Citations

AbstractWe evaluated a commercially available software package that uses B‐mode images to semi‐automatically measure quantitative metrics of ultrasound image quality, such as contrast response, depth of penetration (DOP), and spatial resolution (lateral, axial, and elevational). Since measurement of elevational resolution is not a part of the software package, we achieved it by acquiring phantom images with transducers tilted at 45 degrees relative to the phantom. Each measurement was assessed in terms of measurement stability, sensitivity, repeatability, and semi‐automated measurement success rate. All assessments were performed on a GE Logiq E9 ultrasound system with linear (9L or 11L), curved (C1‐5), and sector (S1‐5) transducers, using a CIRS model 040GSE phantom. In stability tests, the measurements of contrast, DOP, and spatial resolution remained within a ±10% variation threshold in 90%, 100%, and 69% of cases, respectively. In sensitivity tests, contrast, DOP, and spatial resolution measurements followed the expected behavior in 100%, 100%, and 72% of cases, respectively. In repeatability testing, intra‐ and inter‐individual coefficients of variations were equal to or less than 3.2%, 1.3%, and 4.4% for contrast, DOP, and spatial resolution (lateral and axial), respectively. The coefficients of variation corresponding to the elevational resolution test were all within 9.5%. Overall, in our assessment, the evaluated package performed well for objective and quantitative assessment of the above‐mentioned image qualities under well‐controlled acquisition conditions. We are finding it to be useful for various clinical ultrasound applications including performance comparison between scanners from different vendors.

Summary Objective Limited data are available regarding the evolution over time of the rate of sudden unexpected death in epilepsy patients (SUDEP) in drug‐resistant epilepsy. The objective is to analyze a database of 40 443 patients with epilepsy implanted with vagus nerve stimulation (VNS) therapy in the United States (from 1988 to 2012) and assess whether SUDEP rates decrease during the postimplantation follow‐up period. Methods Patient vital status was ascertained using the Centers for Disease Control and Prevention's National Death Index (NDI). An expert panel adjudicated classification of cause of deaths as SUDEP based on NDI data and available narrative descriptions of deaths. We tested the hypothesis that SUDEP rates decrease with time using the Mann‐Kendall nonparametric trend test and by comparing SUDEP rates of the first 2 years of follow‐up (years 1‐2) to longer follow‐up (years 3‐10). Results Our cohort included 277 661 person‐years of follow‐up and 3689 deaths, including 632 SUDEP. Primary analysis demonstrated a significant decrease in age‐adjusted SUDEP rate during follow‐up ( S = −27 P = .008), with rates of 2.47/1000 for years 1‐2 and 1.68/1000 for years 3‐10 (rate ratio 0.68; 95% confidence interval [CI] 0.53‐0.87; P = .002). Sensitivity analyses confirm these findings. Significance Our data suggest that SUDEP risk significantly decreases during long‐term follow‐up of patients with refractory epilepsy receiving VNS Therapy. This finding might reflect several factors, including the natural long‐term dynamic of SUDEP rate, attrition, and the impact of VNS Therapy. The role of each of these factors cannot be confirmed due to the limitations of the study.

