Saturated Fatty Acid Emulsions Open the Blood-Brain Barrier and Promote Drug Delivery in Rat Brains.

We performed this study to evaluate whether saturated fatty acid (SFA) emulsions affect the BBB and determine the duration of BBB opening, thereby promoting drug delivery to the brain. Butyric, valeric, caproic, enanthic, and caprylic acid emulsions were infused into the carotid artery of the rat model. We evaluated the BBB opening and drug delivery over time. The trypan blue and doxorubicin delivery studies were repeated from 30 min to 6 h. In the 1 h rats in each group, transmission electron microscopy (TEM) was performed to morphologically evaluate tight junctions, and the delivery of temozolomide was assessed by desorption electrospray ionization mass spectrometry. The ipsilateral hemisphere was positive for trypan blue staining in all the five SFA emulsion groups. In the valeric, enanthic, and caprylic acid emulsion groups, RGB ratios were significantly higher at 30 min and decreased thereafter. Doxorubicin delivery increased in all emulsion groups at all time points. Tight junctions were observed to be open in all groups. TMZ delivery was significantly higher in the ipsilateral hemisphere. In conclusion, intra-arterially infused SFA emulsions opened the BBB and promoted drug delivery within 30 min, which decreased thereafter. Therefore, SFA emulsions may aid BBB research and promote drug delivery to the brain.

Anisotropically Conductive Hydrogels with Directionally Aligned PEDOT:PSS in a PVA Matrix.

Electrical anisotropy, which is characterized by the efficient transmission of electrical signals in specific directions, is prevalent in both natural and engineered systems. However, traditional anisotropically conductive materials are often rigid and dry, thus limiting their utility in applications aiming for the seamless integration of various technologies with biological tissues. In the present study, we introduce a method for precisely controlling the microstructures of conductive and insulating polymers to create highly anisotropically conductive composite hydrogels. Our methodology involves combining aligned poly(vinyl alcohol) microfibrils, infused poly(3,4-ethylenedioxythiophene) polystyrenesulfonate, and sodium citrate precipitation to form dense, aligned conductive paths. This significantly enhances the electrical conductivity anisotropy (σ∥/σ⊥ ≈ 60.8) within these composite hydrogels.

Suppression of UVB-Induced MMP-1 Expression in Human Skin Fibroblasts Using Lysate of Lactobacillus iners Derived from Korean Women's Skin in Their Twenties.

The process of skin aging is intricate, involving intrinsic aging, influenced by internal factors, and extrinsic aging, mainly caused by exposure to UV radiation, resulting in photoaging. Photoaging manifests as skin issues such as wrinkles and discoloration. The skin microbiome, a diverse community of microorganisms on the skin's surface, plays a crucial role in skin protection and can be affected by factors like humidity and pH. Probiotics, beneficial microorganisms, have been investigated for their potential to enhance skin health by regulating the skin microbiome. This can be accomplished through oral probiotics, impacting the gut-skin axis, or topical applications introducing live bacteria to the skin. Probiotics mitigate oxidative stress, suppress inflammation, and maintain the skin's extracellular matrix, ultimately averting skin aging. However, research on probiotics derived from human skin is limited, and there is no established product for preventing photoaging. The mechanism by which probiotics shield the skin microbiome and skin layers from UV radiation remains unclear. Recently, researchers have discovered Lactobacillus in the skin, with reports indicating a decrease in this microorganism with age. In a recent study, scientists isolated Lactobacillus iners KOLBM20 from the skin of individuals in their twenties and confirmed its effectiveness. A comparative analysis of genetic sequences revealed that strain KOLBM20 belongs to the Lactobacillus genus and closely relates to L. iners DSM13335(T) with a 99.20% similarity. Importantly, Lactobacillus iners KOLBM20 displayed anti-wrinkle properties by inhibiting MMP-1. This investigation demonstrated the inhibitory effect of KOLBM20 strain lysate on MMP-1 expression. Moreover, the data suggest that KOLBM20 strain lysate may prevent UVB-induced MMP-1 expression by inhibiting the activation of the ERK, JNK, and p38 signaling pathways induced by UVB. Consequently, KOLBM20 strain lysate holds promise as a potential therapeutic agent for preventing and treating skin photoaging.

