Liver transplantation, hepatocyte transplantation, and bioartificial liver are means of treating end-stage liver disease and acute liver failure. However, insufficient liver resources and immune rejection after transplantation, as well as a shortage of liver tissue or cell donors, are challenges faced in clinical treatment. The research progress of liver organoid technology in recent years may provide new ways to solve the above problems. Organoids are a kind of three-dimensional cell condensates formed by the self-organization of pluripotent or adult stem cells through three-dimensional culture in vitro, which can imitate the spatial structure and physiological function characteristics of the original organs, can be sub-cultured in vitro, replicated on a large scale, and have the ability of self-renewal. The emergence of organoid technology has brought new hope for providing mechanism exploration models and resolution of hepatocyte resources. In particular, induced pluripotent stem cell-derived organoids do not involve ethical concerns, and are combined with emerging technologies such as gene editing and organ chips, thereby overcoming the constraint of traditional disease research models and establishing a new platform for translational medicine. Additionally, it has expansive application prospects in building disease models, screening drugs, precision medicine, regenerative medicine, and organ transplantation. Thus, this paper summarizes the technical principles, preclinical research, and application progress and challenges of liver organoid technology.

OBJECTIVES: We propose a sparse-view cone-beam CT reconstruction algorithm based on bidirectional flow field guided projection completion (BBC-Recon) to solve the ill-posed inverse problem in sparse-view cone-beam CT imaging. METHODS: The BBC-Recon method consists of two main modules: the projection completion module and the image restoration module. Based on flow field estimation, the projection completion module, through the designed bidirectional and multi-scale correlators, fully calculates the correlation information and redundant information among projections to precisely guide the generation of bidirectional flow fields and missing frames, thus achieving high-precision completion of missing projections and obtaining pseudo complete projections. The image restoration module reconstructs the obtained pseudo complete projections and then refines the image to remove the residual artifacts and further improve the image quality. RESULTS: The experimental results on the public datasets of Mayo Clinic and Guilin Medical University showed that in the case of a 4-fold sparse angle, compared with the suboptimal method, the BBC-Recon method increased the PSNR index by 1.80% and the SSIM index by 0.29%, and reduced the RMSE index by 4.12%; In the case of an 8-fold sparse angle, the BBC-Recon method increased the PSNR index by 1.43% and the SSIM index by 1.49%, and reduced the RMSE index by 0.77%. CONCLUSIONS The BBC-Recon algorithm fully exploits the correlation information between projections to allow effective removal of streak artifacts while preserving image structure information, and demonstrates significant advantages in maintaining inter-slice consistency.
Algorithms ; Cone-Beam Computed Tomography/methods* ; Image Processing, Computer-Assisted/methods* ; Humans

BACKGROUND: The effects of human umbilical cord-derived mesenchymal stem cell (UC-MSC) treatment on coronavirus disease 2019 (COVID-19) patients have been preliminarily characterized. However, real-world data on the safety and efficacy of intravenous transfusions of MSCs in hospitalized COVID-19 patients at the convalescent stage remain to be reported. METHODS: This was a single-arm, multicenter, real-word study in which a contemporaneous external control was included as the control group. Besides, severe and critical COVID-19 patients were considered together as the severe group, given the small number of critical patients. For a total of 110 patients, 21 moderate patients and 31 severe patients were enrolled in the MSC treatment group, while 26 moderate patients and 32 severe patients were enrolled in the control group. All patients received standard treatment. The MSC treatment patients additionally received intravenous infusions of MSCs at a dose of 4 × 10 7 cells on days 0, 3, and 6, respectively. The clinical outcomes, including adverse events (AEs), lung lesion proportion on chest computed tomography, pulmonary function, 6-min walking distance (6-MWD), clinical symptoms, and laboratory parameters, were measured on days 28, 90, 180, 270, and 360 during the follow-up visits. RESULTS: In patients with moderate COVID-19, MSC treatment improved pulmonary function parameters, including forced expiratory volume in the first second (FEV1) and maximum forced vital capacity (VCmax) on days 28 (FEV1, 2.75 [2.35, 3.23] vs . 2.11 [1.96, 2.35], P  = 0.008; VCmax, 2.92 [2.55, 3.60] vs . 2.47 [2.18, 2.68], P  = 0.041), 90 (FEV1, 2.93 [2.63, 3.27] vs . 2.38 [2.24, 2.63], P  = 0.017; VCmax, 3.52 [3.02, 3.80] vs . 2.59 [2.45, 3.15], P  = 0.017), and 360 (FEV1, 2.91 [2.75, 3.18] vs . 2.30 [2.16, 2.70], P  = 0.019; VCmax,3.61 [3.35, 3.97] vs . 2.69 [2.56, 3.23], P  = 0.036) compared with the controls. In addition, in severe patients, MSC treatment notably reduced the proportion of ground-glass lesions in the whole lung volume on day 90 ( P  = 0.045) compared with the controls. No difference in the incidence of AEs was observed between the two groups. Similarly, no significant differences were found in the 6-MWD, D-dimer levels, or interleukin-6 concentrations between the MSC and control groups. CONCLUSIONS: Our results demonstrate the safety and potential of MSC treatment for improved lung lesions and pulmonary function in convalescent COVID-19 patients. However, comprehensive and long-term studies are required to confirm the efficacy of MSC treatment. TRIAL REGISTRATION Chinese Clinical Trial Registry, ChiCTR2000031430.
Humans ; COVID-19/therapy* ; Female ; Male ; Mesenchymal Stem Cell Transplantation/adverse effects* ; Middle Aged ; Adult ; Umbilical Cord/cytology* ; Mesenchymal Stem Cells/cytology* ; SARS-CoV-2 ; Aged ; Treatment Outcome