ABSTRACT BACKGROUND AND PURPOSE SISCOM and STATISCOM were clinically proved to be effective for ictal/inter‐ictal single‐photon emission computed tomography (SPECT) analysis coregistered with magnetic resonance imaging (MRI) for seizure localization. Recently, a software package also became available for this analysis. This study aimed to investigate and compare the performance of these analysis methods for seizure localization. METHODS A total of 378 patients who underwent 99m Tc‐ethyl cysteinate dimer (ECD) SPECT scans were retrospectively reviewed and 28 remained after applying exclusion criteria. Their SPECT and MRI images were analyzed with SISCOM (with z ‐score of 1.5 and 2), STATISCOM, and MIMneuro, resulting in a total of 112 image data sets. Two experienced radiologists participated in the blind review process using a custom tool and they can mark up to two hyper‐ and/or hypoperfusion regions. Their review results were analyzed using the Jackknife Free Response Receiver‐Operating Characteristics (JAFROC) test and the JAFROC figure‐of‐merit (FoM) was reported for each method. The interobserver agreement was also assessed using Cohen's kappa test. RESULTS Based on the readers’ two choices, averaged FoM was 85.7%, 83.9%, 66.1%, and 51.8% for STATISCOM, MIMneuro, SISCOM ( z ‐score = 2), and SISCOM ( z ‐score = 1.5), respectively. The average confidence rating was 2.5, 2.3, 1.6, and 1.1 for STATISCOM, MIMneuro, SISCOM ( z ‐score = 2), and SISCOM ( z ‐score = 1.5), respectively. For interobserver agreement, kappa was .742 for STATISCOM, .816 for MIMneuro, .517 for SISCOM ( z ‐score = 2), and .441 for SISCOM ( z ‐score = 1.5; all P < .001). CONCLUSION Our study demonstrated that STATISCOM showed the best performance for seizure localization, which was closely followed by MIMneuro. In addition, MIMneuro was not inferior to SISCOM with either z ‐score.

ABSTRACT Microglia as immune cells of the central nervous system (CNS) play significant roles not only in pathology but also in physiology, such as shaping of the CNS during development and its proper maintenance in maturity. Emerging research is showing a close association between microglia and the neurovasculature that is critical for brain energy supply. In this review, we summarize the current literature on microglial interaction with the vascular system in the normal and diseased brain. First, we highlight data that indicate interesting potential involvement of microglia in developmental angiogenesis. Then we discuss the evidence for microglial participation with the vasculature in neuropathologies from brain tumors to acute injuries such as ischemic stroke to chronic neurodegenerative conditions. We conclude by suggesting future areas of research to advance the field in light of current technical progress and outstanding questions. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 604–617, 2018

Methods developed previously for studying the effect of cerebroventricular injection or ventriculocisternal perfusion of test substances are unsatisfactory because the test substance is not confined to the central compartment. Most likely the test substance enters the peripheral circulation via the arachnoid villi. The purpose of this paper is to describe a method for perfusing the cerebroventricular system of conscious dogs without passage of test substances to the peripheral circulation. With the method described, the mean (+/- SE) cerebroventricular pressure in conscious dogs was 7.4 +/- 0.8 cmH2O (n = 16), and the mean (+/- SE) production of cerebrospinal fluid (CSF) was 25 +/- 0.3 microliter/min (n = 16). Endogenously occurring migrating myoelectric complexes (MMCs) of the small intestine were recorded in dogs before catheters were implanted in the left and right lateral ventricles and the fourth ventricle and after catheter implantation during cerebroventricular perfusion with artificial CSF alone or with CSF containing sulfated (S-CCK-OP) or nonsulfated cholecystokinin octapeptide (NS-CCK-OP). Only cerebroventricular perfusion with S-CCK-OP (1.2 pmol.kg-1.min-1; n = 20) replaced spontaneously occurring MMCs with a fed-like pattern of myoelectric activity. The results suggest that replacement of the fasting pattern of myoelectric activity with a fed-like pattern in the fasted dog was mediated by CCK-A receptors located in one or more brain nuclei surrounding the third ventricle.

