BACKGROUND

Adjuvant radiotherapy (aRT) can improve biochemical progression-free survival in patients with high-risk features (HRF) after radical prostatectomy (RP). Guidelines from Alberta and the Genitourinary Radiation Oncologists of Canada (GUROC) recommend that patients with HRF be referred to radiation oncologists (RO) based on the findings from three randomized, controlled trials (RCT). Our study examines the impact of these recommendations both pre- (2005) and post- (2012) publication of RCT and GUROC guideline establishment.

METHODS

Patients undergoing RP during 2005 and 2012 were identified from the provincial cancer registry. Charts were retrospectively reviewed and variables of interest were linked to the registry data. RO referral patterns for each year were determined and variables influencing referral (extracapsular extension, positive margin, seminal vesicle invasion, and post-RP prostate-specific antigen [PSA]) were compared.

RESULTS

Median time to referral was 26.4 months in 2005 compared to 3.7 months 2012 (p<0.001). Among patients referred post-RP, a higher proportion was referred within six months in 2012 (21%) as compared to 2005 (13%) (p=0.003). Among eligible patients in 2012, 30% were referred for discussion of aRT compared to 24% in 2005 (p=0.003). There was a marked drop in patients referred for salvage radiation therapy beyond six months and a rise in the number of patients who are never referred.

CONCLUSIONS

Despite an increase in referral rates to RO post-RP from 2005-2012, more than 50% of those patients with HRF did not receive a referral. Initiatives aimed at improving multidisciplinary care and guideline adherence should be undertaken.

Homologous restriction factor (HRF) is a complementary regulatory protein found on the surface of human erythrocytes and other cell types. It has the function of blocking the lytic action of the membrane attack complex (MAC) of complement when incorporated into a membrane. HRF was found to inhibit not only the MAC composed of the proteins C5b-9, but also the C5b-8 complex. When 125I-labelled HRF was allowed to insert into an erythrocyte target, lysis by C5b-8 was reduced by about 80%. When human erythrocytes were treated with antibody to HRF, which bound to and presumably blocked the action of HRF, lysis by C5b-8 increased. This increase was not caused by additional binding of C8 on the cell membrane. When HRF was inserted into a target cell membrane, it had the effect of reducing the amount of C9 that could bind to very low levels, in one experiment from 6000 molecules per cell to about 500 molecules per cell. When this value was compared to the number of C7 molecules that bound, it was found that HRF reduced the amount of C9 bound to the level of C7 that was bound. HRF seemed to reduce the number of molecules of C9 that could bind to the C5b-8 complex so that only one C9 bound per complex.

Vision-based sign language translation (SLT) is a challenging task due to the complicated variations of facial expressions, gestures, and articulated poses involved in sign linguistics. As a weakly supervised sequence-to-sequence learning problem, in SLT there are usually no exact temporal boundaries of actions. To adequately explore temporal hints in videos, we propose a novel framework named Hierarchical deep Recurrent Fusion (HRF). Aiming at modeling discriminative action patterns, in HRF we design an adaptive temporal encoder to capture crucial RGB visemes and skeleton signees. Specifically, RGB visemes and skeleton signees are learned by the same scheme named Adaptive Clip Summarization (ACS), respectively. ACS consists of three key modules, i.e., variable-length clip mining, adaptive temporal pooling, and attention-aware weighting. Besides, based on unaligned action patterns (RGB visemes and skeleton signees), a query-adaptive decoding fusion is proposed to translate the target sentence. Extensive experiments demonstrate the effectiveness of the proposed HRF framework.

OBJECTIVE

To evaluate the intraobserver and interobserver reproducibility of the automatic full field perfusion image analysis (AFFPIA) program on Heidelberg Retina Flowmeter (HRF) derived perfusion images in a multicentre study group.

