The possible influence of third-order shim coils on gradient-magnet interactions: an inter-field and inter-site study

OBJECTIVE

To assess the possible influence of third-order shim coils on the behavior of the gradient field and in gradient-magnet interactions at 7 T and above.

MATERIALS AND METHODS

Gradient impulse response function measurements were performed at 5 sites spanning field strengths from 7 to 11.7 T, all of them sharing the same exact whole-body gradient coil design. Mechanical fixation and boundary conditions of the gradient coil were altered in several ways at one site to study the impact of mechanical coupling with the magnet on the field perturbations. Vibrations, power deposition in the He bath, and field dynamics were characterized at 11.7 T with the third-order shim coils connected and disconnected inside the Faraday cage.

RESULTS

For the same whole-body gradient coil design, all measurements differed greatly based on the third-order shim coil configuration (connected or not). Vibrations and gradient transfer function peaks could be affected by a factor of 2 or more, depending on the resonances. Disconnecting the third-order shim coils at 11.7 T also suppressed almost completely power deposition peaks at some frequencies.

DISCUSSION

Third-order shim coil configurations can have major impact in gradient-magnet interactions with consequences on potential hardware damage, magnet heating, and image quality going beyond EPI acquisitions.

[Stereotactic body radiation therapy for primary kidney cancer]

The incidence of primary renal cancer is increasing, particularly in elderly patients who may have comorbidities and/or a surgical contraindications. Stereotactic body radiotherapy has primarily been evaluated retrospectively to date. The most commonly used dose schedules are 40Gy in five fractions, 42Gy in three fractions, and 26Gy in one fraction. The results in terms of local control and toxicity are very encouraging. The advantages of stereotactic body radiotherapy compared to thermal ablative treatments are its non-invasive nature, absence of general anesthesia, ability to treat larger lesions, and those close to the renal hilum. Prospective evaluations are still necessary.

Walking Ability and Brain Natriuretic Peptide Are Highly Predictive of Kidney Transplant Waiting List Removal

Kidney transplant waitlist management is complex because waiting time is long, and the patients have significant comorbidities. Identification of patients at highest risk for waiting list removal for death and medical complications could allow better outcomes and allocation of resources.

Methods

Demographics, functional and frailty assessment' and biochemical data were retrospectively analyzed on 313 consecutive patients listed for kidney transplant. Troponin, brain natriuretic peptide, components of the Fried frailty metrics, pedometer activity, and treadmill ability were measured at the time of transplant evaluation and at subsequent re-evaluations. Cox proportional hazards models were used to identify factors associated with death or waiting list removal for medical reasons. Multivariate models were created to identify significant predictor sets.

Results

Among 249 patients removed while waitlisted, 19 (6.1%) died and 51 (16.3%) were removed for medical reasons. Mean follow-up duration was 2.3 y (±1.5 y). 417 sets of measurements were collected. Significant (P < 0.05) non-time-dependent variables associated with the composite outcome identified on univariate analysis included N-terminal probrain natriuretic peptide (BNP), treadmill ability, pedometer activity, diagnosis of diabetes and the Center of Epidemiological Studies Depression Scale question asking how many days per week could you not get going. Significant time-dependent factors included BNP, treadmill ability, Up and Go, pedometer activity, handgrip, 30 s chair sit-stand test, and age. The optimal time-dependent predictor set included BNP, treadmill ability, and patient age.

Conclusions

Changes in functional and biochemical markers are predictive of kidney waitlist removal for death and medical reasons. BNP and measures of walking ability were of particular importance.

Insights into How Vietnamese Retailers Utilize Social Media to Facilitate Knowledge Creation through the Process of Value Co-Creation

Social media usage is a direct result of Internet connectivity and is gaining increased prominence in business-to-consumer (B2C), business-to-business (B2B), and consumer-to-business (C2B) relationship building, which is allowing marketers to devise and implement digital marketing strategies that are perceived as enhancing a customer’s well-being. Through the process of utilizing social media (SM) to share information with consumers, marketers are affording themselves with the concept of value co-creation and ensuring that the development of knowledge is given priority. To explain how this happens in an emerging economy, in-depth personal interviews were undertaken with the owners of five retail fashion companies in Vietnam. The findings indicate that fashion retail companies in Vietnam are deploying digital marketing strategies that deliver perceived enhanced value to consumers through the process of value co-creation. This highlights the advantage of using SM in relation to increasing retail staff’s ability to convert information into usable resources such as intelligence and knowledge. By achieving knowledge conversion, retail staff fulfill the role of ‘knowledge broker’ and ‘knowledge connector’, and identify how organizational intervention, such as new operating structures, can help to deliver perceived enhanced value to customers.

