Optic nerve damage is a common cause of blindness. Optic nerve injury is often accompanied by fundus vascular disease, retinal ganglion cell apoptosis, and changes in retinal thickness. These changes can cause alterations in protein expression within neurons in the retina. Proteomics analysis offers conclusive evidence to decode a biological system. Furthermore, animal models of optic nerve injury made it possible to gain insight into pathological mechanisms, therapeutic targets, and effective treatment of such injuries. Proteomics takes the proteome as the research object and studies protein changes in cells and tissues. At present, a variety of proteomic analysis methods have been widely used in the research of optic nerve injury diseases. This review summarizes the application of proteomic research in optic nerve injury diseases and animal models of optic nerve injury. Additionally, differentially expressed proteins are summarized and analyzed. Various optic nerve injuries, including those associated with different etiologies, are discussed along with their potential therapeutic targets and future directions. The optic nerve (ON) is an important sensory nerve made of axons composed of myelinated nerve fibers. This nerve connects to the brain and the retina to transmit vision. Five different types of neurons run through the retina to connect to the thalamus . RetinalThe optic nerve serves as an important bridge between the eyes and the brain. Blood supply to the optic nerve primarily comes from the distal branches of the intraretinal ophthalmic artery and ophthalmic vein . It is aProteomics is a powerful platform for exploring single proteins and complex protein samples. Combining the techniques of gel- and chromatography-based separation enables processing of questions from all areas of basic science and medicine. Proteomics has been widely used to study eye diseases, and numerous studies have collectively identified over 40 proteins in different optic nerve injury-related diseases ,11,12,13Use of animal models in biological studies are essential to understand specific diseases’ etiologies and pathological mechanisms and the underlying causes of the diseases. Such models provide an effective therapeutic target for drug development. The molecular and cellular mechanisms of optic nerve injury have been studied using a variety of animal models. Optic nerve crush (ONC), axotomy, and ocular blast are the three most common models for studying optic nerve trauma . An optiDue to the extremely complex protein composition of the retina, proteomic methods have become the preferred method for analyzing protein changes within it. Compared with the enzyme-linked immunosorbent assay and Western blotting methods, proteomics can obtain more valuable information using simpler experimental operations. Proteins are indispensable sensors and regulators of organisms that directly participate in and regulate the occurrence and development of diseases. Thus, proteomics offers great advantages in the study of disease mechanisms. The combination of proteomic and bioinformatic methods can offer further utility in the discovery of protein changes in various diseases and can also be used to analyze the action pathways of proteins. Proteomics has become an indispensable analysis method in the field of optic nerve eye disease and has helped advance the development of eye disease research. In this review, we summarize and review (i) the application of proteomics in the context of optic nerve injury diseases, (ii) the pathogenesis of optic nerve injury diseases, and (iii) the key proteins involved; we then make recommendations for the future application of proteomics in optic nerve injury diseases.Optic nerve damage ophthalmopathy is a common blinding eye disease in clinical practice, and the accompanying optic nerve damage is irreversible. Approximately 2.2 billion people around the globe are suffering vision impairment/injuries . The preThe optic nerve injury included nontraumatic optic nerve injury and traumatic optic nerve injury. Nontraumatic diseases include glaucoma, diabetic retinopathy, retinopathy caused by hypertension, optic neuroblastoma, and thyroid-induced retinopathy, and these are common in clinical practice ,35. GlauDiabetic retinopathy is a retinal vascular complication. The development of diabetes is related to blood pressure, blood sugar, dyslipidemia, and kidney disease ,47. DiabAs a result of ischemic optic nerve injury, retinal microvascular occlusion puts the optic nerve in a state of ischemia and hypoxia for a long time, and the optic nerves atrophy. Ischemic optic nerve injury is divided into optic nerve head injury and posterior optic nerve injury in accordance with the site of injury ,55,56. AImaging of the retinal fundus is an important tool for the clinical diagnosis of optic nerve damage. The fundus can show the specific state of the blood vessels in the retina of the patient, including the diameter of the blood vessels, the thickness of the wall, the degree of the curvature of the blood vessels, and the existence of new blood vessels. Fundus fluorescein angiography is an invasive diagnostic method for detecting fundus capillary circulation and vascular lesions, which can accurately guide subsequent laser treatment for the fundus lesions ,59. OptiAt present, no effective method exists for the treatment of optic nerve damage caused by optic nerve injury ophthalmopathy. The principal treatment is instead to control the pathogenic factors of optic nerve injury and relieve the clinical symptoms. The optic nerve is difficult to repair and regenerate after damage. Traditional treatment drugs used for optic nerve injury are glucocorticoids, vitamins, and neurotrophic factors, among others, but these drugs can only maintain the condition of optic nerve injury by preventing further deterioration ,62. In rEstablishing a simple, efficient, easy-to-operate, and highly reproducible optic nerve injury model is the basis for the in-depth study of optic nerve injury diseases. An ideal optic nerve injury model should have the following characteristics: (i) the mechanism of optic nerve injury resembles human optic nerve injury, and the process and results of optic nerve injury are as similar as possible to the appearance of human optic nerve injury; (ii) the animals are economical and easy to obtain; and (iii) the model-making process is relatively simple, and the repetition rate is high. The main modeling methods of optic nerve injury include traction injury, crush injury, impact injury, optic nerve transection, clamping injury, compressive injury, toxic injury, and electrical stimulation injury ,64,65. MCommon disease models include glaucoma, cataracts, diabetic retinopathy, traumatic optic nerve injury, and retinal ischemic optic nerve damage ophthalmopathy models. This section provides a brief summary of these optic nerve injury disease models.As shown in (1)Episcleral vein injection: a commonly used method for establishing glaucoma models for scientific research purposes is by injecting hypertonic saline into the scleral surface blood vessels of adult mice to establish an intraocular hypertension model . The adv(2)Superficial scleral vein-burning method: as above, this modeling method is also a way of increasing intraocular pressure, and the change of intraocular pressure depends on the number of cauterized episcleral veins on the sclera. When the number of cauterized veins equals 4, the intraocular pressure can be increased to 60 mmHg, which can be maintained for several weeks to induce the death of RGCs. Compared with episcleral intravenous injections to establish an intraocular hypertension model (as above), its operation is simpler and more reproducible, the intraocular pressure can be maintained for a stable time, and it can induce the degeneration and apoptosis of RGCs in a way that more closely resembles human chronic glaucoma ,70.(3)Microsphere injection: the microsphere injection method uses 10 μm sized latex microspheres to inject into the anterior chamber to prevent the outflow of the aqueous humor and preserve the complete anatomical structure. This method can reduce the inflammatory response. The period whereby high intraocular pressure is maintained is different depending on the size and material of the microspheres. Microspheres of 5–15 μm can raise the intraocular pressure by 5–10 mmHg for 2 weeks . The micTraumatic optic neuropathy is an optic nerve damage disease caused by external trauma to the head, face, and orbit . It is d(1)Direct optic nerve injury modelsOptic nerve transection (ONT) is a direct optic nerve injury model, and its modeling method is based on directly cutting the optic nerve of the model animal. Advantages of this model include simple manipulation, consistent animal injury, and easy reproducibility . After tThe optic nerve crush model (ONC) is an important model for traumatic optic nerve injury and is mainly used to conduct research on the regeneration of RGCs and axonal regeneration. The concrete process is manifested as (2)Indirect optic nerve injury modelsChronic compressive injury to the optic nerve is used to simulate damage caused by either post-traumatic hematoma or tissue inflammatory edema caused by trauma. The method for establishing this model is simple. With the extension of the time after modeling, the optic nerve damage gradually increases. It is often used to simulate pathological changes such as optic nerve axon ectopic and degeneration caused by the gradual increase in post-traumatic hemorrhage and edema. Disadvantages are that this method is relatively more prone to causing inflammation and infection .The eye shock injury model is used to simulate the type of damage to the optic nerve caused by shock wave explosions. Compared with other optic nerve injury models, this model requires a specific blasting and protection system to simulate explosive injuries. The eyes and head are damaged by the shock wave while the body is protected. The disadvantages of this model are that the mortality rate of model animals is high and the retinal tissue is severely damaged during modeling, which greatly interferes with the detection of retinal tissue after the model has been established.Retinal ischemic ophthalmopathy is primarily caused by central retinal arteriovenous vascular occlusion and retinal ischemic ophthalmopathy induced by vascular occlusion (the latter of which is caused by glaucoma and diabetic retinopathy) . The cliRetinal vessel ligation is also a commonly used model of retinal ischemia/reperfusion. In this model, either the internal retinal vein or artery is ligated and then loosened to establish a reperfusion model . Some reOptic nerve damage can significantly reduce the vision of patients, thereby having a serious impact on their daily lives and their families. In clinical practice, optic nerve injury is mainly diagnosed by OCT detection and