Nature Genetics demonstrated that extrachromosomal DNA (ecDNA)-based oncogene amplification frequently occurs in most cancer types and that it is different from chromosomal amplification.1 The authors further showed that ecDNA in multiple cancer types leads to poor outcomes in patients; thus, ecDNA is a novel potential diagnostic or therapeutic target for tumor treatment  show high expression levels of mRNA transcripts.2 Furthermore, researchers have demonstrated that (1) ecDNA is circular, (2) ecDNA drives the expression of massive oncogenes, (3) ecDNA contains highly accessible chromatin, and (4) ecDNA has a significantly greater number of ultra-long-range interactions with active chromatin.5 Although ecDNA-based amplification has been shown to promote intratumoral genetic heterogeneity and accelerated tumor evolution, its frequency and clinical impact are still unclear.Previously, Mischel et al. found that there were many cyclic ecDNAs in human tumor cells that played a key role in the rapid evolution of tumors and in their defense against threats such as chemotherapy, radiation, and other therapies.1 Earlier, Paul S. Mischel et al. developed the ECdetect tool to conduct unbiased integrated ecDNA analyses of WGS datasets from 17 cancer types and showed that ecDNA was detected in nearly half of the samples.2 In this recent study, ecDNA-based circular amplicons were found in 25 of 29 cancer types analyzed; in particular, aggressive histological cancers harbored a high frequency of amplicons.1 All these results demonstrate that ecDNA amplification can be defined as a feature of multiple cancer subtypes.In order to perform a global survey on the frequency of ecDNA-based oncogene amplification, the authors performed ecDNA prediction from whole-genome sequencing (WGS) data using AmpliconArchitect based on three characteristic properties of ecDNA: its circular nature, its highly amplified characteristic, and its lack of a centromere. After analyzing WGS datasets from 3212 tumor samples and 1810 non-neoplastic ones, the authors found that, among all tumor samples, approximately 14.3% carried one or more circular amplicons, which shows that ecDNA-based amplification is a common event in cancer. However, almost no circular amplifications were detected in matched whole-blood or normal tissue samples.1 Furthermore, the authors found that ecDNA was formed through a random process, and most circular amplicon breakpoints showed no or minimal sequence homology, implicating nonhomologous end-joining (NHEJ) in ecDNA-associated breakpoint repair. Subsequently, the authors revealed that ecDNA formation can result from chromothripsis, which is associated with NHEJ. In order to examine the transcriptional consequences of circular ecDNA amplification, the authors investigated the correlation between DNA copy number (CN) and oncogene expression level. They found that ecDNA amplifications resulted in higher levels of oncogene transcription compared to CN-matched linear DNA.1 This is consistent with recent findings that oncogenes amplified on ecDNA have markedly increased numbers of transcripts in cancer cell lines and clinical tumor samples.5 To compare the epigenetic mechanisms governing gene expression between circular amplifications and noncircular regions, ATAC-sequencing profiles from 36 samples were analyzed. The authors revealed that enhanced chromatin accessibility played key roles in the dysregulation of ecDNA oncogenes and that ecDNA amplifications more frequently resulted in transcript fusions.Next, the authors found that the chromosomal distribution of the 579 circular amplicons was highly nonrandom. Then, they analyzed the association between 24 most recurrent amplified oncogenes and circular amplicons, and found that 38% of these genes were most frequently present on ecDNA amplicons.1 Together, these data imply that ecDNA amplifications may provide tumors with tolerance to clinical treatment and aid them in escaping from barriers to evolution.Furthermore, the authors used the lymph node status and gene expression signatures (increased tumor cell proliferation and reduced immune cell infiltration) to investigate the association between ecDNA and aggressive biological features. Their results revealed that ecDNA amplification groups showed more spread to lymph nodes at initial diagnosis, higher cellular proliferation scores, and lower immune infiltration scores. Most importantly, the authors found that the 5-year survival rate was significantly lower in patients whose tumors harbored ecDNA amplification, demonstrating that the presence of ecDNA was associated with aggressive cancer behavior. To illustrate how survival is related to disease subtypes, the authors used a multivariate Cox proportional-hazards model to test survival after controlling for disease subtype and found that circular amplification resulted in significantly higher hazard ratios.1 Oncogenes encoded on ecDNA untether themselves from their chromosomal constraints, which endows tumors with the ability to rapidly change their genomes in response to changing environments, thereby accelerating tumor evolution and contributing to therapeutic resistance. Because ecDNAs widely exist in different types of tumors, deep dives into the basic structure and function of ecDNAs will aid in understanding the mechanism underlying their biogenesis, replication, and trafficking. More importantly, it is promising to find new diagnostic makers depending on the presence of ecDNAs in tumors, as well as to develop innovative therapeutic strategies that can target ecDNA to interfere with their ability to drive tumor growth, drug resistance, and recurrence.In summary, this study revealed that circular ecDNA plays a key role in the development and progression of cancer by not only facilitating enhanced chromatin accessibility and the transcription of oncogenes but also adversely affecting the survival and outcomes of cancer patients.