METHODS

A total of 10 subjects were consecutively recruited in the study. One eye was randomly selected for each patient. Blood flow was assessed by HRF and flow measurements were analyzed by using the AFFPIA program. AFFPIA calculates the Doppler frequency shift and the haemodynamic variables: flow for each pixel. Intraobserver and interobserver reproducibility was calculated for AFFPIA program. The retinal blood flow was calculated in the superior and inferior section, furthermore, each section was divided into three parts: the temporal area, the nasal, and the rim area, as for software, but only the temporal and nasal areas were considered in this study. The blood flow and the area considered were evaluated for each part.

RESULTS

When the intraobserver and intraimage reproducibility was studied, the coefficient of variation ranged from 0.4 to 1.9%. When the interobserver and intraimage reproducibility was studied, the retinal blood flow coefficient of variation ranged from 0.52 to 3.30% for the supero-temporal area, from 0.13 to 2.67% for the inferotemporal area, from 0.15 to 2.75% for the supero-nasal area, and from 0.04 to 5.65% for the infero-nasal area.

CONCLUSIONS

Our results with AFFPIA showed an interobserver coefficient of variation of retinal blood flow measurements always less than 6% in both temporal and nasal areas. No significant difference was found among the four observers for the flow measurements.

Objective: To investigate the efficacy and safety of sildenafil added to inhaled nitric oxide (iNO) for newborn infants with persistent pulmonary hypertension of newborn (PPHN) or hypoxic respiratory failure (HRF) at risk of PPHN.

Study design: Part A of a multinational, randomized, double-blind, placebo-controlled trial. Infants ≤96hrs-old, >34 weeks of gestation, receiving iNO (10-20ppm on ≥50% FiO₂) for PPHN or HRF at risk of PPHN, and oxygen index >15-<60, were randomized (1:1) to IV sildenafil (loading: 0.1mg/kg, over 30 mins; maintenance: 0.03mg/kg/h) or placebo, for up to 14 days. Coprimary endpoints were treatment failure rate (day 14/discharge) and time on iNO without treatment failure. Secondary endpoints included time on ventilation and oxygenation measures.

Results: Of 87 infants screened, 29 were randomized to IV sildenafil and 30 to placebo; 13 discontinued treatment (sildenafil, n=6; placebo: n=7), including 3 deaths (sildenafil: n=2; placebo: n=1). Treatment failure rates did not differ with sildenafil (27.6%) vs. placebo (20.0%; P=0.4935). Mean time on iNO was not different with sildenafil (4.1-days) vs placebo (4.1-days; P=0.9850). No differences were noted in secondary endpoints. Most common adverse events (AEs) with sildenafil (≥10% infants) were: hypotension (n=8/29), hypokalemia (n=7/29), anemia, drug withdrawal syndrome (n=4/29, each), bradycardia (n=3/29). One serious AE (hypotension) was considered treatment-related.

Conclusion: IV sildenafil added to iNO was not superior to placebo in infants with PPHN or HRF at risk of PPHN. A review of AEs did not identify any pattern of events indicative of a safety concern with IV sildenafil. Infants will have developmental follow-up (Part B).

Keywords: PPHN; Sildenafil citrate; infant; inhaled nitric oxide; placebo; treatment failure.

