Frequency over function : raised levels of CD127low/- regulatory T cells in the tumour microenvironment compared with the periphery of head and neck cancer patients

Objective: Regulatory T cells (Tregs) are known to infiltrate the tumour microenvironment of many cancers, including head and neck malignancies, and are thought to contribute to the host's impaired anti-tumour immune response. However, their immunosuppressive function remains poorly understood within the tumour microenvironment and this study aimed to address this. Methods: The frequency and suppressive capacity of two CD4?CD127low/- Treg populations, separated on the basis of different levels of CD25 expression (CD25inter and CD25high), from the tumour/node microenvironment and peripheral circulation of newly-presenting head and neck squamous cell carcinoma patients (n=19), were assessed using multicolour flow cytometry. Results: The proportion of Tregs (CD4?CD25high/?interCD127low/-) in the tumour/node microenvironment was significantly elevated compared with the peripheral circulation (p<0.001) and similar percentages were present in both the primary tumour and metastatic lymph node. The percentage of suppression induced by Tregs isolated from tumour associated nodes on the proliferation of nodal effector T cells was similar to that of peripheral Tregs on peripheral effector T cells. However, when the suppressive activity of both nodal and peripheral Tregs was compared on the same peripheral effectors, peripheral Tregs suppressed proliferation to a greater extent. Conclusion: This work shows that the recruitment and percentages of tumour infiltrating Tregs are key factors in modulating the immune environment of head and neck tumours

Measuring the response of human head and neck squamous cell carcinoma to irradiation in a microfluidic model allowing customized therapy

Radiotherapy is the standard treatment for head and neck squamous cell carcinoma (HNSCC), however, radioresistance remains a major clinical problem despite significant improvements in treatment protocols. Therapeutic outcome could potentially be improved if a patient's tumour response to irradiation could be predicted ex vivo before clinical application. The present study employed a bespoke microfluidic device to maintain HNSCC tissue whilst subjecting it to external beam irradiation and measured the responses using a panel of cell death and proliferation markers. HNSCC biopsies from five newly-presenting patients [2 lymph node (LN); 3 primary tumour (PT)] were divided into parallel microfluidic devices and replicates of each tumour were subjected to single-dose irradiation (0, 5, 10, 15 and 20 Gy). Lactate dehydrogenase (LDH) release was measured and tissue sections were stained for cytokeratin (CK), cleaved-CK18 (cCK18), phosphorylated-H2AX (λH2AX) and Ki.67 by immunohistochemistry. In addition, fragmented DNA was detected using terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Compared with non.irradiated controls, higher irradiation doses resulted in elevated CK18-labelling index in two lymph nodes [15 Gy; 34.8% on LN1 and 31.7% on LN2 (p=0.006)] and a single laryngeal primary tumour (20 Gy; 31.5%; p=0.014). Significantly higher levels of DNA fragmentation were also detected in both lymph node samples and one primary tumour but at varying doses of irradiation, i.e., LN1 (20 Gy; 27.6%; p=0.047), LN2 (15 Gy; 15.3%; p=0.038) and PT3 (10 Gy; 35.2%; p=0.01). The λH2AX expression was raised but not significantly in the majority of samples. The percentage of Ki.67 positive nuclei reduced dose-dependently following irradiation. In contrast no significant difference in LDH release was observed between irradiated groups and controls. There is clear interand intra-patient variability in response to irradiation when measuring a variety of parameters, which offers the potential for the approach to provide clinically valuable information

Development of iridium catalyzed enantioselective C-C bond coupling reactions

Developing new methods to construct enantiomerically enriched higher alcohols via direct C-C bond formation is still a challenge worth pursing in modern synthetic organic chemistry. Enantiomerically enriched alcohols are important due to the abundance of these motifs found in polyketide natural products, a class of molecules widely explored for their bioactive properties. This thesis focuses on the development of iridium catalyzed reductive coupling reactions of allylic acetates with ethanol and symmetric ketones. Chapter 1 describes the utilization of ethanol, the world’s most abundant renewable C-2 feedstock, and its first use as coupling partner in the enantioselective synthesis of higher secondary alcohols. Chapter 2 explains the first systematic study of utilizing symmetric ketones as coupling partners in the synthesis of α-stereogenic tertiary alcohols. Demonstration of the use of these methodologies for the synthesis of pharmacologically inspired molecules is shown through the functional group tolerance of all the top 10 N-heterocycles most commonly found in FDA approve drugs.Chemistr

Maintenance of head and neck tumor on-chip: gateway to personalized treatment?

