Three-Dimensional Printing of Food Foams Stabilized by Hydrocolloids for Hydration in Dysphagia.

Three-dimensional food printing offers the possibility of modifying the structural design, nutrition, and texture of food, which may be used for consumers with special dietary requirements such as dysphagic patients. One of the food matrices that can be used for liquid delivery to dysphagic patients is food foams. Foams are widely used in different food products to adjust food density, rheological properties, and texture. Foams allow the food to stay in the mouth for sufficient time to provide hydration while minimizing the danger of choking. Our work studies the foam properties and printability of both egg white foams and eggless foams with a strong focus on their foaming properties, rheological properties, printability, and suitability for dysphagic patients. Food hydrocolloid, xanthan gum (XG), is added to improve foam stability and rheological properties so that the inks are printable. Rheological and syneresis properties of the pre-printed foam inks are examined. The texture profile and microstructure properties are studied post-printing. International dysphagia diet standardization initiative tests are carried out to assess the inks' potential for dysphagic diets. Inks with XG performed better with minimal water seepage, better foam stability, and excellent printability. This suggests that hydrocolloids lead to more stable food foams that are suitable for 3DFP and safe for hydration delivery to dysphagic patients.

Rapid determination of designer benzodiazepines, benzodiazepines, and Z-hypnotics in whole blood using parallel artificial liquid membrane extraction and UHPLC-MS/MS.

Benzodiazepines (BZD) and Z-hypnotics are frequently analyzed in forensic laboratories, and in 2012, the designer benzodiazepines (DBZD) emerged on the illegal drug scene. DBZD represent a particular challenge demanding new analytical methods. In this work, parallel artificial liquid membrane extraction (PALME) is used for sample preparation of DBZD, BZD, and Z-hypnotics in whole blood prior to UHPLC-MS/MS analysis. PALME of BZD, DBZD, and Z-hypnotics was performed from whole blood samples, and the analytes were extracted across a supported liquid membrane (SLM) and into an acceptor solution of dimethyl sulfoxide and 200 mM formic acid (75:25, v/v). The method was validated according to EMA guidelines. The method was linear throughout the calibration range (R2 > 0.99). Intra- and inter-day accuracy and precision, as well as matrix effects, were within the guideline limit of ± 15%. LOD and LLOQ ranged from 0.10 to 5.0 ng mL-1 and 3.2 to 160 ng mL-1, respectively. Extraction recoveries were reproducible and above 52%. The method was specific, and the analytes were stable in the PALME extracts for 4 and 10 days at 10 and - 20 °C. No carry-over was observed within the calibration range. PALME and UHPLC-MS/MS for the determination of DBZD, BZD, and Z-hypnotics in whole blood are a green and low-cost alternative that provides high sample throughput (96-well format), extensive sample clean-up, good sensitivity, and high reproducibility. The presented method is also the first method incorporating analysis of DBZD, BZD, and Z-hypnotics in whole blood in one efficient analysis. Graphical abstract.

Integration of T-cell receptor, Notch and cytokine signals programs mouse γδ T-cell effector differentiation.

γδ T-cells perform a wide range of tissue- and disease-specific functions that are dependent on the effector cytokines produced by these cells. However, the aggregate signals required for the development of interferon-γ (IFNγ) and interleukin-17 (IL-17) producing γδ T-cells remain unknown. Here, we define the cues involved in the functional programming of γδ T-cells, by examining the roles of T-cell receptor (TCR), Notch, and cytokine-receptor signaling. KN6 γδTCR-transduced Rag2-/- T-cell progenitors were cultured on stromal cells variably expressing TCR and Notch ligands, supplemented with different cytokines. We found that distinct combinations of these signals are required to program IFNγ versus IL-17 producing γδ T-cell subsets, with Notch and weak TCR ligands optimally enabling development of γδ17 cells in the presence of IL-1ß, IL-21 and IL-23. Notably, these cytokines were also shown to be required for the intrathymic development of γδ17 cells. Together, this work provides a framework of how signals downstream of TCR, Notch and cytokine receptors integrate to program the effector function of IFNγ and IL-17 producing γδ T-cell subsets.

Extrusion-based 3D food printing - Materials and machines.

To help people with dysphagia increase their food intake, 3D printing can be used to improve the visual appeal of pureed diets. In this review, we have looked at the works done to date on extrusion-based 3D food printing with an emphasis on the edible materials (food inks) and machinery (printers) used. We discuss several methods that researchers have employed to modify conventional food materials into printable formulations. In general, additives such as hydrocolloids may modify the rheological properties and texture of a pureed food to confer printability. Some examples of such additives include starch, pectin, gelatin, nanocellulose, alginate, carrageenan etc. In the second part, we have looked at various food printers that have been developed for both academic and commercial purposes. We identified several common advantages and limitations that these printers shared. Moving forward, future research into food printer development should aim to improve on these strengths, eliminate these limitations and incorporate new capabilities.

Enforcement of γδ-lineage commitment by the pre-T-cell receptor in precursors with weak γδ-TCR signals.

