Efficacy and pharmacodynamic effect of anti-CD73 and anti-PD-L1 monoclonal antibodies in combination with cytotoxic therapy: observations from mouse tumor models.

CD73 is a cell surface 5'nucleotidase (NT5E) and key node in the catabolic process generating immunosuppressive adenosine in cancer. Using a murine monoclonal antibody surrogate of Oleclumab, we investigated the effect of CD73 inhibition in concert with cytotoxic therapies (chemotherapies as well as fractionated radiotherapy) and PD-L1 blockade. Our results highlight improved survival in syngeneic tumor models of colorectal cancer (CT26 and MC38) and sarcoma (MCA205). This therapeutic outcome was in part driven by cytotoxic CD8 T-cells, as evidenced by the detrimental effect of CD8 depleting antibody treatment of MCA205 tumor bearing mice treated with anti-CD73, anti-PD-L1 and 5-Fluorouracil+Oxaliplatin (5FU+OHP). We hypothesize that the improved responses are tumor microenvironment (TME)-driven, as suggested by the lack of anti-CD73 enhanced cytopathic effects mediated by 5FU+OHP on cell lines in vitro. Pharmacodynamic analysis, using imaging mass cytometry and RNA-sequencing, revealed noteworthy changes in specific cell populations like cytotoxic T cells, B cells and NK cells in the CT26 TME. Transcriptomic analysis highlighted treatment-related modulation of gene profiles associated with an immune response, NK and T-cell activation, T cell receptor signaling and interferon (types 1 & 2) pathways. Inclusion of comparator groups representing the various components of the combination allowed deconvolution of contribution of the individual therapeutic elements; highlighting specific effects mediated by the anti-CD73 antibody with respect to immune-cell representation, chemotaxis and myeloid biology. These pre-clinical data reflect complementarity of adenosine blockade with cytotoxic therapy, and T-cell checkpoint inhibition, and provides new mechanistic insights in support of combination therapy.

Characterization of a novel potency endpoint for the evaluation of immune checkpoint blockade in humanized mice.

Introduction: Humanized mice are emerging as valuable models to experimentally evaluate the impact of different immunotherapeutics on the human immune system. These immunodeficient mice are engrafted with human cells or tissues, that then mimic the human immune system, offering an alternative and potentially more predictive preclinical model. Immunodeficient NSG mice engrafted with human CD34+ cord blood stem cells develop human T cells educated against murine MHC. However, autoimmune graft versus host disease (GvHD), mediated by T cells, typically develops 1 year post engraftment. Methods: Here, we have used the development of GvHD in NSG mice, using donors with HLA alleles predisposed to autoimmunity (psoriasis) to weight in favor of GvHD, as an endpoint to evaluate the relative potency of monoclonal and BiSpecific antibodies targeting PD-1 and CTLA-4 to break immune tolerance. Results: We found that treatment with either a combination of anti-PD-1 & anti-CTLA-4 mAbs or a quadrivalent anti-PD-1/CTLA-4 BiSpecific (MEDI8500), had enhanced potency compared to treatment with anti-PD-1 or anti-CTLA-4 monotherapies, increasing T cell activity both in vitro and in vivo. This resulted in accelerated development of GvHD and shorter survival of the humanized mice in these treatment groups commensurate with their on target activity. Discussion: Our findings demonstrate the potential of humanized mouse models for preclinical evaluation of different immunotherapies and combinations, using acceleration of GvHD development as a surrogate of aggravated antigenic T-cell response against host.

SARS-CoV-2 Spike Protein Expression In Vitro and Hematologic Effects in Mice Vaccinated With AZD1222 (ChAdOx1 nCoV-19).

