polymer–fullerene blends with contrasting photocurrent properties and enthalpic offsets driving separation were studied. By modifying composition, film structures were varied from consisting of molecularly mixed polymer–fullerene domains to consisting of both molecularly mixed and fullerene domains. Transient absorption spectroscopy revealed that CT state dissociation generating separated electron–hole pairs is only efficient in the high energy offset blend with fullerene domains. In all other blends (with low offset or predominantly molecularly mixed domains), nanosecond geminate electron–hole recombination is observed revealing the importance of spatially localized electron–hole pairs (bound CT states) in the electron–hole dynamics. A two-dimensional lattice exciton model was used to simulate the excited state spectrum of a model system as a function of microstructure and energy offset. The results could reproduce the main features of experimental electroluminescence spectra indicating that electron–hole pairs become less bound and more spatially separated upon increasing energy offset and fullerene domain density. Differences between electroluminescence and photoluminescence spectra could be explained by CT photoluminescence being dominated by more-bound states, reflecting geminate recombination processes, while CT electroluminescence preferentially probes less-bound CT states that escape geminate recombination. These results suggest that apparently contradictory studies on electron–hole separation can be explained by the presence of both bound and unbound CT states in the same film, as a result of a range of interface structures.

Erratum: First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector [Phys. Rev. Lett. 121, 051301 (2018)]

This corrects the article DOI: 10.1103/PhysRevLett.121.051301.

Objective Assessment of Arterial Steal Phenomenon in Direct Carotid Cavernous Fistula Using 2D Parametric Parenchymal Blood Flow Analysis

The aim of the study is to evaluate the hemodynamic changes and the parenchymal perfusion associated with carotid cavernous fistulas before and after embolization using two-dimensional (2D) parenchymal blood flow analysis. A 15-year-old boy presented with 2-month history of progressive right eye proptosis, chemosis, and diplopia after a motor vehicle accident. Intracranial liquid embolization using Onyx-18 through the inferior petrosal approach was done with balloon protection at the opening of the fistula in the internal carotid artery, resulting in complete occlusion of the fistula. Parenchymal blood flow analysis was done before and immediately after embolization. 2D parametric parenchymal blood flow analysis is newly introduced software that can provide data cannot be conveyed by conventional digital subtraction angiography alone. The software allows for objective assessment of the arterial steal and the parenchymal perfusion both pre, and post-embolization. Pre-embolization assessment may influence the therapeutic decision, while post-embolization assessment can evaluate the treatment efficacy.

The Manufacturing of a Multi-surface Monolithic Telescope with Freeform Surfaces

Monolithic multi-surface telescopes combined with freeform optical surfaces provide improvements in optical performance in a smaller footprint as compared to systems with spherical surfaces, while providing superior mechanical stability to traditional telescope assemblies. Three different monolithic telescope concepts, in different configurations and optical performance were produced as proof of concepts. The results of the telescopes are presented as well as the unique manufacturing and testing challenges to produce these monolithic optical systems.