H-Ras Expression in Immortalized Keratinocytes Produces an Invasive Epithelium in Cultured Skin Equivalents

Ras proteins affect both proliferation and expression of collagen-degrading enzymes, two important processes in cancer progression. Normal skin architecture is dependent both on the coordinated proliferation and stratification of keratinocytes, as well as the maintenance of a collagen-rich basement membrane. In the present studies we sought to determine whether expression of H-ras in skin keratinocytes would affect these parameters during the establishment and maintenance of an in vitro skin equivalent.Previously described cdk4 and hTERT immortalized foreskin keratinocytes were engineered to express ectopically introduced H-ras. Skin equivalents, composed of normal fibroblast-contracted collagen gels overlaid with keratinocytes (immortal or immortal expressing H-ras), were prepared and incubated for 3 weeks. Harvested tissues were processed and sectioned for histology and antibody staining. Antigens specific to differentiation (involucrin, keratin-14, p63), basement-membrane formation (collagen IV, laminin-5), and epithelial to mesenchymal transition (EMT; e-cadherin, vimentin) were studied. Results showed that H-ras keratinocytes produced an invasive, disorganized epithelium most apparent in the lower strata while immortalized keratinocytes fully stratified without invasive properties. The superficial strata retained morphologically normal characteristics. Vimentin and p63 co-localization increased with H-ras overexpression, similar to basal wound-healing keratinocytes. In contrast, the cdk4 and hTERT immortalized keratinocytes differentiated similarly to normal unimmortalized keratinocytes.The use of isogenic derivatives of stable immortalized keratinocytes with specified genetic alterations may be helpful in developing more robust in vitro models of cancer progression

Supplemental Information for Chapter 12

Supplemental Information for Chapter 12 of the PhD thesis 'Novel Approaches for Illicit-Drug Identification in Forensic Investigations' by R.F. Kranenburg and accompanying the manuscript 'The influence of water of crystallization in NIR-based MDMA∙HCl detection' submitted to Forensic Chemistry.</p

Supplemental Information for PhD thesis Ruben F. Kranenburg

PDF document with direct links to all supplemental information files accompanying the chapters in the PhD thesis 'Novel Approaches for Illicit-Drug Identification in Forensic Investigations' of Ruben F. Kranenburg</p

Supplemental Information for Chapter 12

Supplemental Information for Chapter 12 of the PhD thesis 'Novel Approaches for Illicit-Drug Identification in Forensic Investigations' by R.F. Kranenburg and accompanying the manuscript 'The influence of water of crystallization in NIR-based MDMA∙HCl detection' submitted to Forensic Chemistry.</p

Supplemental Information for PhD thesis Ruben F. Kranenburg

PDF document with direct links to all supplemental information files accompanying the chapters in the PhD thesis 'Novel Approaches for Illicit-Drug Identification in Forensic Investigations' of Ruben F. Kranenburg</p

Bonetti - Instrument-independent chemometric models for rapid, calibration-free NPS isomer differentiation from mass spectral GC-MS data - 2023

RDM dossier of the FSI publication 'Instrument-independent chemometric models for rapid, calibration-free NPS isomer differentiation from mass spectral GC-MS data' (111650, 2023)</p

Bonetti - Instrument-independent chemometric models for rapid, calibration-free NPS isomer differentiation from mass spectral GC-MS data - 2023

RDM dossier of the FSI publication 'Instrument-independent chemometric models for rapid, calibration-free NPS isomer differentiation from mass spectral GC-MS data' (111650, 2023)</p

Mass-Spectrometry-Based Identification of Synthetic Drug Isomers Using Infrared Ion Spectroscopy

Contains fulltext : 219869.pdf (publisher's version ) (Open Access

Isomer-Specific Two-Color Double-Resonance (IRMS3)-M-2 Ion Spectroscopy Using a Single Laser: Application in the Identification of Novel Psychoactive Substances

Contains fulltext : 231408.pdf (Publisher’s version ) (Open Access

Dataset of near-infrared spectral data of illicit-drugs and forensic casework samples analyzed by five portable spectrometers operating in different wavelength ranges.

The increasing amount of globally seized controlled substances in combination with the more diverse drugs-of-abuse market encompassing many new psychoactive substances (NPS) provides challenges for rapid and reliable on-site presumptive drug testing. Long-established colorimetric spot tests tend to fail due to the unavailability of reliable tests for novel drugs and to false-positive reactions on commonly encountered substances. In addition, handling of samples and chemicals is required. Spectroscopic techniques do not have these disadvantages as spectra are compound-specific and non-invasive tests are possible. Near-infrared (NIR) spectroscopy is a promising technique for on-scene forensic drug detection. Numerous portable devices were introduced in the market in recent years. However, most handheld spectrometers operate in different and relatively confined wavelength ranges compared to the full 780 - 2500 nm NIR wavelength range. In addition, their spectral resolution is limited compared to benchtop instruments. This dataset presents the NIR spectra of 430 forensic samples, including regularly encountered illicit-drugs, NPS, commonly used adulterants, bulking-agents and excipients, and seized casework materials (powders and tablets). Data is available from 5 different NIR spectrometers; including a benchmark high-resolution, full range 350-2500 nm laboratory grade instrument and 4 portable spectrometers operating in the ranges of 1300-2600 nm, 1550-1950 nm, 950-1650 nm and 740-1070 nm. Via this dataset, spectra of illicit-drugs become available to institutes that typically do not have access to controlled substances. This data can be used to develop chemometric detection and classification models for illicit-drugs and provide insight in diagnostic spectral features that need to be recorded for reliable detection models. Additionally, the high-resolution, full range VIS-NIR spectra of the benchmark ASD instrument can be used for in-silica predictions of spectra in a certain wavelength range to provide insight in the optimal resolution and wavelength range of a prospective portable device