Lost circulation in fractured formation is the first major technical problem that restricts improvements in the quality and efficiency of oil and gas drilling engineering. Improving the success rate of one-time lost circulation control is an urgent demand to ensure “safe, efficient and economic” drilling in oilfields all over the world. In view of the current situation, where drilling fluid loss occurs and the plugging mechanism of fractured formation is not perfect, this paper systematically summarizes the drilling fluid loss mechanism and model of fractured formation. The mechanism and the main influencing factors to improve the formation’s pressure-bearing capacity, based on stress cage theory, fracture closure stress theory, fracture extension stress theory and chemical strengthening wellbore theory, are analyzed in detail. The properties and interaction mechanism of various types of lost circulation materials, such as bridging, high water loss, curable, liquid absorption and expansion and flexible gel, are introduced. The characteristics and distribution of drilling fluid loss in fractured formation are also clarified. Furthermore, it is proposed that lost circulation control technology for fractured formation should focus on the development of big data and intelligence, and adaptive and efficient intelligent lost circulation material should be continuously developed, which lays a theoretical foundation for improving the success rate of lost circulation control in fractured formation. Safe, economical and efficient drilling is the key premise to accelerating the process of deep and ultra-deep oil and gas exploration and development and to increasing oil and gas production . HoweverThe establishment of an accurate and effective drilling fluid loss model is key to studying the drilling fluid loss mechanism in fractured formations ,8. AccorIn view of the current situation, where lost circulation control technology has not effectively solved the challenge of drilling fluid losses, this paper systematically summarizes the drilling fluid loss mechanisms in fractured formation. The mechanism and main influencing factors for improvements in the formation’s pressure-bearing capacity using stress cage theory, fracture closure stress theory, fracture extension stress theory and chemical strengthening wellbore theory are analyzed in detail. The properties and interaction mechanism of various types of lost circulation materials, such as bridging, high water loss, curable, liquid absorption and expansion and flexible gel, are introduced. The characteristics and distribution of drilling fluid loss in fractured formation are defined, and the development trends in lost circulation control technology in fractured formations are presented, providing a theoretical foundation for the scientific and efficient realization of stable plugging in fractured formations.At present, malignant lost circulation in fractured formations has become a worldwide problem that restricts the progress of oil and gas exploration and development. Improving the success rate of the one-time plugging of malignant lost circulation is an urgent demand for ensuring “safe, efficient and economic” drilling in oilfields around the world. It is one of the key points in the field of drilling engineering research and practice for revealing the loss mechanism of drilling fluid in fractured formation, developing special lost circulation materials, and establishing a strong applicable lost circulation control technology.Fracture formation can be divided into fracture loss, fracture expansion loss and differential pressure loss, according to different loss mechanisms . FracturIt was necessary to analyze the cause of loss based on regional structural characteristics and a formation loss pressure profile to establish the mechanism model of drilling fluid loss in fractured formation . In addiAccording to the coupling effect of the fluid characteristics of drilling fluid migration in extended deformation fractures, a fluid–solid coupling model of fracture deformation and drilling fluid loss was established based on one-dimensional radial fracture and two-dimensional plane fracture loss flow mathematical model . Based oDynamic fracture width prediction was of great significance to the loss control of ultra-deep fractured tight reservoirs. The connected fault boundary and nonlinear deformation behavior were seldom considered in fracture width prediction. Xu et al. determined the fracture deformation equation using fitting stress-sensitivity test data, and, based on the non-Newtonian fluid-loss dynamics theory, established a dynamic fracture width prediction model considering power law fluid, fracture exponential deformation equations and fault boundaries . ThroughIn sum, it was crucial to establish an accurate and effective drilling fluid loss model in the study of drilling fluid-loss mechanisms in fractured formations. Based on the loss mechanism and law of drilling fluid in fractured formations, the loss dynamics model was established to accurately predict the deformation characteristics of fractured formation, and loss-type diagnosis and fracture-width inversion were carried out, which could provide a theoretical basis for the prevention and plugging of drilling fluid. If drilling fluid loss occurs during oilfield drilling, drilling parameters and drilling fluid parameters can be adjusted according to the established dynamic model of drilling fluid loss, or reasonable lost circulation materials and lost circulation control measures can be selected to minimize the influence of drilling fluid loss.To improve the pressure-bearing capacity of fractured formations and seal up the lost zone, experts and scholars at home and abroad have carried out a lot of research and analysis on the loss mechanisms in the drilling process. According to various parameters in the process of drilling fluid loss, the key data parameters, such as the properties of the loss layer, the loss pressure and the shape of the loss channel, were found, and the pressure-plugging dynamic model of fractured formations was established. A series of strengthening theories were formed to improve the pressure-bearing capacity of fractured formations. The representative ones oncluded stress cage theory, increasing fracture closure stress, increasing fracture extension stress, chemical strengthening wellbore theory, etc.(1)Stress cage theoryStress cage theory mainly uses solid particles to bridge and plug in the fracture This compresses the formation around the wellbore to produce additional annular stress near the wellbore zone, enhances the wellbore stress near the wellbore wall, increases the ability of the wellbore wall to bear borehole pressure, and prevents fracturing loss under high borehole pressure . Accordi(2)Fracture closure stress theoryFracture closure stress is the force that maintains the closure of a fractured formation surface . In the (3)Fracture extension stress theoryImproving fracture extension stress means that, after solid particles in drilling fluid enter the formation fractures, they can fill and seal the fractures, isolate the fracture tip, block the fluid pressure in wellbore from transferring to the fracture tip, enhance the extension stress and stability of formation fractures, and effectively improve the formation-bearing capacity ,34. Two (4)Chemical strengthening wellbore theoryThe chemical wellbore strengthening method can not only control the salinity differences between drilling fluid and formation pore fluid, it can also strengthen the wellbore effect . In addiLost circulation materials are the basis of, and key to achieving, successful plugging. Experts and scholars at home and abroad have developed a variety of lost circulation materials, such as bridging, high water loss, curable, liquid absorption and expansion, flexible gel, etc., and explored the properties of different types of lost circulation materials and their interaction mechanism with fractures.Bridge plugging is an the effective means of solving the problem of lost circulation in fractured formation. The plugging layer with a dense structure and high bearing capacity is formed by bridging, stacking and filling the fractures with different shapes and sizes of bridging lost circulation materials . The briDrilling fluid loss easily occurs in the drilling process of deep and ultra-deep fractured formations. The fracture plugging layer formed by the bridge lost circulation material is unstable and damaged in a complex environment, such as a high-temperature, high-pressure and high-in-situ-stress environment, leading to the failure of lost circulation control . Kang etHigh-water-loss lost circulation material refers to the lost circulation material that forms a dense plugging layer through solid-phase water loss and by filling in the loss channel . High-waCommon high-water-loss lost circulation materials are Chevron’s Diaseal M lost circulation material, China’s DSL plugging agent and Z-DTR plugging agent . The losCurable lost circulation material refers to lost circulation material with strong thixotropic and curing properties, which can be quickly cured and blocked in the loss layer . CurableSentinel CemTM cement, developed by the Halliburton company, the MAGNE-SET type curable lost circulation material developed by Baker Hughes Company, HDL-4, and chemical consolidation and cross-linking film composite lost circulation material are common existing curable lost circulation materials . HoweverMost of the liquid absorption expansion lost circulation materials are composed of water absorption and oil absorption resin materials, either alone or combined with other lost circulation materials . Its molCommon liquid absorption expansion lost circulation materials are acrylamide–acrylonitrile copolymer, acrylic acid–acrylic acid sodium copolymer polymer swelling resin and its mixture, and other lost circulation materials. In view of the poor stability and low strength of water absorption resin, Wang et al. prepared a water absorption resin type plugging agent PQ with acrylic acid and acrylamide as experimental raw materials . Water aDrilling in the process of formation environment becomes more demanding and the frequency of lost circulation is sharply increased with the gradual exploration and development of oil and gas under deep, ultra-deep, unconventional and other complex conditions . Gel losCrosslinking gel refers to the injection of a polymer (or monomer), crosslinking agent and initiator into the downhole loss channel in the form of an aqueous solution . The croEvaluation method of drilling fluid lost circulation control is the key to preventing the loss of drilling fluid and an important basis for the choice of plugging measure. It helps to clarify the characteristics and distribution law of the loss of drilling fluid and establish the dynamic model of the loss of drilling fluid.The determination of the lost zone is the key to successful lost circulation control during drilling. The accurate determination of lost circulation location within a short time can effectively improve the success rate of lost circulation control. There are many kinds of classification methods for drilling fluid loss in fractured formation. The classification of drilling fluid loss in fractured formation can reflect the mechanism of drilling fluid loss from different sides. Among them, the most commonly used method of drilling fluid loss classification is based on the characteristics of drilling fluid loss rate and drilling fluid loss channel in fractured formation . The claTo truly reflect the stress state of fractured formation and the law of fluid loss and flow, Sui et al. invented an experimental device and evaluation method to simulate the dynamic loss and plugging of drilling fluid . This caThe pressure-bearing capacity of fractured formations is an important index to measure the loss control effect of drilling fluid. It is of great significance