TH-MYCN tumors, but not tumor-derived cell lines, are adrenergic lineage, GD2+, and responsive to anti-GD2 antibody therapy

Neuroblastoma is a commonly lethal solid tumor of childhood and intensive chemoradiotherapy treatment cures ~50% of children with high-risk disease. The addition of immunotherapy using dinutuximab, a monoclonal antibody directed against the GD2 disialoganglioside expressed on neuroblasts, improves survival when incorporated into front-line therapy and shows robust activity in regressing relapsed disease when combined with chemotherapy. Still, many children succumb to neuroblastoma progression despite receiving dinutuximab-based immunotherapy, and efforts to counteract the immune suppressive signals responsible are warranted. Animal models of human cancers provide useful platforms to study immunotherapies. TH-MYCN transgenic mice are immunocompetent and develop neuroblastomas at autochthonous sites due to enforced MYCN expression in developing neural crest tissues. However, GD2-directed immunotherapy in this model has been underutilized due to the prevailing notion that TH-MYCN neuroblasts express insufficient GD2 to be targeted. We demonstrate that neuroblasts in TH-MYCN-driven tumors express GD2 at levels comparable to human neuroblastomas but rapidly lose GD2 expression when explanted ex vivo to establish tumor cell lines. This occurs in association with a transition from an adrenergic to mesenchymal differentiation state. Importantly, not only is GD2 expression retained on tumors in situ, treatment with a murine anti-GD2 antibody, 14G2a, markedly extends survival in such mice, including durable complete responses. Tumors in 14G2a-treated mice have fewer macrophage and myeloid-derived suppressor cells in their tumor microenvironment. Our findings support the utility of this model to inform immunotherapy approaches for neuroblastoma and potential opportunities to investigate drivers of adrenergic to mesenchymal fate decisions.

Guided by gaze: Prioritization strategy when navigating through a virtual crowd can be assessed through gaze activity

Modelling crowd behavior is essential for the management of mass events and pedestrian traffic. Current microscopic approaches consider the individual's behavior to predict the effect of individual actions in local interactions on the collective scale of the crowd motion. Recent developments in the use of virtual reality as an experimental tool have offered an opportunity to extend the understanding of these interactions in controlled and repeatable settings. Nevertheless, based on kinematics alone, it remains difficult to tease out how these interactions unfold. Therefore, we tested the hypothesis that gaze activity provides additional information about pedestrian interactions. Using an eye tracker, we recorded the participant's gaze behavior whilst navigating through a virtual crowd. Results revealed that gaze was consistently attracted to virtual walkers with the smallest values of distance at closest approach (DCA) and time to closest approach (TtCA), indicating a higher risk of collision. Moreover, virtual walkers gazed upon before an avoidance maneuver was initiated had a high risk of collision and were typically avoided in the subsequent avoidance maneuver. We argue that humans navigate through crowds by selecting only few interactions and that gaze reveals how a walker prioritizes these interactions. Moreover, we pose that combining kinematic and gaze data provides new opportunities for studying how interactions are selected by pedestrians walking through crowded dynamic environments.

Comprehensive development and testing of the ASIST-GBV, a screening tool for responding to gender-based violence among women in humanitarian settings

Background

Conflict affected refugees and internally displaced persons (IDPs) are at increased vulnerability to gender-based violence (GBV). Health, psychosocial, and protection services have been implemented in humanitarian settings, but GBV remains under-reported and available services under-utilized. To improve access to existing GBV services and facilitate reporting, the ASIST-GBV screening tool was developed and tested for use in humanitarian settings. This process was completed in four phases: 1) systematic literature review, 2) qualitative research that included individual interviews and focus groups with GBV survivors and service providers, respectively, 3) pilot testing of the developed screening tool, and 4) 3-month implementation testing of the screening tool. Research was conducted among female refugees, aged ≥15 years in Ethiopia, and female IDPs, aged ≥18 years in Colombia.