The normal variability in breath size and frequency results in breath-to-breath variability of end-tidal PCO₂ (P_ETCO₂), the measured variable, and arterial partial pressure of carbon dioxide (PaCO₂), the independent variable affecting cerebral blood flow (CBF). This study examines the effect of variability in PaCO₂ on the pattern of resting-state functional MRI (rs-fMRI) connectivity. A region of interest (ROI)-to-ROI and Seed-to-Voxel first-level bivariate correlation, hemodynamic response function (hrf)-weighted analysis for measuring rs-fMRI connectivity was performed during two resting-state conditions: (a) normal breathing associated with breath-to-breath variation in PaCO₂ (poikilocapnia), and (b) normal breathing with breath-to-breath variability of P_ETCO₂ dampened using sequential rebreathing (isocapnia). End-tidal PCO₂ (P_ETCO₂) was used as a measurable surrogate for fluctuations of PaCO₂. During poikilocapnia, enhanced functional connections were found between the cerebellum and inferior frontal and supramarginal gyrus (SG), visual cortex and occipital fusiform gyrus; and between the primary visual network (PVN) and the hippocampal formation. During isocapnia, these associations were not seen, rather enhanced functional connections were identified in the corticostriatal pathway between the putamen and intracalacarine cortex, supracalcarine cortex (SCC), and precuneus cortex. We conclude that vascular responses to variations in P_ETCO₂, account for at least some of the observed resting state synchronization of blood oxygenation level-dependent (BOLD) signals.

Keywords: BOLD; end-tidal pressure of CO2; fMRI; functional-connectivity; resting-state.

Purpose: Spectral-domain optical coherent tomography (SD-OCT) is a useful tool for visualizing, treating, and monitoring retinal abnormality in patients with different retinal diseases. However, the assessment of SD-OCT images is thwarted by the lack of image quality necessary for ophthalmologists to analyze and quantify the diseases. This has hindered the potential role of hyperreflective foci (HRF) as a prognostic indicator of visual outcome in patients with retinal diseases. We present a new multi-vendor algorithm that is robust to noise while enhancing the HRF in SD-OCT images.

Methods: The proposed algorithm processes the SD-OCT images in two parallel processes simultaneously. The two parallel processes are combined by histogram matching. An inverse of both logarithmic and orthogonal transforms is applied to the mapped data to produce the enhanced image.

Results: We evaluated our algorithm on a dataset composed of 40 SD-OCT volumes. The proposed method obtained high values for the measure of enhancement, peak signal-to-noise ratio, structure similarity, and correlation (ρ) and a low value for mean square error of 36.72, 38.87, 0.87, 0.98, and 25.12 for Cirrus; 40.77, 41.84, 0.89, 0.98, and 22.15 for Spectralis; and 30.81, 32.10, 0.81, 0.96, and 28.55 for Topcon SD-OCT devices, respectively.

Conclusions: The proposed algorithm can be used in the medical field to assist ophthalmologists and in the preprocessing of medical images.

Translational relevance: The proposed enhancement algorithm facilitates the visualization and detection of HRF, which is a step forward in assisting clinicians with decision making about patient treatment planning and disease monitoring.

Keywords: hyperreflective foci segmentation; image enhancement; morphological reconstruction; spectral domain optical coherence tomography.

X-ray detectors to meet the high-resolution requirements for endovascular image-guided interventions (EIGIs) are being developed and evaluated. A new 49.5-micron pixel prototype detector is being investigated and compared to the current suite of high-resolution fluoroscopic (HRF) detectors. This detector featuring a 300-micron thick CsI(Tl) scintillator, and low electronic noise CMOS readout is designated the HRF-CMOS50. To compare the abilities of this detector with other existing high resolution detectors, a standard performance metric analysis was applied, including the determination of the modulation transfer function (MTF), noise power spectra (NPS), noise equivalent quanta (NEQ), and detective quantum efficiency (DQE) for a range of energies and exposure levels. The advantage of the smaller pixel size and reduced blurring due to the thin phosphor was exemplified when the MTF of the HRF-CMOS50 was compared to the other high resolution detectors, which utilize larger pixels, other optical designs or thicker scintillators. However, the thinner scintillator has the disadvantage of a lower quantum detective efficiency (QDE) for higher diagnostic x-ray energies. The performance of the detector as part of an imaging chain was examined by employing the generalized metrics GMTF, GNEQ, and GDQE, taking standard focal spot size and clinical imaging parameters into consideration. As expected, the disparaging effects of focal spot unsharpness, exacerbated by increasing magnification, degraded the higher-frequency performance of the HRF-CMOS50, while increasing scatter fraction diminished low-frequency performance. Nevertheless, the HRF-CMOS50 brings improved resolution capabilities for EIGIs, but would require increased sensitivity and dynamic range for future clinical application.