Severe COVID-19 can be associated with a prothrombotic state, increasing risk of morbidity and mortality. The SARS-CoV-2 spike glycoprotein is purported to directly promote platelet activation via the S1 subunit and is cleaved from host cells during infection. High plasma concentrations of S1 subunit are associated with disease progression and respiratory failure during severe COVID-19. There is limited evidence on whether COVID-19 vaccine-induced spike protein is similarly cleaved and on the immediate effects of vaccination on host immune responses or hematology parameters. We investigated vaccine-induced S1 subunit cleavage and effects on hematology parameters using AZD1222 (ChAdOx1 nCoV-19), a simian, replication-deficient adenovirus-vectored COVID-19 vaccine. We observed S1 subunit cleavage in vitro following AZD1222 transduction of HEK293x cells. S1 subunit cleavage also occurred in vivo and was detectable in sera 12 hours post intramuscular immunization (1x1010 viral particles) in CD-1 mice. Soluble S1 protein levels decreased within 3 days and were no longer detectable 7-14 days post immunization. Intravenous immunization (1x109 viral particles) produced higher soluble S1 protein levels with similar expression kinetics. Spike protein was undetectable by immunohistochemistry 14 days post intramuscular immunization. Intramuscular immunization resulted in transiently lower platelet (12 hours) and white blood cell (12-24 hours) counts relative to vehicle. Similarly, intravenous immunization resulted in lower platelet (24-72 hours) and white blood cell (12-24 hours) counts, and increased neutrophil (2 hours) counts. The responses observed with either route of immunization represent transient hematologic changes and correspond to expected innate immune responses to adenoviral infection.

Unity yield of deterministically positioned quantum dot single photon sources.

We report on a platform for the production of single photon devices with a fabrication yield of 100%. The sources are based on InAsP quantum dots embedded within position-controlled bottom-up InP nanowires. Using optimized growth conditions, we produce large arrays of structures having highly uniform geometries. Collection efficiencies are as high as 83% and multiphoton emission probabilities as low as 0.6% with the distribution away from optimal values associated with the excitation of other charge complexes and re-excitation processes, respectively, inherent to the above-band excitation employed. Importantly, emission peak lineshapes have Lorentzian profiles indicating that linewidths are not limited by inhomogeneous broadening but rather pure dephasing, likely elastic carrier-phonon scattering due to a high phonon occupation. This work establishes nanowire-based devices as a viable route for the scalable fabrication of efficient single photon sources and provides a valuable resource for hybrid on-chip platforms currently being developed.

Effectiveness of a Novel ω-3 Krill Oil Agent in Patients With Severe Hypertriglyceridemia: A Randomized Clinical Trial.

