Poor patient outcome correlates with active engulfment of cytokeratin positive CTCs within cancer-associated monocyte population in lung cancer.

High rates of mortality in non-small cell lung cancer lung cancer is due to inherent and acquired resistance to systemic therapies and subsequent metastatic burden. Metastasis is supported by suppression of the immune system at secondary organs and within the circulation. Modulation of the immune system is now being exploited as a therapeutic target with immune checkpoint inhibitors. The tracking of therapeutic efficacy in a real-time can be achieved with liquid biopsy, and evaluation of circulating tumour cells and the associated immune cells. A stable liquid biopsy biomarker for non-small cell lung cancer lung cancer has yet to be approved for clinical use. We performed a cross-sectional single-site study, and collected liquid biopsies from patients diagnosed with early, locally advanced, or metastatic lung cancer, undergoing surgery, or systemic therapy (chemotherapy/checkpoint inhibitors). Evaluation of overall circulating tumour cell counts, or cluster counts did not correlate with patient outcome. Interestingly, the numbers of Pan cytokeratin positive circulating tumour cells engulfed by tumour associated monocytes correlated strongly with patient outcome independent of circulating tumour cell counts and the use of checkpoint inhibitors. We suggest that Pan cytokeratin staining within monocytes is an important indicator of tumour-associated inflammation post-therapy and an effective biomarker with strong prognostic capability for patient outcome.

A robust experimental and computational analysis framework at multiple resolutions, modalities and coverages.

The ability to study cancer-immune cell communication across the whole tumor section without tissue dissociation is needed, especially for cancer immunotherapy development, which requires understanding of molecular mechanisms and discovery of more druggable targets. In this work, we assembled and evaluated an integrated experimental framework and analytical process to enable genome-wide scale discovery of ligand-receptors potentially used for cellular crosstalks, followed by targeted validation. We assessed the complementarity of four different technologies: single-cell RNA sequencing and Spatial transcriptomic (measuring over >20,000 genes), RNA In Situ Hybridization (RNAscope, measuring 4-12 genes) and Opal Polaris multiplex protein staining (4-9 proteins). To utilize the multimodal data, we implemented existing methods and also developed STRISH (Spatial TRanscriptomic In Situ Hybridization), a computational method that can automatically scan across the whole tissue section for local expression of gene (e.g. RNAscope data) and/or protein markers (e.g. Polaris data) to recapitulate an interaction landscape across the whole tissue. We evaluated the approach to discover and validate cell-cell interaction in situ through in-depth analysis of two types of cancer, basal cell carcinoma and squamous cell carcinoma, which account for over 70% of cancer cases. We showed that inference of cell-cell interactions using scRNA-seq data can misdetect or detect false positive interactions. Spatial transcriptomics still suffers from misdetecting lowly expressed ligand-receptor interactions, but reduces false discovery. RNAscope and Polaris are sensitive methods for defining the location of potential ligand receptor interactions, and the STRISH program can determine the probability that local gene co-expression reflects true cell-cell interaction. We expect that the approach described here will be widely applied to discover and validate ligand receptor interaction in different types of solid cancer tumors.

Three common faults in current practice that influence the validity of data obtained from electronic air pollution instrumentation.

Instrumental development is now entering a more logical era, where the former artistic character of electronics is being replaced by cold technology. Because of this, one should be expect more reliability; however, there still exist many weak links in practical application. Digital readout systems and computer processing induce a false sense of security. In reality, it is the sample-measurement relationship that determines an instrument's credibility and not the number of digits on its meter. In describing three faulty practices that greatly influence an instrument's performance, it is hoped that measurement may be more closely related to the sample!

Computerized gas chromatographic-mass spectrometric analysis of polycyclic aromatic hydrocarbons in environmental samples.

Substantial progress has been made in the last few years in the development of a rapid method for determining polycyclic aromatic hydrocarbons (PAH) in environmental samples. The three-step method consists of (i) a preliminary separation of PAH by solvent and/or column chromatography, (ii) identification by a combination of gas chromatography with quadrupole mass spectrometry and computer, and (iii) measurement by computerized gas chromatography using internal standards. Samples of industrial effluents, coke oven emissions, coal tar and airborne particulates have been investigated. The efficiencies of different gas chromatographic columns were evaluated during these investigations.

Volatility of fungicidal mercury compounds on wheat seeds.

The volatility of two fungicidal seed dressings, Panogen 15 B liquid and Panogen PX powder, containing methyl mercuric dicyandiamide in equivalent amounts at the dosage used, was compared with that of triple distilled mercury. Tests were made in the absence and presence of cleaned Manitou wheat of 12.0% and 17.1% moisture content. The Panogen formulations were compared at the recommended and twice the recommended rate at different dosages, storage periods and storage temperatures. The Hg content of air samples was determined by the Corte-Monkman method, capable of determining 0.4 ng of Hg, which in a 1-L air sample is equivalent to 0.049 ppb (v/v). The volatility of the interstitial air expressed as mug of Hg vapor/m3 air depended on temperature, wheat moisture content and storage duration and ranged from 150 to 2,240 for metallic Hg, 21 to 350 for Panogen 15 B, and 31 to 380 for PX. In the absence of wheat the volatility of 15 B was greatest (395) at -17.5 degees C and least (75) at 4.5 degrees C, but increased rapidly thereafter with increased temperature. Volatility of metallic Hg after application to wheat of 12.0% and 17.1% moisture content was not significantly reduced after four days storage, but that of Panogen 15 B and PX was reduced considerably, particularly at the higher moisture level. Thus, volatility of mercurial seed dressings cannot be predicted from Hg content alone. Reduction of volatility through possible irreversible chemical bonding of Hg with seed components is suggested for more detailed investigation.

Mercury vapor as an atmospheric contaminant of dental offices.

Airborne mercury from dental offices was selectively trapped by silber gauze elements in borosilicate glass obsorbers, followed by heat-desorption and spectrophotometric measurement at 2537A. As little as 0.4 ng of Hg could be accurately determined, which is equivalent to 49 ppt in a wone-L air sample on a v/v basis. Over 860 air samples were taken over a range of locations and working conditions at 88 different dental offices, and at the Dental Training Clinic of the University of Manitoba. The Hg vapor concentrations at the dental facilities ranged from 0.45 to 742 mug/m3 of air, 29% of the samples were within 0.45 to 5 mug; 37.8 were within 5.1 to 25mug;and 33.2% were above 25 mug. Mercury concentrations varied during the working day, depending on the time of sampling, the number of amalgams placed, and the interval between placements. The lowest concentrations were obtained in the morning. Disturbance of residual mercury droplets on floors or working areas by sweeping or dusting, or immediately after attempted clean-up of a mercury spill, sharply increased the amount of airborne mercury.

Improved methods for sampling and analysis of vinyl chloride.

An analytical scheme was developed for vinyl chloride, which is applicable to ambient and in-plant atmospheres. Using computerized gas chromatographs equipped with automatic injection system and flow rate control, high reproducibilities are achieved in the ppb range. Samples from various sources have been analyzed.