Direct measurements of the colloidal Debye force.

Colloids often behave in a manner similar to their counterparts in molecular space and are used as model systems to understand molecular behavior. Here, we study like-charged colloidal attractions between a permanent dipole on an interfacial particle and its induced dipole on a water-immersed particle caused by diffuse layer polarization. We find that the scaling behavior of the measured dipole-induced dipole (D‒I) interaction via optical laser tweezers is in good agreement with that predicted from the molecular Debye interaction. The dipole character propagates to form aggregate chains. Using coarse-grained molecular dynamic simulations, we identify the separate roles of the D‒I attraction and the van der Waals attraction on aggregate formation. The D‒I attraction should be universal in a broad range of soft matter, such as colloids, polymers, clays, and biological materials, motivating researchers to further conduct in-depth research on these materials.

Unsaturated free fatty acid emulsion infusion into carotid artery enhances drug delivery to the rat brain.

AIMS: To determine whether the blood-brain barrier (BBB) opens to enhance drug delivery during the acute stage of unsaturated fat embolism. METHODS: We infused oleic, linoleic, and linolenic acid emulsions through the right common carotid artery of rats, followed by trypan blue for gross and lanthanum for electron microscopic (EM) examination. Doxorubicin and temozolomide were also administered, and then the rats were euthanized at 30 min, 1 h, and 2 h. Trypan blue hue was analyzed to semiquantitatively measure BBB opening. Desorption electrospray ionization-mass spectrometry (DESI-MS) imaging was used to evaluate drug delivery. RESULTS: Trypan blue staining observed in each group 30 min after emulsion infusion increased at 1 h and decreased after 2 h in the oleic acid group. The linoleic and linolenic acid groups showed weak staining over time. The hue and trypan blue analysis results were corroborative. EM showed tight junction opening, whereas DESI-MS imaging showed increased doxorubicin and temozolomide signal intensities in ipsilateral hemispheres of all three groups. CONCLUSION: We demonstrated that oleic, linoleic, and linolenic acid emulsions opened the BBB, promoting drug delivery to the brain. Hue analysis and DESI-MS imaging are appropriate for analysis of doxorubicin and temozolomide concentrations in brain tissue.

[Development of Rabbit Brain Tumor Model Using VX2 Cells and Verification with the MRI in Neuroradiologic Research]. / Neuroradiology 연구를 위한 VX2 세포를 이용한 í† ë¼ ë‡Œì¢ ì–‘ 모델 ì œìž‘ê³¼ MRI를 이용한 검증.

Purpose: To evaluate the development, location, and volume of a VX2 carcinoma using four inoculation methods in a rabbit brain. Materials and Methods: Inoculation of a VX2 cell suspension was performed 1) on the appointed day, 2) seven days after storing a VX2 carcinoma in a freezer or 3) seven days after storing a VX2 carcinoma in a deep freezer after sacrificing the donor rabbits. 4) Without sacrificing the rabbits, the VX2 cell suspension was obtained using a gun biopsy, inoculation was performed on the appointed day. MR imaging was performed 10 days after inoculation. Brain tissues were obtained the day after. The development, location, and volume of the tumor were evaluated. Results: Seventeen of the 18 rabbits inoculated on the appointed day developed tumors (average tumor volume, 106.32 mm3). One of five inoculated seven days after storing the VX2 tumor in the freezer, and three of five inoculated seven days after storing the VX2 tumor in the deep freezer developed tumors. Inoculation with a VX2 cell suspension obtained with a gun biopsy from five rabbits revealed development of tumors in only two rabbits. The tumors mostly developed in the superficial cortex. Conclusion: TVX2 rabbit brain tumor model is easy to develop and revealed variable reproducibility. This model can be applicable in radiologic imaging, treatment planning, interventional treatment and drug delivery research. VX2 cell can be successfully innoculated into the brain using variable methods under researcher's variable conditions.