Across sub-Saharan Africa, evidence-based clinical guidelines to screen and manage hypertension exist; however, country level application is low due to lack of service readiness, uneven health worker motivation, weak accountability of health worker performance, and poor integration of hypertension screening and management with chronic care services. The systems analysis and improvement approach (SAIA) is an evidence-based implementation strategy that combines systems engineering tools into a five-step, facility-level package to improve understanding of gaps , guide identification and prioritization of low-cost workflow modifications (process mapping), and iteratively test and redesign these modifications . As hypertension screening and management are integrated into chronic care services in sub-Saharan Africa, an opportunity exists to test whether SAIA interventions shown to be effective in improving efficiency and coverage of HIV services can be effective when applied to the non-communicable disease services that leverage the same platform. We hypothesize that SAIA-hypertension (SAIA-HTN) will be effective as an adaptable, scalable model for broad implementation.We will deploy a hybrid type III cluster randomized trial to evaluate the impact of SAIA-HTN on hypertension management in eight intervention and eight control facilities in central Mozambique. Effectiveness outcomes include hypertension cascade flow measures , as well as hypertension and HIV clinical outcomes among people living with HIV. Cost-effectiveness will be estimated as the incremental costs per additional patient passing through the hypertension cascade steps and the cost per additional disability-adjusted life year averted, from the payer perspective . SAIA-HTN implementation fidelity will be measured, and the Consolidated Framework for Implementation Research will guide qualitative evaluation of the implementation process in high- and low-performing facilities to identify determinants of intervention success and failure, and define core and adaptable components of the SAIA-HTN intervention. The Organizational Readiness for Implementing Change scale will measure facility-level readiness for adopting SAIA-HTN.SAIA packages user-friendly systems engineering tools to guide decision-making by front-line health workers to identify low-cost, contextually appropriate chronic care improvement strategies. By integrating SAIA into routine hypertension screening and management structures, this pragmatic trial is designed to test a model for national scale-up.ClinicalTrials.gov NCT04088656 . Contributions to the literatureOur study examines whether introduction of a user-friendly, low-cost package of systems engineering tools delivered iteratively by trained mentors through health facility teams in a low-income, public sector health system improves health system delivery of hypertension care and related patient outcomes.Our study is designed to provide decision-makers with the evidence they need to decide whether and how to further scale-up the approach, specifically through targeted guidance on implementation across heterogeneous settings as well as costs of this approach.Research on systems engineering tools has largely come from high-resourced health systems, with little data from low-income countries.Contributions to the literatureOur study examines whether introduction of a user-friendly, low-cost package of systems engineering tools delivered iteratively by trained mentors through health facility teams in a low-income, public sector health system improves health system delivery of hypertension care and related patient outcomes.Our study is designed to provide decision-makers with the evidence they need to decide whether and how to further scale-up the approach, specifically through targeted guidance on implementation across heterogeneous settings as well as costs of this approach.Research on systems engineering tools has largely come from high-resourced health systems, with little data from low-income countries.Hypertension is the leading risk factor for death globally and is more prevalent in sub-Saharan Africa (sSA) . A systeHuman immunodeficiency virus (HIV) and hypertension comorbidity is common and increasing, in large part due to an aging people living with HIV (PLHIV) population and side effects of antiretroviral therapy (ART). Survivorship among PLHIV has increased due to improvements in ART access and effectiveness, thus expanding the number of older PLHIV, who are more likely to experience comorbid hypertension –12. The Across sSA (including Mozambique), efficacious, low-cost, and safe hypertension (HTN) screening and treatment options exist, and evidence-based clinical guidelines for hypertension management have been developed and disseminated by the Pan-African Society of Cardiology (PASCAR) that recommend routine screening and management of adult PLHIV for CVD risk factors . Yet guihealth systems barriers receive less attention [Approaches to optimize care cascades are needed to maximize the benefits of hypertension screening and management for PLHIV . Barrierttention , presentttention , 35. LowThe systems analysis and improvement approach (SAIA) is designed to optimize cascade performance, is feasible for frontline healthcare workers and managers, and may be applicable to optimize the hypertension testing and treatment cascade for PLHIV across multiple contexts. SAIA, an evidence-based strategy, which is flexible to local context, supports frontline facility staff to gain a comprehensive view of their complex delivery system, identify and prioritize areas to improve, and iteratively test modifications to increase system outputs and patient outcomes , 37. HeaThe overall goal of this study is to evaluate a model for systematic assessment and improvement of hypertension diagnosis and management services for PLHIV individuals in Mozambique (SAIA-HTN). Over the 5-year project, the investigators will conduct a facility-level parallel hybrid type III cluster randomized trial  to evaluStep 1: Understand targeted cascade performance, and identify priority areas for improvement. The HTN cascade analysis tool (HCAT) Fig.  uses rouStep 2: Process mapping to identify facility-level modifiable bottlenecks. Enabling facility-level staff to identify and gain consensus on bottlenecks to address in their hypertension system is essential to defining innovations to implement. SAIA-HTN applies sequential process flow mapping procedures , 42, couStep 3: Define and implement facility-specific workflow adaptations to address modifiable bottlenecks. After identifying modifiable barriers within cascade steps, facility staff identify a simple, specific change to improve performance within the targeted step. Selected workflow adaptations should be feasible to implement, be within the scope of influence of facility management and frontline staff, and be expected to lead to rapid, substantial improvements in the targeted cascade step. Ideas for adaptations come from brainstorming solutions with facility staff, complemented by best practices from the literature and high performing services in Mozambique. An implementation plan for the innovation is described in writing by facility and study personnel to ensure consensus among facility staff, and clarify operational design and roles. Steps 3 and 4 are analogous to continuous quality improvement.Step 4: Monitor changes in routine performance. Facility staff monitor change in routinely reported data from the cascade step selected for improvement. Measuring the absolute change in the proportion of patients progressing through targeted steps captures large, rapid improvements accompanying modifications.Step 5: Repeat cycle. Systems engineering improvement processes are by definition iterative, with ongoing testing of innovations responsive to evolving, contextually specific barriers. Facility staff repeat steps 1–5 at the end of each cycle to identify new approaches to modify previously identified barriers, or if the first cycle was successful, focusing on improving priority bottlenecks identified in a repeated systems analysis.SAIA-HTN packages systems engineering tools into an iterative, five-step process applied at the facility level to give clinic staff and managers a system-wide view of their cascade performance, identify priority areas for improvement, discern modifiable opportunities for improvement, and test these workflow modifications Fig. . SAIA haUsing a 3-year parallel hybrid type III cluster randomized controlled design, we will prospectively implement SAIA-HTN and evaluate its impact for PLHIV individuals in eight intervention and eight control facilities in central Mozambique , including the delivery and training schedules as well as the intervention guides and tools , were developed during the initial SAIA-HTN pilot and will be refined in preparation for the SAIA-HTN trial. In the 3 months prior to initiation of the intensive phase, facility teams (including managers and staff from ambulatory and pharmacy services) receive a 5-day orientation from study teams and district health authorities on using the SAIA-HTN SOPs, including an introduction to the SAIA tools, the implementation schedule, and the data collection procedures. During this first