for the efficient development of oil and gas resources in fractured formations to effectively improve the formations’ pressure-bearing capacity, establish the pressure-plugging prediction model of fractured formations and form the pressure-bearing-capacity strengthening method. At present, the performance of gel lost circulation materials is mainly evaluated by devices and methods such as high-temperature and high-pressure water loss meters, artificial core-simulation crack loss plugging, nano-composite organic/inorganic gel plugging agent devices, and high-temperature and high-pressure water loss meter sand bed evaluation experiments ,73. To sAn artificial fracture is used to simulate the loss formation channel in the commonly used lost circulation control evaluation devices. Zhu et al. provided a kind of fracture lost circulation control instrument, which could solve the problem with the existing lost circulation control evaluation device, which finds it difficult to simulate the formation loss channel . ExpertsThe following technical challenges occur in the study of lost circulation control evaluation methods and theories in fractured formations: (1) The loss and plugging mechanisms of drilling fluid in fractured formations are not clear; therefore, scientific predictions of the actual properties of lost circulation formation  cannot be supported, and technological research, as well as the development of lost circulation control materials, cannot be scientifically guided. (2) The existing bridge plugging materials poorly match the characteristics and types of lost circulation and lack a quantitative evaluation and lack optimization methods of bridge plugging materials for fractured formation. Additionally, the formation and pressure evolution mechanisms of the bridge plugging layer are unclear, and there is no scientific basis for bridge plugging formula design, resulting in a low success rate.At present, great progress has been made in the research aiming to improve formation-bearing capacity, but the lost circulation control mechanisms of fractured formation are still not perfect. Most theories only include a qualitative cognition, rather than quantitative calculation, and several theoretical models are independent of each other, leading to shortcomings. At the same time, the existing research is mainly focused on the lost circulation control mechanism of rigid granular materials, and there are few studies on the lost circulation control mechanism of flexible materials. In particular, the migration, filling and plugging mechanisms of flexible or composite lost circulation control materials in three-dimensional fractures needs further research. Therefore, the lost circulation control mechanisms have great limitations in their ability to guide the research and development of lost circulation control technology and field construction. Additionally, the site construction of a malignant lost circulation has high levels of blindness and the lost circulation control effect is not ideal.In view of the above problems, more attention should be paid to studying the mechanisms of lost circulation control in fractured formations. The lost circulation control mechanism of drilling fluid loss was accurately revealed regarding the loss channel, mechanical balance and lost circulation control methods, and the laws of drilling fluid loss in different formations and at different scales were clarified. The migration, filling and plugging mechanisms of flexible or composite lost circulation control materials in three-dimensional fractures should be studied. This would provide strong basis for the scientific and efficient selection of lost circulation control materials, formulae, methods and technologies.In recent years, many kinds of lost circulation control materials have been developed by experts and scholars at home and abroad, and all of them have achieved good results to a certain extent. However, the available lost circulation control materials are limited for seriously fractured formations. For the fractured-vuggy formation, which is prone to malignant lost circulation, it is difficult for the lost circulation control material to form a high-strength plugging layer. At present, most of the bridging, gel and composite lost circulation control materials are used to effectively solve the problem of lost circulation in fractured formations. The success rate of lost circulation control for malignant lost circulation in fractured formations is low. Therefore, with the rapid development of material science theory and technology, it is important to promote the development of an intelligent lost circulation control theory for drilling fluid with an efficient lost circulation control material.The compatibility between conventional lost circulation control material and complex fractured formation is poor, so the grading relationship between lost circulation control materials and complex fractured formations should be determined according to drilling fluid loss and plugging mechanism, to avoid the “sealing door” phenomenon. Attention should be paid to the research and development of adaptive lost circulation control materials with fracture space morphology. Conventional lost circulation materials have a weak residence ability in large-scale fracture space, it is difficult to effectively fill the space, and the plugging effect is not good. According to the parameters of the fracture loss channel and the physical and chemical characteristics of the material, an efficient lost circulation control material with a strong residence and full filling effect should be developed. By clarifying its self-adaptive filling law in the loss channel, the bearing capacity can be effectively improved. In view of conventional lost circulation control materials’ lack of high-temperature resistance in deep and ultra-deep high temperature wells, it is difficult to achieve long-term stable plugging. Therefore, we should pay attention to the research into the high-temperature resistance of lost circulation control materials. The research and development of high-temperature lost circulation control materials for deep and ultra-deep high-temperature wells could improve the success rate of the lost circulation control.At present, lost circulation control technology of fractured formations at home and abroad is mainly based on the plugging treatment experience of similar well conditions or neighboring loss wells. There is no scientific optimization and evaluation expert system for lost circulation control technology, and no unified lost circulation control technology specification has been formed. American Petroleum Institute (API) lost circulation control evaluation experimental devices are used to evaluate and study the pressure-bearing capacity at home and abroad. However, the lost circulation control devices cannot simulate the re-opening of fractures after they are closed under pressure. Therefore, with the expansion and application of the big data era and artificial intelligence technology in the field of oil and gas exploration and development, intelligent lost circulation control equipment and technology will become an inevitable development trend.In view of the existing lost circulation control technology, which has strong experience and low intelligence, it is difficult to effectively solve the problems of drilling fluid loss in deep and ultra-deep fractured formations. Therefore, we should pay attention to the development of big data and intelligent lost circulation control technology. Firstly, the data for key areas of drilling fluid loss should be summarized into a database to form a universal expert system for lost circulation control prediction and analysis. Secondly, the research and development regarding intelligent lost circulation control materials and key equipment should be strengthened, promoting the rapid development of lost circulation control methods and technologies in the intelligent direction, and realizing the efficient and intelligent lost circulation control technology for deep and ultra-deep fractured formations.(1) Lost circulation, especially in fractured formations, is the first major technical problem restricting improvements in oil and gas drilling quality and efficiency. The mechanism of drilling fluid loss in fractured formations is revealed, a dynamic model of drilling fluid loss in fractured formations is established, and a strengthening theory to improve the pressure-bearing capacity of fractured formations is formed, which can provide a theoretical basis for the lost circulation control of drilling fluids.(2) Lost circulation materials form the basis of, and key to, successful lost circulation control. Experts and scholars at home and abroad have successively developed various types of lost circulation materials such as bridging, high water loss, curable, liquid absorption expansion and flexible gel, which can solve the problem of lost circulation in fractured formations to a certain extent. However, efficient lost circulation materials that can effectively solve the loss of drilling fluid in deep and ultra-deep high-temperature wells are lacking, and it is important to develop efficient intelligent lost circulation materials to achieve the long-term and stable plugging of fracture formations.(3) The pressure-bearing capacity of fractured formations is an important index to measure the loss control effect of drilling fluids. This is key to improving the lost circulation control success rate of fractured formations, clarifying the characteristics and distribution law of drilling fluid loss, deeply analyzing the causes of drilling fluid loss, and forming a method to strengthen the pressure-bearing capacity of fractured formations.


Colorectal cancer (CRC) is one of the most common and deadly cancers in the world and is a typical inflammatory tumor. In recent years, the incidence of CRC has been increasing year by year. There is evidence that the intake of high-fat diet and overweight are associated with the incidence of CRC, among which bile acids play a key role in the pathogenesis of the disease. Studies on the relationship between bile acid metabolism and the occurrence of CRC have gradually become a hot topic, improving the understanding of metabolic factors in the etiology of colorectal cancer. Meanwhile, intestinal flora also plays an important role in the occurrence and development of CRC In this review, the classification of bile acids and their role in promoting the occurrence of CRC are discussed, and we highlights how a high-fat diet affects bile acid metabolism and destroys the integrity of the intestinal barrier and the effects of gut bacteria. Bile acid is a metabolite of cholesterol in the liver. Bile acid can promote the absorption of fat and fat-soluble vitamins in the intestine and plays an important role in lipid metabolism in the liver . In addiIn the human body, bile acids are synthesized in the liver cells by oxidation of cholesterol. They can be divided into free bile acids and conjugated bile acid according to their structure. Bile acids can also be divided into PBAs and secondary bile acids according to their source. The production of PBAs occurs mainly through the classical and alternative pathways . The claEpidemiological data showed that the incidence of CRC is also higher in patients with higher fecal bile acid (FBA) concentrations. Due to the rich diet of fat and protein, the incidence of FBA in the feces and CRC in European and American populations is significantly higher than that in Asian and African populations whose diet contains less fat and protein and is rich in cellulose . In all These findings show that in our country, high secondary bile acid (SBA) levels in CRC patients may be found as animal experiments have shown that giving a high-fat diet increases the concentration of animal waste FBA and also increases bowel cancer rates; directly increasing the experimental animal intestinal bile acid