Reflection hologram recording in DuPont HRF-800X071-20 photopolymer films has been demonstrated by use of pulsed laser exposure with pulse lengths of 25 ns. An expected weak reflectance of the recorded mirror holograms could be significantly increased by preillumination. Although pulsed preillumination enhanced only the reflectance, continuous incoherent preillumination significantly increased both the diffraction efficiency (which reached ~80%) and the sensitivity (which reached an increase of ~100 times, thus approaching the sensitivity of cw recording). The results are compared with those for hologram recordings obtained with cw exposure under the same processing conditions. Spectral absorbance curves of recorded holograms are presented, and possible mechanisms of hologram formation are discussed.

Holographic stars fabricated on DuPont's holographic recording film HRF 600X010 by the use of He-Ne laser light are demonstrated. The stars operate with plane waves, the transmitted portions of the input beams are used at the corresponding outputs, and the gratings are in the volume regime of diffraction. Multiple exposure based on the Bragg degeneracy effect is employed, which drastically reduces the number of multiplexed gratings and requires a three-dimensional arrangement of the replay beams.The star operates at different wavelengths only by the readjustment of the Bragg angles.

Objective: fMRI-based neurofeedback (NF) interventions represent the method of choice for the neuromodulation of localized brain areas. Although we have already validated an fMRI-NF protocol targeting the facial expressions processing network (FEPN), its dissemination is hampered by the economical and logistical constraints of fMRI-NF interventions, which may be however surpassed by transferring it to EEG setups, due to their low cost and portability. One of the major challenges of this procedure is then to reconstruct the BOLD-fMRI signal measured at the FEPN using only EEG signals. Because these types of approaches have been poorly explored so far, here we systematically investigated the extent at which the BOLD-fMRI signal recorded from the FEPN during a fMRI-NF protocol could be reconstructed from the simultaneously recorded EEG signal.

Approach: Several features from both scalp and source spaces (the latter estimated using continuous EEG source imaging) were extracted and used as predictors in a regression problem using random forests. Furthermore, three different approaches to deal with the hemodynamic delay of the BOLD signal were tested. The resulting models were compared with the only approach already proposed in the literature that uses spectral features and considers different time delays.

Main results: The combination of linear and non-linear features (particularly the largest Lyapunov exponent and entropy measures) projected into the source space, spatially filtered by independent component analysis (ICA) and convolved with multiple HRF functions peaking at different latencies, increases significantly the reconstruction accuracy (defined as the correlation between the measured and approximated BOLD signal) from 20% (direct comparison with the method used in the current literature) to 56%.

Significance: With this pipeline, a more accurate reconstruction of the BOLD signal can be obtained, which will positively impact the transfer of fMRI-based neurofeedback interventions to EEG setups, and more importantly, their dissemination and efficacy in modulating the activity of the desired brain areas.

Objective. To compare on- and off-campus snacking patterns among college students pursuing degrees in health-related fields (HRFs) and nonhealth-related fields (NHRFs). Materials and Methods. Snack frequency questionnaire, scales measuring barriers, self-efficacy, and stage of change for healthy snacking, and a snack knowledge test (SKT). Participants. 513 students, 46% HRFs, and 54% NHRFs. The students' mean ± SD BMI was 24.1 ± 4.3 kg/m(2) (range 14.6 to 43.8), and 32.2% were overweight/obese. Results. Softdrinks (on-campus), lowfat milk (off-campus), and sports drinks were popular among HRFs and NHRFs. Cost and availability were barriers to healthy snacking, students felt least confident to choose healthy snacks when emotionally upset, and 75% (65%) of HRFs (NHRFs) self-classified in the action stage of change for healthy snacking. The HRFs scored higher on the SKT. Conclusions. Neither location nor field of study strongly influenced snacking patterns, which featured few high-fiber foods.