Results

The systematic review and meta-analysis identified a range of GBV experiences and estimated a 21.4 % prevalence of sexual violence (95 % CI:14.9-28.7) among conflict-affected populations. No existing screening tools for GBV in humanitarian settings were identified. Qualitative research with GBV survivors in Ethiopia and Colombia found multiple forms of GBV experienced by refugees and IDPs that occurred during conflict, in transit, and in displaced settings. Identified forms of violence were combined into seven key items on the screening tool: threats of violence, physical violence, forced sex, sexual exploitation, forced pregnancy, forced abortion, and early or forced marriage. Cognitive testing further refined the tool. Pilot testing in both sites demonstrated preliminary feasibility where 64.8 % of participants in Ethiopia and 44.9 % of participants in Colombia were identified with recent (last 12 months) cases of GBV. Implementation testing of the screening tool, conducted as a routine service in camp/district hospitals, allowed for identification of GBV cases and referrals to services. In this phase, 50.6 % of participants in Ethiopia and 63.4 % in Colombia screened positive for recent experiences of GBV. Psychometric testing demonstrated appropriate internal consistency of the tool (Cronbach’s α = 0.77) and item response theory demonstrated appropriate discrimination and difficulty of the tool.

Conclusion

The ASIST-GBV screening tool has demonstrated utility and validity for use in confidential identification and referral of refugees and IDPs who experience GBV.

Narrow band imaging: clinical applications in oral and oropharyngeal cancer

Narrow Band Imaging (NBI) is an endoscopic optical imaging enhancement technology that improves the contrast of mucosal surface texture, and enhances visualisation of mucosal and submucosal vasculature. White light is filtered to emit two 30-nm narrow bands of blue (415 nm) and green light (540 nm) light simultaneously, the former corresponding to the main peak absorption spectrum of haemoglobin, and the latter allowing visualisation of blood vessels in the deeper mucosal and submucosal layers. NBI has been used to better assess oral potentially malignant disorders (OPMD), identify oral and oropharyngeal squamous cell carcinoma (SCC), and to define surgical margins of head and neck malignancies. NBI shows great potential in improving detection rates of OPMD, facilitating better assessment of oral and oropharyngeal SCC, and reducing the risk of recurrence for oral SCC. Although further research is required to better understand and define intrapapillary capillary loop (IPCL) patterns and to relate these with clinical, histopathological and molecular parameters especially for early mucosal changes, there is building evidence to recommend its use as the new gold standard for endoscopic assessment in head and neck oncology.

Discovery of novel selective norepinephrine inhibitors: 1-(2-morpholin-2-ylethyl)-3-aryl-1,3-dihydro-2,1,3-benzothiadiazole 2,2-dioxides (WYE-114152)

Sequential modification of the previously identified 4-[3-aryl-2,2-dioxido-2,1,3-benzothiadiazol-1(3H)-yl]-1-(methylamino)butan-2-ols led to the identification of a new series of 1-(2-morpholin-2-ylethyl)-3-aryl-1,3-dihydro-2,1,3-benzothiadiazole 2,2-dioxides that are potent and selective inhibitors of the norepinephrine transporter over both the serotonin and dopamine transporters. One representative compound 10b (WYE-114152) had low nanomolar hNET potency (IC(50) = 15 nM) and good selectivity for hNET over hSERT (>430-fold) and hDAT (>548-fold). 10b was additionally bioavailable following oral dosing and demonstrated efficacy in rat models of acute, inflammatory, and neuropathic pain.

Annualized was found better than absolute risk reduction in the calculation of number needed to treat in chronic conditions

BACKGROUND AND OBJECTIVE

Recent studies have calculated number needed to treat (NNT) estimates based on annualized rates; however, the ramifications of altering the NNT statistic have not yet been explored in the literature. Here we introduce the concept of annualized NNT (ANNT), and apply it to data from randomized controlled trials (RCTs).

METHODS

Incidence rates from RCTs for serious adverse events for three medicines were compared to an older class of drugs. NNT and ANNT were calculated from the event rates for these events.

RESULTS

Based on the data, the NNT to prevent one adverse event a year vs. older medications was drug A, ANNT = 88; drug B, ANNT = 77; drug C, ANNT = 68. Equivalent calculations based on Bayesian statistics are drug C, ANNT = 54; drug B, ANNT = 49. Drug A produced a bimodal distribution, with one mode within the NNT range and the other in the number needed to harm range.