concentration intake also increases the rate of CRC, indicating that a link between diet and FBA levels and CRC exists, and that FBA is a cause of large intestine cancer rather than a result of the disease . LaboratSBAs mainly include DCA, LCA, and a small amount of UDCA (UDCA), the levels of which are closely related to the occurrence of CRC, especially DCA, which is considered to be a carcinogenic and carcinogenic factor. The occurrence of CRC is a multigene, multistep and multipathway process involving chromosome instability, gene mutation, mismatch modification gene inactivation, and multiple cell signal transduction pathway abnormalities. A high-fat diet and gallbladder disease can increase the content of secondary bile acids in the intestinal cavity, especially the level of DCA, thereby promoting the occurrence and development of CRC.On the other hand, some reports have confirmed that DCA can also participate in intestinal metabolism to maintain intestinal immune balance. Campbell, Clarissa et al.  found thWith the development of research, we gradually found that not all bile acids have a role in promoting CRC. Many experiments have shown that during the development of CRC, high concentrations of SBAs play a role in tumor promotion .via several mechanisms, including oxidative damage to DNA, damage to mitochondria and the endoplasmic reticulum, an increase in the micronucleus rate, and chromosome aneuploid mutations . The production of excessive ROS releases Ca ions from the ER membrane through the activation of inositol triphosphate and alanine receptors, which damages the ER membrane. ER membrane damage leads to impaired protein folding, and the production of excessive ROS exceeds the antioxidant capacity of the cell, leading to the death of colonic epithelial cells . Wachs eThere are two mechanisms by which DCA induces an increase in the micronucleus rate and chromosome aneuploid mutation: (1) chromosomal deletion and translocation through the instability of the centromere and telomere, and (2) the disruption of the gene-controlled process of mitosis, resulting in asymmetric segregation of chromosomes, initiation of autocatalytic karyotypes, and progression to the cancer cell phenotype .DCA induces CRC by causing genomic instability. Existing mechanisms include DNA oxidative damage, mitochondrial and endoplasmic reticulum damage, increased micronucleus rate, and chromosomal aneuploid mutations. However, the research on the relevant mechanism is still relatively simple and needs to be further explored.DCA is a strong promoter in the early stage of tumor formation and can promote the development of CRC through several mechanisms. The mechanism of inducing cell proliferation and apoptosis is as follows: stable and translocated pronucellin through tyrosine phosphorylation enters the nucleus and stimulates the expression of uPA, uPAR and cyclin D1. Tyrosine phosphorylates and decomposes proctin-catenin to induce cell adhesion loss, while uPA/uPAR receptor-mediated proteolytic enzymes degrade the extracellular matrix and induce cell proliferation with cyclin D1/uPA/uPA, thereby improving the growth and progression of colon cancer cells.Kong et al. found that DCA could cause miRNA dysfunction and play a role in promoting tumor formation. The growth, migration and invasion of colorectal tumor cells were inhibited by the highly expressed miR-199a-5p, and the cell cycline-related protein CAC1 was regulated by miR-199a-5p. DCA can promote tumor formation by inhibiting the effect of miR-199a-5p and/or promoting the increase in CAC1 expression . ReducedDCA treatment of BCS-TC2 colonic tumor cells results in apoptosis within 30 min to 2 h; the cells separate into single cells, the cell membranes lose symmetry, the chromatin is condensed, the DNA degrades, mitochondrial permeability changes occur, and the Caspase family and antiapoptotic proteins (Bax) are activated, causing an enzymatic cascade that increases the production of ROS, which leads to mitochondrial membrane potential alteration and the release of apoptosis factors within the cell .Donato F proposed that DCA is an endogenous carcinogen that can promote DNA damage and inhibit the expression of the brca-1 gene in the colonic mucosal epithelium, which is responsible for inducing apoptosis and DNA repair. Dianhua Qiao et al. demonstrated that DCA inhibits the P53 gene through the degradation of the P53 protein mediated by protein kinase. P53 is a well-known tumor suppressor gene, and its inhibition can promote tumors . DanielaAt present, the main conclusion of DCA on the proliferation and apoptosis of CRC cells is that DCA further promotes the proliferation of CRC cells and inhibits the apoptosis of CRC cells. However, there is still no new breakthrough in the specific mechanism and further research is needed.The EGFR signaling axis is closely related to the proliferation, apoptosis and survival of colonic epithelial cells and plays an important role in maintaining cell homeostasis . There aThe signaling proteins of the Wnt family are involved in several developmental processes during embryogenesis and are involved in tissue homeostasis in adults. The Wnt signaling pathway is pleiotropic and is involved in promoting mitosis, determining cell fate, and differentiation. There are three Wnt pathways, the classical Wnt/b-catenin pathway, the PCP pathway and the Wnt/Ca2+ pathway. Current research focuses on the classical Wnt pathway, that is, that Wnt regulates the expression of b-catenin protein through its Frizzled receptor, thereby regulating the transcriptional expression of downstream genes and ultimately affecting the cell cycle pathway . After tThe specific signaling pathways induced by DCA in CRC mainly include two categories –EGFR signaling axis and Wnt signaling pathway. DCA induces CRC by activating these two major signaling pathways. Related studies involve cell and animal levels, providing reliable information for us to understand the occurrence and development of DCA and CRC.Bile acids in the intestinal tract play an important self-regulating role in the regeneration and differentiation of the mucosal epithelium of the large intestine. UDCA may reduce chemical-induced carcinogenesis. UDCA has been found to be chemoprophylactic for colon cancer in patients with primary sclerosing cholangitis . Two to Long-term oral administration of UDCA did not increase the incidence of CRC but showed a decreasing trend. Animal studies have shown that UDCA significantly reduces the number and volume of colon cancer cells induced by carcinogenic agents such as azomethane oxide (AOM). In patients with UC and primary sclerosing cholangitis, the incidence of atypical hyperplasia and carcinoma of the colon decreased after UDCA administration. After administration of UDCA, the concentration of UDCA in the bile increased significantly and the level of DCA in the feces decreased, while UDCA inhibited colonic epithelial hyperplasia. The mechanism may be inhibition of cancer cells by the activation of the apoptotic gene bax, which activates the activity of basic spatholinase (8mase) and caspase-3 (caspase-3), inhibiting the mutation of k-ras and the expression of ras-dependent cox-2, and inhibiting the activation of erk, fra-1 and epidermal growth factor receptor (egfr) caused by DCA. The UDCA concentration in normal bile is very low. Therefore, whether UDCA can inhibit cancer in normal bile metabolism should be further studied.Cell-level studies have shown that UDCA can induce the apoptosis of CRC cells in the early stage, while DCA mainly induces the apoptosis and necrosis of normal intestinal cells. Therefore, bile acids play an important role in regulating the survival and death of colon cancer cells. UDCA is a hydrophilic bile acid that exists as a protective component of cells. It prevents a variety of stressors, including DCA-induced apoptosis, and its role in the colon was demonstrated by the molecular mechanism of UDCA against the effects of DCA. Pretreatment with UDCA can reduce the occurrence of apoptosis after DCA exposure. UDCA can also significantly affect the activity of neurophospholipase (smase), affecting cell proliferation and colon cell apoptosis depending on the cell conditions , 52. TheIn Laurie Barclay’s double-blind study , 1285 paZhang, Huan et al.  exploredPBAs (cholic acid and chenodeoxycholic acid) are synthesized in the liver and excreted into the duodenum, where they facilitate the absorption of dietary lipids. A small volume of bile acids escapes the enterohepatic circulation and enters the colon; these bile acids are extensively metabolized by bacterial flora to form the SBAs DCA and LCA . SubstanDCA has been demonstrated to stimulate MAPK signaling through epidermal growth factor receptor activation and calcium signaling in HT-29 colon cancer cells . LCA hasIL-8 has been detected in CRC and contributes to poor patient prognosis. However, the effect of LCA on IL-8 expression is still undefined. LCA treatment induces IL-8 expression in CRC HCT116 cells. The results of pharmacological inhibition and mutagenesis studies indicated that Erk1/2 is critical for LCA-induced IL-8 expression. Furthermore, LCA reduces the phosphorylation of STAT3, and the STAT3 inhibitor Stattic accelerates LCA-induced IL-8 expression, suggesting that STAT3 is involved in LCA-induced IL-8 expression. Activation of Erk1/2 functions as an upstream signal of STAT3 suppression induced by LCA. In conclusion, LCA activates Erk1/2 and in turn suppresses STAT3 phosphorylation to induce IL-8 expression in HCT116 cells, thus stimulating endothelial cell proliferation and tube-like formation.The intestinal flora is the largest and most important microecosystem in the human body. Healthy adult intestines contain more than 500 species of bacteria from 30 genera, including 1014 bacteria with a weight of approximately 1000 g and a total genome content that is 100 times greater than that of humans . These bThe intestinal flora of the human body is large and versatile. These bacteria can form a biological barrier in the intestinal tract through the placeholding effect, nutrition competition, and several secreted metabolites , which cIntestinal bacteria interact with bile acids, which also affect the composition of the intestinal flora. Bile acids promote the growth of bile acid-metabolizing bacteria and inhibit the proliferation of bile acid-sensitive bacteria . Bile duHelicobacter pylori and inhibit its growth and proliferation  is an important virulence factor of deputy hemolytic Vibrio transcription regulatory proteins  A and C; two transcription factors form the barrel complex and this complex was identified as free bile acid that activates the downstream VtrB, which in combination with its promoter sequences, activates T3SS transcription, induces the expression of downstream virulence factors, and enhances the virulence of the pathogen , 81.Campylobacter invasion antigen (Cia) promoter and upregulate the expression of Cia, thus greatly improving the infection capacity of Campylobacter in epithelial cells  leading to spore germination and Clostridium difficile that are capable of pathogenic infection  expression in the colon, thus altering the metabolism of bile acid . As the The intestinal epithelium and the substances it secretes are the first barrier against the invasion of bacteria and other pathogens. A decrease in intestinal barrier function and the thinning of the mucus layer leads to the infiltration and transfusion of harmful bacterial products such as lipopolysaccharides (LPS), which leads to a systemic inflammatory response. The normal human body sustains intestinal injury when absorbing fat, which is repaired after 50 min , while lIt has been recognized that chronic low-grade inflammation is closely related to the occurrence and development of CRC. Markers of chronic inflammation, such as C-reactive protein (CRP), in the blood have a certain suggestive effect on the risk for CRC . In