Aim: Head and neck squamous cell carcinomas (HNSCC) are solid tumors with low overall survival (40–60%). In a move toward personalized medicine, maintenance of tumor biopsies in microfluidic tissue culture devices is being developed. Methodology/ results: HNSCC (n = 15) was dissected (5–10 mg) and either analyzed immediately or cultured in a microfluidic device (37°C) for 48 h. No difference was observed in morphology between pre- and postculture specimens. Dissociated samples were analyzed using trypan blue exclusion (viability), propidium iodide flow cytometry (death) and MTS assay (proliferation) with no significant difference observed highlighting tissue maintenance. Computational fluid dynamics showed laminar flow within the system. Conclusion: The microfluidic culture system successfully maintained HNSCC for 48 h, the culture system will allow testing of different treatment modalities with response monitoring. Lay abstract: Head and neck cancers often have a poor treatment outcome. In order to study the response of the tissue, a miniaturized culture system has been developed to keep a small piece of tumor alive. In the current study, we show that small pieces of cancer tissue can be maintained in the system, using tissue structure and viability of single cells as a guide. In future work, patient equivalent treatments can be applied to these microculture systems to investigate individual patient tumor responses, which could help to guide treatment selection

Exposure, hazard, and survival analysis of diffusion on social networks

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144676/1/sim7658_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144676/2/sim7658.pd

Effect of treatment on systemic cytokines in head and neck squamous cell carcinoma patients

The aim of this study was to determine the effect of HNSCC tumour treatment on systemic Th1 and Th2 cytokine levels and investigate correlations with clinicopathological parameters. IL2, IL4, IL5, IL6, IL8, IL10, IL13, GMCSF, IFNγ and TNFα were measured in the serum of 101 newly-presenting HNSCC patients (9 oral cavity, 27 oropharynx, 57 laryngopharynx, 1 sinonasal, 1 parotid and 6 unknown), prior to and following treatment, using a Quantibody® array based multiplex sandwich ELISA (Raybiotech). Data were analysed with respect to T stage, nodal status, age and sex of the patient as well as time between collection of pre- and post-treatment serum. A significant decrease in the levels of the Th2 cytokines IL4, IL5, IL6 and IL10 and the Th1 cytokines IL2 and IL8 was observed between the pre- and post-treatment serum samples. IL13 and TNFα were significantly higher in early stage (T1/T2) tumours compared with late stage (T3/T4) and this trend was maintained for nodal involvement. IL4 was higher in node positive patients compared with node negative, whereas the converse was true for IL2; IL4 was also higher in younger patients compared with the older age group. These results suggest that removal of HNSCC tumours from patients results in reduced circulating Th2 cytokines without a concurrent increase in Th1 cytokines, indicative of a partial rebalance of the Th1/Th2 system following treatment. Furthermore the cytokine profile may be influenced by the size and nodal involvement of the tumour

Constructing Globular, Sheeted, and Helical Polyalanine Structures using Nanotubes as Templates for Computational Studies

In this experiment polyalanine was folded into globular, sheeted, and helical structures through the use of carbon nanotubes. The rigidity of the nanotubes allowed for molding the polyalanine into the various structures. Nanotubes of different diameters and volumes were used in this experiment. Once the three dimensional peptide structures were formed and detached from the carbon nanotubes, a number of thermodynamic calculations were performed. Computational meth­ods were used to calculate parameters such as Gibbs free energy, enthalpy, entropy, and molecular volume. By attaining the measure­ments of the phi and psi angles, Ramachandran plots were constructed using linear, globular, sheeted, and helical protein structures

Pattern of activation of pelvic floor muscles in men differs with verbal instructions

AimsTo investigate the effect of instruction on activation of pelvic floor muscles (PFM) in men as quantified by transperineal ultrasound imaging (US) and to validate these measures with invasive EMG recordings