Diabetic retinopathy (DR) has become a major worldwide health problem due to the increase in blindness among diabetics at early ages. The detection of DR pathologies such as microaneurysms, hemorrhages and exudates through advanced computational techniques is of utmost importance in patient health care. New computer vision techniques are needed to improve upon traditional screening of color fundus images. The segmentation of the entire anatomical structure of the retina is a crucial phase in detecting these pathologies. This work proposes a novel framework for fast and fully automatic blood vessel segmentation and fovea detection. The preprocessing method involved both contrast limited adaptive histogram equalization and the brightness preserving dynamic fuzzy histogram equalization algorithms to enhance image contrast and eliminate noise artifacts. Afterwards, the color spaces and their intrinsic components were examined to identify the most suitable color model to reveal the foreground pixels against the entire background. Several samples were then collected and used by the renowned convexity shape prior segmentation algorithm. The proposed methodology achieved an average vasculature segmentation accuracy exceeding 96%, 95%, 98% and 94% for the DRIVE, STARE, HRF and Messidor publicly available datasets, respectively. An additional validation step reached an average accuracy of 94.30% using an in-house dataset provided by the Hospital Sant Joan of Reus (Spain). Moreover, an outstanding detection accuracy of over 98% was achieved for the foveal avascular zone. An extensive state-of-the-art comparison was also conducted. The proposed approach can thus be integrated into daily clinical practice to assist medical experts in the diagnosis of DR.

Keywords: Blood vessel segmentation; Convexity shape prior; Diabetic retinopathy; Foveal avascular zone detection.

The general linear model (GLM) is a well established tool for analyzing functional magnetic resonance imaging (fMRI) data. Most fMRI analyses via GLM proceed in a massively univariate fashion where the same design matrix is used for analyzing data from each voxel. A major limitation of this approach is the locally varying nature of signals of interest as well as associated confounds. This local variability results in a potentially large bias and uncontrolled increase in variance for the contrast of interest. The main contributions of this paper are two fold: 1) we develop a statistical framework that enables estimation of an optimal design matrix while explicitly controlling the bias variance decomposition over a set of potential design matrices and 2) we develop and validate a numerical algorithm for computing optimal design matrices for general fMRI data sets. The implications of this framework include the ability to match optimally the magnitude of underlying signals to their true magnitudes while also matching the "null" signals to zero size thereby optimizing both the sensitivity and specificity of signal detection. By enabling the capture of multiple profiles of interest using a single contrast (as opposed to an F-test) in a way that optimizes for both bias and variance enables the passing of first level parameter estimates and their variances to the higher level for group analysis which is not possible using F-tests. We demonstrate the application of this approach to in vivo pharmacological fMRI data capturing the acute response to a drug infusion, to task-evoked, block design fMRI and to the estimation of a haemodynamic response function (HRF) in event-related fMRI. Although developed with motivation from fMRI, our framework is quite general and has potentially wide applicability to a variety of disciplines.

The results of the ecological and epidemiological study of hemorrhagic fever with the renal syndrome (HFRS) in the Kirov region for the period of 1987-2000 are presented. HFRS morbidity rate varied from 1.3 to 13.7 per 100,000 population, which corresponded to the figures registered in the Volga Vyatka region. Cases of HRFS were mainly (90%) registered in three southern districts of the region. The moderate degree of correlation between morbidity rate and the number of wild mammals (r = 0.55) was established. Periodic morbidity rise occurred every 3 years. In 1998-2000 the contamination of wild mammals with HFRS virus increased and reached 7.6-9.5%. Infection factors connected with everyday human activities somewhat prevailed, industrial and agricultural types of infection constituting 43.8%. Males aged 20-49 years prevailed among the patients. Morbidity rate among urban dwellers exceeded that among town residents.