week of SAIA-HTN implementation, facility teams also populate and interpret the HCAT, develop process maps of current PLHIV patient care pathways to hypertension diagnosis and management, define micro-interventions, and indicators to monitor these modifications.Subsequently, district non-communicable disease (NCD) and HIV supervisors, together with study nurses, introduce SAIA-HTN to intervention health facilities over a 2-day period. Within each district, SAIA-HTN is introduced one facility at a time, until all intervention facilities are covered in each district. Facility teams receive bi-weekly supervision visits by study personnel and district supervisors for the first month, followed by monthly visits throughout the remainder of the 24-month intensive implementation period. During the third year after SAIA-HTN introduction (sustainment), monthly mentorship visits will be conducted by district authorities without support from study personnel to evaluate SAIA-HTN sustainability with moderate resource investment (including transport to facilities and per diem for staff).Based on the SAIA trial and SAIA-HTN pilot, it is expected that analysis and improvement cycles will occur monthly, with an average of 12 cycles per year per facility. A SAIA core component that will be maintained in SAIA-HTN is provision to intervention facilities of a flexible facility support fund to address basic equipment needs for hypertension management , as well as to support workflow modifications, which will continue throughout both the intervention and sustainment periods.Manica and Sofala provinces  offer chronic HIV treatment in adult ambulatory services . In thisTo maximize the potential impact of SAIA-HTN, and reflecting the higher burden of hypertension in high volume health facilities, we will select facilities in either provincial or district capitals offering HIV treatment services through ambulatory clinics Fig. . EligiblGiven these criteria, 29 facilities in Manica and Sofala provinces meet eligibility. From these 29, 16 study facilities will be randomly selected (representing 18 of 25 districts in the two provinces) by the study team. Clinics will then be randomly assigned 1:1 to intervention or control using constrained randomization to balance province, urban/ peri-urban, total number of PLHIV, and providers by arm . All aduThrough a mentored process of solution identification and testing, we hypothesize that SAIA-HTN will lead to rapid and sustainable improvements in hypertension service delivery in the eight intervention clinics, assessed via routinely available process indicators and patient-level outcome measures.All PLHIV-adults (> 14 years) accessing ambulatory care services at study facilities during the study period, including those diagnosed during the consult as well as those diagnosed prior to presentation at care.Facilities will be considered unexposed prior to the initiation of the SAIA-HTN intervention in their health facility and exposed thereafter. Individuals’ exposure to the intervention will be based on the exposure status of the facility in the calendar month in which they enter care .The primary SAIA-HTN study process outcome is hypertension screening among PLHIV in ambulatory care services, while the primary clinical outcome is controlled hypertension. Secondary outcomes will include additional quantitative measures that reflect successful progression through steps in the hypertension cascade for PLHIV, as well as HIV-related clinical outcomes Table . ProcessClinical outcomes were included to determine the effect of SAIA-HTN on meaningful hypertension and HIV control over time, which are more dependent on patient behavior and characteristics and may be less sensitive to systems-level improvements.Patient-level hypertension and HIV clinical outcomes will be sourced from existing Ministry of Health patient level forms with slight modifications designed to capture the entire hypertension care cascade for PLHIV from screening to controlled hypertension. Data will be abstracted at least weekly into a study database via a RedCAP questionnaire on tablets by study personnel. As part of routine care, each PLHIV patient is assigned a unique identification number that links across service points and clinics, which will be used to abstract registry data for study outcome measures. The database will generate on-demand reports with monthly indicators to populate the HCAT.Power calculations are based on the primary process outcome of the proportion of ambulatory care visits by PLHIV at which blood pressure is measured, comparing the intervention and control facilities during the final 