receSclerotinia will be increased. If the proportion of Enterococcus returns to normal, weight loss can be achieved, and metabolic disorders such as obesity can be relieved -positive cells in the gut-associated lymphoid tissues (GALTS). The expression of MHC-II promotes the occurrence and development of CRC . A high-relieved . In addiresponse . Recent response . In addie of CRC .Therefore, various studies have shown that a high-fat diet will affect the metabolism of bile acids and destroy the integrity of the intestinal barrier, thus promoting the occurrence and development of CRC.In summary, bile acids increase the risk for CRC, and the mechanism and influencing factors of bile acids on CRC development are complex, including influencing the proliferation and apoptosis of colonic epithelial cells, destroying the intestinal barrier to increase intestinal permeability, and changing the intestinal flora. Research and exploration of the above mechanisms can provide a reference for the prevention and treatment of CRC in the future. The application of nonsteroidal anti-inflammatory drugs, probiotics and their products, lifestyle changes and other means may become effective interventions. We look forward to further research and exploration in the future to provide a further theoretical basis for the occurrence and development of CRC and new treatment directions.HX and GJ contributed to the conceptualization of this paper and made the frame. YL and SZ contributed to original draft preparation. DH participated in part of the text arrangement and image conception. WZ, GJ, and HX revised the manuscript. All authors contributed to the article and approved the submitted version.This work was supported by National Nature Science Foundation of China, No. 81620108030, 81874206, 82104466; Shanghai Frontier Research Base of Disease and Syndrome Biology of Inflammatory cancer transformation, No. 2021KJ03-12; Shanghai Rising-Star Program, No. 20QA1409300; and the Program for Young Eastern Scholar at Shanghai Institutions of Higher Learning, No. QD2019034. Artificial Intelligence Cooperation project of Xuhui District Science and Technology Commission, No. 2020-004.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.The reviewer WC declared a shared affiliation with the authors to the handling editor at time of review.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Extra-spinal causes of sciatic pain are normally underdiagnosed, as they are extremely uncommon. Although pyriformis syndrome is recognized as one of the main causes of sciatic pain, other pelvic muscles that could cause sciatic pain are often overlooked. The present article describes a swollen inferior gemellus muscle with hematoma initially diagnosed with ultrasonography and later confirmed with magnetic resonance imaging (MRI) scan. Ultrasound revealed a swollen muscle with hematoma between the ischial tuberosity and the medial surface of the greater trochanter of the femur. MRI scan showed edematous change with an increased enhancement of the right inferior gemellus muscle. Ultrasound could be used to diagnose inferior gemellus pathology, but the muscle is easy to miss. Therefore, MRI could be preferred for conditions that impact deep or large areas in confirming inferior gemellus pathology. Either spinal or extra-spinal causes could cause sciatic pain. Extra-spinal causes of sciatic pain are underdiagnosed due to their rarity. Pyriformis syndrome is probably the most well-known extra-spinal cause of sciatic pain, but due to the lack of literature and general knowledge is often under-recognized. Nevertheless, other pelvic muscles could cause sciatic pain, which is often overlooked .The inferior gemellus muscle is an abductor and external rotator muscle of the hip that stabilizes the head of the femur in the acetabulum. It originated from the upper part of the lateral surface of the ischial tuberosity and the medial surface (intrapelvic origin). The muscle passes through the tendon of the obturator internus and together with the superior gemellus muscle, subsequently inserts into a medial surface of the greater trochanter of the femur . Strain Herein, the present article reports a patient suffering from inferior gemellus muscle strain with hematoma after a basketball practice game. Clinical, ultrasonographic, and magnetic resonance imaging (MRI) findings are described to underline the importance of considering the condition in the diagnostic algorithm of hip pain of unknown origin. This case is of considerable clinical value due to its rare clinical, ultrasonographic, and MRI findings.A 57-year-old man with an unremarkable past medical history presented to the outpatient clinic with right gluteal pain. One week before the presentation, the patient had a basketball practice game. During the game, he made sudden lower limb turning movements. A snapping sound originating from his right gluteal area was heard immediately after the movement, and the man reported sudden onset of right-sided gluteal pain radiating towards the right hip area. The pain was only partially relieved by over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) to curb inflammation.On clinical examination, inspection revealed an antalgic gait and inability to hyperextend the right hip. There was local tenderness over the right deep gluteal area, but no swelling or bruising over the right groin, thigh, or buttock was noted. There was no tenderness of the paraspinal muscle, the greater trochanter, the insertion of the hip adductor muscles, or the iliotibial band. The straight leg raise test was positive on the right side. The flexion, adduction, internal rotation tests were positive. Patrick’s test was also positive. However, the springing test of lumbar region was negative.Plain radiographs of the right hip revealed a hip with subtle subchondral bone sclerosis, which is compatible with early-stage OA, as shown in As the severe pain became more frequent, musculoskeletal sonography was performed to identify the cause. The sonography revealed a swollen inferior gemellus with hematoma between the ischial tuberosity and the medial surface of the greater trochanter of the femur, indicating the muscle strain with hematoma as shown in The patient was treated with an ultrasound-guided steroid injection (Triamcinolone 10 mg mixed with lidocaine 10 mg), also as a diagnostic treatment, followed by oral NSAID (Diclofenac 75 mg divided three times per day for 7 days) and rehabilitation therapies, including hot packing, ultrasound therapy, interferential current, and therapeutic exercises. The pain immediately improved after the steroid injection and local anesthetics. Upon weekly follow-up visits, both the pain and the range of movement of the right hip improved. A half month later after the steroid injection, the patient received ultrasound-guided platelet-rich plasma injection shown in B per monInferior gemellus, superior gemellus, and obturator internus muscles are called triceps coxae  and are part of a larger, three-headed muscle complex . The insTo perform the sonographic examination of the inferior gemellus muscle, the medial end of the transducer needed to be rotated caudally while maintaining the fixed position at the lateral end. The procedure required the operator to turn the transducer slowly and carefully while making passive rotation of the hip. As the origin of the inferior gemellus muscle was at the ischium , immediately inferior to where the obturator internus passes, misidentification is potential. The heel–toe maneuver could be performed to facilitate the visualization of the ischial attachment of the inferior gemellus muscle .The pathway of the sciatic nerve is deep to the piriformis muscle and superficial to the triceps coxae muscles. If the sciatic nerve is compressed by these muscles, whenever there is inflammation or trauma, it will cause sciatic pain, which needs the differential diagnosis of non-discogenic sciatica ,8. The mNo cases of inferior gemellus hematoma had been published previously. Overall, reports of sonographic pathology of inferior gemellus or even superior gemellus were lacking in published literature. However, the patient with gluteal pain from obturator internus tendinitis and bursitis successfully treated with ultrasound-guided injection had been reported .This article is the first case report describing ultrasound for diagnosing the inferior gemellus problem.


With the increase in world population, the demography of humans is estimated to be exceeded and it has become a major challenge to provide an adequate amount of food, feed, and agricultural products majorly in developing countries. The use of chemical fertilizers causes the plant to grow efficiently and rapidly to meet the food demand. The drawbacks of using a higher quantity of chemical or synthetic fertilizers are environmental pollution, persistent changes in the soil ecology, physiochemical composition, decreasing agricultural productivity and cause several health hazards. Climatic factors are responsible for enhancing abiotic stress on crops, resulting in reduced agricultural productivity. There are various types of abiotic and biotic stress factors like soil salinity, drought, wind, improper temperature, heavy metals, waterlogging, and different weeds and phytopathogens like bacteria, viruses, fungi, and nematodes which attack plants, reducing crop productivity and quality. There is a shift toward the use of biofertilizers due to all these facts, which provide nutrition through natural processes like zinc, potassium and phosphorus solubilization, nitrogen fixation, production of hormones, siderophore, various hydrolytic enzymes and protect the plant from different plant pathogens and stress conditions. They provide the nutrition in adequate amount that is sufficient for healthy crop development to fulfill the demand of the increasing population worldwide, eco-friendly and economically convenient. This review will focus on biofertilizers and their mechanisms of action, role in crop productivity and in biotic/abiotic stress tolerance. The world population will reach 9 billion by 2050 in accordance with Food and Agricultural Organization; as a result, there should be an enhancement in crop yield to meet the food demand. Soil is an important source of food production in human lifespan. In the last decades, due to the increase in agricultural practices such as pesticides and chemical fertilizers it has been degraded at a universal scale and causes lower fertility due to loss in biodiversity, water retention, and disturbance in biogeochemical cycles. Soil health and plant productivity are severely influenced by numerous interactions among plant, soil, and microorganisms  associated with non-leguminous plants , Azolla and the blue-green alga Anabaena azollae, and association of cyanobacteria with gymnosperms   increased the K content in maize and protects plants from salinity stress  is the third major constituent of the macro-nutrients required by plants. It is mainly intricate in the regulation of stomatal closing and opening, nutrient uptake, protein synthesis improving the quality of products and provides resistance against stress environment  effectively release the unavailable potassium through the solubilization process  into an available form of sulfur known as sulfate (SO4−2), and the reverse of this process is known assimilatory sulfate reduction which is mediated by sulfate-reducing bacteria 2, ZnCO3, and metallic Zn. The usable form of zinc by the plant is divalent cations  is a micronutrient that performs various functions like photosynthesis, respiration, chlorophyll, and many of the enzymatic reactions in plants , a producer of endotoxins that can be used as biopesticide and a source of genes for the creation of transgenic plants that are resistant to insects, is currently the most effective biopesticide on the market , polyphenol oxidase, phenylalanine ammonia-lyase (PAL), lipoxygenase, and chitinase  