by fundus angiography. However, these two methods are not ideal for detecting early-stage optic nerve injuries. Additionally, there currently exists no effective treatment used in clinical practice for optic nerve damage eye disease. To remedy these two issues, proteomics can be used to analyze the composition and content of proteins in retinal tissue to obtain the changes in proteins during the development of diseases, thus offering the potential to obtain potential diagnostic targets to provide a means of early detection as well as key therapeutic sites to help in the development of novel effective treatments. The outcomes of proteomics analysis are summarized in Proteomics has been widely used in the research of optic nerve injury diseases. The number of differentially expressed proteins and their main roles were obtained from the literature for this review. Targeted proteomic studies using only ELISA or other immunological assays were excluded. Weber et al.  used 23 Traumatic optic nerve injury is one of the more common forms of optic nerve injury. It is characterized by either direct or indirect damage to the optic nerve that occurs when the face or head is damaged by an external force and involves the degeneration or death of retinal ganglion cells (RGCs). Yan  establisTo study the changes in RGCs after optic nerve transection in rats, Kwong et al.  establisRetinal blood vessel blockage, deformation, and prolonged poor blood flow can each cause damage to the optic nerve. At least 70 proteins are known to play a key role in optic nerve ischemic diseases. Tian et al.  performeDue to the difficulty in obtaining retina and optic nerve tissue in clinical practice, most experiments substitute this need by using animal models. Due to differences between animal species, retinal tissue preservation conditions, proteomic analysis methods, screening conditions, and experimental purposes, the same disease model study showed different results, including the number of differentially expressed proteins, the types of differentially expressed proteins, and the main action pathways, depending on these variables. Through analysis, it was found that most of the differentially expressed protein action pathways were enriched in the processes of neuronal damage, RGC degeneration and apoptosis, mitochondrial dysfunction, and carbon metabolism, among others.Diabetic retinopathy is a major microvascular complication of diabetes that can be divided into nonproliferative DR and proliferative DR in clinical practice. In diabetic retinopathy, the duration and degree of hyperglycemia maintenance in diabetic patients are closely related to the occurrence and progression of DR . Retinal. After vitreous degeneration activates the proteinase A signaling pathway, the number of endothelia in retinal blood vessels increases, the vessel wall thickens, and the diameter of blood vessels decreases, which ultimately leads to retinal hyperproteinemia, reflecting the regulation of retinal angiogenesis after diabetic retinopathy [When blood sugar rises, the glycolytic pathway is activated. Abnormal glucose metabolism leads to an increase in carbon metabolism, changes in glucose homeostasis in the vitreous, and changes in the vitreous environment to induce vitreous degenerationinopathy . Studiesinopathy ,104 , different diseases, different disease models, and differences in the proteomic detection methods employed ,109. AltAnother disadvantage of proteomics is in the analysis of differentially expressed proteins. Due to different experimental purposes, the choice of data analysis method, differences in the parameter settings of differentially expressed proteins, and the number of differentially expressed proteins in each experiment are quite different. Bioinformatic analysis of differentially expressed proteins, including pathway analysis and enrichment analysis, is an important means to uncover how differentially expressed proteins play roles to mediate disease progression and outcomes. However, large-scale bioinformatic correlation analysis of differentially expressed proteins may result in some false-positive results. Given this occurrence, the error frequency should be reduced and adjusted accordingly. The pathway activities and gene enrichment results that are consistent with the differentially expressed proteins should be selected for the bioinformatic analysis.There is difficulty in normalizing experimental proteomics data. Due to the different requirements set forth by various journals, it is difficult for researchers to reduce data for unified management, and few researchers are willing to make their data public. At the request of some journals, researchers may upload the original data of proteomics as supplementary materials. Due to differences in experimental design methods, purposes, research methods of proteomics, and sample preparation, these data are difficult to use by other researchers. This culture exacerbates the difficulty of screening diagnostic or therapeutic targets for the same diseases.The concept of proteomics was first proposed by Australian researcher Wilkins in 1994 . ProteomTo date, proteomics technologies have continuously been improved, while the depth and breadth of protein research have also improved. In proteomic analysis, there are marked differences between the data findings due to different experimental purposes, different experimental modeling choices, and differences in sample sources and storage conditions. For these reasons, differentially expressed proteins obtained by different researchers for the same disease are very different; hence, it is difficult to obtain unified answers to research questions. The excessive number of differentially expressed proteins obtained in research is also one of the key issues that make it difficult to truly identify disease targets or therapeutic sites. Oxidative stress injury, inflammation, and glutamate pathway activation are common mechanisms underlying optic nerve injury diseases. In future studies, researchers should compare the results of this review with those of other studies of the same type, with emphasis on identifying the differences between experiments as well as differences in the obtained results.The field of proteomics does not yet have strict executable test samples or experimental performance testing methodology standards. This may be one major reason underlying the large discrepancies between experimental results. In future research, unified test standards should be formulated for proteomics-based methodological steps, different sample processing methods, data analysis methods, and differentially expressed protein screening settings. This would be conducive to the standardized and unified operation of proteomics to reduce the impact of erroneous factors. This kind of standardization may help push the diagnosis and treatment of optic nerve-injuring eye diseases to new heights. In addition, improvements in proteins isolation, quantification, and expression pattern measurements along with qualitative animal models will improve the outcomes of results of interest, and reliable data will be generated for required databases.


This Research Topic called for article contributions addressing a broad array of optimization strategies to induce and sustain endogenous wound healing and tissue regeneration . The timIn response to this call, we received seven articles that included four reviews and three original research papers emphasizing a spectrum of robust and diverse effort in this emerging and fast-developing field .Fok et al. The authors attempted to improve bone morphogenetic protein-2 (BMP-2) retention and presentation by cells using a technique called micromolecular crowding (MMC), which mimics the structure of native cellular microenvironment, using an MMC agent, λ -carragreenan, a red seaweed-derived polysaccharide, in combination with detergent-free decellularization. Using this approach, they were able to significantly improve mineralized tissue formation in a murine model suggesting that this platform could be used to improve the effectiveness of BMP-2 and other growth factor-based therapies.The need for targeted growth factor delivery to tissues to prevent off target and other adverse systemic effects was addressed by the article of Kolliopoulos et al. The results show that collagen scaffolds incorporating placental products—natural matrices derived from amnion and chorion placental membranes—into the scaffold’s architecture, induce powerful osteogenic response and enhance immunomodulatory and angiogenic potential of hMSC in vitro.A strategy for improving osteogenic activity of human mesenchymal stromal cells (hMSCs) was presented by the article of Wu et al. addressed the need for low-cost, biocompatible skin dressings that can adapt to complex mechanical demands of severe skin wounds and promote healing. To this end, the authors generated a hybrid membrane composed of hot-pressed flat silk cocoons (FSC) crosslinked with carboxymethyl chitosan (CMCS) that mimic the 3-dimensional structural components of the skin. The FSC/CMCS substrates exhibit excellent biocompatibility and mechanical properties. Furthermore, they reduce inflammatory cell infiltration, and promote neovascularization in full-thickness skin wounds in a rat model.On the topic of wound healing, the study of Lu et al. reviewed the state of the art and future promise of native and engineered extracellular vesicles (EVs) as therapeutic agents for tissue regeneration and wound healing. They describe how native nano sized EVs derived from different cell types, such as blood cells, skin, and endothelial cells, can be used to deliver a cargo of various growth factors and immunomodulatory molecules to injured cell populations and tissues. They point out that advantages of native EVs as therapeutic agents lie in their excellent biocompatibility as well as in their low immunogenicity and toxicity. Among native EVs’ disadvantages are their low concentration in tissues, a low payload capacity, and a short half-life in vivo. To address these issues, engineered EVs have been explored as alternatives to native EVs. The engineering approaches include genetic EV modifications, direct EV membrane modification and combining EVs with nanomaterials.Kozan et al. surveyed design criteria for biomaterial scaffolds to promote endogenous skeletal muscle regeneration to aid in recovery from traumatic muscle injury. Although skeletal muscle possesses the inherent ability to regenerate small-scale injuries, larger injuries (volumetric muscle injuries) heal poorly and result in a severe loss of muscle functionality. The article focuses on the use of biomaterial scaffolds that mimic endogenous skeletal muscle tissue microenvironment and can be implanted into the site of injury to promote regeneration of muscle tissue. The authors argue that the major criteria for the design of such scaffolds, which