Objective To investigate the short-term efficacy of CT-guided microwave ablation(MWA)combined with percutaneous vertebroplasty(PVP)for spinal metastases,and to analyze the risk factors for postoperative cement leakage.Methods The clinical data of 50 patients with spinal metastases(74 diseased vertebrae in total),who were treated with CT-guided MW A combined with PVP at the authors'hospital from January 2020 to June 2023,were retrospectively analyzed.Numerical Pain Rating Scale(NRS),daily morphine consumption(DMC)and Activity of Daily Living Scale(ADL)were used to evaluate the short-term efficacy.Regular postoperative CT reexamination was carried out to assess the condition of local tumor control and bone cement leakage.Univariate analysis and multivariate binary logistic analysis of gender,age,maximum diameter of metastatic lesion,type of metastasis,Tomita classification of primary tumor,level of affected vertebrae,injected volume of bone cement,injection side,pathological fracture,and posterior vertebral wall rupture were performed to determine the risk factors for postoperative occurrence of bone cement leakage.Results The preoperative,and the postoperative one-day,one-week,one-month,3-month and 6-month NRS were(7.24±1.41),(4.76±1.45),(3.42±1.34),(2.86±0.90),(2.20±0.57),(1.66±0.72)points respectively.The preoperative,and the postoperative one-day,one-week,one-month,3-month and 6-month DMC were(110.40±94.61),(66.10±51.23),(47.30±37.49),(32.90±22.84),(25.60±18.97),(15.36±13.43)mg respectively.The preoperative,and the postoperative one-week,one-month,3-month and 6-month ADL were(40.80±11.45),(53.20±6.68),(60.40±5.14),(62.90±4.75),(64.80±4.51)points respectively.The differences in NRS,DMC,ADL between their preoperative values and postoperative 6-month values were statistically significant(all P＜0.05).Postoperative 6-month imaging follow-up check revealed that tumor was controlled in 46 patients and the tumor recurrence rate was 8％(4/50),and mild bone cement leakage occurred in 17 of 74 vertebrae(22.97％).Multivariate regression analysis indicated that pathological fracture(OR=9.581,95％CI=2.292-40.055,P=0.002)and rupture of posterior wall of vertebra(OR=5.105,95％CI=1.041-25.022,P=0.044)were the independent risk factors for bone cement leakage,the pathological fracture(OR=35.333,95％CI=4.029-309.840,P=0.001)was the independent risk factor for cortical bone cement leakage.No independent risk factor for vascular bone cement leakage was observed.The rupture of posterior wall of vertebra(OR=48.400,95％CI=4.725-495.753,P=0.001)was the independent risk factor for leakage of bone cement in spinal canal.Conclusion MW A combined with PVP can rapidly relieve pain,improve the ability of daily activity and quality of life of patients with spinal metastases,which can be further improved within 6 months after treatment.The combination use of MW A and PVP carries lower incidence of bone cement leakage.The pathological fracture and posterior wall rupture of vertebra are the independent risk factors for bone cement leakage.