used to control Mycosphaerella graminicola induced pathogenesis-related proteins (PR1) which is considered as marker of SAR. Application of Bacillus aryabhattai activated a durable defense response against pathogens facilitated through salicylic acid/ethylene pathways  induced defense-related genes protein (PR1) and phytoalexin-deficient 3 in A. thaliana. PR1 gene expression was found to be 20-fold higher in treated plants than control, and other genes found in the study were associated with jasmonic and salicylic acid pathways  under water-deficit conditions via enhanced antioxidant enzyme activities, soluble sugars, and proteins  improves tolerance and growth of plants due to the upregulation of aquaporins. Bacillus megaterium also regulates the aquaporin genes during salt stress in maize plants and improved root growth and leaf water content  via EPS and biofilm production  via increasing the CAT and POD genes. Inoculation of Penicillium and Ampelomyces spp. improved drought and salinity stress tolerance in tomato plants via the production of osmolytes, stress-responsive genes, and antioxidant enzymes  which helped to improve the stress tolerance in plants during salt stress  growth via the production of polyamine under Pb and Cd toxicity (Wang et al., Citrobacter and Enterobacter cloacae mitigate the Cd and Pb toxicity, improve the wheat plant health parameters, and protect from stress via the generation of antioxidant enzymes (Ajmal et al., Pseudarthrobacter oxydans improved Sulla spinosissima growth and can be used as biofertilizer at heavy metal-contaminated sites. Cadmium tolerance bacteria such as Curtobacterium ocenosedimentum having P-solubilizing, IAA, and siderophore-producing possessions improved chili growth and increased shoot/root length (Patel et al., Pseudoarthrobacter and Vibrio neocaledonicus improved the Salicornia ramosissima growth at As- and Cu-polluted sites (Mesa-Marín et al., Rhizobium inoculation can promote soil nutrient cycling by increasing enzyme activity in metal-contaminated soil, thereby providing more N and P for microbial activity and growth of plants (Ma et al., Extreme usage of inorganic chemical fertilizers in agriculture system causes the accumulation of toxic metals such as nickel, manganese, cadmium, iron, and zinc in soil (Ghori et al., n et al. . ToxicitAgriculture systems have to face the task of food production, stress management, and dependency on agrochemicals. The presence of pest and pathogen in crops causes decrease in crop yield and heavy crop losses every year. The occurrence of abiotic stresses due to the change in climatic conditions leads to difficult challenge to crop production worldwide. Different effective approaches should be employed to reduce crop output loss and control diseases. Hence, the necessity to implement the eco-friendly approaches such as biofertilizers is of great importance for sustainable agriculture. The application of biofertilizers not only improves plant heath parameters but also enhances the crop productivity, soil health and protects from stress environment. More research has been focused on physiological and molecular aspects under different conditions with different crops using biofertilizers under field conditions.PC: conceptualization and wrote the manuscript. SS, AC, AS, and GK: editing the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The beef cattle industry in China has advanced remarkably since its reform and opening up; consequently, China has become the world’s third-largest beef cattle producer. China is also one of the countries with the most substantial research input and output in the field of beef cattle feed and nutrition. The progress and innovation by China in the research field of beef cattle feed and nutrition have undoubtedly promoted the development of the domestic beef cattle industry. This review summarizes recent advances in feed resource development, nutrient requirements, and nutritional regulation of beef cattle in China. Limitations in current research and perspectives on future work are also discussed. The vigorous development of beef cattle farming can alleviate the competition for grains between humans and livestock and help improve the dietary structure of humans. Additionally, beef cattle farming contributes to rural revitalization in China. Given these factors, China has been increasing support for beef cattle farming and related research over the past decades.https://www.statista.com). The low per capita beef consumption in China is due to the Chinese dietary habit of preferring pork and chicken. Beef cattle industry in China was established late. Before that, cattle, as important draught animals, were forbidden to be slaughtered without permission, which made it difficult to establish beef consumption habits. However, as machines have replaced cattle for ploughing in recent decades, slaughtering cattle for food is no longer restricted. Chinese people have gradually incorporated more beef into their diet, resulting in the sustained and rapid growth of per capita consumption of beef, highlighting China as a promising market. Driven by domestic beef consumption demand, the beef industry in China is expected to further develop and become more prominent in the global beef industry. However, China’s beef cattle industry has been facing multiple issues that restrict its efficient and sustainable development (Bos taurus) breeds, including 55 local breeds, 15 imported breeds, and 10 cultivated breeds. Local beef cattle breeds and their hybrid offspring make up the main body of the beef cattle farming industry in China. However, the body size and production efficiency of most of these breeds are poor. Beef cattle often face various environmental stresses, such as heat and cold stresses, which deteriorate animal welfare and farming profits [China has become the world’s third-largest beef cattle producer, with an annual beef output of 6.72 million tonnes in 2020 . At preselopment . The pro profits . In addiFeed and nutrition research plays a vital role in resolving the abovementioned problems, thus promoting the transformation and modernization of the beef cattle industry in China. In this review, we summarize the research progress in this field over the past decade.In recent years, the rising costs of raw materials have led to an increase in the costs of feeding beef cattle in China. The agriculture, forestry, and food industry produce many by-products that can be used as cheap feed resources to reduce feeding costs .Previous studies have reported the nutritional components of these by-products ,7. MoreoSince the promulgation of the “Feeding Standard of Beef Cattle” (FSBC) in 2004, China has continued to strengthen its research on the nutrient requirements of beef cattle, mainly focusing on energy and protein requirements of growing-finishing beef cattle . HoweverWe compared the conclusions of previous studies with the recommendations of the FSBC , and theThe average production efficiency of beef cattle in China has been lower than that in developed countries for a long time, which reduces the profit and market competitiveness of the domestic beef cattle industry. Improving the production efficiency of beef cattle is thus a critical problem for the beef cattle industry in China.The growth performance of beef cattle can be improved by adjusting the feed composition in the diet and adding functional substances. For adjusting diet structure, it has been reported that the growth performance and meat quality improved when beef cattle consumed high-quality roughage . MoreoveIn addition, the rumen, the main digestive organ of ruminants, provides 70% to 80% of the energy requirements for growth. Previous studies have reported that regulating dietary energy  and crudBeef quality is one of the most important factors affecting price and consumers’ purchase behavior. In China, the emphasis on the nutritional regulation of beef quality is for improving the intramuscular fat (IMF) content and optimization of meat fatty acid composition. Previous studies reported that increased dietary energy levels can increase the transcription and translation of adipogenic genes, promote the differentiation of preadipocytes into adipocytes, and decrease transcription and translation of lipidolytic genes, thus promoting the accumulation of IMF in beef ,28. In aUnsaturated fatty acids (UFA), which as an important component of meat, are important for human health . Wang etAgastache rugosa essential oil [Heat, cold, and transportation are the most common and harmful sources of stress for beef cattle. Heat stress can impair the antioxidant, immune, and digestive functions of beef cattle ,37. Prevtial oil  can alleCold stress can damage the immune and antioxidant functions of beef cattle by activating the hypothalamus–pituitary–thyroid axis . A recenAstragalus polysaccharides [Transport stress can lead to an imbalance in rumen flora, nutritional metabolism, and immunity of beef cattle ,49. It hcharides  and creacharides  can alleHigh pollutant emission is a basic characteristic of the current beef cattle farming industry in China. Stricter environmental protection constraints in recent years have thus resulted in severe challenges for the beef cattle industry in China.4) is one of the main pollutants released from beef cattle farming. In 2009, methane emissions from beef cattle farming in China accounted for nearly two-thirds of all CH4 produced by domestic ruminant farming [4 emissions from ruminants account for 2% to 12% of total dietary energy [4 emissions is particularly important for the efficient and sustainable development of the beef cattle industry. The nutritional regulation strategies for mitigating CH4 emissions can be mainly divided into optimizing the diet structure and adding functional substances to the diet . A recent study reported that balancing the dietary ratio of nitrogen to sulfur can help increase nitrogen retention and reduce urinary nitrogen content of beef cattle [2O-N emissions by transferring nitrogen from the urine to the feces. Additionally, Gao et al [2O-N emissions of beef cattle by increasing urinary hippuric acid excretion.In addition to CHf cattle . Dietaryf cattle , vitaminf cattle , and N-cf cattle  can alsof cattle  and gallf cattle  to the dao et al  showed tChina has abundant unconventional feed resources; however, these resources are not utilized effectively. Therefore, it is necessary to further evaluate the nutritional and feeding values of these resources and study appropriate processing and storage technologies to expand their application in beef cattle farming.Because of the improvements in intensive beef cattle farming in China, the original extensive feeding management strategy has been gradually replaced with precision feeding techniques. Understanding the precise nutrient requirements of beef cattle is the premise of precision feeding. We compared the conclusions of previous studies with the recommendations of the FSBC . The resNutritional regulation plays an essential role in beef cattle farming. Functional additives, especially plant extracts and probiotics, have been the focus of research in China in recent years. In addition, based on the importance of the IMF deposition of beef, numerous studies have been conducted on the relationship between nutrition intervention and IMF deposition ,29. HoweIn general, China has a relatively solid foundation of research in the field of beef cattle feed and nutrition that strongly supports the development of domestic beef cattle industry. However, there are still many limitations in current research, which restrict the efficient and sustainable development of beef cattle industry. In the future, more studies should focus on developing unconventional feed resources, studying the regulation mechanisms for efficient feed utilization and high-quality beef production, and establishing technologies of precision nutrition and low-carbon farming for beef cattle.


