DEVELOPMENT OF NEEDLE-BASED MICROENDOSCOPY FOR FLUORESCENCE MOLECULAR IMAGING OF BREAST TUMOR MODELS

Fluorescence molecular imaging enables the visualization of basic molecular processes such as gene expression,enzyme activity,and disease-specific molecular interactions in vivo using targeted contrast agents,and therefore,is being developed for early detection and in situ characterization of breast cancers.Recent advances in developing near-infrared fluorescent imaging contrast agents have enabled the specific labeling of human breast cancer cells in mouse model systems.In synergy with contrast agent development,this paper describes a needle-based fluorescence molecular imaging device that has the strong potential to be translated into clinical breast biopsy procedures.This microendoscopy probe is based on a gradient-index(GRIN)lens interfaced with a laser scanning microscope.Specifications of the imaging performance,including the field-of-view,transverse resolution,and focus tracking characteristics were calibrated.Orthotopic MDA-MB-231 breast cancer xenografts stably expressing the tdTomato red fluorescent protein(RFP)were used to detect the tumor cells in this tumor model as a proof of principle study.With further development,this technology,in conjunction with the development of clinically applicable,injectable fluorescent molecular imaging agents,promises to perform fluorescence molecular imaging of breast cancers in vivo for breast biopsy guidance.

Endoscopic imaging:How far are we from real-time histology?

Currently,in gastrointestinal endoscopy there is increasing interest in high resolution endoscopic technologies that can complement high-definition white light endoscopy by providing real-time subcellular imaging of the epithelial surface.These 'optical biopsy' technologies offer the potential to improve diagnostic accuracy and yield,while facilitating real-time decision-making.Although many endoscopic techniques have preliminarily shown high accuracy rates,these technologies are still evolving.This review will provide an overview of the most promising high-resolution imaging technologies,including high resolution microendoscopy,optical coherence tomography,endocytoscopy and confocal laser endoscopy.This review will also discuss the application and current limitations of these technologies for the early detection of neoplasia in Barrett's esophagus,ulcerative colitis and colorectal cancer.

MICROENDOSCOPIC SPECTRAL IMAGING AS A TOOL FOR SMALL DUCTUAL DIAGNOSTICS:PRELIMINARY EXPERIENCE

A technical feasibility of autofluorescence ductoscopy in breast milk ducts as blood vessels phantoms has been assessed as successful.Malignant tumor can be clearly identified through the milk ducts.We also present the operation principle as well as the preliminary experimental results of a new type of microsize multicorefiber that enables imaging through blood vessel phantoms.Imaging of a manipulated microwire through a drilled phantom is presented.

Comparison of nerve conduction and injury degree in patients with lumbar disc herniation after microendoscopic discectomy and fenestration discectomy

Objective: To study the difference of nerve conduction and injury degree in patients with lumbar disc herniation after microendoscopic discectomy and fenestration discectomy. Methods: Patients with single-segment lumbar disc herniation who were treated in Dazhou Central Hospital between May 2014 and February 2017 were selected as the research subjects, the history data were reviewed and the operation methods were referred to divide them into FD group and MED group who received fenestration discectomy and microendoscopic discectomy respectively. The conduction velocity of common peroneal nerve and tibial nerve were detected before operation and 4 weeks after operation;serum levels of nerve and muscle injury-related molecules as well as inflammation and stress-related molecules were detected before operation and 3 days after operation. Results: MNCV levels of common peroneal nerve and tibial nerve 4 weeks after operation as well as serum CRP, TNF-α, MDA and AOPP contents 3 d after operation of both groups of patients were significantly higher than those before operation, and the MNCV levels of common peroneal nerve and tibial nerve of MED group 4 weeks after operation were significantly higher than those of FD group while serum CRP, TNF-α, MDA and AOPP contents of MED group 3 d after operation were not significantly different from those of FD group;serum NSE, S100B, Tau, pNF-H, CPK, Myo and LDH contents of FD patients 3 d after operation were significantly higher than those before operation while serum NSE, S100B, Tau, pNF-H, CPK, Myo and LDH contents of MED group were not significantly different from those before operation. Conclusion: Microendoscopic discectomy for lumbar disc herniation can relieve the nerve and muscle injury, and is equivalent to fenestration discectomy in activating the systemic stress and inflammatory response.

Hybrid multimode - multicore fibre based holographic endoscope for deep-tissue neurophotonics

In-vivo microendoscopy in animal models became a groundbreaking technique in neuroscience that rapidly expands our understanding of the brain.Emerging hair-thin endoscopes based on multimode fibres are now opening up the prospect of ultra-minimally invasive neuroimaging of deeply located brain structures.Complementing these advancements with methods of functional imaging and optogenetics,as well as extending its applicability to awake and motile animals constitute the most pressing challenges for this technology.Here we demonstrate a novel fibre design capable of both,high-resolution imaging in immobilised animals and bending-resilient optical addressing of neurons in motile animals.The optimised refractive index profile and the probe structure allowed reaching a spatial resolution of 2μm across a 230μm field of view for the initial layout of the fibre.Simultaneously,the fibre exhibits negligible cross-talk between individual inner-cores during fibre deformation.This work provides a technological solution for imaging-assisted spatially selective photo-activation and activity monitoring in awake and freely moving animal models.