Objective To investigate the spatial distribution of Aedes albopictus in China at different time periods from 2000 to 2019, so as to provide insights into precise management of Ae. albopictus in China. Methods Data pertaining to the distribution of Ae. albopictus in China from 2000 to 2019 were collected through literature retrieval with terms of “Aedes albopictus”, “monitoring”, “survey”, “density”, “distribution”, and “outbreak” in national and international databases. The title and time of the publication, sampling sites, sampling time, mosquito capture methods, and mosquito species and density were extracted, and the longitude and latitude of sampling sites were obtained through Baidu Map. Meteorological element data at meteorological observation stations within China were obtained from the National Climatic Data Center of the United States, and the annual maximum temperature, annual minimum temperature, average temperature in January, average temperature in July, annual temperature range, daily temperature range and relative humidity were calculated and subjected to Kriging interpolation. Monthly cumulative precipitation grid data and monthly average temperature grid data with a resolution of 1 km for China from 2000 to 2019 were obtained from the National Tibetan Plateau Scientific Data Center, and the annual precipitation and annual average temperature were calculated cumulatively. Population density data in China from 2000 to 2019 were obtained from the WorldPop Hub, and the gross domestic product (GDP) in China was obtained from the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences. The above data were divided into 5-year intervals to calculate data during the periods from 2000 to 2004, from 2005 to 2009, from 2010 to 2014, and from 2015 to 2019. Ae. albopictus distribution data were modeled in China from 2000 to 2019 and during each period with the classification random forest (RF) model, to predict the distribution of Ae. albopictus across the country and analyze the distribution of Ae. albopictus based on the seven major climate zones in China. The performance of RF models was evaluated by accuracy, precision, recall, and area under the receiver operating characteristic curve (AUC), and the importance of each feature in the RF model was evaluated with mean decrease accuracy (MDA). Results A total of 1 191 Chinese publictions and 391 English publications were retrieved, among which 580 articles provided detailed data on the sampling sites of Ae. albopictus and specific sampling years, meeting the inclusion criteria. A total of 2 234 Ae. albopictus sampling sites were included in China from 2000 to 2019, and RF modeling results showed that the overall Ae. Albopictus distribution area was mainly found in southeastern and southwestern provinces of China from 2000 to 2019, with scattered distribution in coastal areas of northeastern provinces, such as Liaoning Province. The accuracy, precision, recall and AUC of the RF model were 0.915 to 0.947, 0.933 to 0.975, 0.898 to 0.978, and 0.902 to 0.932 for the distribution of Ae. albopictus at different time periods from 2000 to 2019. Among all features in the RF models, population density was the most contributing factor to the distribution of Ae. albopictus in China, followed by GDP, and all meteorological variables contributed relatively less to the predictive power of the RF model. In China’s seven major climate zones, Ae. albopictus was almost entirely distributed in the marginal tropical humid region, the north subtropical humid region, and the warm temperate semi-humid region. The combined distribution area of these three zones accounted for 100.0% of the national distribution area from 2000 to 2004, from 2005 to 2009, and from 2010 to 2014, and 99.9% from 2015 to 2019, and the proportion of Ae. albopictus distribution area in the warm temperate semihumid region increased gradually from 20.2% to 30.2%. Conclusions Ae. albopictus is mainly distributed in the southeastern and southwestern provinces of China and is greatly influenced by population and economic factors. The warm temperate semi-humid region in China is gradually becoming a hot spot for the distribution of Ae. albopictus.

Liver transplantation, hepatocyte transplantation, and bioartificial liver are means of treating end-stage liver disease and acute liver failure. However, insufficient liver resources and immune rejection after transplantation, as well as a shortage of liver tissue or cell donors, are challenges faced in clinical treatment. The research progress of liver organoid technology in recent years may provide new ways to solve the above problems. Organoids are a kind of three-dimensional cell condensates formed by the self-organization of pluripotent or adult stem cells through three-dimensional culture in vitro, which can imitate the spatial structure and physiological function characteristics of the original organs, can be sub-cultured in vitro, replicated on a large scale, and have the ability of self-renewal. The emergence of organoid technology has brought new hope for providing mechanism exploration models and resolution of hepatocyte resources. In particular, induced pluripotent stem cell-derived organoids do not involve ethical concerns, and are combined with emerging technologies such as gene editing and organ chips, thereby overcoming the constraint of traditional disease research models and establishing a new platform for translational medicine. Additionally, it has expansive application prospects in building disease models, screening drugs, precision medicine, regenerative medicine, and organ transplantation. Thus, this paper summarizes the technical principles, preclinical research, and application progress and challenges of liver organoid technology.