Juvenile idiopathic arthritis (JIA) is one of the common rheumatic diseases in pediatrics. Persistent synovitis and joint pain cause reduced range of motion, deformity and gait interruption, which are important reasons for children's disability and a decline in their quality of life. Rheumatology experts have explored good treatment strategies, among which intra-articular corticosteroid injections (IACIs) targeting joints can greatly reduce these systemic adverse reactions while still obtaining local anti-inflammatory effects. Local inhibition of synovitis by the use of steroid hormones in a joint cavity can avoid or reduce adverse reactions of systemic therapy, prevent or treat leg length variance and joint contracture, solve Baker's cyst, improve tenosynovitis, promote physical therapy and rehabilitation, make gait change smoothly, relieve pain, and restore joint function. Given the importance of IACIs in treating JIA, this paper reviewed the case selection, drug injection, dose selection, current anesthesia and injection techniques, the efficacy, recurrence, and influencing factors of IACIs, the management of physiotherapy intervention post-injection, the application of ultrasound guidance and the safety and complications of IACIs in children with JIA. This study aims to guide the use of IACIs for the best approach throughout the review. Intra-articular corticosteroid injections (IACIs) are mainly applicable to chronic rheumatoid arthritis and osteoarthritis of the knee . StudiesIn this study, MEDLINE, PubMed, EMBASE, the web of science and Cochrane libraries were used for comprehensive literature retrieval. The inclusion criteria were: meta-analysis, RCT, cohort study, observational study, case series (prospective/retrospective), and its outcome variables evaluated the clinical case selection dose and efficacy, safety, adverse reactions and/or puncture technology, anesthesia technology, and radiologic effects of IAGs on patients.Depot corticosteroids are most suitable for intra-articular injection therapy. The solubility of these drugs is low, and they can continue to play a role at the injection site of the joint. The duration of efficacy is inversely proportional to the solubility of the drug; the lower the solubility, the longer the duration of efficacy. At present, commonly used drugs include methylprednisolone (MP), triamcinolone acetonide (TA), triamcinolone hexanoate (TH), where the solubility is MP > TA > TH . For preLiterature shows that, although triamcinolone is the best glucocorticoid for IACIs, more soluble glucocorticoids (such as MP) are recommended for use at the facet joints , 9 to avBefore performing joint cavity punctures, the main concern is the anxiety and pain related to the operation. Many factors interact with and affect children's painful experiences, including environmental, cognitive, behavioral and biological factors. Children's anxiety before undergoing painful medical procedures is directly related to the pain experienced. Nieto-González and Monteagudo strongly recommends the use of local anesthesia before or during surgery and the use of conscious sedatives in specific cases for evaluation . The pur2O) and oxygen inhalation mixture to help with children's painful operations, including IACIs. This procedure has the advantages of short-term hospitalization and avoiding the risks caused by intravenous sedation or general anesthesia  can provide safe and effective analgesics for some adolescent patients with idiopathic arthritis and pediatric arthritis. The use of IACIs provides a low-cost alternative to general anesthesia  is used at the same time and whether uveitis is accompanied result in different curative effects. Breit's research showed that the median duration of curative effect varies with joints and disease subtypes. Patients with oligoarthritis before the age of five had the longest median duration, while patients with systemic arthritis had the shortest duration . RavelliIn a study involving 220 patients with JIA with 1,096 IACIs, the strongest predictor of synovitis recurrence after the IACIs was positive for CRP, negative ANA, lack of simultaneous administration of MTX, and the occurrence of multiple joints (as opposed to fewer joints) diseases . RavelliAt present, the benefit of specific physical therapy in patients with JIA after IACIs is still inconclusive. In 2003, Cleary et al. reported that the problems of rest, splint and physical therapy post-injection were still controversial and had not been studied in children's controlled trials. In adults, the evidence is confusing and inconclusive, according to Cleary. There are persistent and significant differences in the improvement of clinical and laboratory functions among patients who have been on strict bed rest for 24 h post-injection, though some studies suggest that strict bed rest is beneficial but unnecessary for IACIs . McKay'sIn the pediatric population, there is not enough scientific evidence to recommend the use of ultrasound scanning guidance in all IACI procedures . There aThere are many studies on the safety of IACIs, and most of them think IACIs are a safe and effective treatment for patients with JIA , 54, 55.Although systemic and local adverse reactions have also been reported, they are significantly less than those of systemic medication, with an incidence of only 2% reported in the literature .Local atrophy (skin or subcutaneous) is the most common adverse event , which iAlthough systemic absorption of corticosteroids may lead to obvious adrenal suppression and transient clinical manifestations from slight cosmetic changes to obvious Cushing's syndrome, it has nothing to do with long-term adverse reactions and is transient. The use of IACIs may cause systemic adverse events, such as Cushingoid habitus, transient adrenal suppression, acne-like rash, and insomnia , 56–58.Another known complication of IACIs is the development of periarticular calcifications. The majority of these abnormalities are asymptomatic and are detected coincidentally on radiological follow-up. Nicolau syndrome has even been reported after IACIs . AbnormaThe use of IACIs for JIA is a safe and effective method for treating synovitis. It can be performed under local anesthesia with or without conscious sedation or under general anesthesia, and is an important treatment choice for children with JIA. This treatment, the so-called “bridge” effect, is an alternative to the use of systemic corticosteroids. However, due to the lack of controlled studies, the current position of IACI treatment in the management of children with JIA is still uncertain. Systematic, controlled and prospective research is needed to determine the best role of IACIs in children with JIA. In addition, it is necessary to support the training of pediatric rheumatologists in IACI technology and further explore the value of physiotherapy and ultrasound guidance.SL and YL conceived the study and participated in its design and coordination. WZ helped to draft the manuscript. All authors have read and approved the final manuscript.This work was supported by 2020 Sichuan Maternal and Child Health Association Maternal and Child Medicine Science and Technology Innovation Project (Key Project) 2020ZD06, Chen Xiaoping Foundation for the Development of Science and Technology for Hubei Province CXPJJH121002-202149, 2020 Sichuan Health Research Project (Key Research Project) 20ZD019, and Chengdu High-Level Key Clinical Specialty Construction Project.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


This paper presents a new global dataset on contemporary witchcraft beliefs and investigates their correlates. Witchcraft beliefs cut across socio-demographic groups but are less widespread among the more educated and economically secure. Country-level variation in the prevalence of witchcraft beliefs is systematically linked to a number of cultural, institutional, psychological, and socioeconomic characteristics. Consistent with their hypothesized function of maintaining order and cohesion in the absence of effective governance mechanisms, witchcraft beliefs are more widespread in countries with weak institutions and correlate positively with conformist culture and in-group bias. Among the documented potential costs of witchcraft beliefs are disrupted social relations, high levels of anxiety, pessimistic worldview, lack of entrepreneurial culture and innovative activity. I see witch beliefs as the standardized nightmare of a group, and I believe that the comparative analysis of such nightmares is not merely an antiquarian exercise but one of the keys to the understanding of society.Monica Hunter Wilson (1951)Beliefs in witchcraft, defined as an ability of certain people to intentionally cause harm via supernatural means, have been documented all over the world, both recently and in the distant past , 2. AlthThis paper presents a new global dataset on contemporary witchcraft beliefs that covers countries and territories representing roughly one half of the world’s adult population. The data reveal that, far from being a remnant of the past limited to small isolated communities, witchcraft beliefs are highly widespread throughout the modern world. At the same time, there are significant differences in their prevalence within and across nations, and we explore this variation at the individual and country levels.Our individual-level analysis shows that witchcraft beliefs cut across socio-demographic groups and are negatively associated with age, education, and material well-being. Furthermore, witchcraft beliefs are positively correlated with belief in god and religiosity, but affiliation with Christianity (versus Islam) does not make a significant difference.Guided by the key themes from the literature, our cross-country analysis focuses on the following four issues: 1) the role of witchcraft beliefs in maintaining conformity and self-governance, 2) their relationship to social capital, psychological well-being, and world outlook, 3) the link between witchcraft beliefs, innovation, and economic development, 4) exposure to misfortunes as a factor in sustaining witchcraft beliefs. We examine 60 characteristics and establish the following patterns. First, witchcraft beliefs are substantially more prevalent in countries with weak institutions and low quality of governance. Second, they are strongly positively correlated with measures of cultural conformity and in-group bias. Third, witchcraft beliefs are associated with the erosion of social capital manifested in low levels of trust and other antisocial attitudes and behaviors. Fourth, people in countries with more widespread witchcraft beliefs display lower levels of life satisfaction, diminished sense of control over life and self-efficacy, along with a higher degree of fatalism. Fifth, witchcraft beliefs are negatively related to creative culture and metrics of innovative activity. Sixth, there is a nonlinear, inverted-U relationship between standard metrics of economic development and the prevalence of witchcraft beliefs. Finally, there is mixed evidence on the role of exposure to misfortunes in promoting witchcraft beliefs. These patterns are robust to accounting for continental fixed effects and a number of potentially confounding characteristics, and are generally consistent with existing views on the costs and benefits of witchcraft beliefs in societies.Our study relies on the working definition of witchcraft introduced above. This definition matches the survey question used to construct the main variables in our analysis, captures the essence of witchcraft beliefs, and is sufficient to build a basic conceptual framework explaining their behavioral consequences. The key idea of this framework is that witchcraft beliefs generate two types of fear, ubiquitous in communities where such beliefs are present: the fear of witchcraft