can be comprised of natural or synthetic biomaterials, should be their porosity, interconnectivity of the pores, alignment of the material comprising the scaffold, and the biomaterial’s mechanical properties. The optimization of these parameters is essential for achieving a robust cellular response which includes myoblast infiltration, myofiber ingrowth and nutrient transfer during skeletal muscle regeneration.Another review article in the series by Short et al. discussed novel approaches for non-invasive longitudinal monitoring and imaging of chronic wounds - an area of a strong need, as non-invasive methods are still not commonplace in clinical practice. The discussion includes the survey of the bioengineering advances in non-invasive monitoring of the chronic wounds; imaging and modeling wounds’ ECM, and machine learning algorithms as well as other computational tools for evaluation and integration of different sets of data to allow prediction of healing outcomes and planning therapeutic intervention.Cell tracing, tissue biosensing and imaging strategies to aid in wound healing and tissue regeneration are addressed in two review articles in this series. Hu et al. focused on the methods for quantification of individual cell migration. The authors discuss the analytical metrics characterizing this process, such as cell trajectory, velocity, and migration angles, and highlight the experimental approaches for a quantitative assessment of these metrics in vitro and in vivo. Additionally, they consider quantitative models of cell migration, and the application of such models to elucidation of the role of cell migration in the biological function.It is well-recognized that the migratory behavior of different cell types, including stem and progenitor cells, immune cells, and endothelial cells, among others, strongly influence tissue regenerative outcomes. Accordingly, The breadth of the themes comprising this article collection illuminates the complexity of the field and the many questions to be addressed for achieving effective control of tissue microenvironment for optimizing wound healing and regeneration. The concentration on musculoskeletal tissues in this assemblage mirrors the current focus of the field on regeneration of structural components. Additionally, our collective understanding of inflammation, the foreign body response to implantation, and the triggers of the diverse mechanisms of host immunity and their impacts on tissue regeneration accentuates the need for multi-disciplinary research in a field with such diverse inputs. Undoubtedly, advanced biomaterials and bioengineering tools will play a key role in reaching these goals . We are


This study aimed to investigate the effects of malignant neoplasms on the morphological characteristics of laparotomy wound granulation tissue in the muscular-aponeurotic layer. The study involved a sample of 34 deceased individuals who had undergone abdominal organ surgery. Biopsy samples were taken from the muscular-aponeurotic layer of the anterior abdominal wall and subjected to histological examination, including staining with hematoxylin and eosin and methylene blue/Chromotrope 2B using N.Z. Slinchenko’s method. Descriptive methods and morphometry were used to evaluate pathomorphological changes. The results suggest that malignant neoplasms significantly impede and decelerate the maturation of laparotomy wound granulation tissue. Surgeries performed at the late stages of abdominal organ malignant neoplasms result in an uneven and slow maturation of the tissue, characterized by a higher prevalence of lymphoid cells, increased blood vessel volume, reduced optical density of stained collagen fibers, and pronounced chromotropophilia of collagen fibers. These distinct features should be considered to prevent postoperative eventration, a complication that is more likely to occur in this patient group. Clinicians should be aware of the possible consequences of malignant neoplasms on laparotomy wound granulation tissue, which may require additional measures to prevent postoperative complications in these patients. Postoperative eventration remains one of the most dangerous and threatening complications of abdominal surgery despite advancements in modern medicine. The mortality rate associated with postoperative eventration is estimated at 24%, and some authors suggest it to be as high as 65% -3. GenerPatients with oncological diseases of the abdominal organs are known to suffer from secondary immune deficiency, cachexia, anemia, etc., which is likely to influence the rate of regeneration and the risk of development of purulent-septic complications in the postoperative wound -11.Understanding the morphology of granulation tissue in patients with malignant neoplasms of the abdominal organs may aid in the prevention of postoperative complications. Therefore, this study aimed to investigate the morphological features of the granulation tissue of the laparotomy wound in the muscular-aponeurotic layer after the removal of malignant neoplasms of the abdominal organs ,13.To achieve the research objective, we conducted a post-mortem examination of 34 deceased individuals who underwent abdominal organ surgery. The main group included 16 patients with malignant neoplasms of the abdominal organs at stages ІІІ-IV, who died within the first 7 days of the early postoperative period. The comparison group included 18 patients with acute non-oncological surgical pathology of the abdominal organs, who also died within the first 7 days of the early postoperative period ,15. Tabl2) [The biopsy material obtained from the muscular-aponeurotic layer of the anterior abdominal wall for histological examination was fixed in a 10% neutral formalin solution. Paraffinic sections were prepared and stained with hematoxylin and eosin to visualize tissue structure. Additionally, N.Z. Slinchenko’s method of histological specimen staining with methylene blue/Chromotrope 2B was used to identify collagen fibers and fibrin. The morphological changes were analyzed using a descriptive method , and mor2) .Statistical analysis was performed using Microsoft Excel and PAST software package. To assess normality, the Shapiro-Wilk test was conducted, and the Mann-Whitney test was utilized to compare differences between groups. A p-value of ≤ 0.05, which is generally accepted in medical-biological studies, was used as the threshold for determining the reliability of the results .The microscopic pictures of the specimens obtained from deceased individuals in both groups during the first day of the early postoperative period showed comparable features, such as a high concentration of fibrin, minimal lymphocyte presence, and areas with hemorrhages . HoweverMethylene blue/Chromotrope 2B staining revealed elongated collagen fibers and an accumulation of fibroblasts, lymphocytes, and a number of lymphoid cells and macrophages, which is specific for the immature granulation tissue . The micThe formation of collagen fibers was not well-defined, and a considerable number of lymphoid cells were observed using the Methylene blue/Chromotrope 2B-stained microscopic slides according to N.Z. Slinchenko's method .During the 4-5th day of the early postoperative period, microscopic images in the main group displayed relatively more fibroblasts, fewer irregularly located lymphoid cells, and subtle muscle fibers . The sloDuring the later stages of the early postoperative period (6-7th days), the microscopic examination in the main group showed a less mature granulation tissue compared to the comparison group, as evidenced by the higher concentration of lymphoid cells and fibroblasts, and a clear chromotropophilia of collagen -11.A morphometric examination was performed to obtain an objective comparison of the granulation tissue maturation processes in the muscular-aponeurotic layer of the laparotomy wound ,20. The The results in Further analysis of the study results, as presented in Despite advances in modern medicine, postoperative eventration remains one of the most dangerous and serious complications of abdominal surgery. General risk factors associated with the development of postoperative eventration include advanced age, comorbidities, urgent surgery, relaparotomy, pneumonia, diabetes mellitus, and cachexia, among others ,22. SurgThus, summing up the results of the study it should be noted that malignant neoplasms considerably inhibit and slow down the processes of the laparotomy granulation tissue maturation. This is characterized by a reliable increase in the number of cells , as well as an increase in the specific volume of blood vessels and a decrease in the optical density of the stained collagen fibers. These findings suggest that the vascular-exudative inflammation reaction is not effectively completed in patients with malignant neoplasms. In addition, these processes are accompanied by uneven maturation of granulation tissue, expressed by the chromotropophilia of collagen fibers -26.Moreover, uneven maturation of the granulation tissue and marked chromotropophilia of the collagen fibers are registered in the microscopic slides of physical bodies of the deceased individuals who suffered from malignant neoplasms of the abdominal organs. When staining sectioned slides with water blue/chromotrope 2B, the microscopic analysis revealed the presence of elongated collagen fibers and accumulation of fibroblasts, lymphocytes, and a significant number of lymphoid cells and macrophages. These characteristics are indicative of the presence of immature granulation tissue, which can impede the process of wound healing.Slower maturation of the laparotomy wound granulation tissue is explained by larger surgical trauma caused by a complete removal of a malignant neoplasm with underlying pathological changes in the body resulting in their considerable deterioration -30.This distinctive characteristic should be carefully taken into consideration in order to prevent the development of postoperative eventration, which is significantly more likely to occur in this patient population.Our study found that surgical intervention for malignant neoplasms of the abdominal organs at advanced stages is associated with a slower and uneven maturation of the laparotomy wound granulation tissue. This was demonstrated by an increased number of cells, mainly lymphoid, an increase in the specific volume of blood vessels, and a decrease in the optical density of stained collagen fibers. Furthermore, marked chromotropophilia of the collagen fibers was observed. These findings indicate a higher risk of postoperative eventration in patients with malignant neoplasms of the abdominal organs at advanced stages compared to those without oncological pathology in the same location. Our study highlights the importance of careful monitoring and management of wound healing in this patient population to reduce the risk of postoperative complications.