BACKGROUND:With the aging of the global population,the incidence rate of osteoporosis is also increasing.It is very important to further understand its pathogenesis and propose new therapeutic targets.Recent studies have shown that ferroptosis is closely related to the pathogenesis of some bone diseases,such as inflammatory arthritis,osteoporosis and osteoarthritis. OBJECTIVE:To summarize the previous studies on the mechanism of ferroptosis in osteoporosis,so as to provide new therapeutic ideas and potential therapeutic targets for osteoporosis. METHODS:The first author used the computer to search the documents published from 2000 to 2022 in CNKI,WanFang,VIP,PubMed and Web of Science with the key words of"ferroptosis,osteoporosis,osteoblasts,osteoclasts,iron chelators,reactive oxygen species,nuclear factor erythroid 2-related factor 2,heme oxygenase-1,glutathione peroxidase 4,review"in Chinese and English.A total of 70 articles were finally included according to the inclusion criteria. RESULTS AND CONCLUSION:Ferroptosis is significantly different from necrosis,apoptosis and autophagy.In terms of cell morphology and function,it does not have the morphological characteristics of typical necrosis,nor does it have the characteristics of traditional apoptosis,such as cell contraction,chromatin condensation,the formation of apoptotic bodies and the disintegration of cytoskeleton.Contrary to autophagy,ferroptosis does not form a classical closed bilayer membrane structure(autophagic vacuole).Morphologically,ferroptosis is mainly manifested by obvious contraction of mitochondria,increased membrane density,and reduction or disappearance of mitochondrial cristae,which are different from other cell death modes.Iron overload can destroy bone homeostasis by significantly inhibiting osteogenic differentiation and stimulating osteoclast formation,leading to osteoporosis.Iron overload interferes with the differentiation of stem cells to osteoblasts,leading to a weakened osteoblast function and further imbalance of bone metabolism in the body,which eventually leads to osteoporosis.Stimulated by iron overload,osteoclast bone resorption is enhanced and bone loss exceeds new bone formation.Iron chelators have been proved to have osteoprotective effects by inhibiting osteoclast activity and stimulating osteogenic differentiation of osteoblasts.Its potential mechanism is related to inhibiting osteoclast differentiation and promoting osteoblast differentiation.Antioxidants can prevent reactive oxygen species production and inhibit bone absorption,thus improving bone metabolism and effectively preventing osteoporosis.

In humans, the liver is a central metabolic organ with a complex and unique histological microenvironment. Hepatocellular carcinoma (HCC), which is a highly aggressive disease with a poor prognosis, accounts for most cases of primary liver cancer. As an emerging hallmark of cancers, metabolic reprogramming acts as a runaway mechanism that disrupts homeostasis of the affected organs, including the liver. Specifically, rewiring of the liver metabolic microenvironment, including lipid metabolism, is driven by HCC cells, propelling the phenotypes of HCC cells, including dissemination, invasion, and even metastasis in return. The resulting formation of this vicious loop facilitates various malignant behaviors of HCC further. However, few articles have comprehensively summarized lipid reprogramming in HCC metastasis. Here, we have reviewed the general situation of the liver microenvironment and the physiological lipid metabolism in the liver, and highlighted the effects of different aspects of lipid metabolism on HCC metastasis to explore the underlying mechanisms. In addition, we have recapitulated promising therapeutic strategies targeting lipid metabolism and the effects of lipid metabolic reprogramming on the efficacy of HCC systematical therapy, aiming to offer new perspectives for targeted therapy.

Coronary CT angiography(CCTA)has emerged as the preferred imaging method for assessing effectiveness after stent implantation,which could effectively reduce unnecessary invasive examinations.However,the diagnostic accuracy of CCTA is highly dependent on image quality.The research progresses of affecting factors on image quality of CCTA after coronary stent implantation were reviewed in this article.

The combination of Artificial Intelligence(AI)and medical applications has derived a large number of uses and scenarios,which has engaged and changed the healthcare industry from multiple dimensions,such as diagnosis and treatment processes,data fusion,and empowered medical devices,etc.AI large model is a machine learning model based on huge parameter scales and complexity,with a high degree of accuracy and extensive generalization capabilities.In facing the problems such as rapid growth of the data in medical scenarios,data multimodality,large and complex knowledge graphs,AI large model connects the medical processes such as diagnosis,decision-making,treatment and management by series connection,which further broadens and extends the space of AI's medical applications,which will highly utilizes medical data.In view that,we summarized the typical application scenarios of conventional AI and large models in the application of medical field,and discussed the problems of large models in data governance,modal fusion and credibility,so as to promote the landing and application of the combination of large models and medical treatment.