3 months of the intensive intervention period. Blood pressure screening was selected as the primary outcome as existing guidelines call for it to be routinized into outpatient services for all patients, and it affects the greatest number of PLHIV. Minimum detectable difference calculations were conducted in Stata 14.2 , based on a range of plausible values for endline proportion of visits in the control arm and intracluster correlation coefficient . Models will account for clustering by health facility and will assess the impact of adjustment for patient-level covariates  as well as facility-level covariates , and time (in months since study initiation). Secondary analyses will test for interaction between arm and time, and between arm and study phase . We will also conduct a controlled, segmented time-series analysis that incorporates monthly facility-level estimates from the entire 36-month study period . This secondary analysis will allow us to fully use available data to assess intervention impact, address both serial and intra-class correlation, and assess temporal patterns in study outcomes.We will apply four implementation science theories, models, and frameworks to examine the implementation process, focusing on clinics as the organizational level.n = 48) and eight health workers per intervention facility (n = 64). Analysis will test whether sufficient inter-rater reliability and inter-rater agreement exist to aggregate individual responses to the facility level. If tests do not justify aggregation, we will use a measure of intra-facility variability in readiness rather than a facility-level mean in our analysis. The resulting analysis will provide readiness profiles for each facility as they initiate implementation, which will complement adoption, implementation, and effectiveness data in understanding the broad impact of SAIA-HTN.Organizational readiness for implementing change (ORIC) assesses the extent to which organizational members are psychologically and behaviorally prepared to implement organizational change, which affects decisions to adopt implementation strategies like SAIA-HTN , 51. ReaStandardized readiness assessments, adapted from the SARA tool  and usedWe have developed an approach to measure implementation dose adapted from McHugh et al.’s dimensions of implementation for SAIA-HTN . In thishttp://cfirguide.org/; see Table n = 56–80) participating in the SAIA-HTN [We will use the Consolidated Framework for Implementation Research (CFIR) to guide an in-depth examination of the implementation process, define SAIA-HTN core elements, and describe determinants of success and failure across implementing facilities. During the SAIA-HTN pilot, we adapted CFIR tools (SAIA-HTN . FacilitSAIA-HTN . By purpn = 24) and district (n = 12) managers who participate in the SAIA-HTN trial to collect potentially sensitive information that staff members might be hesitant to share in group settings, such as opinions that lower ranking staff feel uncomfortable sharing with their superiors, or sensitive issues related to staffing that higher ranking staff members feel uncomfortable discussing with lower-ranking team members . The IDIs will allow for exploration of the individual experience with disseminating and implementing SAIA-HTN, and capture intervention adaptations over time, such as staff attitudes or identification with the organization. All FGD and IDI participants will be purposively selected by the study staff, to ensure balance of representation across service location and roles. To understand the implementation process and adaptation during the sustainment phase, we will repeat an equal number of FGDs and IDIs at the end of the sustainment period (year 4), using the same sampling scheme as described above. In addition, implementation tracking (reporting on training and supervision) will be conducted to quantify the executing construct within the implementation process domain.Additional IDIs will be held with facility (FGDs and IDIs will be conducted in Portuguese by an experienced facilitator accompanied by a note-taker (FGDs only), audio-recorded, transcribed verbatim into Portuguese by trained Mozambican staff, and translated into English by staff fluent in both language. First, two coders in a stepwise, iterative process will code the IDI and FGD transcripts, and will conduct content analysis within a deductive framework to identify key implementation themes . Coding will be compared across pairs and differences discussed prior to final coding. Case memos will be written and three analysts will assign ratings for each construct. Using a rating process previously