Comparable humoral and cellular immunity against Omicron variant BA.4/5 of once-boosted BA.1/2 convalescents and twice-boosted COVID-19-naïve individuals.

The fourth vaccination dose confers additional protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in individuals with no prior coronavirus disease-19 (COVID-19). However, its immunological benefit against currently circulating BA.4/5 is unclear in individuals who have received a booster shot and been infected with Omicron variant BA.1/2. We analyzed immune responses in whom had been boosted once and did not have COVID-19 (n = 16), boosted once and had COVID-19 when BA.1/2 was dominant in Korea (Hybrid-6M group, n = 27), and boosted twice and did not have COVID-19 (Vx4 group, n = 15). Antibody binding activities against RBDo BA.1 and RBDo BA.4/5 , antigen-specific memory CD4+ and CD8+ T-cell responses against BA.4/5, and B-cell responses against SARS-CoV-2 wild-type did not differ statistically between the Hybrid-6M and Vx4 groups. The humoral and cellular immune responses of the Hybrid-6M group against BA.4/5 were comparable to those of the Vx4 group. Individuals who had been boosted and had an Omicron infection in early 2022 may not have high priority for an additional vaccination.

Screening fundus photography predicts and reveals risk factors for glaucoma conversion in eyes with large optic disc cupping.

This study aimed to investigate the risk factors for glaucoma conversion and progression in eyes with large optic disc cupping without retinal nerve fiber layer defect (RNFLD). Five hundred forty-two eyes of 271 subjects who had a vertical cup-to-disc ratio (CDR) ≥ 0.6 without RNFLD were enrolled. Characteristics for optic disc configuration (including CDR, vertical cupping, ISNT rule, disc ovality, peripapillary atrophy [PPA]-to-disc area [DA] ratio, and lamina cribrosa pore visibility) and blood vessels (including central retinal vessel trunk [CRVT] nasalization, bayoneting of vessels, baring of circumlinear vessels, history of disc hemorrhage [DH] and vessel narrowing/sclerotic change) were evaluated. From a median follow-up of 11.3 years, 26.6% of eyes (n = 144) developed RNFLD within a median of 5.1 years. Baseline factors, including vertical CDR ≥ 0.7 (hazard ratio [HR] = 2.12), vertical cupping (HR = 1.93), ISNT rule violation (HR = 2.84), disc ovality ≥ 1.2 (HR = 1.61), PPA-to-DA ratio ≥ 0.4 (HR = 1.77), CRVT nasalization ≥ 60% (HR = 1.77), vessel narrowing/sclerotic change (HR = 2.13), DH history (HR = 5.60), and baseline intraocular pressure ≥ 14 mmHg (HR = 1.70) were significantly associated with glaucoma conversion (all Ps < 0.05). An HR-matched scoring system based on initial fundus photography predicted glaucoma conversion with specificity of 90.4%. Careful examination of the optic nerve head and vascular structures can help to predict the risk of glaucoma conversion in eyes with large optic disc cupping.

Nasal and temporal curvatures of lamina CRIBROSA in myopic eyes.

Little is known about the myopic characteristics of lamina cribrosa (LC) curvature. As such, we investigated nasal and temporal LC curvatures in myopia. In this retrospective, cross-sectional study, 144 myopic eyes (refraction < - 2D) and 88 non-myopic eyes (refraction > - 0.5D) underwent swept-source optical coherence tomography scanning of the LC. The anterior border of LC curvature was delineated with 17 points and interpolated with the "cardinal spline" curve-fitting method. The average curvature indices of the temporal and nasal sides were presented as the temporal and nasal curvatures. Myopic eyes had a mean refraction of - 6.7 ± 2.8D, while for non-myopic eyes, the value was 0.3 ± 1.0D. Nasal LC curvature was visible in 54 myopia (37.5%) and 42 non-myopia (47.7%) cases (P = 0.126), and temporal LC curvature was visible in 142 myopia (98.6%) and 68 non-myopia (77.3%) cases (P = 0.001). The nasal LC curvature was significantly larger in myopia than in non-myopia (P < 0.001). Contrastingly, the temporal LC curvature was significantly smaller in myopia than in non-myopia (P < 0.001). Axial length was associated with larger nasal LC curvature, smaller temporal LC curvature, and larger nasal-temporal LC curvature difference (all P's < 0.05). In myopic relative to non-myopic eyes, LC curvature was decreased temporally and increased nasally.

