Tumor-Localized Administration of α-GalCer to Recruit Invariant Natural Killer T Cells and Enhance Their Antitumor Activity against Solid Tumors

Invariant natural killer T (iNKT) cells have the capacity to mount potent anti-tumor reactivity and have therefore become a focus in the development of cell-based immunotherapy. iNKT cells attack tumor cells using multiple mechanisms with a high efficacy; however, their clinical application has been limited because of their low numbers in cancer patients and difficulties in infiltrating solid tumors. In this study, we aimed to overcome these critical limitations by using α-GalCer, a synthetic glycolipid ligand specifically activating iNKT cells, to recruit iNKT to solid tumors. By adoptively transferring human iNKT cells into tumor-bearing humanized NSG mice and administering a single dose of tumor-localized α-GalCer, we demonstrated the rapid recruitment of human iNKT cells into solid tumors in as little as one day and a significantly enhanced tumor killing ability. Using firefly luciferase-labeled iNKT cells, we monitored the tissue biodistribution and pharmacokinetics/pharmacodynamics (PK/PD) of human iNKT cells in tumor-bearing NSG mice. Collectively, these preclinical studies demonstrate the promise of an αGC-driven iNKT cell-based immunotherapy to target solid tumors with higher efficacy and precision.     

Genetic Elements Orchestrating Lactobacillus crispatus Glycogen Metabolism in the Vagina

Glycogen in the female lower reproductive tract is a major carbon source for colonization and acidification by common vaginal Lactobacillus species, such as Lactobacillus crispatus. Previously, we identified the amylopullulanase encoding gene pulA of Lactobacillus crispatus to correlate with the ability to autonomously utilize glycogen for growth. Here, we further characterize genetic variation and differential regulation of pulA affecting the presence of its gene product on the outer surface layer. We show that alpha-glucan degrading activity dissipates when Lactobacillus crispatus is grown on glucose, maltose and maltotriose, in agreement with carbon catabolite repression elements flanking the pulA gene. Proteome analysis of the S-layer confirmed that the amylopullulanase protein is highly abundant in an S-layer enriched fraction, but not in a strain with a defective amylopullulanase variant or in an amylopullulanase-sufficient strain grown on glucose. In addition, we provide evidence that Lactobacillus crispatus pulA mutants are relevant in vivo, as they are commonly observed in metagenome datasets of human vaginal microbial communities. Analysis of the largest publicly available dataset of 1507 human vaginal metagenomes indicates that among the 270 samples that contain a Lactobacillus crispatus pulA gene, 62 samples (23%) had a defective variant of this gene. Taken together, these results demonstrate that both environmental, as well as genetic factors explain the variation of Lactobacillus crispatus alpha-glucosidases in the vaginal environment.     

Silver-ion high-performance liquid chromatographic separation and identification of conjugated linoleic acid isomers

This is the first report of the application of silverion impregnated high-performance liquid chromatography (Ag⁺-HPLC) to the separation of complex mixtures of conjugated linolenic acid (CLA) isomers present in commercial CLA sources and foods and in biological specimens. This method showed a clear separation of CLA isomers into three groups related to their trans,trans, cis,trans or trans,cis, and cis,cis configuration of the conjugated double-bound system. In addition, this method separated within each geometrical isomeric group. Following Ag⁺-HPLC isolation, gas chromatography (GC)-electron impact mass spectrometry, and GC-direct deposition-Fourier transformed infrared spectroscopy were used to confirm the identity of two major positional isomers in the cis/trans region, i.e., Δ8,10- and Δ11,13-octadecadienoic acid, which had not been chromatographically resolved previously, Furthermore, the potential of this method was demonstrated by showing different Ag⁺-HPLC profiles exhibiting patterns of isomeric distributions for biological specimens from animals fed a diet containing a commerical CLA preparation, as well as for a commerical cheese product.     

Examining cognitive function across the lifespan using a mobile application

Many studies conducted in a laboratory or university setting are limited by funding, personnel, space, and time constraints. In the present study, we introduce a method of data collection using a mobile application that circumvents these typical experiment administration issues. Using the application, we examined cross-sectional age differences in cognitive function. We obtained data from more than 15,000 participants and replicated specific patterns of age-related differences in cognition. Using a subset of these participants, we also examined the processing speed account of age-related cognitive differences, and the association of exercise and leisure activity with cognitive function across the lifespan. We discuss the relative advantages and disadvantages of data collection with a mobile application, and provide recommendations for the use of this method in research.     