Importance: Intense interest exists in novel ω-3 formulations with high bioavailability to reduce blood triglyceride (TG) levels. Objective: To determine the phase 3 efficacy and safety of a naturally derived krill oil with eicosapentaenoic acid and docosahexaenoic acid as both phospholipid esters (PLs) and free fatty acids (FFAs) (ω-3-PL/FFA [CaPre]), measured by fasting TG levels and other lipid parameters in severe hypertriglyceridemia. Design, Setting, and Participants: This study pooled the results of 2 identical randomized, double-blind, placebo-controlled trials. TRILOGY 1 (Study of CaPre in Lowering Very High Triglycerides) enrolled participants at 71 US centers from January 23, 2018, to November 20, 2019; TRILOGY 2 enrolled participants at 93 US, Canadian, and Mexican centers from April 6, 2018, to January 9, 2020. Patients with fasting TG levels from 500 to 1500 mg/dL, with or without stable treatment with statins, fibrates, or other agents to lower cholesterol levels, were eligible to participate. Interventions: Randomization (2.5:1.0) to ω-3-PL/FFA, 4 g/d, vs placebo (cornstarch) for 26 weeks. Main Outcomes and Measures: The primary outcome was the mean percentage of change in TG levels at 12 weeks; persistence at 26 weeks was the key secondary outcome. Other prespecified secondary outcomes were effects on levels of non-high-density lipoprotein cholesterol (non-HDL-C), very-low-density lipoprotein cholesterol (VLDL-C), HDL-C, and low-density lipoprotein cholesterol (LDL-C); safety and tolerability; and TG level changes in prespecified subgroups. Results: A total of 520 patients were randomized, with a mean (SD) age of 54.9 (11.2) years (339 men [65.2%]), mean (SD) body mass index of 31.5 (5.1), and baseline mean (SD) TG level of 701 (222) mg/dL. Two hundred fifty-six patients (49.2%) were of Hispanic or Latino ethnicity; 275 (52.9%) had diabetes; and 248 (47.7%) were receiving statins. In the intention-to-treat analysis, TG levels were reduced by 26.0% (95% CI, 20.5%-31.5%) in the ω-3-PL/FFA group and 15.1% (95% CI, 6.6%-23.5%) in the placebo group at 12 weeks (mean treatment difference, -10.9% [95% CI, -20.4% to -1.5%]; P = .02), with reductions persisting at 26 weeks (mean treatment difference, -12.7% [95% CI, -23.1% to -2.4%]; P = .02). Compared with placebo, ω-3-PL/FFA had no significant effect at 12 weeks on mean treatment differences for non-HDL-C (-3.2% [95% CI, -8.0% to 1.6%]; P = .18), VLDL-C (-3.8% [95% CI, -12.2% to 4.7%]; P = .38), HDL-C (0.7% [95% CI, -3.7% to 5.1%]; P = .77), or LDL-C (4.5% [95% CI, -5.9% to 14.8%]; P = .40) levels; corresponding differences at 26 weeks were -5.8% (95% CI, -11.3% to -0.3%; P = .04) for non-HDL-C levels, -9.1% (95% CI, -21.5% to 3.2%; P = .15) for VLDL-C levels, 1.9% (95% CI, -4.8% to 8.6%; P = .57) for HDL-C levels, and 6.3% (95% CI, -12.4% to 25.0%; P = .51) for LDL-C levels. Effects on the primary end point did not vary significantly by age, sex, race and ethnicity, country, qualifying TG level, diabetes, or fibrate use but tended to be larger among patients taking statins or cholesterol absorption inhibitors at baseline (mean treatment difference, -19.5% [95% CI, -34.5% to -4.6%]; P = .08 for interaction) and with lower (less than median) baseline blood eicosapentaenoic acid plus docosahexaenoic acid levels (-19.5% [95% CI, -33.8% to -5.3%]; P = .08 for interaction). ω-3-PL/FFA was well tolerated, with a safety profile similar to that of placebo. Conclusions and Relevance: This study found that ω-3 -PL/FFA, a novel krill oil-derived ω-3 formulation, reduced TG levels and was safe and well tolerated in patients with severe hypertriglyceridemia. Trial Registration: ClinicalTrials.gov Identifiers: NCT03398005 and NCT03361501.

Optical fibre-based single photon source using InAsP quantum dot nanowires and gradient-index lens collection.

We present a compact, fibre-coupled single photon source using gradient-index (GRIN) lenses and an InAsP semiconductor quantum dot embedded within an InP photonic nanowire waveguide. A GRIN lens assembly is used to collect photons close to the tip of the nanowire, coupling the light immediately into a single mode optical fibre. The system provides a stable, high brightness source of fibre-coupled single photons. Using pulsed excitation, we demonstrate on-demand operation with a single photon purity of 98.5% when exciting at saturation in a device with a source-fibre collection efficiency of 35% and an overall single photon collection efficiency of 10%. We also demonstrate "plug and play" operation using room temperature photoluminescence from the InP nanowire for room temperature alignment.

Multiparametric MRI of early tumor response to immune checkpoint blockade in metastatic melanoma.