OBJECTIVE

To observe changes in T cell subsets and TH1/TH2 secreted cytokines in the plasma of patients with hemorrhagic fever with renal syndrome (HFRS).

METHODS

Totally 22 patients with HFRS (9 mild cases and 13 moderate cases) were enrolled. Blood samples were taken 1, 4, and 12 weeks after presentation. T cell subsets were tested by flow cytometry (FCM), and the expression of cytokines in plasma were analysed with enzyme-linked immunosorbent assay (ELISA). Another 16 healthy blood donors were enrolled as the control group.

RESULTS

CD3 + CD8 + T lymphocytes increased at week 1 and 4 (P < 0.01), which was more significant in mild cases than in moderate cases (P < 0.05). The change of CD3 + CD4 + T lymphocytes during the disease course were not significantly different from that in control group (P>> 0.05). One week after presentation, TH1 [interleukin (IL)-2 and interferon-gamma (IFN-gamma)] and TH2 (IL-6, IL-10) cytokine productions were significantly higher in HFRS patients than in the control group (P < 0.01); IL-2 and IL-10 remained high levels during the whole observation period, and were still significantly higher than in the control group (P < 0.01). At week 4, the plasma IL-5 level was significantly higher in HFRS patients than in the control group (P < 0.01), and were still significantly higher than in the control group at week 12 (P < 0.01). At week 1 and 4, the plasma INF-gamma levels were significantly higher in moderate patients than in mild patients (P < 0.05); at week 12, the plasma IL-10 level was significantly higher in moderate patients than in mild patients(P < 0.05).

CONCLUSIONS

CD3 + CD4 + T lymphocytes remarkably increases at the early stage of disease in patients with mild HFRS. The early cell mediated immune response is helpful for disease control. The cytokines INF-gamma and IL-10 increase more obviously in moderate patients, indicating that cytokines also are key pathogenic factors of HRFS.

In the field of electronic countermeasure, the recognition of radar signals is extremely important. This paper uses GNU Radio and Universal Software Radio Peripherals to generate 10 classes of close-to-real multipulse radar signals, namely, Barker, Chaotic, EQFM, Frank, FSK, LFM, LOFM, OFDM, P1, and P2. In order to obtain the time-frequency image (TFI) of the multipulse radar signal, the signal is Choi-Williams distribution (CWD) transformed. Aiming at the features of the multipulse radar signal TFI, we designed a distinguishing feature fusion extraction module (DFFE) and proposed a new HRF-Net deep learning model based on this module. The model has relatively few parameters and calculations. The experiments were carried out at the signal-to-noise ratio (SNR) of -14 ∼ 4 dB. In the case of -6 dB, the recognition result of HRF-Net reached 99.583% and the recognition result of the network still reached 97.500% under -14 dB. Compared with other methods, HRF-Nets have relatively better generalization and robustness.

The aims of this study were; 1) to identify different movement profiles in sixth graders, and 2) to investigate if there are differences in their mathematical basic (BasicMath) and problem solving (ProbSol) skills between existing movement profiles. The sample included 461 (223 girls, 238 boys) students with a mean age of 11.27 ± .32 years from southern and middle Finland. A latent profile analysis (LPA) revealed four movement profiles: "poor movers", "average movers", "skilled movers" and "expert movers". These profiles differed substantially in their motor competence (MC) and health-related fitness (HRF). A multivariate analysis of variance (MANOVA) also revealed that "poor movers" and "average movers" obtained lower results in BasicMath comparing with "skilled movers". The results of this study suggest that cardiorespiratory and muscular fitness, MC and BasicMath are interrelated.

Keywords: Motor competence; basic mathematical skills; cardiorespiratory fitness; mathematical problem-solving skills; muscular fitness.