Patterns of Optical Coherence Tomography Imaging in Preperimetric Open Angle Glaucoma: A Comparative Study With Young-Age-Onset and Old-Age-Onset Eyes.

PRCIS: Optic coherence tomography imaging in preperimetric open angle glaucoma (OAG) differed between young-age-onset and old-age-onset eyes. Inferior and superior quadrants were thinner in young and old-age-onset eyes, respectively. Understanding the specific patterns of early glaucomatous damage based on age-at-onset may improve glaucoma diagnosis and monitoring. PURPOSE: To investigate the patterns of retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) thinning in preperimetric OAG by optical coherence tomography based on age at onset ("young-age onset (<40 y)" vs. "old-age onset (≥40 y)". MATERIALS AND METHODS: The RNFL and GCIPL deviation images were acquired by Cirrus HD-optical coherence tomography, and overlaid, thus converted to a "deviation frequency map", respectively. The topographic thinning patterns and parameters of RNFL and GCIPL thickness measurements were compared. RESULTS: A total of 194 eyes of 194 patients with preperimetric OAG and 97 eyes of 97 age-matched normal subjects were analyzed. Young-age-onset eyes of preperimetric OAG mainly had RNFL defects inferotemporally (264-296 degrees) with GCIPL defects in the inferior region (213-357 degrees). Old-age-onset preperimetric OAG eyes had RNFL defects inferotemporally (266-294°) and superotemporally (33-67 degrees), with GCIPL defects in the inferior and superior regions (206-360 degrees, 0-22 degrees). The inferior quadrant of RNFL and GCIPL thicknesses were significantly thinner in young-age-onset eyes compared with old-age-onset eyes ( P =0.012, 0.016), while the superior quadrant of those were significantly thinner in the old-age-onset eyes ( P =0.003, 0.005). CONCLUSION: Young-age-onset and old-age-onset eyes of preperimetric OAG present different specific patterns of RNFL and GCIPL thinning.

Comparison of a Deep Learning-Based Reconstruction Algorithm with Filtered Back Projection and Iterative Reconstruction Algorithms for Pediatric Abdominopelvic CT.

OBJECTIVE: To compare a deep learning-based reconstruction (DLR) algorithm for pediatric abdominopelvic computed tomography (CT) with filtered back projection (FBP) and iterative reconstruction (IR) algorithms. MATERIALS AND METHODS: Post-contrast abdominopelvic CT scans obtained from 120 pediatric patients (mean age ± standard deviation, 8.7 ± 5.2 years; 60 males) between May 2020 and October 2020 were evaluated in this retrospective study. Images were reconstructed using FBP, a hybrid IR algorithm (ASiR-V) with blending factors of 50% and 100% (AV50 and AV100, respectively), and a DLR algorithm (TrueFidelity) with three strength levels (low, medium, and high). Noise power spectrum (NPS) and edge rise distance (ERD) were used to evaluate noise characteristics and spatial resolution, respectively. Image noise, edge definition, overall image quality, lesion detectability and conspicuity, and artifacts were qualitatively scored by two pediatric radiologists, and the scores of the two reviewers were averaged. A repeated-measures analysis of variance followed by the Bonferroni post-hoc test was used to compare NPS and ERD among the six reconstruction methods. The Friedman rank sum test followed by the Nemenyi-Wilcoxon-Wilcox all-pairs test was used to compare the results of the qualitative visual analysis among the six reconstruction methods. RESULTS: The NPS noise magnitude of AV100 was significantly lower than that of the DLR, whereas the NPS peak of AV100 was significantly higher than that of the high- and medium-strength DLR (p < 0.001). The NPS average spatial frequencies were higher for DLR than for ASiR-V (p < 0.001). ERD was shorter with DLR than with ASiR-V and FBP (p < 0.001). Qualitative visual analysis revealed better overall image quality with high-strength DLR than with ASiR-V (p < 0.001). CONCLUSION: For pediatric abdominopelvic CT, the DLR algorithm may provide improved noise characteristics and better spatial resolution than the hybrid IR algorithm.