With the progressive lengthening of the average age of the population, especially in some countries such as Italy, vaccination of the elderly is a fixed point on which most of the public health efforts are concentrating as epidemic infectious diseases, especially those of the winter, have a major impact on the progression of severe disease, hospitalization, and death. The protection of the elderly against acute infectious diseases should not only limit mortality but also have a positive impact on the fragility of these people in terms of less disability and fewer care needs. However, vaccination of the elderly population differs in efficacy and safety compared to that of other population categories since aging and the consequent loss of efficiency of the immune system lead to a reduction in the immunogenicity of vaccines without achieving a lasting antibody coverage. There are various strategies to avoid the failure of immunization by vaccines such as resorting to supplementary doses with adjuvant vaccines, increasing the dosage of the antigen used, or choosing to inoculate the serum relying on various routes of administration of the vaccine. Vaccination in the elderly is also an important factor in light of growing antibiotic resistance because it can indirectly contribute to combating antibiotic resistance, reducing theoretically the use of those agents. Furthermore, vaccination in old age reduces mortality from infectious diseases preventable with vaccines and reduces the same rate of resistance to antibiotics. Given the importance and complexity of the topic, in this review, we will deal with the main aspects of vaccination in the elderly and how it can influence mortality and healthcare costs, especially in those countries where population aging is more evident. Therefore, we conducted a systematic literature search in PubMed to identify all types of studies published up to 31 May 2023 that examined the association between vaccination and the elderly. Data extraction and quality assessment were conducted by two reviewers (PC and TC) who independently extracted the following data and assessed the quality of each study. Vaccination in the elderly is an important public health aspect for the protection of this category of individuals from various infectious diseases, including those caused by viruses such as influenza, pneumonia, and, more recently, COVID-19. Vaccines can significantly reduce the risk of serious illness, hospitalization, and death in older individuals  Figure . EspeciaWe conducted a systematic literature search in PubMed to identify all types of studies published up to 31 May 20223 that examined the association between vaccines and the elderly. We used the following search: (‘Vaccines ‘ OR ‘Vaccination coverage’ OR ‘Immunization’) AND (‘elderly’ OR ‘geriatric patients’ OR ‘frail patients’ OR ‘frailty’). The inclusion criteria for the evaluation of each single contribution were the following: clinical, molecular, experimental, observational studies and meta-analyses. The exclusion criteria were as follows: comments, animal studies, or case reports. Studies that are duplicated or repeated or have great similarity in sample or content to another study. Data extraction and quality assessment were conducted by two reviewers (PC and TC) who independently extracted the following data and assessed the quality of each study. Any discrepancies between reviewers in research selection, quality assessment, or data extraction were addressed by re-evaluating the original with two other authors (GM and OP). The supervision of all the work carried out was carried out by MG, the creator, and the coordinator of the research.Immunosenescence is not the only factor that can influence the efficacy of vaccines in the elderly but the latter depends both on the vaccine used and on some individual factors such as age, underlying health conditions, immune status, and the specific characteristics of the whey ,22,23. HBefore vaccines are approved for use, they undergo rigorous testing in clinical trials that include participants of various age groups, including the elderly ,45,46. TVaccines play a crucial role in reducing mortality rates in the elderly by preventing serious infections and associated complications. For this reason, the data available in the literature on the use of the main vaccines also confirm the positive impact of this therapeutic strategy in reducing annual mortality in the population due to preventable diseases and complications or conditions associated with them ,56,57,58Antibiotic resistance and vaccination appear to be two separate topics but inevitably are two interrelated issues when it comes to tackling infectious disease in the elderly, particularly in this post-pandemic period where both frailty and resistance to antibiotics are unresolved weaknesses in our healthcare systems ,83,84. TVaccination in the immunocompromised elderly may provide important safety and benefits, although there are some considerations to keep in mind ,103,104.Burden of disease: The impact of a disease on morbidity, mortality, and healthcare costs influences the potential benefits of vaccination;Vaccine effectiveness: The effectiveness of a vaccine in preventing disease transmission and reducing its severity directly affects its cost-effectiveness;Immunization coverage: Higher vaccination rates within a population lead to greater overall protection and more cost-effective outcomes;Vaccine price: The cost of the vaccine itself can have a significant impact on the cost-effectiveness of a vaccination program.Healthcare costs: Vaccinations reduce the need for medical care, hospital stays, and related costs associated with treating vaccine-preventable diseases;Lost productivity: Vaccination prevents lost working days and productivity losses due to illness which has economic implications;Herd immunity: When a sufficient percentage of a population is immunized, herd immunity can develop, providing indirect protection to those who are not immunized;Vaccine safety: Addressing vaccine safety concerns is critical to maintaining public trust and encouraging participation.Up to now, we have said that vaccinations provide positive effects in terms of significant gains in the effectiveness of invested resources and in terms of the benefit/risk ratio. However, in public opinion, the perception of the real usefulness of vaccines does not always correspond to what the scientific community has been able to observe in decades of vaccination campaigns ,110. TheThe resurgence of vaccine-preventable diseases: Low vaccination coverage can result in the resurgence of vaccine-preventable diseases (VPDs) such as measles, mumps, pertussis, and polio. These diseases can spread rapidly in communities with low immunity levels ;Increased Disease Transmission: When vaccination rates are low, the overall level of community immunity (herd immunity) decreases. This allows diseases to spread more easily, including to vulnerable populations such as infants, elderly individuals, and those with compromised immune systems ;Outbreak-Related Healthcare Costs: Disease outbreaks can strain healthcare systems, leading to increased hospitalizations and medical costs. Low vaccination coverage can exacerbate these costs, burdening both individuals and healthcare facilities ;Impact on Vulnerable Populations: Low vaccination coverage disproportionately affects vulnerable populations, including infants who are too young to be vaccinated and those with medical contraindications to vaccination. These individuals are at higher risk of severe disease and complications ;Loss of Public Trust: Ongoing vaccine hesitancy and low vaccination rates erode public trust in vaccines and public health systems. This can further reduce vaccine uptake, creating a vicious cycle of declining coverage and increased disease risk ;International Disease Spread: Low vaccination coverage in one region or country can lead to international disease spread. Travelers can carry diseases across borders, resulting in outbreaks in areas with higher vaccination coverage ;Impact on Eradication Efforts: For diseases targeted for eradication, such as polio and measles, low vaccination coverage hinders progress. It can make it difficult to achieve and sustain disease elimination goals .On the other hand, low vaccination coverage can have significant consequences, leading to disease outbreaks and associated health, economic, and social impacts. Potential consequences of this phenomenon are:In summary, low vaccination coverage can lead to the reemergence of vaccine-preventable diseases, increased disease transmission, healthcare costs, and a range of negative consequences for public health. These consequences underscore the importance of achieving and maintaining high vaccination coverage rates to protect both individuals and communities.Vaccination is an important preventive measure to protect the health and well-being of older adults. It not only reduces the risk of severe infections but also decreases mortality rates associated with vaccine-preventable diseases;Many vaccine-preventable infections, such as pneumonia, meningitis, and certain respiratory and bloodstream infections, are commonly associated with antibiotic use. By vaccinating older adults against these diseases, the incidence of infections can be reduced, thereby potentially decreasing the need for antibiotics and reducing the selection pressure for antibiotic-resistant bacteria;The safety of vaccines in the elderly has been extensively studied and vaccines are generally considered safe for older adults. Vaccination plays a crucial role in protecting older individuals from vaccine-preventable diseases and their associated complications;Vaccines can significantly reduce the risk of infections and related complications. The efficacy of vaccines can be influenced by factors such as age, underlying health conditions, immune status, and the specific vaccine’s characteristics;Promoting the integration of various institutions and professionals in the field of health care should be considered to maintain successful national immunization programs;Promote a massive information campaign on the part of the scientific world, state health authorities, and various health operators which makes vaccination perceived as a healthy element of life, using high-quality forms of vaccination advice and thus further contributing to the increase in immunization rates in the elderly population and their caregivers.Vaccines play a crucial role in reducing mortality rates in the elderly by preventing severe infections and associated complications. Any vaccine-preventable infections, such as pneumonia, meningitis, and certain respiratory and bloodstream infections, are commonly associated with antibiotic use. By vaccinating older adults against these diseases, the incidence of infections can be reduced, thereby potentially decreasing the need for antibiotics and reducing the selection pressure for antibiotic-resistant bacteria. Older adults may be more susceptible to antibiotic-resistant infections due to factors such as weakened immune systems, higher rates of healthcare-associated infections, and more frequent antibiotic use. Despite these positive effects, vaccine resistance is observed specifically in the elderly population. Age-related changes in the immune system, the individual’s immune response, and the individual’s overall health status often limit vaccine efficacy. Certain medical conditions, such as immunodeficiency or chronic diseases, may impair the immune system’s ability to mount a robust response to vaccines. As a result, the level of protection provided by vaccines may be reduced in these individuals. Despite these factors, vaccination remains crucial for older adults as it can still provide significant benefits in terms of reducing the risk of severe illnesses, hospitalizations, and complications.