Introduction: To analyze the morphological and functional features of choroidal neovascularizations (CNVs) in eyes affected by pattern dystrophies (PD), evaluating their long-term response to intravitreal ranibizumab, and comparing them with CNVs in age-related macular degeneration (AMD). The mean goal is to identify possible disease biomarkers and to evaluate the long-term prognosis of CNVs in PD.

Materials and methods: A retrospective study of 42 patients with naïve CNV (26 PD and 16 AMD), for a total of 47 eyes (29 eyes in the PD group and 18 eyes in the AMD group). Each patient received a loading dose of ranibizumab (one monthly for three months) followed by pro re nata (PRN) reinjection protocol for a period of at least three years. Morphological OCT parameters (CRT, central retinal thickness; SRF, subretinal fluid; IRF, intraretinal fluid; SHRM, subretinal hyperreflective material; HRF, hyperreflective foci; HCD, hyperreflective crystalline deposits; cCT, central choroidal thickness; slCT, sublesional choroidal thickness; EZd, ellipsoid zone disruption; and best corrected visual acuity (BCVA in logMAR scale)) were reported at baseline and last follow-up.

Results: At baseline, no significant differences were found between the two groups, except for choroidal thickness parameters that were significantly greater in the PD group (p = 0.009). Longitudinal PD analysis demonstrated reduction in BCVA (p = 0.009), decrease in CRT (p = 0.046), resolution of SRF in 61.6% of cases (p = 0.004) and SHRM in 30% (p = 0.034), and choroidal thinning both centrally (p = 0.004) and sublesional (p = 0.011) compared to baseline. At 3 years, the PD group received significantly more injections than the AMD (p = 0.011) and showed significantly thicker choroid (p = 0.033) and more frequent HRF (p = 0.006). Regarding the PD group, we found a negative correlation between age and choroidal thicknesses at baseline and at 3 years (p < 0.05); significant positive correlations were found between baseline BCVA and at 3 years (p < 0.001), BCVA at 3 years and IRF (p = 0.003) and SHRM at 3 years (p = 0.003); CRT baseline and CRT 3 years (p = 0.017); HCD at 3 years was associated with greater CRT (p = 0.04) and IRF at 3 years (p = 0.019).

Conclusions: Early and long-term morphofunctional features of CNVs in PD and in AMD are overlapping. CNVs in PD have poorer long-term response to ranibizumab and higher choroidal thickness suggesting different pathogenetic and evolutionary mechanisms.

Binding of antibodies to their receptors is a core component of the innate immune system. Understanding the precise interactions between antibodies and their Fc receptors has led to the engineering of novel monoclonal antibody (mAb) biotherapeutics with tailored biological activities. One of the most significant findings is that afucosylated mAbs demonstrate increased affinity towards the receptor FcγRIIIa, with a commensurate increase in antibody-dependent cellular cytotoxicity (ADCC). Crystal structure analysis has led to the hypothesis that afucosylation in the Fc-region results in reduced steric hindrance between antibody-receptor intermolecular glycan interactions, enhancing receptor affinity; however, solution-phase data has yet to corroborate this hypothesis. In addition, recent work has shown that the antigen-binding region (Fab) may directly interact with Fc receptors; however, the biological consequences of these interactions remains unclear. By probing differences in solvent accessibility between native and afucoslyated IgG1 using hydroxyl radical footprinting (HRF)-mass spectrometry, we provide the first solution-phase evidence that an IgG1 bearing an afucosylated Fc-region appears to require fewer conformational changes for FcγRIIIa binding. In addition, we performed extensive molecular dynamic (MD) simulations to understand the molecular mechanism behind the effects of afucosylation. The combination of these techniques provides molecular insight into the steric hindrance from the core Fc-fucose in IgG1, and corroborates previously proposed Fab-receptor interactions. Furthermore, MD-guided rational mutagenesis enabled us to demonstrate that Fab-receptor interactions directly contribute to the modulation of ADCC activity. This work demonstrates that in addition to Fc-polypeptide and glycan-mediated interactions, the Fab provides a third component that influences IgG-Fc receptor biology.

