抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Ju Mei,†,‡,∥ Nelson L. C. Leung,†,‡,∥ Ryan T. K. Kwok,†,‡ Jacky W. Y. Lam,†,‡ and Ben Zhong Tang*,†,‡,§ †HKUST-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China ‡Department of Chemistry, HKUST Jockey Club Institute for Advanced Study, Institute of Molecular Functional Materials, Division of Biomedical Engineering, State Key Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China Guangdong Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China

Aggregation-Induced Emission: Together We Shine, United We Soar!

Luminescent Functional Metal–Organic Frameworks

New technologies for imaging molecules, particularly optical technologies, are increasingly being used to understand the complexity, diversity and in vivo behaviour of cancers. 'Omic' approaches are providing comprehensive 'snapshots' of biological indicators, or biomarkers, of cancer, but imaging can take this information a step further, showing the activity of these markers in vivo and how their location changes over time. Advances in experimental and clinical imaging are likely to improve how cancer is understood at a systems level and, ultimately, should enable doctors not only to locate tumours but also to assess the activity of the biological processes within these tumours and to provide 'on the spot' treatment.

/pdf/imaging-in-the-era-of-molecular-oncology-1t27xevmwt.pdf

Imaging in the era of molecular oncology

A system for visualizing melanin present in tissue can include an imaging system to record a signal based on a presence of melanin in tissue and a display device to display an image based on the signal. A first laser source can emit a Stokes pulse train and a second laser source can emit a pump pulse train. Both the first laser source and the second laser source comprise a tunable center wavelength or frequency. An energy difference between a frequency of the Stokes pulse train and a frequency of the pump pulse train is from 1750 cm -1 to 2250 cm -1 . The Stokes and the pump pulse train overlap in space and time. A scanning mechanism focuses the combined Stokes pulse train and pump pulse train within the tissue and scans across the tissue. A detector detects the signal based on a presence of melanin within the tissue.

Non-invasive visualization and quantification of natural pigments

Deep learning (DL), in particular Convolutional Neural Networks (CNNs), can be used to build powerful quantitative image analysis tools. To take advantage of these capabilities and establish tractable goals and problem solving approaches, it is crucial to understand how both imaging and computational tools have been developed and used together. Different advanced optical imaging methods, whether invasive or non-invasive, are applicable to a wide variety of biomedical research, and CNN algorithms can be tailored to assist with extracting meaningful results from imaging data.

Convolutional Neural Networks in Advanced Biomedical Imaging Applications

Luminescence Oxygen & pH Sensing A swellable color-changing hydrogel dressing featuring a red-to-green “traffic light” response to oxygen is developed in article number 2101605 by Conor L. Evans and co-workers. Using simple macroscopic photography, intensity-independent quantification of oxygen is enabled though image conversion to the HSB color space, while the green channel intensity can be used to monitor pH. The “traffic light” response is maintained despite high autofluorescence from skin, thereby providing clinician-friendly naked-eye feedback. Cover art courtesy of Juan Pedro Cascales Sandoval. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/adhm.202270048

Quantitative Luminescence Photography of a Swellable Hydrogel Dressing with a Traffic‐Light Response to Oxygen (Adv. Healthcare Mater. 10/2022)

Melanoma is the most deadly form of skin cancer with a yearly global incidence over 232,000 patients. Individuals with fair skin and red hair exhibit the highest risk for developing melanoma, with evidence suggesting the red/blond pigment known as pheomelanin may elevate melanoma risk through both UV radiation-dependent and -independent mechanisms. Although the ability to identify, characterize, and monitor pheomelanin within skin is vital for improving our understanding of the underlying biology of these lesions, no tools exist for real-time, in vivo detection of the pigment. Here we show that the distribution of pheomelanin in cells and tissues can be visually characterized non-destructively and noninvasively in vivo with coherent anti-Stokes Raman scattering (CARS) microscopy, a label-free vibrational imaging technique. We validated our CARS imaging strategy in vitro to in vivo with synthetic pheomelanin, isolated melanocytes, and the Mc1re/e, red-haired mouse model. Nests of pheomelanotic melanocytes were observed in the red-haired animals, but not in the genetically matched Mc1re/e; Tyrc/c (“albino-red-haired”) mice. Importantly, samples from human amelanotic melanomas subjected to CARS imaging exhibited strong pheomelanotic signals. This is the first time, to our knowledge, that pheomelanin has been visualized and spatially localized in melanocytes, skin, and human amelanotic melanomas.

In vivo coherent Raman imaging of the melanomagenesis-associated pigment pheomelanin

Acne vulgaris is a common chronic skin disease in teenagers and young adults. Minocycline, an antibiotic, has thus far been widely utilized to treat acne, but only via oral administration. Recently, a topical minocycline gel (BPX-01) was developed to directly deliver minocycline to the epidermis and pilosebaceous unit to achieve localized treatment with lower doses of drug. In order to evaluate the effectiveness of topical drug delivery in terms of pharmacokinetics and pharmacodynamics, visualization and quantification of drug within a biological tissue is essential. As minocycline is a known fluorophore, we demonstrate a method for visualization and quantification of minocycline within human skin tissue by utilizing a phasor approach to fluorescence lifetime microscopy (FLIM). In phasor analysis of FLIM, the fluorescence decay trace from each pixel in the FLIM image is plotted as a single point in the phasor plot. Since every fluorophore has a specific decay trace, we can identify a specific molecule by its position in the phasor plot. To demonstrate the feasibility of this visualization and quantification method, the human facial skin samples treated with various concentrations of BPX-01 were investigated using the phasor approach to FLIM. The unique signature of minocycline in FLIM phasor analysis was successfully differentiated from the endogenous fluorescence of human tissue. Furthermore, by sorting the individual pixels of minocycline signature in FLIM image, the distribution of minocycline within human facial skin can be visualized and quantified. Based on these results, we believe that the visualization and quantification method using a phasor approach to FLIM can play an important role in future pharmacokinetics and pharmacodynamics analyses.

Phasor approach to fluorescence lifetime imaging microscopy for visualization and quantification of drug distribution of a topical minocycline gel in human facial skin (Conference Presentation)

Conor L. Evans

Papers

Non-invasive visualization and quantification of natural pigments

Convolutional Neural Networks in Advanced Biomedical Imaging Applications

Quantitative Luminescence Photography of a Swellable Hydrogel Dressing with a Traffic‐Light Response to Oxygen (Adv. Healthcare Mater. 10/2022)

In vivo coherent Raman imaging of the melanomagenesis-associated pigment pheomelanin

Phasor approach to fluorescence lifetime imaging microscopy for visualization and quantification of drug distribution of a topical minocycline gel in human facial skin (Conference Presentation)