attacks and the fear of witchcraft accusations and ensuing punishment. These fears affect people’s attitudes and behaviors in fundamental ways as they seek to avoid provoking a witch and being labeled as one, which explains both the negative consequences and the social functions of witchcraft beliefs. The former include depleted trust and mutual help, anxiety and paranoid worldview, limited social mobility, avoidance of risks and unorthodox views or actions, disregard for creativity and innovation. On the flip side is the ability of witchcraft-related fears to generate cultural conformity and maintain group-level cohesion under the threat of punishment (in the form of bewitchment or accusation) for transgressing existing norms and challenging the status quo. Thus, our definition of witchcraft is both parsimonious and powerful enough to generate testable predictions, construct relevant survey-based metrics, and conduct an exploratory empirical analysis.This paper contributes to the vast interdisciplinary literature on witchcraft beliefs, most recently summarized in , 3. MoreThe data on contemporary witchcraft beliefs come from a sequence of six survey waves conducted by the Pew Research Center (PRC) between 2008 and 2017 in cooperation with professional survey organizations and covering 95 countries and territories around the world. As detailed in Table A.1 of Overall, in their design and content the PRC surveys are similar to the “values surveys”  and regional “barometers”  widely used across social sciences to measure culture and conduct comparative analyses at the individual and country levels . HoweverAlthough the areas covered by the dataset represent roughly a half of the global adult population, Before delving into cross-country patterns, we examine the socio-demographic correlates of personal witchcraft beliefs based on the individual-level data in the merged survey sample. The bivariate patterns and regression estimates yield qualitatively similar conclusions. Witchcraft beliefs are slightly more prevalent among younger people, women, and urban residents in the raw data, although the role of gender is not robust across specifications in The relationship between witchcraft beliefs and religion is illustrated in the third row of Our analysis thus far shows that witchcraft beliefs are present throughout the world and cut across socio-demographic groups while also revealing certain regularities at the individual level. The following section examines cross-country variation in the prevalence of witchcraft beliefs and its links to cultural, institutional, psychological, and socioeconomic characteristics.In the spirit of an exploratory analysis, our main goal is to establish robust patterns of correlation rather than identify causal relationships, the latter being complicated by the challenge of finding quasi-experimental variation in witchcraft beliefs or any other country-level characteristics. To this end, we expand our dataset to include dozens of relevant variables constructed and compiled using a variety of data sources described in section A of We formalize the analysis by estimating multivariate linear regression equations, in which witchcraft beliefs appear either on the left- or the right-hand side, depending on the theoretical hypothesis being explored and pre-existing evidence . For example, when considering the indicators typically viewed in the literature as the social costs, or consequences, of witchcraft beliefs, it is more natural to model the latter as an “independent” variable. In contrast, when exploring the hypothesized determinants of witchcraft beliefs, it is natural to view them as a “dependent” variable. Although this flexible approach makes the presentation and interpretation of results more convenient, it is important to be mindful of the correlational nature of cross-country relationships estimated below.For consistency, we rely on a similar set of control variables across specifications. First, we include continental fixed effects  making sure that our estimates do not simply reflect differences across world regions. Second, we control for several key geographic characteristics, namely absolute latitude, terrain ruggedness, agricultural suitability of land, and distance to the coastline, all of which have been argued to represent important exogenous determinants of socioeconomic and cultural outcomes –19. ThirThe idea that witchcraft-related fears enforce cultural conformity and social cohesion goes back to the classical work of Evans-Pritchard on the Azande  and KlucThis relationship is robust to potentially confounding characteristics, including income per capita, and is quantitatively important: for example, other things equal, a one-standard-deviation increase in the rule-of-law index is associated with an average reduction in the prevalence of witchcraft beliefs by more than 0.5 standard deviations (or 9 percentage points) in models accounting for geography, income, religiosity, and kinship tightness, in addition to continental fixed effects. Given this strong connection, the following analyses incorporate the rule-of-law index as an additional control variable.The main channel through which witchcraft beliefs have been argued to maintain social cohesion is the enforcement of conformity due to expected punishment for norm violation in the form of witchcraft attacks or accusations. The patterns documented in The second line of evidence is based on more specific aspects of conformist culture. When asked about issues and character traits they consider valuable, respondents in countries with more widespread witchcraft beliefs are more likely to stress the importance of tradition and downplay the role of creativity and risk taking, based on the data from the World Values Survey (WVS) and the European Values Study (EVS). Similar conformist pattern is seen in the approaches to child socialization, both at home and in school, across societies where witchcraft beliefs are more common: independence and imagination are less frequently mentioned in WVS/EVS as important qualities to cultivate in children, while the prevalent style of instruction, as captured in the 2018 Global Competitiveness Report (GCR), is focused on memorizing and rule-following rather than promoting creative and critical thinking.The last four panels of The evidence presented so far supports the view that witchcraft beliefs represent a simple mechanism of self-governance and operate to maintain traditional order, promote conformism, and contribute to in-group cohesion. While this constitutes one of the plausible social benefits of witchcraft beliefs, it likely comes with a range of individual and social costs explored in the following sections.As argued in previous studies, witchcraft beliefs and related fears are associated with the erosion of social capital including diminished cooperation and mutual help, mistrust, and a general lack of friendly social interactions –6, 29. CThe same witchcraft-related fears that disrupt normal social relations have also been argued to drive anxiety and a pessimistic worldview. The stress-inducing impact of witchcraft beliefs is well-documented in both early ethnographic work on the subject and recent studies , 30–32. Closely related to fatalism and the lack of personal agency is the zero-sum mindset commonly underlying witchcraft accusations . AccordiAlthough eroded social relations, anxiety, and perceived loss of control over life are all plausible costly consequences of witchcraft beliefs, causality may simultaneously run in the opposite direction. For instance, by hampering cooperation, witchcraft beliefs may aggravate the living conditions of community members and increase the incidence of misfortunes driving mutual accusations. Similarly, by providing an “explanation” for the apparent lack of control over life and poor state of health, witchcraft beliefs may address the basic need for “making sense” of certain life events and coping with adversity and stress. In general, the apparent coexistence of witchcraft beliefs, poor social relations, and pessimistic worldview may be seen as a “cultural package” of mutually reinforcing antisocial beliefs and norms. This stands in sharp contrast to the prosocial cultural package typically associated with religions featuring moralizing high gods .The conformist culture and resistance to change promoted by witchcraft beliefs poses a threat to the process of innovation, a backbone of long-run economic growth. Country-level data from the GCR are consistent with this hypothesis, as shown in The interplay between witchcraft beliefs and economic development broadly defined is more complicated. As shown in the top row of quadratic, inverted-U-type association between development indicators and witchcraft beliefs. This nonlinearity suggests that, other things equal, countries at an intermediate level of development are characterized by the highest prevalence of witchcraft beliefs. One, admittedly speculative interpretation is that the “modernity” effect dominates at relatively early stages of development but eventually gives way to the “modernization” effect at higher levels of socioeconomic maturity. Such pattern and its tentative interpretation are reminiscent of [Interestingly, as shown in the second row of scent of  which foThrough the ages, the most obvious purpose of witchcraft beliefs has been to provide an ultimate explanation for unfortunate events in people’s lives and thus help with coping. Examples of misfortunes historically and presently attributed to witchcraft include death, disease, weather shocks, crop failure, enslavement, accidents, business problems, joblessness, infertility, and marital issues , 8, 38.In her seminal paper quoted in the epigraph , Monica These multiple facets must be taken into account when considering the implications of witchcraft beliefs in the context of policy interventions, technological, institutional, and cultural changes. One attractive but potentially ineffective avenue is to focus on the large social costs of witchcraft beliefs and attempt drastic changes without thinking through the unintended consequences. An example of such an attempt are various anti-witchcraft laws implemented by colonial and current administrations in developing countries with the goal of preventing witchcraft accusations and persecutions. While reasonable on the surface, such laws have often been disregarded in practice or, even when enforced, raised rather than assuaged witchcraft-related fears since the alleged witches were viewed as being “let loose” and protected by the new laws , 43.Another reasonable but superficial strategy is to focus on education, modernization, and promotion of a scientific worldview as solutions to the issue of witchcraft. While people with higher levels of education and economic security are indeed less likely to believe in witchcraft, these beliefs generally cut across socio-demographic strata. Furthermore, technological development, urbanization, and other aspects of globalization may actually revive rather than alleviate witchcraft concerns by rupturing pre-existing traditional social organization and triggering the conformity-inducing function of witchcraft beliefs and accusations . A focusFinally, an obvious danger is to simply disregard witchcraft beliefs as irrelevant when conducting policy interventions or development projects, that is, fail to take culture into account . PolicymGiven the goal of minimizing the costs of witchcraft beliefs while minding the functions they may perform in communities, a constructive way to think about policy implementation in this context is the “cultural mismatch” framework recently proposed in . A mismaS1 AppendixThis appendix provides further details of the data used in the study, robustness checks, and illustrations.(PDF)Click here for additional data file.