BACKGROUND: Immune checkpoint inhibitors are now standard of care treatment for many cancers. Treatment failure in metastatic melanoma is often due to tumor heterogeneity, which is not easily captured by conventional CT or tumor biopsy. The aim of this prospective study was to investigate early microstructural and functional changes within melanoma metastases following immune checkpoint blockade using multiparametric MRI. METHODS: Fifteen treatment-naïve metastatic melanoma patients (total 27 measurable target lesions) were imaged at baseline and following 3 and 12 weeks of treatment on immune checkpoint inhibitors using: T2-weighted imaging, diffusion kurtosis imaging, and dynamic contrast-enhanced MRI. Treatment timepoint changes in tumor cellularity, vascularity, and heterogeneity within individual metastases were evaluated and correlated to the clinical outcome in each patient based on Response Evaluation Criteria in Solid Tumors V.1.1 at 1 year. RESULTS: Differential tumor growth kinetics in response to immune checkpoint blockade were measured in individual metastases within the same patient, demonstrating significant intertumoral heterogeneity in some patients. Early detection of tumor cell death or cell loss measured by a significant increase in the apparent diffusivity (Dapp) (p<0.05) was observed in both responding and pseudoprogressive lesions after 3 weeks of treatment. Tumor heterogeneity, as measured by apparent diffusional kurtosis (Kapp), was consistently higher in the pseudoprogressive and true progressive lesions, compared with the responding lesions throughout the first 12 weeks of treatment. These preceded tumor regression and significant tumor vascularity changes (Ktrans, ve, and vp) detected after 12 weeks of immunotherapy (p<0.05). CONCLUSIONS: Multiparametric MRI demonstrated potential for early detection of successful response to immune checkpoint inhibitors in metastatic melanoma.

Use of human splenocytes in an innovative humanised mouse model for prediction of immunotherapy-induced cytokine release syndrome.

OBJECTIVES: Humanised mice have emerged as valuable models for pre-clinical testing of the safety and efficacy of immunotherapies. Given the variety of models available, selection of the most appropriate humanised mouse model is critical in study design. Here, we aimed to develop a model for predicting cytokine release syndrome (CRS) while minimising graft-versus-host disease (GvHD). METHODS: To overcome donor-induced variation, we directly compared the in vitro and in vivo immune phenotype of immunodeficient NSG mice reconstituted with human bone marrow (BM) CD34+ haematopoietic stem cells (HSCs), peripheral blood mononuclear cells (PBMCs) or spleen mononuclear cells (SPMCs) from the same human donors. SPMC engraftment in NSG-dKO mice, which lack MHC class I and II, was also evaluated as a strategy to limit GvHD. Another group of mice was engrafted with umbilical cord blood (UCB) CD34+ HSCs. Induction of CRS in vivo was investigated upon administration of the anti-CD3 monoclonal antibody OKT3. RESULTS: PBMC- and SPMC-reconstituted NSG mice showed short-term survival, with engrafted human T cells exhibiting mostly an effector memory phenotype. Survival in SPMC-reconstituted NSG-dKO mice was significantly longer. Conversely, both BM and UCB-HSC models showed longer survival, without demonstrable GvHD and a more naïve T-cell phenotype. PBMC- and SPMC-reconstituted mice, but not BM-HSC or UCB-HSC mice, experienced severe clinical signs of CRS upon administration of OKT3. CONCLUSION: PBMC- and SPMC-reconstituted NSG mice better predict OKT3-mediated CRS. The SPMC model allows generation of large experimental groups, and the use of NSG-dKO mice mitigates the limitation of early GvHD.

Spectrum-free integrated photonic remote molecular identification and sensing.

Absorption spectroscopy is widely used in sensing and astronomy to understand remote molecular compositions. However, dispersive techniques require multichannel detection, reducing detection sensitivity while increasing instrument cost when compared to spectrophotometric methods. We present a novel non-dispersive infrared molecular detection and identification scheme that performs spectral correlation optically using a specially tailored integrated silicon ring resonator. We show experimentally that the correlation amplitude is proportional to the number of overlapping ring resonances and gas lines, and that molecular specificity can be achieved from the phase of the correlation signal. This strategy can enable on-chip detection of extremely faint remote spectral signatures.

Intratumoral IL12 mRNA Therapy Promotes TH1 Transformation of the Tumor Microenvironment.

