Long-term Intravital Investigation of an Orthotopic Glioma Mouse Model via Optical Coherence Tomography Angiography.

BACKGROUND/AIM: Probing brain tumor microvasculature holds significant importance in both basic cancer research and medical practice for tracking tumor development and assessing treatment outcomes. However, few imaging methods commonly used in clinics can noninvasively monitor the brain microvascular network at high precision and without exogenous contrast agents in vivo. The present study aimed to investigate the characteristics of microvasculature during brain tumor development in an orthotopic glioma mouse model. MATERIALS AND METHODS: An orthotopic glioma mouse model was established by surgical orthotopic implantation of U87-MG-luc cells into the mouse brain. Then, optical coherence tomography angiography (OCTA) was utilized to characterize the microvasculature progression within 14 days. RESULTS: The orthotopic glioma mouse model evaluated by bioluminescence imaging and MRI was successfully generated. As the tumor grew, the microvessels within the tumor area slowly decreased, progressing from the center to the periphery for 14 days. CONCLUSION: This study highlights the potential of OCTA as a useful tool to noninvasively visualize the brain microvascular network at high precision and without any exogenous contrast agents in vivo.

Intravital photoacoustic brain stimulation with high-precision.

Significance: Neural regulation at high precision vitally contributes to propelling fundamental understanding in the field of neuroscience and providing innovative clinical treatment options. Recently, photoacoustic brain stimulation has emerged as a cutting-edge method for precise neuromodulation and shows great potential for clinical application. Aim: The goal of this perspective is to outline the advancements in photoacoustic brain stimulation in recent years. And, we also provide an outlook delineating several prospective paths through which this burgeoning approach may be substantively refined for augmented capability and wider implementations. Approach: First, the mechanisms of photoacoustic generation as well as the potential mechanisms of photoacoustic brain stimulation are provided and discussed. Then, the state-of-the-art achievements corresponding to this technology are reviewed. Finally, future directions for photoacoustic technology in neuromodulation are provided. Results: Intensive research endeavors have prompted substantial advancements in photoacoustic brain stimulation, illuminating the unique advantages of this modality for noninvasive and high-precision neuromodulation via a nongenetic way. It is envisaged that further technology optimization and randomized prospective clinical trials will enable a wide acceptance of photoacoustic brain stimulation in clinical practice. Conclusions: The innovative practice of photoacoustic technology serves as a multifaceted neuromodulation approach, possessing noninvasive, high-accuracy, and nongenetic characteristics. It has a great potential that could considerably enhance not only the fundamental underpinnings of neuroscience research but also its practical implementations in a clinical setting.

Robust Vascular Segmentation for Raw Complex Images of Laser Speckle Contrast Based on Weakly Supervised Learning.

Laser speckle contrast imaging (LSCI) is widely used for in vivo real-time detection and analysis of local blood flow microcirculation due to its non-invasive ability and excellent spatial and temporal resolution. However, vascular segmentation of LSCI images still faces a lot of difficulties due to numerous specific noises caused by the complexity of blood microcirculation's structure and irregular vascular aberrations in diseased regions. In addition, the difficulties of LSCI image data annotation have hindered the application of deep learning methods based on supervised learning in the field of LSCI image vascular segmentation. To tackle these difficulties, we propose a robust weakly supervised learning method, which selects the threshold combinations and processing flows instead of labor-intensive annotation work to construct the ground truth of the dataset, and design a deep neural network, FURNet, based on UNet++ and ResNeXt. The model obtained from training achieves high-quality vascular segmentation and captures multi-scene vascular features on both constructed and unknown datasets with good generalization. Furthermore, we intravital verified the availability of this method on a tumor before and after embolization treatment. This work provides a new approach for realizing LSCI vascular segmentation and also makes a new application-level advance in the field of artificial intelligence-assisted disease diagnosis.

Research progress on the application of optical coherence tomography in the field of oncology.

Optical coherence tomography (OCT) is a non-invasive imaging technique which has become the "gold standard" for diagnosis in the field of ophthalmology. However, in contrast to the eye, nontransparent tissues exhibit a high degree of optical scattering and absorption, resulting in a limited OCT imaging depth. And the progress made in the past decade in OCT technology have made it possible to image nontransparent tissues with high spatial resolution at large (up to 2mm) imaging depth. On the one hand, OCT can be used in a rapid, noninvasive way to detect diseased tissues, organs, blood vessels or glands. On the other hand, it can also identify the optical characteristics of suspicious parts in the early stage of the disease, which is of great significance for the early diagnosis of tumor diseases. Furthermore, OCT imaging has been explored for imaging tumor cells and their dynamics, and for the monitoring of tumor responses to treatments. This review summarizes the recent advances in the OCT area, which application in oncological diagnosis and treatment in different types: (1) superficial tumors:OCT could detect microscopic information on the skin's surface at high resolution and has been demonstrated to help diagnose common skin cancers; (2) gastrointestinal tumors: OCT can be integrated into small probes and catheters to image the structure of the stomach wall, enabling the diagnosis and differentiation of gastrointestinal tumors and inflammation; (3) deep tumors: with the rapid development of OCT imaging technology, it has shown great potential in the diagnosis of deep tumors such in brain tumors, breast cancer, bladder cancer, and lung cancer.

[The Blood Group Serology Combined Irregular Antibody Prenatal Screening Strategies for RhD-Pregnant Women in Xiamen].

OBJECTIVE: To investigate the distribution of Rh phenotype, irregular antibodies screenting and postpartum follow-up of RhD- pregnant women in Xiamen. METHODS: The samples of 313 RhD- pregnant women from June 2018 to May 2020 were collected. Rh serotype phenotypes were identified by tube physiological saline method, irregular antibodies were screened and confirmed by DiaMed Low ion indirect anti-human gel card. By recording the medical，the pregnant women production process and the occurrence of HDN were investigated. RESULTS: The Rh serological phenotypes of 313 RhD- pregnant women were ccdee 180 cases (57.51%), Ccdee 97 cases (30.99%), ccdEe 10 cases(3.19%), CCdee 21 cases (6.71%), CcdEe 5 cases (1.60%), the ccdee and ccdee were the most common in the serological phenotype. Eleven irregular antibodies were detected in 313 RhD- pregnant women, accounting for 351% of the total. There were 8 cases of anti-D antibody, 1 case of anti-E antibody, and 2 cases of anti-D combined with anti-C antibody. The medical records of 21 RhD- pregnant women were reviewed, 19 cases of RhD+ and 2 RhD- newborns were successfully delivered, in which 2 cases developed RhD-HDN, 1 case developed RHE-HDN, and the remaining 18 cases did not develop HDN. CONCLUSION: The Rh serological phenotype of RhD- pregnant women in Xiamen area is mainly for ccdee. Maternal history and blood transfusion history are the main causes of irregular RhD- pregnant antibodies. It is recommended that serological phenotype combined with irregular antibody screening should be applied for RhD- pregnant women in clinic, to reduce the risk of RhD-HDN and ensure the safety of RhD- blood transfusion.