Developing thymocytes bifurcate from a bipotent precursor into αß- or γδ-lineage T cells. Considering this common origin and the fact that the T-cell receptor (TCR) ß-, γ-, and δ-chains simultaneously rearrange at the double negative (DN) stage of development, the possibility exists that a given DN cell can express and transmit signals through both the pre-TCR and γδ-TCR. Here, we tested this scenario by defining the differentiation outcomes and criteria for lineage choice when both TCR-ß and γδ-TCR are simultaneously expressed in Rag2(-/-) DN cells via retroviral transduction. Our results showed that Rag2(-/-) DN cells expressing both TCRs developed along the γδ-lineage, down-regulated CD24 expression, and up-regulated CD73 expression, showed a γδ-biased gene-expression profile, and produced IFN-γ in response to stimulation. However, in the absence of Inhibitor of DNA-binding 3 expression and strong γδ-TCR ligand, γδ-expressing cells showed a lower propensity to differentiate along the γδ-lineage. Importantly, differentiation along the γδ-lineage was restored by pre-TCR coexpression, which induced greater down-regulation of CD24, higher levels of CD73, Nr4a2, and Rgs1, and recovery of functional competence to produce IFN-γ. These results confirm a requirement for a strong γδ-TCR ligand engagement to promote maturation along the γδ T-cell lineage, whereas additional signals from the pre-TCR can serve to enforce a γδ-lineage choice in the case of weaker γδ-TCR signals. Taken together, these findings further cement the view that the cumulative signal strength sensed by developing DN cells serves to dictate its lineage choice.

The TCR ligand-inducible expression of CD73 marks γδ lineage commitment and a metastable intermediate in effector specification.

Numerous studies indicate that γδ T cell receptor (γδTCR) expression alone does not reliably mark commitment of early thymic progenitors to the γδ fate. This raises the possibility that the γδTCR is unable to intrinsically specify fate and instead requires additional environmental factors, including TCR-ligand engagement. We use single cell progenitor assays to reveal that ligand acts instructionally to direct adoption of the γδ fate. Moreover, we identify CD73 as a TCR ligand-induced cell surface protein that distinguishes γδTCR-expressing CD4(-)CD8(-) progenitors that have committed to the γδ fate from those that have not yet done so. Indeed, unlike CD73(-) γδTCR(+) progenitors, which largely adopt the αß fate upon separation from the intrathymic selecting environment, those that express CD73 remain CD4(-)CD8(-) and committed to the γδ fate. CD73 is expressed by >90% of peripheral γδ cells, suggesting this is a common occurrence during development. Moreover, CD73 induction appears to mark a metastable intermediate stage before acquisition of effector function, suggesting that γδ lineage and effector fate are specified sequentially. These findings have important implications for the role of ligand in γδ lineage commitment and its relationship to the specification of effector fate.

HES1 opposes a PTEN-dependent check on survival, differentiation, and proliferation of TCRß-selected mouse thymocytes.

The developmental progression of immature thymocytes requires cooperative input from several pathways, with Notch signals playing an indispensable role at the T-cell receptor (TCR)-ß selection checkpoint. Notch signals affect the activation of the PI3K/Akt pathway, which is required for pTα/TCRß (pre-TCR)-induced survival, differentiation, and proliferation of developing αß-lineage thymocytes. However, the molecular players responsible for the interaction between the Notch and PI3K pathways at this critical developmental stage are unknown. Here, we show that Notch induction of Hes1 is necessary to repress the PI3K/Akt pathway inhibitor, PTEN (phosphatase and tensin homolog), which in turn facilitates pre-TCR-induced differentiation. In support of this mechanism, deletion or down-regulation of Pten overcomes the Notch signaling requirement for survival and differentiation during ß-selection. In addition, c-Myc is a critical target of Notch at this stage, as c-Myc expression overcomes the Notch signaling requirement for proliferation during ß-selection. Collectively, our results point to HES1, via repression of PTEN, and c-Myc as critical mediators of Notch function at the ß-selection checkpoint.

gammadelta and alphabeta T cell lineage choice: resolution by a stronger sense of being.

A common bipotent thymocyte precursor gives rise to both lineages of T cells, alphabeta and gammadelta. However, the cell intrinsic and extrinsic factors that influence alphabeta- versus gammadelta-lineage bifurcation remain controversial. gammadelta T cells play a unique and vital role in host defense, from maintaining integrity at epithelial and mucosal barriers to their newly defined role as an important innate source of interleukin-17. Although a T cell receptor (TCR)-independent fate choice may take place, emerging data supports a model in which the differential signaling capacity of alphabeta and gammadeltaTCRs play an instructional role in specifying lineage fate, with strength of signal measured by the amount of ERK/MAPK pathway activation. Here we discuss how the interplay between intrinsic TCR signals and cell extrinsic signals provided by Notch and TCR ligands help to assign and support a final lineage fate decision.

Marked induction of the helix-loop-helix protein Id3 promotes the gammadelta T cell fate and renders their functional maturation Notch independent.

alphabeta and gammadelta T cells arise from a common thymocyte progenitor during development in the thymus. Emerging evidence suggests that the pre-T cell receptor (pre-TCR) and gammadelta T cell receptor (gammadeltaTCR) play instructional roles in specifying the alphabeta and gammadelta T-lineage fates, respectively. Nevertheless, the signaling pathways differentially engaged to specify fate and promote the development of these lineages remain poorly understood. Here, we show that differential activation of the extracellular signal-related kinase (ERK)-early growth response gene (Egr)-inhibitor of DNA binding 3 (Id3) pathway plays a defining role in this process. In particular, Id3 expression served to regulate adoption of the gammadelta fate. Moreover, Id3 was both necessary and sufficient to enable gammadelta-lineage cells to differentiate independently of Notch signaling and become competent IFNgamma-producing effectors. Taken together, these findings identify Id3 as a central player that controls both adoption of the gammadelta fate and its maturation in the thymus.