PURPOSE: While immune checkpoint inhibitors such as anti-PD-L1 are rapidly becoming the standard of care in the treatment of many cancers, only a subset of treated patients have long-term responses. IL12 promotes antitumor immunity in mouse models; however, systemic recombinant IL12 had significant toxicity and limited efficacy in early clinical trials. EXPERIMENTAL DESIGN: We therefore designed a novel intratumoral IL12 mRNA therapy to promote local IL12 tumor production while mitigating systemic effects. RESULTS: A single intratumoral dose of mouse (m)IL12 mRNA induced IFNγ and CD8+ T-cell-dependent tumor regression in multiple syngeneic mouse models, and animals with a complete response demonstrated immunity to rechallenge. Antitumor activity of mIL12 mRNA did not require NK and NKT cells. mIL12 mRNA antitumor activity correlated with TH1 tumor microenvironment (TME) transformation. In a PD-L1 blockade monotherapy-resistant model, antitumor immunity induced by mIL12 mRNA was enhanced by anti-PD-L1. mIL12 mRNA also drove regression of uninjected distal lesions, and anti-PD-L1 potentiated this response. Importantly, intratumoral delivery of mRNA encoding membrane-tethered mIL12 also drove rejection of uninjected lesions with very limited circulating IL12p70, supporting the hypothesis that local IL12 could induce a systemic antitumor immune response against distal lesions. Furthermore, in ex vivo patient tumor slice cultures, human IL12 mRNA (MEDI1191) induced dose-dependent IL12 production, downstream IFNγ expression and TH1 gene expression. CONCLUSIONS: These data demonstrate the potential for intratumorally delivered IL12 mRNA to promote TH1 TME transformation and robust antitumor immunity.See related commentary by Cirella et al., p. 6080.

Multiplexed Single-Photon Source Based on Multiple Quantum Dots Embedded within a Single Nanowire.

Photonics-based quantum information technologies require efficient, high emission rate sources of single photons. Position-controlled quantum dots embedded within a broadband nanowire waveguide provide a fully scalable route to fabricating highly efficient single-photon sources. However, emission rates for single-photon devices are limited by radiative recombination lifetimes. Here, we demonstrate a multiplexed single-photon source based on a multidot nanowire. Using epitaxially grown nanowires, we incorporate multiple energy-tuned dots, each optimally positioned within the nanowire waveguide, providing single photons with high efficiency. This linear scaling of the single-photon emission rate with number of emitters is demonstrated using a five-dot nanowire with an average multiphoton emission probability of <4% when excited at saturation. This represents the first ever demonstration of multiple single-photon emitters deterministically incorporated in a single photonic device and is a major step toward achieving GHz single-photon emission rates from a scalable multi-quantum-dot system.

Optimization of RNA extraction from laser captured microdissected glomeruli from formalin-fixed paraffin-embedded mouse kidney samples for Nanostring analysis.

Optimized protocols for the microdissection of specific areas from archival tissues and the subsequent RNA analysis are needed but challenging due to RNA degradation and chemical modifications. The aim of this study was to present the most appropriate protocol for utilizing mouse FFPE kidney for laser capture microdissection and Nanostring gene expression analysis. We evaluated different section thicknesses (3, 5, 10 µm), 2 RNA extraction kits (Qiagen and Roche) and different H&E staining methods to optimize microdissection and RNA extraction from glomeruli and cortical tubules samples from FFPE mouse kidney. RNA quality and quantity were assessed via Nanodrop and Qubit. The protocol providing the best results consisted of 5 µm sections, a shorter protocol for H&E staining, and RNA extracted with the Roche kit. Higher Nanostring gene counts and lower qPCR cT significantly correlated with RNA concentrations measured with the Qubit, but not with measures obtained with the Nanodrop. The Nanostring data showed that none of the genes included in the panel was differentially expressed in the cortical tubule compartment compared to the whole kidney. However, 25 genes were differentially expressed in the glomerular compartment compared to the whole kidney. Our data showed that sufficient RNA can be extracted from small compartments like mouse renal glomeruli from archival FFPE tissue, and that whole kidney analysis does not accurately represent the transcriptome state of the glomeruli, which comprise only a small proportion of the overall kidney volume.