CONCLUSIONS

NNT can erroneously inflate differences between treatments when based on absolute and not differential safety. We propose that NNT be limited to acute conditions with short-term, well-defined treatment courses, and that ANNT be used for chronic conditions.

Valdecoxib is associated with improved dyspepsia-related health compared with nonspecific NSAIDs in patients with osteoarthritis or rheumatoid arthritis

OBJECTIVES

Dyspepsia and related gastrointestinal (GI) symptoms are commonly reported by patients taking nonspecific nonsteroidal anti-inflammatory drugs (NSAIDs) and significantly impact treatment effectiveness, cost, and quality of life. This study sought to evaluate dyspepsia-related health in osteoarthritis (OA) and rheumatoid arthritis (RA) patients taking valdecoxib compared with patients taking nonspecific NSAIDs.

METHODS

Analysis of two separate, double-blind, placebo-controlled studies: one in RA patients randomized to placebo, valdecoxib (10 and 20 mg once daily [o.d.]) and naproxen (500 mg twice daily [b.i.d.]); one in OA patients randomized to placebo, valdecoxib (10 and 20 mg o.d.), diclofenac (75 mg b.i.d.), or ibuprofen (800 mg three times daily [t.i.d.]). Study population comprised patients with RA in flare or clinically documented OA who required chronic symptomatic treatment with NSAIDs/analgesics. Dyspepsia-related health was evaluated at baseline and weeks 2, 6, and 12 (or early termination) using the validated Severity of Dyspepsia Assessment (SODA) questionnaire. This patient self-report tool consists of scales for evaluating dyspepsia pain intensity, nonpain symptoms, and satisfaction. Analysis was based on the intent-to-treat population with the last observation carried forward.

RESULTS

Valdecoxib was significantly better at endpoint than standard doses of naproxen, diclofenac, and ibuprofen for pain intensity scores (p < 0.05), and provided significantly improved nonpain symptom and satisfaction scores compared with naproxen for patients with RA (p < 0.05). For RA patients, the difference between valdecoxib and naproxen pain intensity scores were clinically meaningful; at all the time points, significantly fewer patients receiving valdecoxib reported severe dyspepsia pain intensity increases (>/=10 points) than those receiving naproxen. At 12 wk, fewer patients receiving valdecoxib reported severe dyspepsia pain intensity increases versus those receiving ibuprofen and diclofenac.

CONCLUSIONS

The GI tolerability of valdecoxib is superior to that of nonspecific NSAIDs, and therefore can potentially have a favorable impact on patient quality of life.

Effect of acute physiologic derangements on outcome after subarachnoid hemorrhage

OBJECTIVE

To determine the effect that acute physiologic derangements have on outcome after subarachnoid hemorrhage (SAH) and to design a composite score summarizing these abnormalities.

DESIGN

Prospective observational study.

SETTING

Neuroscience intensive care unit in a tertiary care academic center.

PATIENTS

Consecutive cohort of 413 patients with SAH admitted within 3 days of SAH onset with 3-month modified Rankin Scale scores.

INTERVENTIONS

None.

RESULTS

Among 20 physiologic variables assessed within 24 hrs of admission, four were independently associated with death or severe disability (modified Rankin Scale score, 4-6) at 3 months in a multivariate analysis: arterio-alveolar gradient of >125 mm Hg (odds ratio [OR], 4.5; 95% confidence interval [CI], 2.7-7.6), serum bicarbonate of <20 mmol/L (OR, 2.9; 95% CI, 1.6-5.6), serum glucose of >180 mg/dL (OR, 2.8; 95% CI, 1.6-4.8), and mean arterial pressure of <70 or >130 mm Hg (OR, 1.7; 95% CI, 1.0-2.9). Based on their proportional contribution to outcome, we constructed the SAH Physiologic Derangement Score (SAH-PDS; range, 0-8) by assigning the following weights for abnormal findings: arterio-alveolar gradient, 3 points; bicarbonate, 2 points; glucose, 2 points; and mean arterial pressure, 1 point. After controlling for known predictors of death or severe disability (age, admission neurologic status, loss of consciousness, aneurysm size, intraventricular hemorrhage, and rebleeding), the SAH Physiologic Derangement Score was independently associated with poor outcome (OR, 1.3 for each point increase; 95% CI, 1.1-1.6). By contrast, the systemic inflammatory response syndrome score and the Acute Physiology and Chronic Health Evaluation II physiologic subscore did not add predictive value to the model.