Corrigendum: Distinct Immune Response at 1 Year Post-COVID-19 According to Disease Severity.

[This corrects the article DOI: 10.3389/fimmu.2022.830433.].

Capsule Endoscopy versus Magnetic Resonance Enterography for Evaluation of Pediatric Small Bowel Crohn's Disease: Prospective Study.

BACKGROUND: Magnetic resonance enterography (MRE) and capsule endoscopy (CE) are currently used for the evaluation of small bowel involvement in pediatric Crohn's disease (CD). Several studies have been conducted to investigate the usefulness and diagnostic accuracy of each test. However, only a few studies have been conducted to compare the performance of both tests in the assessment of pediatric small bowel CD upon diagnosis and during follow-up. Therefore, the purpose of this study was to assess the diagnostic accuracy and diagnostic consistency of CE and MRE for the evaluation of pediatric small bowel CD at the time of diagnosis and during follow-up. METHODS: Fifteen patients with pediatric CD were recruited for this study. They underwent MRE and CE concomitantly at the time of diagnosis and 10-12 weeks and one year after induction therapy for CD. MRE was interpreted using MRE global score (MEGS) and bowel wall inflammation severity diffusion-weighted imaging score (BWI-DWIS), whereas CE was interpreted using Lewis's score (LS). The two diagnostic modalities were then compared. RESULTS: Eleven patients completed MRE and CE at the time of diagnosis. Analysis of the results showed that LS had a strong correlation with MEGS and BIS-DWIS (ρ = 0.633, p = 0.037, and ρ = 0.629, p = 0.038, respectively). Nine patients completed three MREs and three CEs. LS significantly decreased throughout the sessions (p = 0.044), whereas MEGS and BIS-DWIS did not show any statistically significant changes. When LS was compared with MEGS and BIS-DWIS, both MRE indicators showed statistically significant differences throughout the sessions. CONCLUSIONS: At the time of diagnosis, the severity indexes of MRE and CE showed very good agreement. However, throughout management, MRE and CE did not show consistent changes.

Bilayered laponite/alginate-poly(acrylamide) composite hydrogel for osteochondral injuries enhances macrophage polarization: An in vivo study.

Addressing osteochondral defects, the objective of current study was to synthesize bilayered hydrogel, where the cartilage layer was formed by alginate (Alg)-polyacrylamide (PAAm) with and without the addition of TGF-ß3 and bone layer by laponite XLS/Alg-PAAm and characterize by in vitro and in vivo experiments. Exceeding the mechanical strength of Alg-PAAm (32.95 ± 1.23 kPa) and XLS based (317.5 ± 21.72 kPa) hydrogels, XLS/Alg-PAAm hydrogel (469.7 ± 6.1 kPa) activated macrophages towards M2 phenotype and stimulated the expression of anti-inflammatory factors. The addition of TGF-ß3 accelerated transition of macrophage polarization, especially between day 4 and 7. The expression levels of M1-related genes such as CD80, iNOS and TNF-α decreased gradually after day 4, reaching lowest values at day 13, whereas the expression levels of M2-related genes, CD206, Arg1 and STAT6 significantly increased promoting M2 macrophage polarization, which might be associated with accelerated bone repair. Moreover, bilayer structure exhibited a better cell viability as well as repairment thorough the XLS contents. In vivo histological examinations verified the significant surface regularity and hyaline like tissue formation employment, along with synchronized degradation profile of the hydrogel with tissue healing at the end of 12 weeks. A mechanically durable, biocompatible and immunocompatible hydrogel was formulated to be utilized in bone-cartilage engineering applications.

Broad humoral and cellular immunity elicited by one-dose mRNA vaccination 18 months after SARS-CoV-2 infection.