Empirical model for the temperature dependence of silicon refractive index from O to C band based on waveguide measurements.

An accurate model for the silicon refractive index including its temperature and wavelength dependence is critically important for many disciplines of science and technology. Currently, such a model for temperatures above 22°C in the optical communication bands is not available. The temperature dependence in the spectral response of integrated echelle grating filters made in silicon-on-insulator is solely determined by the optical properties of the slab waveguide, making it largely immune to dimensional uncertainties. This feature renders the echelle filters a reliable tool to evaluate the thermo-optic properties of silicon. Here we investigate the temperature dependence of silicon echelle filters for the wavelength range of both O and C bands, measured between 22°C to 80°C. We show that if a constant thermo-optic coefficient of silicon is assumed for each band, as is common in the literature, the predictions show an underestimate of up to 10% in the temperature-induced channel wavelength shift. We propose and assess a model of silicon refractive index that encompasses both the wavelength and temperature dependence of its thermo-optic coefficients. We start from literature data for bulk silicon and further refine the model using the echelle filter measurement results. This model is validated through accurate predictions of device channel wavelengths and their temperature dependence, including the quadratic term, over a wide wavelength and temperature range. This work also demonstrates a new high-precision method for characterizing the optical properties of a variety of materials.

Evaluation of OM3-PL/FFA Pharmacokinetics After Single and Multiple Oral Doses in Healthy Volunteers.

PURPOSE: The US Food and Drug Administration has approved several omega-3 (OM3)-containing prescription drugs for the treatment of severe hypertriglyceridemia (HTG). However, there is still a need to develop formulations with high bioavailability irrespective of the fat content and time of the meal. OM3-phospholipid (PL)/free fatty acid (FFA) is an investigational drug for the treatment of severe HTG containing naturally derived krill oil mixture of OM3, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as PL esters and as FFA. Both forms in OM3-PL/FFA are believed to be readily bioavailable. Per gram, OM3-PL/FFA contains a lower dose of EPA/DHA in comparison with already approved prescription drugs. The study aim was to evaluate OM3-PL/FFA pharmacokinetic (PK) properties after single and multiple oral doses of 1, 2, and 4 g in healthy subjects when receiving a Therapeutic Lifestyle Change (TLC) diet. The dose proportionality of the study drug, the effect of a high-fat (HF) meal on its PK properties and its safety profile after multiple administration were also explored. METHODS: In this Phase I, open-label, randomized, multiple-dose, single-center, parallel-design study, 42 healthy volunteers following a TLC diet were randomly assigned into 1 of 3 treatment groups in a 1:1:1 ratio to receive a single dose at day 1, followed by multiple oral doses of 1, 2, and 4 g/d for 14 days. At day 15, all subjects received a HF breakfast. FINDINGS: After once-daily dosing, based on graphic assessment, OM3-PL/FFA levels reached steady state within 7-10 days. Exposure of total EPA + DHA, total DHA, and total EPA (Cmax and AUC) appeared to be approximately proportional over the 1-4 g/d dose range. After 14 days of repeated daily dosing, accumulation was observed and was greater at the higher dose of the study product. When administered after a HF breakfast on day 15, median tmax, the geometric mean of AUC0-24 and Cmax were comparable with the values on day 14 across the 3 dose levels. IMPLICATIONS: OM3-PL/FFA was found to be well tolerated in healthy subjects. The study drug PK properties appeared to be approximately dose proportional over the 1-4 g/d dose range. The bioavailability of OM3-PL/FFA did not appear to be meaningfully affected by the fat content of the meal consumed before dose administration. This is clinically relevant because a low-fat diet is part of the management of patients with HTG.