Keywords: Antibody-Dependent Cellular Cytotoxicity; Fab-Fc Receptor Interactions; Fast Photochemical Oxidation of Proteins (FPOP); FcγRIIIa; Hydroxyl Radical Footprinting-Mass Spectrometry; IgG1; Molecular Dynamics; Monoclonal Antibody; afucosylation.

BACKGROUND

Inhaled nitric oxide (iNO) is a well-established treatment for neonatal hypoxic respiratory failure (HRF). However, iNO therapy initiation criteria have not been standardized. This report describes a follow-up survey administered to neonatologists who had completed an Awareness, Trial, and Usage Survey. The objectives were to compare stated target oxygenation index (OI) versus actual OI at which iNO is initiated in respondents' patients and identify factors associated with iNO initiation at other levels.

METHODS

Neonatologists provided iNO-treated HRF patient data. Target and actual OI at initiation were determined. Patient groups were stratified by actual OI deviation from target [<4; at (±3); above: 4-10, 11-20, >20; not measured]. Reasons for above-target OI were determined.

RESULTS

Of 83 invited neonatologists, 26 (31%) participated, providing data for 128 patients; 85/128 patients (66%) had OI measured at initiation with neonatologist-stated mean target OI 18.8±5.8. Actual mean OI was 26.2±10.3. iNO was initiated ≤ target in 30/85 patients (35%); most [55/85 (65%)] had iNO initiated when OI was above target. Patients aged ≤1 day and those receiving a fraction of inspired oxygen (FiO2) of 1.0 for more than 1 h had highest OIs at initiation.

CONCLUSIONS

Among surveyed neonatologists who treat infants with HRF with pulmonary hypertension (PH), there is a disparity between stated target versus actual OI for iNO initiation, particularly among infants <1 day old and those receiving FiO2 of 1.0 for more than 1 h. In term/near-term neonates with HRF with PH, neonatologists should consider implementing treatment protocols to ensure iNO initiation at stated target OI levels.

Purpose: By optical coherence tomography (OCT) imaging, hyperreflective foci (HRF) indicate progression risk for advanced age-related macular degeneration (AMD) and are in part attributable to ectopic retinal pigment epithelium (RPE). We hypothesized that ectopic RPE are molecularly distinct from in-layer cells and that their cross-retinal course follows Müller glia.

Methods: In clinical OCT (61 eyes, 44 patients with AMD, 79.4 ± 7.7 years; 29 female; follow-up = 4.7 ± 0.9 years), one HRF type, RPE plume (n = 129 in 4 morphologies), was reviewed. Twenty eyes of 20 donors characterized by ex vivo OCT were analyzed by histology (normal, 4; early/intermediate AMD, 7; geographic atrophy, 6; neovascular AMD, 3). Cryosections were stained with antibodies to retinoid (RPE65, CRALPB) and immune (CD68, CD163) markers. In published RPE cellular phenotypes, red immunoreactivity was assessed semiquantitatively by one observer (none, some cells, all cells).

Results: Plume morphology evolved over time and many resolved (40%). Trajectories of RPE plume and cellular debris paralleled Müller glia, including near atrophy borders. RPE corresponding to HRF lost immunoreactivity for retinoid markers and gained immunoreactivity for immune markers. Aberrant immunoreactivity appeared in individual in-layer RPE cells and extended to all abnormal phenotypes. Müller glia remained CRALBP positive. Plume cells approached and contacted retinal capillaries.

Conclusions: HRF are indicators not predictors of overall disease activity. Gain and loss of function starts with individual in-layer RPE cells and extends to all abnormal phenotypes. Evidence for RPE transdifferentiation, possibly due to ischemia, supports a proposed process of epithelial-mesenchyme transition. Data can propel new biomarkers and therapeutic strategies for AMD.