Towards solving the crystal structure of polytype 3R2 Mg–Al layered double hydroxides

An analysis of the crystal structure of polytype 3R₂ layered double hydroxides has been carried out based on XRPD diffractograms. Measurement of the transmission-XRPD pattern carried out in a spinning and tilting capillary using synchrotron radiation has been shown to diminish the preferred orientation effect of the sample. In order to approach the structure of polytype 3R₂, structural models, based on possible interlayer anion arrangement as revealed by FT-IR, 27-Al solid state NMR and XRPD, were constructed. A structural model is proposed that is consistent with the by XRPD measured interlayer distance, in which tetrahedral aluminate ions are grafted with their apical oxygen ions onto the octahedral sheet. The presence of a measured extra reflection at 2θ value of 6.3, which is not predicted by this structure, can be obtained however by enlargement of the unit cell to a′ = a√3 = 0.5279 nm and c′ = c = 2.1985 nm, which simulates the aluminate anions ordering in the interlayer.     

Nonequilibrium theory of dirty,current-carrying superconductors: phase-slip oscillators in narrow filaments near T c

General equations for the dynamic behavior of dirty superconductors in the Ginzburg-Landau regime T _c-T T _care derived from microscopic theory. In the immediate vicinity of T _ca local equilibrium approximation leads to a simple generalized time-dependent Ginzburg-Landau equation. The oscillatory phase-slip solutions presented previously are discussed in greater detail.Supported by the Science Research Council (England) under grant GR/A65218, and by the Deutsche Forschungsgemeinschaft.     

Grafting Kinetics of End-Functional Polymers at Melt Interfaces

Expressions for the kinetics of grafting chains from a pure end-functional polymer melt to a reactive interface are derived under the assumption that the free energy of reaction is very large and negative. Two cases are considered: a case where the grafting is controlled by diffusion of free end-functional chains through the “brush” of previously grafted chains and a case where the grafting is controlled by the kinetics of the interface reaction itself. Both cases lead to the same form of the grafting kinetics, but with different characteristic times τ_D = R_ga/D, where R_g is radius of gyration, a is the statistical segment length, and D is the diffusion coefficient of the end-functional polymer; and τ_R = R_g/(ak_f[B]) where k_f is a forward rate constant and [B] is the concentration of groups at the interface that react with the end-function of the polymer chains. The grafting density Σ approaches a practical limit after long times for each value of the degree of polymerization N, and this limit decreases strongly with N. These predictions are compared with the results of recent experiments in which deuterated polystyrene chains with carboxylic acid end groups were grafted to either epoxy- or amine-rich cross-linked epoxy networks. The reaction-controlled grafting model fits the data best and permits us to extract forward rate constants of ˜0.18 kg s⁻¹ mol⁻¹ for the epoxy-rich networks and ˜5 × 10⁻³ kg s⁻¹ mol⁻¹ for the amine-rich ones.     

Qualification of a fluorescence spectrometer for measuring true fluorescence spectra

New analytical methods using fluorescence detection are becoming increasingly quantitative and require easy-to-use material standards for fluorometer qualification and method validation. NIST is responding to this need by developing and producing such standards. Reported here is the first step in this process, which is to qualify a research-grade fluorescence spectrometer for measuring true fluorescence spectra of reference material candidates. "True" spectra are defined here as those with fluorescence intensity, either relative or absolute as required, and wavelength both being reported with high accuracy and known precision, after wavelength has been calibrated and corrections for excitation intensity and detection system response have been applied. The uncertainties determined in relative and absolute intensity-corrected fluorescence spectra using both calibrated source (CS)- and calibrated detector (CD)-based methods were compared. The CS-based method gave uncertainties, typically about +/-5% for relative spectral correction, that were about half that of the CD-based method for determining both relative and absolute spectral correction factors. Absolute spectral correction factors can be determined using either method without knowing the optical geometry of the instrument. The absolute spectral correction factors were found to have much larger uncertainties than the corresponding relative correction factors with uncertainties for the CS-based method of +/-10% to +/-15% being typical and +/-20% or more not being uncommon, particularly for excitation and emission wavelengths below 400 nm. Uncertainties arising from detection system nonlinearity and instrument polarization ratios were also explored.