Pressure-dependent sensitivity of a single-pass methane detection system using a continuous-wave distributed feedback laser at 3270 nm.

A single-pass, compact, and low-power-consumption methane sensing system is presented, and its sensitivity is examined for a set of reference cells with pressures of 7.4, 74, and 740 Torr and the same methane concentration at laboratory temperature of 23°C. A GaSb-based continuous-wave distributed feedback tunable diode laser at 3270 nm and wavelength modulation spectroscopy were employed to collect 2f spectra in the ν3, R3 band of CH412. The collected 2f spectra were fitted to a modulated Voigt line profile model. An Allan-Werle variance analysis shows that the best detectivity, 4 ppbm, is obtained for the highest pressure cell. At pressures of 74 and 7.4 Torr the detectivities are 16 and 28 ppbm, respectively. For these low-pressure cells, further sensitivity improvements were achieved using a large modulation depth (m>2.2) at the expense of spectral resolution.

A Single-dose, Comparative Bioavailability Study of a Formulation containing OM3 as Phospholipid and Free Fatty Acid to an Ethyl Ester Formulation in the Fasting and Fed States.

PURPOSE: Formulations of ω (OM)-3 with adequate bioavailability in the low-fat fed state are advantageous in patients with severe hypertriglyceridemia (HTG), as these patients are advised to adhere to a low-fat diet. The OM3-containing prescription drugs approved by the US Food and Drug administration (FDA) provide OM3 in either ethyl ester (EE) or free fatty acid (FFA) forms. The OM3 FFA form and formulations with micelle-forming ability have shown improved bioavailability versus the EE form. OM3 phospholipid (PL)/FFA, a krill oil-derived OM3 mixture containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) present as PL esters and FFA, is being developed for the treatment of severe HTG. Both forms of OM3 in OM3-PL/FFA are believed to be digested and absorbed more efficiently as compared to OM3 in EE. This hypothesis was tested by comparing the relative bioavailabilities of EPA and DHA from a single 4-g dose administration of OM3-PL/FFA to those the FDA-approved HTG drug OM3-EE in the fed (high-fat meal) and fasted states. The effects of food on the bioavailability of both drugs were also tested. METHODS: This open-label, randomized, 4-way crossover bioavailability study was conducted in 56 healthy adults who were randomly assigned to receive a single 4-g dose of OM3-PL/FFA or OM3-EE in the fasted and fed (high-fat meal) states. The relative bioavailabilities of EPA and DHA were compared between the 2 formulations using pharmacokinetic analysis. FINDINGS: In the fasted state, the AUC0-72 and Cmax of EPA + DHA were 5- and 2.7-fold higher, respectively, with OM3-PL/FFA versus OM3-EE. These values were 3- and 4-fold lower in the fed state with OM3-PL/FFA versus OM3-EE. On administration of OM3-EE, the AUC0-72 and Cmax of EPA + DHA were 25- and 11-fold higher, respectively, in the fed versus the fasted state. A much lower increase (1.7-fold) in the AUC0-72 of EPA + DHA was observed on administration of OM3-PL/FFA in the fed versus the fasted state, with similar Cmax values. IMPLICATIONS: These results demonstrate that the bioavailabilities of EPA and DHA with OM3-PL/FFA, as FFA and conjugated to PL, are far less affected by the fat content of a meal as compared to the EPA and DHA EEs in OM3-EE. These findings suggest a potential clinical advantage with OM3-PL/FFA, since patients with HTG are advised to follow a fat-restricted diet.

Bragg filter bandwidth engineering in subwavelength grating metamaterial waveguides.

Bragg gratings are fundamental building blocks for integrated photonic circuits. In the high-index contrast silicon-on-insulator material platform, it is challenging to accurately control the grating strength and achieve narrow spectral bandwidths. Here we demonstrate a novel Bragg grating geometry utilizing a silicon subwavelength grating (SWG) waveguide with evanescently coupled periodic Bragg loading segments placed outside the SWG core. We report experimental 3 dB filter bandwidths in a range from 8 nm to 150 pm by adjusting the distance of the Bragg loading segments from the core and the relative phase shift of the segments on the two sides of the waveguide, with a structure that has a minimum feature size of 100 nm.