The present study tested the hypothesis that the presence of renal prostaglandin E2 (PGE2) is necessary for full natriuretic response to increased renal interstitial hydrostatic pressure (RIHP) during increased renal perfusion pressure (RPP). In control untreated pentobarbital-anesthetized dogs (n = 7), fractional excretion of sodium (FENa) was 1.17 +/- 0.48, 1.07 +/- 0.24, and 2.69 +/- 0.57% at RPP of 90, 122, and 148 mmHg, respectively. These changes in FENa were associated with effective renal blood flows (ERBF) of 1.43 +/- 0.20, 1.49 +/- 0.23, and 1.99 +/- 0.40 ml.min-1.g kidney wt-1, respectively. Similarly, glomerular filtration rate (GFR) was 0.53 +/- 0.10, 0.71 +/- 0.10, and 0.72 +/- 0.14 ml.min-1.g kidney wt-1, respectively. Treatment with indomethacin, a cyclooxygenase inhibitor, significantly lowered FENa to 0.45 +/- 0.13, 0.77 +/- 0.21, and 1.19 +/- 0.59% at RPP of 91, 121, and 146 mmHg, respectively. Additionally, indomethacin treatment lowered ERBF (0.51 +/- 0.15, 0.52 +/- 0.10, and 0.85 +/- 0.21 ml.min-1.g kidney wt-1) and GFR (0.28 +/- 0.09, 0.34 +/- 0.09, and 0.47 +/- 0.09 ml.min-1.g kidney wt-1) at low, middle, and high RPP, respectively. PGE2 replacement (n = 6) into renal artery at 0.01 microgram.min-1.kg body wt-1 returned FENa, ERBF, and GFR to control levels over the same range of RPP, whereas prostacyclin (PGI2) infusion (n = 7) at the same dose did not. RIHP was 4.2 +/- 1.2, 4.2 + 0.5, and 7.5 +/- 1.7 mmHg with increasing RPP in control untreated group and increased to similar levels with indomethacin treatment and during PGE2 or PGI2 replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

This report describes the relationship between bone formation and mRNA levels for selected bone proteins. Dynamic bone histomorphometry was used to measure bone formation in tibial periosteum of male rats from weanling (3 wk) to 52 wk old. Northern blot analysis of freshly isolated periosteal cells from the long bones was used to determine steady-state mRNA levels for the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAP), the bone matrix proteins osteocalcin (BGP), and prepro-alpha-2 (I) chain of type 1 precollagen (collagen), the osteoblast marker enzyme alkaline phosphatase (AP), and the osteoblast-derived signaling factor (growth factor) transforming growth factor-beta (TGF-beta). Radial growth at the tibial diaphysis achieved a maximum value in 8-wk-old rats and decreased progressively with age thereafter. This age-related decrease in the radial growth rate was initially due to reduced osteoblast activity; however, in older rats (greater than 17 wk old) reduced osteoblast number contributed to the decrease in bone formation. There was a strong correlation between the steady-state mRNA level for collagen and the periosteal bone formation rate. In contrast, the mRNA levels for the other bone proteins were more weakly correlated (TGF-beta and AP) or not correlated (BGP). These results suggest that the decreased bone matrix synthesis by periosteal cells in long bones of maturing rats is due to decreased expression of genes for bone matrix proteins.

Objective: Predictors of long-term functional impairment in acute respiratory failure of all causes are poorly understood. Our objective was to assess the frequency and predictors of long-term functional impairment or death after invasive mechanical ventilation for acute respiratory failure of all causes. Design: Population-based, observational cohort study. Setting: Eight adult ICUs of a single center. Patients: All adult patients from Olmsted County, Minnesota, without baseline functional impairment who received mechanical ventilation in ICUs for acute respiratory failure of all causes from 2005 through 2009. Interventions: None. Measurements and Main Results: In total, 743 patients without baseline functional impairment received mechanical ventilation in the ICU. At 1- and 5-year follow-up, the rates of survival with return to baseline functional ability were 61% (366/597) and 53% (356/669). Among 71 patients with new functional impairment at 1 year, 55% (39/71) had recovered and were alive without functional impairment at 5 years. Factors predictive of new functional impairment or death at 1 year were age, comorbidities, discharge to other than home, mechanical ventilation of 7 days or longer, and stroke. Of factors known at the time of intubation, the following are predictive of new functional impairment or death: age, comorbidities, nonsurgical condition, Acute Physiology and Chronic Health Evaluation III score, stroke, and sepsis. Post hoc sensitivity analyses revealed no significant change in predictor variables in patient populations when stroke was excluded or who received more than 48 hours of mechanical ventilation. Conclusions: At 1- and 5-year follow-up, many patients who received mechanical ventilation for acute respiratory failure from all causes are no longer alive or have new moderate-to-severe functional impairment. Functional recovery between year 1 and year 5 is possible and common. Sepsis, stroke, illness severity, age, and comorbidities predict long-term functional outcome at intubation.