Siderophores are small metal chelators synthesized by numerous organisms to access iron. These secondary metabolites are ubiquitously present on Earth, and because their production represents the main strategy to assimilate iron, they play an important role in both positive and negative interactions between organisms. In addition, siderophores are used in biotechnology for diverse applications in medicine, agriculture and the environment. The generation of non-natural siderophore analogs provides a new opportunity to create new-to-nature chelating biomolecules that can offer new properties to expand applications. This review summarizes the main strategies of combinatorial biosynthesis that have been used to generate siderophore analogs. We first provide a brief overview of siderophore biosynthesis, followed by a description of the strategies, namely, precursor-directed biosynthesis, the design of synthetic or heterologous pathways and enzyme engineering, used in siderophore biosynthetic pathways to create diversity. In addition, this review highlights the engineering strategies that have been used to improve the production of siderophores by cells to facilitate their downstream utilization. Siderophores (iron carrier in Greek) are metabolites produced and secreted by many organisms, such as fungi, bacteria, and plants. Siderophores are a class of narrow-spectrum metallophores able to scavenge iron from the extracellular medium to make it accessible intracellularly. Indeed, in most habitats, iron is present in its oxidized state Fe(III), forming stable ferric oxide hydrate complexes and lowering its solubility. For aerobic microorganisms, the secretion of siderophores is their main strategy to access iron, as these molecules chelate Fe(III) with very high affinity ,2. SiderSiderophore synthesis follows two different pathways depending on the chemical nature of the molecule: the non-ribosomal peptide synthetase (NRPS) pathway and the NRPS-independent siderophore (NIS) synthetase pathway ,5. Once Because of their involvement in iron acquisition, siderophores play an essential role in the growth and virulence of many microorganisms ,14,15, aIn parallel to their numerous biological roles in nature, siderophores are used in biotechnology in many fields. In agriculture, bacterial siderophores promote plant growth by providing plants with iron ,25. MoreWith the notable exception of the antibiotic Trojan horse strategy, these various applications are based mainly on natural siderophores. A wider range of applications can now be envisaged by obtaining their synthetic analogs. The structure of natural siderophores has been optimized by millions of years of evolution for the efficient chelation of iron(III) and its assimilation by microorganisms through specific recognition by dedicated outer-membrane transporters. Therefore, the quest for non-natural siderophores with significantly improved iron(III) chelation properties or affinity for the proteins involved in uptake could be considered to be futile. Nonetheless, the generation of siderophore analogs is of particular importance for obtaining molecules that show, for example, (1) increased denticity of the siderophore ,46, (2) We aim to provide a comprehensive overview of the combinatorial biosynthesis strategies that have been used to generate bacterial siderophore analogs. Although numerous reviews can be found on combinatorial biosynthesis for the production of new molecules ,51, theyEfficient use of combinatorial biosynthesis requires that the biosynthetic route of the siderophore be known and the enzymes characterized. Several detailed reviews provide an overview of the synthesis and regulation of siderophores ,5,52. SiGenes encoding the proteins that participate in siderophore biosynthesis are generally organized as biosynthetic gene clusters (BGCs) ,14,61,62Precursor-directed biosynthesis (PDB) aims to generate analogs of natural products by cultivating a microorganism in a medium supplemented with compatible exogenous precursor substrates. This strategy takes advantage of the substrate promiscuity of the enzymes in the biosynthetic pathways to incorporate non-native natural or synthetic substrates, leading to the production of various natural product analogs .Streptomyces pilosus. Its biosynthesis involves a NIS synthetic pathway involving the activity of four independent enzymes . DFOB is used for the treatment of beta-thalassemia to tackle iron accumulation due to repeated red blood cell transfusions . S. SE. coloic acid . In totaoic acid .Directed evolution is a high-throughput protein engineering process that mimics Darwinian evolution in the laboratory. The iterative process involves steps of random mutagenesis on the gene of interest, the construction of large mutant libraries, and the use of high-throughput screening methods to identify the clones with the desired property ,117. ThiBacillus subtilis with applications in agriculture, in particular, to promote plant growth [Bacillibactin is a cyclic catechol siderophore produced by t growth ,120. In t growth . With thMicroorganisms produce siderophores at various yields from 10 to 1600 μmol/L, depending on the bacteria and the culture conditions . ImproviPseudomonas species, the optimal conditions are generally strain dependent. The use of succinate as the carbon source is a well-recognized approach to boost PVD production, along with the presence of certain metals, such as Mg(II), Mn(II), and Zn(II). However, there is no consensus in the literature concerning the preferred source of nitrogen and phosphorus [In addition to the culture conditions, the formulation of the culture medium has a direct effect on the amount of siderophore produced. Soares recently reviewed the impact that carbon, nitrogen, and phosphorus sources, in addition to the presence of metals, have on bacterial siderophore synthesis . In addiosphorus .The modification of the culture conditions can also be combined with the strategies previously presented to generate analogs. For example, improvement in the titer of the siderophore yersiniabactin in a heterologous host was achieved by Moscatello et al. . To assePseudomonas aeruginosa is regulated by the transcription factor PvdS, itself under the control of the ferric uptake regulator Fur. In the presence of iron, Fur binds to the promoter of the gene coding for the sigma factor PvdS, inhibiting its transcription. Consequently, PVD production occurs in iron-depleted conditions and stops when the intracellular iron concentration increases [Pseudomonas has been used in asbestos bioweathering to dissolve iron from the fibers [pvdS promoter with the arabinose-inducible promoter AraC pBAD, the authors showed that PaM1 produced PVD solely in response to arabinose and regardless of the concentration of iron. The mutant strain PaM1 showed significantly improved PVD production in the presence of asbestos waste, thus improving the capacity of alteration through iron dissolution [Pseudomonas putida by Becker et al. by adding a plasmid that carries an additional copy of the pvdS gene placed under a constitutive promoter [Bacillus licheniformis and reported increased production of the siderophores schizokinen and bacillibactin [Siderophore production is tightly regulated. The transcription of the genes encoding the enzymes involved in the synthesis and transport of siderophore is controlled by specific regulators and transcription factors. A low intracellular iron concentration is the triggering factor for siderophore production. Modification of the regulatory pathway can modulate siderophore biosynthesis to trigger production in conditions in which the siderophore is not naturally produced. PVD production in ncreases . PVD-proe fibers ,124. Howsolution . Higher promoter . A simillibactin .Shewanella oneidensis was reported by Liu et al. upon deletion of the outer membrane siderophore receptor and the reductase PutA [Overproduction of the siderophore putrebactin by ase PutA . This isase PutA ,130. MorPseudomonas syringae, which is involved in syringomicin biosynthesis. Both A-domains recognize L-serine but they observed a 30-fold loss of activity relative to wildtype EntF. They performed directed evolution on the chimeric NRPS using mutagenic PCR to generate a mutant library and screened it using an iron-limited medium. They were able to select clones with a higher growth rate and enterobactin production, showing that directed evolution can salvage and even improve the production rate of the engineered product [As described above, generating diversity by random mutagenesis requires the development of a powerful screening method to identify potential mutants with the desired property. Zhou et al. studied enterobactin and performed directed evolution of EntB, the enzyme that incorporates 2,3-dihydroxybenzoic acid in enterobactin biosynthesis . The sel product .Most siderophore analogs produced thus far by combinatorial biosynthesis have been generated by precursor-directed biosynthesis. This strategy takes advantage of the natural promiscuity of certain enzymes of the pathway. However, biosynthetic pathways in which multimodular NRPSs are involved are less prone to successfully incorporate non-native substrates. This is due to the high specificity of the enzymes for the substrate and the constraints posed by the interconnection between the modules, domains, and enzymes of these biosynthetic pathways. These factors limit the entry of substrates into the assembly line to those that will result in the correct intermediates necessary for the synthesis. Thus, generating siderophore analogs has been achieved with higher success using engineering strategies such as domain swapping. The application of random or rational enzyme engineering strategies to modify substrate specificity has had limited success in producing siderophore analogs. However, such approaches could help decipher structural specificity or highlight key residues involved in the function of the enzyme . AlthougCombinatorial biosynthesis and engineering approaches have been shown to be remarkable strategies to generate molecular diversity but thus far, attention has focused mainly on metabolites, such as antibiotics ,135. Fur


Computed Tomography Urography (CTU) is a multiphase CT examination optimized for imaging kidneys, ureters, and bladder, complemented by post-contrast excretory phase imaging. Different protocols are available for contrast administration and image acquisition and timing, with different strengths and limits, mainly related to kidney enhancement, ureters distension and opacification, and radiation exposure. The availability of new reconstruction algorithms, such as iterative and deep-learning-based reconstruction has dramatically improved the image quality and reducing radiation exposure at the same time. Dual-Energy Computed Tomography also has an important role in this type of examination, with the possibility of renal stone characterization, the availability of synthetic unenhanced phases to reduce radiation dose, and the availability of iodine maps for a better interpretation of renal masses. We also describe the new artificial intelligence applications for CTU, focusing on radiomics to predict tumor grading and patients’ outcome for a personalized therapeutic approach. In this narrative review, we provide a comprehensive overview of CTU from the traditional to the newest acquisition techniques and reconstruction algorithms, and the possibility of advanced imaging interpretation to provide an up-to-date guide for radiologists who want to better comprehend this technique. Computed Tomography Urography (CTU) is defined as an abdominal multiphase CT examination optimized for imaging kidneys, ureter, and bladder, including post-contrast excretory phase imaging .Over the past decade, CTU has become the primary imaging technique for evaluating the urinary tract and is widely accepted as part of the routine evaluation of patients with hematuria .According to the 2019 American College of Radiology Appropriateness Criteria, CTU is recommended as the first-line imaging method in patients with microhematuria and risk factors for urologic malignancy . The AmeThe