Modern society faces many biomedical challenges that require urgent solutions. Two of the most important include the elucidation of mechanisms of socially significant diseases and the development of prospective drug treatments for these diseases. Experimental cell models are a convenient tool for addressing many of these problems. The power of cell models is further enhanced when combined with gene technologies, which allows the examination of even more subtle changes within the structure of the genome and permits testing of proteins in a native environment. The list and possibilities of these recently emerging technologies are truly colossal, which requires a rethink of a number of approaches for obtaining experimental cell models. In this review, we analyze the possibilities and limitations of promising gene technologies for obtaining cell models, and also give recommendations on the development and creation of relevant models. In our opinion, this review will be useful for novice cell biologists, as it provides some reference points in the rapidly growing universe of gene and cell technologies. Modern society faces many biomedical challenges, including epidemics of infectious diseases, age-related diseases, metabolic disorders, and cancers caused by increased lifespan and environmental degradation ,2,3. TheCell-based models represent an in vitro artificial system that allows the simplification and approximation of the physiological and pathological processes taking place in the tissues or organs of living organisms ,5,6,7. CThe potential of cell models can be drastically expanded via the use of modern genetic engineering approaches that enable researchers to edit specific sections of the genome, including coding DNA, regulatory DNA, and/or RNA, and to vary the expression levels of target proteins. These approaches include cis-/transgene expression in a cell line, genome editing, and trans-splicing. Each of these techniques has both advantages and limitations, which will be discussed and further analyzed below. Such a discussion is valuable because choosing the most appropriate genetic engineering approach at the start of a study allows researchers to obtain quickly the cell model system with the required properties for their research goal.Cis-/transgene expression is a method of forced ectopic gene expression  Figure A in whicA promoter is a DNA sequence that controls gene expression; it contains binding sites for transcription factors and RNA polymerases . The numCis-/transgene expression can be used not only for therapeutic correction, but also for the creation of cell models. Plasmids—as well as both integrating and non-integrating viral vectors—can be used as transgene delivery vectors, either with or without modification ,24. Cis-Therefore, this approach makes it possible to establish the general function of an unknown gene, but it is not suitable for the study of the subtleties of gene regulation, for understanding how pathologies affect gene function, or for the development of promising therapeutic approaches.To control the expression of a target gene, both constitutive and inducible promoters can be used, and the efficiency of promoters is largely determined by the type of cell line. For instance, many primary cells have the ability to inactivate viral-derived promoters quickly, which can reduce the effectiveness of cis-/transgene expression approaches ,31.A newer trend in this technique involves the use of genetically encoded sensors ,33 that Significant disadvantages associated with this approach include the delay in the reaction of the sensor in response to promoter induction, differences in degradation dynamics of the fluorescent protein and/or its mRNA relative to the target protein, as well as discrepancies in regulation between the promoter of the sensor and its natural homologue. In the latter case, this can be due to difficulties in modeling the involvement of distant genetic elements  during regulation. Significant improvements in the sensitivity and accuracy of sensor proteins can be achieved by introducing the cDNA of a fluorescent protein directly into the structure of the studying gene using genome editing. However, this procedure is difficult, especially when working with primary or hard-to-edit cell cultures .Constitutively expressed sensors can be used to detect changes in membrane potential, cell signaling and biochemistry via registration of alterations in certain parameters: sensor brightness, fluorescence specter changes, compartmentalization, that can be quantified ,38. ThesAt the same time, data obtained using such sensors in transformed cells may not correlate with the data obtained in primary cells, a discrepancy that may be due to significant differences in the regulation of pre-mRNA splicing and expression profiles between different cell types ,44. For An example of the productive use of constitutively expressed sensor proteins is the family of luciferase-based assays that are used to identify and study genome and transcriptome regulatory sequences  ,47. The In general, cis-/transgene expression of a cell line is a fairly effective but rough tool that permits the overexpression of a target protein or microRNA in model cells. A more subtle approach to creating cell models involves genome editing, since this technique changes the nucleotide sequence itself within its natural context.Genome editing (GE) technologies such as the zinc finger nuclease, transcription activator-like effector nuclease, and CRISPR/Cas9 systems, as well as their modifications, collectively possess tremendous potential for creating cell models and the study of the function of proteins, regulatory RNA, and their underlying genes ,51,52. GAt present, GE is a crucial technology for the elucidation of pathogenic mechanisms and perspective therapeutic approaches. For example, CRISPR/Cas9 made it possible to establish that LRP1 is one of the main proteins responsible for the capture and distribution of the misfolded tau protein within the brain , and to Due to its modularity, CRISPR/Cas9 and similar systems permit both whole-genome or restricted screenings of genes involved in particular signaling cascades and biological processes ,62. ImmoAn important feature of genome editing induced by double-strand DNA breaks is that it can be difficult to predict the result, since modifications occurring during DNA repair are determined by the performance of DNA repair mechanisms , microhomology-mediated end joining (MMEJ), homology-directed repair (HDR)) ,69, whicSome authors have proposed the use of CRISPR-mediated DNA double-strand breaks within miRNA and lncRNA genes to destroy them in order to study their function ,77,78. TFurthermore, the introduction of random indels within the region of a double-strand DNA break makes it difficult to obtain the required nucleotide sequence during knockout and HDR modifications, however, they are essential for the CARLIN (CRISPR array repair lineage tracing) technology, which allows the fate of cells in healthy or diseased conditions to be tracked . The NHEWhen considering new approaches that can be used to create cell models, it is also important to mention that there is a tendency to move from a “rough” gene knockout to modeling more subtle changes within the structure of DNA , RNA, or proteins. This approach makes it possible to create more “physiological” cell models that take into account the variety of mutations within a particular gene and allow researchers to identify the molecular mechanisms responsible for a disease that represents new targets for precision therapies.Existing modifications of GE make it possible to introduce many precise changes in the genome. The greatest efficiency can be achieved when modeling point mutations and SNPs ,87, as wAn ideal precise genome editing technique would feature the ability to introduce a new sequence with high fidelity or to replace an existing sequence of choice with any other sequence of any arbitrary length. A similar approach, prime editing, was proposed in 2019 by Anzalone et al. . The autAnother significant limitation of prime editing was the maximal length of possible modification: insertions were limited to 40 base pairs and deletions to 80 base pairs . The latGenome editing techniques can be harnessed not only to modify the DNA/RNA nucleotide sequence, but also to study the epigenetic regulation of genome functioning ,100, labGE permit the permanent modification of DNA/RNA sequences, including in noncoding/regulatory regions of the genome (which distinguishes GE favorably from siRNA/shRNA approaches). However, GE has several limitations, including moderate efficiency, especially in HDR-mediated modifications in primary cells and a significant probability of non-targeted DNA modification . Some ofTrans-splicing is a natural mechanism for splicing several pre-mRNAs into a single mature mRNA C. This mTrans-splicing approaches permit us to simulate any modifications of the coding part of target genes, from point substitutions and substitutions of individual exons to large-scale insertions and labeling of target proteins. At the same time, trans-splicing is less efficient than cis-splicing and often leads to the formation of non-physiological mRNA splice forms and proteins ,113. TheIn conclusion, here we have considered three main cutting-edge genetic engineering techniques designed to modify the sequences and/or expression levels of target genes in order to study their function in physiological and pathological conditions. Each is characterized by its own advantages and disadvantages , and theThe creation of cell models based on transformed cell lines is quite simple: they have a high proliferative potential , suppressed expression of DNA damage markers (to prevent cell death after massive DNA cleavage), and high susceptibility to transfection and transgene expression . HoweverADCY1, ADRB2 and ADRB3 genes)—and CRISPR nickase SpCas9D10A  were found be the most effective. Conventional SpCas9 was found to be ineffective for introducing mutations into protein genes or for excising DNA fragments (miRNA genes). Potentially, the efficiency of the GE of primary cells can be improved via the use of ribonucleotide-protein complexes (RNPs) by creating high peak-concentrations of them within the nucleus [TP53 gene expression [Efficient genetic modification of transformed cell cultures can be achieved using any of the approaches mentioned above , and the efficiency of GE can be further increased by reprocessing, as described previously . For the nucleus ,123, viapression ,125, or pression ,127. Thepression .iPSCs have a number of advantages over primary cell cultures: they have virtually unlimited clonal potential and stable diploid genome, they can be differentiated into almost any cell type, and they can be used for creation of organoids . For effOne of the clearest trends in the use of cell cultures is the transition to the supracellular level, which makes it possible to model and study complex intercellular communication within tissues, to study stem cell niches, to visualize embryo-, histo- and organogenesis in 3D cultures, and to create a basis for tissue engineering ,133. DepA significant limitation of such 3D structures is their relatively small size (thickness) and the restricted number of layers, which is due to the absence of capillaries and adequate trophism in the thickness of such structures. The genetic modification of whole organoids using electroporation and viral particles is also possible, although the multilayer nature of an organoid greatly reduces its effectiveness for studying cells in the inner layers ,137. MorTechniques for visualizing the structure of such 3D objects , which are being developed simultaneously, greatly increase the potential of organoid technologies for the future ,139.Despite the active development of animal models, cell-based models are an essential part and, possibly, a predominant tool in experimental biology and regenerative medicine in the near future, since they make it possible to establish the functions of certain molecules and genomic variants, and to determine the mechanisms of action of prospective drug treatments by simplifying the complex systems involved in whole organisms ,12,13. CIn this review, we described the main cutting-edge approaches used for gene modification of cell cultures, including their advantages and limitations. None of the described approaches is universal and cannot be unconditionally recommended for the creation of model cell lines since the required efficiency and accuracy are largely determined by the nature of the object and the type of modification desired. The most complex objects for genetic modification are primary cells, iPSCs, and assembled 3D structures. In our opinion, the most effective and promising techniques for the development of new cells lines are cis-/transgene expression and trans-splicing, along with GE technologies such as the CRISPR-BE and prime editing system or variants of ribonucleoprotein complexes  ,122. Dat