CONCLUSION

Acute interventions specifically targeting hypoxemia, metabolic acidosis, hyperglycemia, and cardiovascular instability may improve the outcome of SAH patients. The SAH Physiologic Derangement Score may prove useful for rapidly quantifying the severity of important physiologic derangements in acute SAH.

Effects of systemic hemodynamics on flow within vascular accesses used for hemodialysis

Absolute value of access flow (QA) and change in flow (deltaQA) over time are major determinants of access patency. However, QA may change in response to variation in systemic hemodynamics among dialysis sessions. We examined the effect of mean arterial pressure (MAP), cardiac output (CO), and segmental resistances (R) on QA. Access flow and CO (L/min) were determined by Transonic ultrasound dilution. Static intra-access pressures (mm Hg) at the arterial segment (AS) and venous segment (VS) were determined with the access unoccluded. During access occlusion (O), the AS pressure was equated to arterial pressure (MAPo), whereas the VS pressure reflected venous pressure (VP). Total and segmental vascular resistances (mm Hg-min/L) were calculated as deltaP/Q. We studied 58 arteriovenous (AV) grafts and 35 autologous AV fistulae (AVF) with measurements on two or more occasions in 43 grafts and 25 AVF. MAPC differed from MAPo by >20 mm Hg in 22% of patients. AS (58 +/- 2 vs. 31 +/- 2) and VS (40 +/- 1 vs. 25 +/- 2) were greater in grafts than in AVF, whereas VP was equal. Access flow (0.91 +/- 0.03 vs. 0.91 +/- 0.05 L/min), cardiac output (5.1 +/- 0.1 vs. 5.5 +/- 0.2 L/min), and total access resistance (115 +/- 5 vs. 11 +/- 6) were equal in grafts and AVF, but non-access systemic R was lower in patients with AVF that those with grafts (26 +/- 1 vs. 30 +/- 1). AS and VS resistances were greater in AVF than grafts (87 +/- 6 vs. 54 +/- 3 and 37 +/- 3 vs. 16 +/- 3). Multivariate analysis indicated that CO and ipsilateral MAPo affected flow in both access types. In grafts, all three access resistance elements, AS, VS, and total independently influenced flow, whereas in AVF, the VS did not. Unexpectedly, the ratio of systemic to access resistance also influenced access flow. The pressure in the venous system draining the access affected access flow in AVF but not grafts. We conclude that the hemodynamics of grafts and AVF differ. Cardiac output, MAP, and the arterial segment resistance influence QA in both access types and need to be considered when evaluating QA as part of the trend analysis for detecting access dysfunction.

[Papillomatous and nevus of the caruncle]

A 63-year-old male patient was operated of a single conjunctival papillomatous lesion located on the left caruncle. The curative tumoral excision was followed by its histological analysis. Histologically, the tumor associated an epithelial squamous papilloma with a subepithelial nevus, confirming a combination of two different lesions.

Interaction between terminal complement proteins C5b-7 and anionic phospholipids

We have recently shown that C5b-6 binds to the erythrocyte membrane via an ionic interaction with sialic acid before the addition of C7 and subsequent membrane insertion. In this study we assessed the role of anionic lipids in the binding of the terminal complement proteins to the membrane and the efficiency of subsequent hemolysis. Human erythrocytes were modified by insertion of dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylserine (DPPS), dipalmitoyl phosphatidylethanolamine (DPPE), or dipalmitoyl phosphatidic acid (DPPA). Lipid incorporation and the hemolytic assays were done in the presence of 100 micromol/L sodium orthovanadate to prevent enzymatic redistribution of lipid. We found that the neutral lipids, DPPC and DPPE, did not affect C5b-7 uptake or hemolysis by C5b-9. In contrast, the two acidic phospholipids, DPPS and DPPA, caused a dose-dependent increase in both lysis and C5b-7 uptake. We conclude that the presence of anionic lipids on the exterior face of the membrane increases C5b-7 uptake and subsequent hemolysis. It is known that sickle cell erythrocytes have increased exposure of phosphatidylserine on their external face and are abnormally sensitive to lysis by C5b-9. The data presented here provide a plausible mechanism for this increased sensitivity.