usefulness of CTU as a diagnostic tool is connected to its optimized acquisition technique. The principal aim is to achieve optimal distension and opacification of the upper tract collecting system, ureters, and urinary bladder in the excretory phase, ; the othThere is no consensus on a standard protocol or national and institutional guidelines, and CTU is still performed with widely different acquisition and contrast administration protocols ,11.The most widely used technique consists of three post-contrastographic phases including corticomedullary (CMP), nephrographic, and excretory phases.The unenhanced phase enables stone detection and helps the characterization of renal masses, as it allows the differentiation of non-enhanced to enhance lesions  .CMP is usually acquired 25 s after reaching 200 HU in the region of interest in the abdominal aorta and has the highest sensitivity (95%) and negative predictive value (99%) for bladder cancer  Figure  and renaThe nephrographic and excretory phases can be set at 100 s and 10–15 min after contrast medium injection, respectively .Some studies demonstrated the superiority of the nephrographic phase in the identification of urothelial carcinoma when compared to the excretory phase ,15,16, wThis study aims to provide an overview of all CTU acquisition protocols, ancillary techniques for exam implementation, and reconstruction algorithms. The principal available novelties such as Dual-Energy CT acquisition and artificial intelligence applications are also addressed. A good understanding of basic and advanced acquisition and post-processing techniques may help radiologists in identifying the best acquisition protocols and available technology for each purpose.Different protocols of contrast administration are available and listed in The traditional study technique includes the acquisition of a non-contrast phase, followed by the injection of the full dose of contrast medium and acquisition of the nephrographic (80 to 120 s) and delayed excretory phases (5 to 15 min); additional acquisition of the CMP (30 to 40 s) is optional  Table 2Table 2 .The first acquired phase is the CMP, usually acquired with a bolus tracking technique, placing a region of interest in the abdominal aorta, with a threshold of 200 HU, with an estimated acquisition delay set at 25 s. In this phase, the kidney contrast enhancement is related to the arterial inflow. The nephrographic phase is then acquired at a delay of about 40 s when the renal parenchyma is almost homogeneous in density.In the excretory phase, the renal parenchyma is homogeneous but characterized by a markedly reduced density in comparison with the previous phases, with the calyces and pelvis filled with iodinated urine.This single bolus technique allows maximal opacification and distension of the urinary tract as the whole contrast volume contributes to the nephrographic and excretory phases ,19. ThisDue to the increase in radiation exposure, there is no consensus about the need for CMP acquisition. The advantages of the CMP are precise vascular and perfusion information , a betteThe acquisition timing can vary for each acquisition phase, particularly for the nephrographic and delayed excretory phases. The nephrographic phase is usually performed between 80 and 120 s post-contrast injection . Images The excretory phase begins at 3 min post-contrast administration  with timA timing delay should be considered in patients with impaired renal function and known dilatation of the excretory system: in these cases, an excretory phase performed in a prone position can help the distension and opacification of the urinary tract.To avoid acquiring images too early, some authors proposed the use of a single-slice, low-dose test image at the mid-ureter level to verify the opacification and confirm the timing of the excretory phase imaging , but thiAn excessive delay can increase the density of contrast within the collecting system, resulting in difficulties in the identification of subtle filling defects through the dense contrast  and in bSome authors proposed the acquisition of a phase intermediate between the CMP and nephrographic phases, at 60–70 s post contrast medium injection, called the urothelial phase, which demonstrated a high detection rate for upper tract urothelial lesions, with a sensitivity and specificity of 95% and 97%, respectively , and higThe single bolus technique is the simplest to perform for technologists due to the need for just a single contrast administration, at least partially accounting for the diffusion of this technique.The split bolus protocol is recommended for lower radiation exposure .In the split bolus technique, the nephrographic  and excretory phases  are acquired at the same time, avoiding one acquisition, and thereby reducing the radiation dose by approximately one-third .In this protocol, the contrast bolus is administered in two separate injections. After the unenhanced phase, the first part  of the contrast is injected and the optional CMP is obtained, then the second part of the contrast , is injected about 5–10 min later, and combined nephrographic–excretory phase images are acquired at 2–5 min when the kidneys show enhancement of the renal parenchyma and opacification of the collecting systems occurs  Table 2Table 2.The administration of contrast varies widely among different studies with different ratios between the first and second portions of the split bolus, as well as the optimal delay time ,30,31.Some authors suggested the use of a larger bolus as a second injection to improve renal parenchymal enhancement and a delay time of 8 min from the first injection to maximize ureteral distension and opacification . Others The advantage of this technique is the combination of two separate contrast phases (nephrographic and excretory phases) into a single acquisition, thereby reducing the total number of images acquired and, accordingly, the total radiation exposure, which is important in younger patients.The main disadvantage encountered is a lower contribution of contrast medium to kidney enhancement and to distension and opacification of the urinary collecting system, which may reduce image quality and sensitivity for the detection of small renal cell carcinomas  and subtThe triple bolus technique is performed in a few institutions and is based on the separation of the total contrast volume into three injections. An optional unenhanced phase can be acquired, the first bolus part is then injected, followed by a delay time, the second bolus part is then injected, a delay time elapses, then the third portion of the bolus is administered, and finally, post-contrast images are acquired. The resulting acquisition combines CMP, nephrographic, and excretory phases, allowing simultaneous arterial, parenchymal, and collecting system enhancement .This protocol significantly decreases the total radiation dose because of the reduction in the total number of acquired contrast phases; however, due to the bolus splitting, only a portion of the total contrast medium volume contributes to excretory imaging, thus resulting in potential limited distension and opacification of the ureters.This protocol also provides limited accuracy in renal cell carcinoma detection, due to the absence of a dedicated arterial phase image acquisition, which is the most sensitive to clear cell renal cell carcinomas .To achieve adequate distension and whole opacification of the urinary tract in a single excretory phase, ancillary techniques have been proposed, but none have been universally adopted in practice.These techniques include oral or intravenous hydration before the acquisition; intravenous furosemide administered before the intravenous contrast material; use of abdominal compression devices (belts); prone patient positioning; and, if images of the excretory phase are suboptimal, additional delayed phase imaging ,32.Hydration has a role in improving excretory system distension and contrast dilution and is usually performed with the administration of 100–250 mL of saline solution intravenously before the study, or with oral administration of 400 mL of water before the study ,34.The administration of a diuretic, usually intravenous furosemide, has also been reported to increase the urine flow rate and enhance urinary tract opacification and distension ,36. MoreA recent study supported the use of 5 mg of furosemide to achieve optimal bladder filling in CTU to increase the identification of tumors . HoweverThe use of other ancillary techniques is less supported by the literature; in particular, no evidence supports the use of a compressive belt or acquisition in the prone position in the improvement of ureteral distension and opacification, and these techniques risk resulting in increased complexity of the technique, prolonged examination time, and additional acquisitions with increased radiation exposure .Some institutions have also modified the volume of contrast material and the saline solution administration to maximize ureteral distension; for example, the use of a larger volume of more dilute contrast has been proposed to increase excretion into the collecting system .No consensus has been reached about these attempts to optimize the excretory phase.The number of CTU phases varies between two and four, and the effective dose can reach 25–35 mSv, especially when using dated equipment, depending on the performed phases and acquisition parameters . As the To generate diagnostically optimal images at a lower tube voltage, reconstruction algorithms different from filtered back projection should be applied.IR applies a correction loop in the image reconstruction from the raw image data and shows the effectiveness of reducing radiation without any degradation of image quality, thanks to the reduction of the image noise, while still maintaining an optimal image quality ,41. DiffLow tube voltage CT protocols with IR reduce the image noise and help in the identification of enhanced urothelial cells and decreases the attenuation of fat within renal lesions such as angiomyolipoma .Deep convolutional neural network-based models have been applied to low-dose CT examinations to imitate standard-dose filtered back projection (FBP) image texture while ensuring low image noise, streak artifacts suppression, increased low contrast lesion detectability, and high resolution .Phantom studies have demonstrated the ability of these new reconstruction algorithms both in lowering image noise and in improving spatial resolution with no increases in noise levels  Figure .Although standard axial image analysis may be sufficient for the study of other organs in the abdomen and pelvis, the application of post-processing image techniques is beneficial for the evaluation of the collecting system and in the detection of subtle urothelial tumors.Multiplanar, Maximum Intensity Projection (MIP), and tridimensional volume rendering reconstructions can be performed to increase sensitivity and visualization of the kidneys and urothelium.Native thin (0.5–0.75 mm) axial images are usually submitted to coronal and sagittal reformations, then further to MIP and 3D reconstructions .MIP reformations are constructed from the highest attenuation voxels in a dataset and projected into a 3D format. These reconstructions are particularly helpful in evaluating the collecting systems and ureters, allowing a complete and quick overview of the high-density contrast within the collecting systems, and highlighting subtle filling defects, focal thickening of the excretory system walls, luminal narrowing or strictures, calyceal abnormalities, hydronephrosis, and hydroureter.Three-dimensional reconstructions provide specific colors to each voxel in a data set according to its attenuation and relationship to other adjacent voxels, allowing the visualization of the whole opacified excretory system. Some authors support their role in the identification of slight urothelial thickening, especially in cases of reduced excretion of the contrast into the collecting system, when MIP reformations are of limited usefulness ,19,46.DECT technology is based on the analysis of the attenuation spectra of materials at different