BACKGROUND: Practical guidance is needed regarding the vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals in resource-limited countries. It includes the number of vaccine doses that should be given to unvaccinated patients who experienced COVID-19 early in the pandemic. METHODS: We recruited COVID-19 convalescent individuals who received one or two doses of an mRNA vaccine within 6 or around 18 months after a diagnosis of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Their samples were assessed for IgG-binding or neutralizing activity and cell-mediated immune responses against SARS-CoV-2 wild-type and variants of concern. RESULTS: A total of 43 COVID-19 convalescent individuals were analyzed in the present study. The results showed that humoral and cellular immune responses against SARS-CoV-2 wild-type and variants of concern, including the Omicron variant, were comparable among patients vaccinated within 6 versus around 18 months. A second dose of vaccine did not significantly increase immune responses. CONCLUSION: One dose of mRNA vaccine should be considered sufficient to elicit a broad immune response even around 18 months after a COVID-19 diagnosis.

Fracture Toughness and Blocking Force of Temperature-Sensitive PolyNIPAAm and Alginate Hybrid Gels.

In the field of actuator materials, hydrogels that undergo large volume changes in response to external stimuli have been developed for a variety of promising applications. However, most conventional hydrogels are brittle and therefore rupture when they are stretched to moderate strains (~50%). Thus, gels to be used for actuators still require improved mechanical properties and actuation performance. In this study, we synthesized a tough and thermo-sensitive hydrogel with a large actuation force by forming interpenetrating networks between covalently crosslinked poly(N-isopropylacrylamide) and ionically crosslinked alginate. Poly(N-isopropylacrylamide) was used as a thermo-sensitive actuation material, and alginate was found to enhance the mechanical properties of the hydrogels. Due to the enhanced elastic modulus and energy dissipation in the hybrid gel, the toughness was increased by a factor of 60 over that of pure PNIPAAm gel. Further, based on the results showing that the hybrid gel exhibits an actuation force that is seven times higher than that of pure PNIPAAm gel, the hybrid gel is more applicable to real actuators.

Radiologic placement of Hickman catheters using intravenous sedation in pediatric patients under 20 kg.

ABSTRACT: Surgeons generally perform Hickman catheter insertion in children under general anesthesia. At times, it is difficult to perform procedures with an anesthesiologist for an interventional radiologist. Several diagnostic and therapeutic procedures are efficiently and safely conducted using intravenous (IV) sedation in children with a pediatrician. This study aims to evaluate the efficacy and safety of radiologically placed Hickman catheters using IV sedation in children under 20 kg.Fifty-nine catheters were inserted in 45 children under IV sedation. With continuous monitoring of vital signs, IV midazolam and ketamine were slowly infused by a pediatrician. Mean age and body weights were 3.2 years and 15.2 kg, respectively. Acute leukemia was the most common disease for the procedure (72.9%). The location of the catheter tip was evaluated by measuring the height of the thoracic vertebra.Technical success rate was 100%, and IV sedation-related complications did not occur. The right internal jugular vein was accessed for 51 catheters (86.4%), and the mean procedure time was 21.5 minutes. The 2 vertebral body units below the carina were the cavoatrial junction on a fluoroscopy image. Mean catheter life was 285 days, and catheters were removed post-treatment (35.6%). During follow-up, complications occurred in 29 cases (1.72 per 1000 catheter-days). Catheter-related infections were suspected in 4 patients (6.8%), with 1 positive result.Radiological Hickman catheter placement in children under 20 kg using IV sedation by pediatricians is effective and safe, with minimal complications. The carina is a landmark to estimate the cavoatrial junction in pediatric patients.

Distinct Immune Response at 1 Year Post-COVID-19 According to Disease Severity.

