ABSTRACT The programmed death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) pathway plays a significant role in immune evasion. PD-1 or PD-L1 immune checkpoint inhibitors (ICIs) have become a standard treatment for multiple types of cancer. To date, PD-L1 has served as a biomarker for predicting the efficacy of ICIs in several cancers. The need to establish an effective detection method that could visualize PD-L1 expression and predict the efficacy of PD-1/PD-L1 ICIs has promoted a search for new imaging strategies. PD-L1-targeting immuno-imaging could provide a noninvasive, real-time, repeatable, dynamic, and quantitative assessment of the characteristics of all tumor lesions in individual patients. This study analyzed the existing evidence in the literature on PD-L1-based immuno-imaging (2015-2022). Original English-language articles were searched using PubMed and Google Scholar. Keywords, such as “PD-L1,” “PET,” “SPECT,” “PET/CT,” and “SPECT/CT,” were used in various combinations. A total of nearly 50 preclinical and clinical studies of PD-L1-targeting immuno-imaging were selected, reviewed, and included in this study. Therefore, in this review, we conducted a study of the advances in PD-L1-targeting immuno-imaging for detecting the expression of PD-L1 and the efficacy of ICIs. We focused on the different types of PD-L1-targeting agents, including antibodies and small PD-L1-binding agents, and illustrated the strength and weakness of these probes. Furthermore, we summarized the trends in the development of PD-L1-targeting immuno-imaging, as well as the current challenges and future directions for clinical workflow.
X ray CT is a vital technology for inspecting the internal structure of some objects. Various computing method models have been used to CT reconstruction. When image of the scanned object is recorded by the detector unit of finite area, the strip-based projection model is more suitable. In this paper, a simultaneous algebraic reconstruction technique (SART) for strip-based parallel beam projection model have been adopted. Furthermore, in order to reduce the radiation dose and avoid the blurring effect resulting from changes in physical and chemical properties of specimens during scanning, it is necessary to reduce the number of step-scanning. This algorithm combined with cubic spline interpolation can reconstruct high quality CT images in a small amount of data projection in numerical simulation.
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive decline in multiple cognitive domains and it becomes the most common cause of dementia in the elderly. There is an urgent need for the early diagnosis and treatment of AD to ease caregiver burden and medical costs, as well as improve patients' living activities associated with the dramatic increasing number of affected individuals. Molecular imaging with target-specific probes is contributing to identify the underlying biology in AD, which benefits to the early diagnosis of AD and the evaluation of anti-AD therapy. Molecular imaging probes, such as 11C-PIB, 11C-MP4A, 18F-AV-45, and 11F-FDG, can selectively bind to special bimolecular of AD or accurately accumulate at the location of damage areas, thus become an edge tool for a better management of the diseases in the clinical practice and new drug development. In the past decades, a large variety of probes is being developed and tested to be useful for the early and accurate diagnosis of Alzheimer's disease, patient selection for disease-modifying therapeutic trials and monitoring the effect of anti-amyloid therapy. Since imaging probes may also help to guide physicians to identify those patients that could best benefit from a given therapeutic regimen, dose, or duration of drug, this paper is to present a perspective of the available imaging probes for AD, classified on different modalities. Meanwhile, recent advances of those probes that have been selected for clinical trials and are at the different stages of the US Food and Drugs Administration (FDA) approval are outlined. Additionally, future directions and specific application of imaging strategies designed for both diagnosis and treatment for AD are discussed. Keywords: Alzheimer's disease, biomarker, molecular imaging, PET, probe.
Abstract Nonhuman primates are ideal animal models for studying intervertebral disc degeneration. Radiomics technology could be used to accurately evaluate intervertebral disc degeneration, which is the basis for disc-related studies. In the study of nonhuman primates, the number of precious animals is limited, which cannot meet the sample size requirements of radiomics for study subjects, while these radiomics models could be obtained more easily in humans. Therefore, it is possible to construct radiomics models based on human intervertebral disc data, and then apply the models to nonhuman primates. However, cross-species application of the radiomics models has not previously been well established in the literature. Here we show that a total of 12.30% (438/3562) of radiomics features are reproducible between humans and cynomolgus monkeys. Furthermore, the human dataset is used as the training set to construct radiomics models, and the cynomolgus monkey’s dataset is used as the testing set to verify the inter species universality of the radiomics models. We found that the radiomics models constructed using human datasets as training sets still has good performance in cynomolgus monkeys. This study provides a theoretical basis for the cross-species application of radiomics model.
Groundwater resource is the main source of water supply in Hebei plain. But the continual reduction of groundwater has great impact on the regional sustainable utilization of water resources and the development of agriculture. This paper studied the spatial structure and variation characteristics of 5 factors of groundwater, such as chloride ion (CI), groundwater level (GL), nitrate nitrogen (NN), sulfate (S) and total hardness (TH), by the geostatistics method on the platform of GIS. The results showed that, (1) the spatial heterogeneity of nitrate nitrogen (NN) is mainly in small scale and of groundwater level (GL) are mainly in large scale. The spatial heterogeneity of other three factors is both reflected in small and large scale, (2) From the point of spatial distribution of groundwater level, the groundwater level is deepened from east to west, from the coastal plain to the piedmont plain and three great funnels of groundwater level were formed around the Shijiazhuang city, Xingtai city and Hand an city, (3) From the point of spatial distribution of groundwater quality, the high-value areas of chloride ion, sulfate and total hardness is distributed in the eastern and central, low-value distributed in the west. But the distribution of nitrate nitrogen is opposite, (4) in total, the distribution characteristics of the five groundwater indices were greatly impacted by the human activities.
The aim of the present study was to examine the expression of phosphoglycerate mutase 1 (PGAM1) in astrocytomas, and to investigate its role in the progression of astrocytomas. The expression of PGAM1 mRNA in rat C6 glioma cells and normal astrocytes was determined using the reverse transcription‑semi‑quantitative polymerase chain reaction, and immunohistochemistry was used to detect the expression of PGAM1 protein in human astrocytomas and adjacent brain tissue. These data suggested that the expression of PGAM1 in rat C6 glioma cells was significantly increased compared with that of normal astrocytes (P<0.05), and the expression of PGAM1 protein in human astrocytoma tissue was significantly increased compared with that of the brain tissue surrounding the tumor (P<0.05). In addition, PGAM1 protein was more frequently expressed in high‑grade astrocytomas compared with low‑grade astrocytomas. These data indicate that the expression of PGAM1 is increased in C6 cells and human astrocytomas, and PGAM1 is probably involved in the tumorigenesis and progression of glioma, which may be a potential target for glioma treatment.
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