energies, enabling material characterization .Different CBCT technologies are available: dual source  , rapid sBy examining the attenuation spectra of the same anatomical district at multiple energies, DECT provides attenuation characteristics of the structures. The interaction between the X-rays and scanned material, which is connected to the physical features of the material such as density and atomic number, determines the extent of change in attenuation between the low- and high-energy spectra .Low-energy photons with high attenuation and high-energy photons with low attenuation characterize the X-ray beam intensity. Attenuation increases as the density and the atomic number of the material grows, while the energy of the X-ray beam decreases.As a result, different materials have different attenuation curves related to both the material’s intrinsic properties and the energy of the beam employed.Due to larger iodine attenuation coefficients at lower energy levels, low-energy pictures typically exhibit stronger contrast and enhanced lesion detection in post-contrast acquisitions; however, they are characterized by higher image noise .Low-energy images emphasize iodine, whose density increases when the beam voltage is dropped, resulting in a larger contrast with the background tissues, improving the detection of contrast-enhancing lesions.The principal aim of DECT protocols is to achieve high-contrast images with low noise by combining the stronger iodine attenuation of the low kVp spectrum through monoenergetic imaging with the lower image noise of the high kVp spectrum through post-processing noise-optimizing algorithms .The high- and low-energy data from DECT acquisition can be used to create a single-energy CT-like image including attenuation values and structural information or to make other material-specific reconstructions .DECT has a large number of benefits. First, owing to decomposition analysis and the generation of virtual non-contrast CT images, which are obtained by separating iodine from soft tissue and water, DECT reduces the radiation exposure .Virtual unenhanced images  enable tVirtual non-contrast images allow the identification of calculi and hemorrhagic changes and help in the characterization of renal masses, but without the acquisition of a distinct unenhanced phase, thus limiting the radiation dose ,55.The sensitivity of stone detection of virtual non-contrast images reached 95% ; false nFalse positives may be generated by the presence of dense contrast urine foci accumulated within the urinary tract and falsely recognized as urinary stones on virtual non-contrast reconstructions . The dilDECT also allows the reduction of the contrast medium dose  by usingThe treatment strategies for stones not only depend on the size and degree of obstruction but also on their chemical composition; for example, uric acid calculi can dissolve in urine at a higher pH and thus an important role is played by urine alkalization, whereas non-invasive treatments, such as extracorporeal shock wave lithotripsy, are less effective in the management of oxalic acid stones. Therefore, the characterization of the chemical composition of ureteral calculi helps in their management. In this regard, the accuracy of DECT is not only helpful for morphological and anatomical evaluation but also for chemical composition.The attenuation patterns and low and high energy levels are helpful in spectral separation and thus in understanding the chemical composition of the materials, as lighter materials show small differences in attenuation between low and high energy levels. In contrast, those heavier materials show larger differences in attenuation between low and high energy levels.DECT demonstrated high accuracy in the distinction between uric acid calculi from non–uric acid calculi ,69 and pAccording to attenuation levels, the composition of the stones can also be classified as hydroxyapatite, uric acid, cysteine, oxalic acid, and mixed stones . AccuracDECT images can also be post-processed to create maps that show the concentration of different components including iodine, fat, and calcium. The construction of iodine maps aids in the identification of tissues with higher or lower iodine concentrations .Iodine density measurements have different applications. First, they enable the management of incidentally detected renal masses, allowing their characterization from a single examination and avoiding additional imaging and diagnostic timing delays . VirtualIodine density measurements and iodine overlay images provide a visual depiction of enhancement that helps in the discrimination between avidly enhancing clear cell renal cell carcinoma and hypoenhancing papillary renal cell carcinoma  and is aThe advantages of DECT are listed in Artificial intelligence models have demonstrated great advances in image analyses  with difComputer-aided detection (CAD) is a helpful technique in cancer detection ,84. A crSince urothelial cancer segmentation, particularly in the bladder region, is extremely difficult, researchers’ attention is now concentrated on this issue, and, to our knowledge, no computer-aided detection method for the automatic identification of tumors in the excretory system is currently available.A computer-aided detection system has been developed and tested to identify exophytic renal lesions on computed tomographic colonography with a 95% sensitivity ,86; anotAccurate segmentation of bladder lesions in CTU is challenging: the bladder can be inhomogeneously filled with contrast medium during the excretory phase, bladder shape varies widely with the level of distension, and the edges of bladder lesions are hardly distinguishable from surrounding soft tissues. Additionally, a hypertrophic prostate protruding into the bladder may be an adjunctive confounding factor. Micro-ultrasound may acquire a role in the urological field in the future, particularly in terms of bladder and prostate cancer detection and infiltration estimation, even if the evidence is still limited at present .When trained with a substantial amount of data, convolutional neural networks demonstrated the ability to categorize medical images, and are used to identify and classify pathological patterns in medical images. They can be trained to recognize patterns inside and outside the bladder and to construct a bladder probability map to assist level set segmentation, with encouraging results in automatic bladder lesion segmentation ,89,90,91There is an increasing interest in texture and radiomics analysis as non-invasive tools for the assessment of oncologic and non-oncologic disorders ,93.Image texture analyses can identify the differences in the gray scale included in a region of interest : the imaRadiomics is based on the extraction of many quantitative features from medical images  by takinThe identification of histological variants of malignancies has a central role in treatment planning ,100; howThis tool can aid clinicians in further sub-classifying bladder cancers on routine imaging, with adjustments of the treatment and patient care .Different histological kidney tumors have different gene expression patterns, prognoses, and responses to molecularly targeted therapies, especially in advanced and metastatic diseases ,104,105.Non-invasive biomarkers are needed for a distinction between different malignant lesions . PromisiAnother determinant of treatment planning is tumor staging .Non-muscle-invasive and muscle-invasive bladder cancers have significant differences in prognoses and treatment management. Patients with stage T2 to T4 carcinomas of the bladder are recommended for treatment with neoadjuvant chemotherapy.The local staging and definition of the muscle invasion in bladder cancer are based on cystoscopy and histological evaluation of the biopsied tissues. However, this is an invasive examination and biopsy is dependent both on the operator’s experience and on the sampled portion of the tumor, resulting in wrong staging in up to 25% of cases ,112. RepArtificial intelligence algorithms have been applied to predict the muscle-invasive status of bladder cancers. Different models are available. Deep learning has gained significant attention in recent years; deep-learning models can automatically learn features extracted from radiological images without any need for prior labeling by human experts, reducing the time for manual pre-processing tasks. They can automatically segment pathological tissues and provide phenotypic features of the tissues to enable an accurate characterization.A proposed deep-learning model based on CT images demonstrated good accuracy in establishing the muscle-invasive status of bladder cancer preoperatively .Texture parameters extracted from urothelial cancer segmentations demonstrated a significant role in the differentiation between both low-grade urothelial cancers from high-grade urothelial cancer and non-muscle-invasive cancer from muscle-invasive on unenhanced, arterial-phase, and venous-phase CT . The comThe grade of clear cell renal carcinoma is usually performed by applying the World Health Organization and International Society of Urological Pathology grading system , involviOne of the main applications of artificial intelligence models is represented by the prediction of response to treatment in oncological patients .In patients affected by bladder cancer with muscular involvement, neoadjuvant chemotherapy before radical cystectomy can improve the resectability of larger neoplasms before radical cystectomy and patients’ survival, and reduce the rate of metastatic disease . HoweverNo reliable method yet exists to predict the response of individual cases; therefore, there is an increasing interest in the development of computerized artificial intelligence-based predictive models and decision support systems to help the physician in the most appropriate selection of treatment options .Deep learning convolutional neural network systems can be trained to predict the patients who will be responsive to neoadjuvant therapies by correlating imaging features in the pre-treatment and post-treatment CT with histology post cystectomy. Multiple features were identified on the pre- and post-treatment CT images, including shape, size, and texture characteristics which were extracted through lesion segmentation and included in the analysis ,129.Immunotherapy is one of the most significant advancements in cancer treatment, although it is only effective in a small number of patients. Because there are currently no biomarkers that can be used to identify individuals who are candidates for this treatment, researchers have turned to artificial intelligence models . ConvoluThese newly developed tools can assist oncologists in the selection of patients eligible for different treatments  to proviAlthough it is a valid and gold standard method for the evaluation of urinary pathologies, CTU has some limitations.First, the triple phase acquisition protocol, including the non-contrast enhanced phase, the corticomedullary, nephrographic, and excretory phases, is associated with significant radiation exposure . The useAs the identification of urothelial lesions relies on optimal distention and opacification of the excretory system, CTU can be limited by ureteral peristaltic contractions that may impede the complete distention of the ureters. Delayed or suboptimal opacification may be also related to excretory system obstruction or altered renal function, resulting in potential missed urothelial lesions in unopacified segments. Prone acquisitions may improve excretory system distention and opacification but increase the radiation dose.Moreover, CTU is based on iodinated contrast medium administration, and this fact represents a limitation in patients with impaired renal function. The diffusion of DECT with a reduction of the needed contrast may represent a partial solution to this issue.CTU is one of the cornerstone examinations of radiology. A great knowledge of different acquisition protocols, as well as reconstruction algorithms, dual-energy applications, and new perspectives provided by artificial intelligence tools may help radiologists in optimizing everyday practice.