Background: Despite the fact of ongoing worldwide vaccination programs for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), understanding longevity, breadth, and type of immune response to coronavirus disease-19 (COVID-19) is still important to optimize the vaccination strategy and estimate the risk of reinfection. Therefore, we performed thorough immunological assessments 1 year post-COVID-19 with different severity. Methods: We analyzed peripheral blood mononuclear cells and plasma samples at 1 year post-COVID-19 in patients who experienced asymptomatic, mild, and severe illness to assess titers of various isotypes of antibodies (Abs) against SARS-CoV-2 antigens, phagocytic capability, and memory B- and T-cell responses. Findings: A total of 24 patients (7, 9, and 8 asymptomatic, mild, and severe patients, respectively) and eight healthy volunteers were included in this study. We firstly showed that disease severity is correlated with parameters of immune responses at 1 year post-COVID-19 that play an important role in protecting against reinfection with SARS-CoV-2, namely, the phagocytic capacity of Abs and memory B-cell responses. Interpretation: Various immune responses at 1 year post-COVID-19, particularly the phagocytic capacity and memory B-cell responses, were dependent on the severity of the prior COVID-19. Our data could provide a clue for a tailored vaccination strategy after natural infection according to the severity of COVID-19.

Image quality and diagnostic accuracy of reduced-dose computed tomography enterography with model-based iterative reconstruction in pediatric Crohn's disease patients.

This study assessed the image quality and diagnostic accuracy in determining disease activity of the terminal ileum of the reduced-dose computed tomography enterography using model-based iterative reconstruction in pediatric patients with Crohn's disease (CD). Eighteen patients were prospectively enrolled and allocated to the standard-dose (SD) and reduced-dose (RD) computed tomography enterography (CTE) groups (n = 9 per group). Image quality, reader confidence in interpreting bowel findings, accuracy in determining active CD in the terminal ileum, and radiation dose were evaluated. Objective image quality did not show intergroup differences, except for image sharpness. Although reader confidence in detecting mural stratification, ulcer, and perienteric fat stranding of the RD-CTE were inferior to SD-CTE, RD-CTE correctly diagnosed active disease in all patients. The mean values of radiation dose metrics (SD-CTE vs. RD-CTE) were 4.3 versus 0.74 mGy, 6.1 versus 1.1 mGy, 211.9 versus 34.5 mGy∙cm, and 4.4 versus 0.7 mSv mGy∙cm for CTDIvol, size-specific dose estimation, dose-length product, and effective dose, respectively. RD-CTE showed comparable diagnostic accuracy to SD-CTE in determining active disease of the terminal ileum in pediatric CD patients. However, image quality and reader confidence in detecting ulcer and perienteric fat stranding was compromised.

Impact of Glaucoma Severity on Rates of Neuroretinal Rim, Retinal Nerve Fiber Layer, and Macular Ganglion Cell Layer Thickness Change.

PURPOSE: To determine the impact of glaucoma severity on rates of change of minimum rim width (MRW), peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell layer (GCL) thickness. DESIGN: Prospective, cohort study. METHODS: Glaucoma patients and healthy subjects had optical coherence tomography scans at 6-month intervals. Individual rates of change for MRW, RNFL, and GCL thickness were estimated with ordinary least-squares regression. Linear mixed-effect models were used to estimate the rate of change of each parameter and evaluate the impact of glaucoma severity (expressed by visual field mean deviation, MD) and age on these rates. RESULTS: A total of 132 glaucoma patients and 57 healthy subjects were followed for a median of 4.3 years and 3.7 years, respectively. Healthy subjects had a statistically significant deterioration in MRW (-1.66 µm/year), RNFL (-0.46 µm/year), and GCL thickness (-0.22 µm/year). While glaucoma patients had a faster rate of change in each parameter compared with healthy subjects, only GCL thickness showed a statistically significant group difference (mean difference: -0.17 µm/year; P = .03). Older baseline age was associated with faster GCL thickness change (-0.07 µm/year; P = .03), but not other parameters. Baseline MD had no impact on the subsequent rates of change in any of the parameters. CONCLUSIONS: The rates of MRW, RNFL, and GCL thickness change were not significantly influenced by glaucoma severity at baseline; however, GCL thickness was able to statistically contrast the rate of change between healthy subjects and glaucoma patients throughout the disease spectrum.