Monoclonal antibody targeting of fibroblast growth factor receptor 1c causes cardiac valvulopathy in rats.

Fibroblast Growth Factors (FGFs) and their receptors (FGFRs) have been proposed as potential drug targets for the treatment of obesity. The aim of this study was to assess the potential toxicity in rats of three anti-FGFR1c mAbs with differential binding activity prior to clinical development. Groups of male rats received weekly injections of either one of two FGFR1c-specific mAbs or an FGFR1c/FGFR4-specific mAb at 10 mg/kg for up to 4 weeks. All three mAbs caused significant reductions in food intake and weight loss leading to some animals being euthanized early for welfare reasons. In all three groups given these mAbs, microscopic changes were seen in the bones and heart valves. In the bones of the femoro-tibial joint, thickening of the diaphyseal cortex of long bones, due to deposition of well organized new lamellar bone, indicated that an osteogenic effect was observed. In the heart, valvulopathy described as an endocardial myxomatous change affecting the mitral, pulmonary, tricuspid and aortic valves was observed in all mAb-treated animals. The presence of FGFR1 mRNA expression in the heart valves was confirmed using in situ hybridization. Targeting the FGF-FGFR1c pathway with anti-FGFR1c mAbs leads to drug induced valvulopathy in rats. In effect, this precluded the development of these mAbs as potential anti-obesity drugs. The valvulopathy observed was similar to that described for fenfluramine and dexafenfluramine. The pathogenesis of the drug-induced valvulopathy is considered FGFR1c-mediated, based on the specificity of the mAbs and FGFR1 mRNA expression in the heart valves.

Nonalcoholic steatohepatitis severity is defined by a failure in compensatory antioxidant capacity in the setting of mitochondrial dysfunction.

AIM: To comprehensively evaluate mitochondrial (dys) function in preclinical models of nonalcoholic steatohepatitis (NASH). METHODS: We utilized two readily available mouse models of nonalcoholic fatty liver disease (NAFLD) with or without progressive fibrosis: Lepob/Lepob (ob/ob) and FATZO mice on high trans-fat, high fructose and high cholesterol (AMLN) diet. Presence of NASH was assessed using immunohistochemical and pathological techniques, and gene expression profiling. Morphological features of mitochondria were assessed via transmission electron microscopy and immunofluorescence, and function was assessed by measuring oxidative capacity in primary hepatocytes, and respiratory control and proton leak in isolated mitochondria. Oxidative stress was measured by assessing activity and/or expression levels of Nrf1, Sod1, Sod2, catalase and 8-OHdG. RESULTS: When challenged with AMLN diet for 12 wk, ob/ob and FATZO mice developed steatohepatitis in the presence of obesity and hyperinsulinemia. NASH development was associated with hepatic mitochondrial abnormalities, similar to those previously observed in humans, including mitochondrial accumulation and increased proton leak. AMLN diet also resulted in increased numbers of fragmented mitochondria in both strains of mice. Despite similar mitochondrial phenotypes, we found that ob/ob mice developed more advanced hepatic fibrosis. Activity of superoxide dismutase (SOD) was increased in ob/ob AMLN mice, whereas FATZO mice displayed increased catalase activity, irrespective of diet. Furthermore, 8-OHdG, a marker of oxidative DNA damage, was significantly increased in ob/ob AMLN mice compared to FATZO AMLN mice. Therefore, antioxidant capacity reflected as the ratio of catalase:SOD activity was similar between FATZO and C57BL6J control mice, but significantly perturbed in ob/ob mice. CONCLUSION: Oxidative stress, and/or the capacity to compensate for increased oxidative stress, in the setting of mitochondrial dysfunction, is a key factor for development of hepatic injury and fibrosis in these mouse models.