Traumatic brain injury (TBI) is one of the major causes of disability and mortality worldwide. Rapid and precise clinical assessment and decision-making are essential to improve the outcome and the resulting complications. Due to the size and complexity of the data analyzed in TBI cases, computer-aided data processing, analysis, and decision support systems could play an important role. However, developing such systems is challenging due to the heterogeneity of symptoms, varying data quality caused by different spatio-temporal resolutions, and the inherent noise associated with image and signal acquisition. The purpose of this article is to review current advances in developing artificial intelligence-based decision support systems for the diagnosis, severity assessment, and long-term prognosis of TBI complications. Traumatic Brain Injury (TBI), often referred to as the silent epidemic ,2,3, is Despite the remarkable progress in understanding brain injury, the development of TBI remains complex which makes the assessment of the patient upon admission and during their hospital stay challenging. The pathophysiology of TBI is often divided into two phases. After the initial physical insult to the brain, irreversible lesions known as the primary injury occurs ,18. ThenThe injury assessment of TBIs relies on clinical examinations based on the Glasgow Coma Scale (GCS) and pupillary reactivity as well as brain imaging, primarily computed tomography (CT) scans ,25. The The purpose of this paper is to review the past two decades’ efforts in developing computer-aided decision support systems for TBI diagnosis and prognostication and discuss the limitations of current methods that have not allowed them to be implemented into the daily practice of clinicians. The future research direction for advancing such systems is also discussed in the last sections. Hematoma is one of the most common sequelae of TBI. Based on its location within or outside of the brain parenchyma, a hematoma can be classified as intra-axial or extra-axial. Extra-axial hematomas include subdural hematomas (SDH), epidural hematomas (EDH), and subarachnoid hemorrhage (SAH). An intra-axial hematoma can variably be termed intraparenchymal hemorrhage (IPH), intracerebral hemorrhage (ICH), or cerebral contusion ,30. PrevMore recently, deep learning techniques have been applied to acute brain hematoma segmentation and quantification. Nag et al.  used an According to the Guidelines for the Management of Severe Traumatic Brain Injury , increasMLS is the measurement of horizontal displacement in the brain structure via imaging modalities. The amount of MLS is correlated with increased ICP  and is oOver the past years, a great number of MLS estimation models have been proposed. Liao et al. classified these models into symmetry-based models and landmark-based models . In symmIn landmark-based algorithms, specific anatomical structures, often parts of the lateral ventricles, are selected as landmarks to assess MLS. Chen et al.  proposedEEG refers to the standard digital recording of the brain’s electrical activity. Quantitative interpretations of EEG signal (qEEG) and identification of slight changes in the patterns or type of EEG activity have been suggested to be an indication of mild TBI (mTBI) ,97,98. OBecause the majority of patients with traumatic brain injury die as a result of the withdrawal of life-sustaining treatments due to perceived poor prognosis, accurate prognostication of TBI outcomes is extremely important in determining outcomes and making individualized treatment decisions ,101. WhiThe Federal Interagency Traumatic Brain Injury Research Informatics System (FITBIR) , foundedAmong core FITBIR datasets is the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) . TRACK-TMIMIC-III   and eICUTBI is a heterogenous condition that results in a wide spectrum of injuries in terms of symptoms, severity, and outcome. Over the past two decades, there has been a plethora of research on developing automated clinical decision-support systems that can detect and quantify the imaging features of TBI, analyze the brain status and patients’ homeostasis in ICU, assess the injury severity, guide clinical diagnosis, and predict patients’ outcome.Despite the great potential of AI-based decision support systems in TBI, there is still a noticeable gap between the available technology and clinical practice, which is also reflected in some limitations of this survey.Apart from a brief section on EEG data, most of the reviewed methods are based on still image data such as CT, MRI, and ultrasound. This is because, beside clinical examinations, current practice in TBI diagnosis primarily employs neuroimaging techniques. Furthermore, the rapid development of computer vision, especially deep-learning-based algorithms in the past decade, has outperformed other data modalities by a considerable margin, thus heavily influencing the scope of this survey.In sharp contrast to the great number of automated clinical decision support systems and ML algorithms presented in this survey, their performance has not been validated and compared in a uniform manner. This is due to a lack of publicly available benchmark datasets for TBI, especially a large amount of imaging data with annotations provided by clinical experts, which are vital for the training of most deep-learning-based computer vision algorithms.Therefore, the current state of potential applications of AI-based decision support systems in TBI calls for more collaboration within the field of TBI research, both between the clinical and AI research communities, and within different aspects of TBI such as various types of data and feature modalities, pathology, and severity spectrums.The most urgent issue is the development of TBI-focused AI research platforms and benchmark datasets which require a lot of effort from the clinical side of the TBI research community. This will facilitate researchers by providing them with large training, validation, and testing datasets, especially a sufficient quantity of annotated images for deep-learning-based computer vision models and other sophisticated models which have a higher chance of overfitting. In this regard, FITBIR provides an invaluable platform to share the standard raw data, methodologies, and related tools.Most of the existing methods for TBI severity assessment are developed for a specific pathology  or severity group of TBI patients . Future approaches need to be more inclusive, considering all TBI pathologies and severity categories. A hierarchical framework with multiple models that covers the full TBI severity spectrum is recommended.Although neuroimaging-based methods provide an excellent structural and functional mapping of TBI, they are limited to momentary views of the dynamically evolving brain injury and may fail to detect mild to moderate injuries . In contCurrent advances in developing TBI prognostication models suggest that developing complicated models will not drastically improve the injury outcome prediction so future studies need to focus on identifying the most informative variables. Intelligible feature selection methods such as SHAP that return the contribution value of each variable can enable researchers to select the most relevant features. Moreover, adding another layer of validation from clinical experts on TBI on the selected features is necessary for the adoption of the developed model in the clinical domain. Another major problem of many ML models with clinical applications is their “black box” essence with limited understandability and transparency. Ideally, a rule-based model with explainable rules aligned with clinical domain knowledge should be considered. This will improve the acceptability of the outputs and facilitate the integration of the developed decision support system into the medical management of TBI. In this regard, using FNN-based models that allow extracting human interpretable data as “if-then” rules would be helpful. These models allow the integration of clinical domain knowledge into the learning process which improves model performance and reduces the amount of required training data. Furthermore, it provides the advantage of rule extraction from a few factors when some of the variables are not available.Given the heterogeneity of TBI, future computer-aided decision support systems should be more comprehensive, covering different TBI severity spectrums and abnormalities. This model needs to be validated in multiple settings, including small, rural hospitals that are less likely to participate in research. Because the prognostic information given to families plays a major role in determining prognosis, mediated by the withdrawal of life-sustaining treatment, predictive models must be highly accurate before they can confidently be deployed in clinical practice. Ideally, the logic of their predictions can be understood and interpreted by individual clinicians, which will aid in adoption into clinical practice.