applied to the CFIR , 59, ratWe will estimate total incremental and unit costs of integrating hypertension diagnosis and management into HIV care. Pending effectiveness, a cost-utility analysis to measure the cost per additional disability adjusted life years (DALY) will be conducted.A payer perspective  will be used for the analyses Table . Since iMathematical models will simulate the SAIA-HTN intervention to dynamically evaluate the population-level impact of the intervention. We will parameterize the model using a combination of study data  and estimates from the literature. Model outcomes will include deaths averted due to cardiovascular and cerebrovascular events, and DALYs averted. We will conduct sensitivity analyses to account for uncertainty in key parameters. We will also model the impact of adhering to regional (PASCAR) guidelines for hypertension management for a national cohort of adults in Mozambique and validate the model using Mozambique’s stepwise approach to surveillance (STEPS) survey data on hypertension prevalence , as wellstatus quo  will be combined to calculate the incremental cost effectiveness ratio (ICER) defined as the incremental cost per death or disability adjusted life year (DALY) averted. We will use the study effectiveness data to estimate the net deaths averted due to cardiovascular and cerebrovascular events. We will estimate the number of DALYs averted to capture the gap between current and ideal health, using study outcomes and assumptions reflecting the Mozambique context  [payer perspective, taking into consideration productivity and health system costs, as well as future health system costs averted due to prevention of hypertension in PLHIV.Cost and outcomes comparing SAIA-HTN with the s, etc.) . Followis, etc.) , and to s, etc.) , 64. AnaPreparations for SAIA-HTN initiated in May 2019. Initiation of the SAIA-HTN trial is planned for June 2020.SAIA-HTN is a pragmatic trial to test a novel, scalable approach to optimize hypertension diagnosis and management in PLHIV. The implementation approach aligns with existing administrative structures, providing a practical tool to integrate into routine functions of district and facility supervisors. SAIA uses systems engineering tools to visualize and quantify interconnected service delivery steps, allowing health workers to prioritize interventions that can move more individuals through critical care steps in their clinic. SAIA is flexible and adaptable to local settings, and empowers health care workers to test their ideas for optimization through a series of “micro-changes.” Rather than testing a single strategy that may become irrelevant after policy or technology changes, SAIA has longevity, as the approach is adaptable to the changing service landscape, which increasingly includes co-morbid conditions like hypertension.Our design includes multiple novel implementation science methods. The CFIR provides a guide for intervention planning, implementation, and by addressing “what works, where and why”; identifies local barriers to implementation; and contributes to the knowledge base around implementation of interventions across diverse settings . AssessiAdditional File 1: CONSORT Checklist Facility eligibility and randomization


Hepatocellular carcinoma (HCC) is the most common primary liver cancer and is the second leading cause of cancer-related death worldwide. Fibrosis and cirrhosis are important risk factors for the development of HCC. Hepatic myofibroblasts are the cells responsible for extracellular matrix deposition, which is the hallmark of liver fibrosis. It is believed that myofibroblasts are predominantly derived from hepatic stellate cells (HSCs), also known as Ito cells. Nevertheless, depending on the nature of insult to the liver, it is thought that myofibroblasts may also originate from a variety of other cell types such as the portal fibroblasts (PFs), fibrocytes, hepatocytes, hepatic progenitor cells (HPCs), and mesothelial cells. Liver myofibroblasts are believed to transform into cancer-associated fibroblasts (CAFs) while HCC is developing. There is substantial evidence suggesting that activated HSCs (aHSCs)/cancer-associated fibroblasts (CAFs) may play an important role in HCC initiation and progression. In this paper, we aim to review current literature on cellular origins of myofibroblasts with a focus on hepatitis B virus (HBV)- and hepatitis C virus (HCV)-induced hepatic fibrosis. We also address the role of aHSCs/CAFs in HCC progression through the regulation of immune cells as well as mechanisms of evolvement of drug resistance. HCC is the most common primary liver cancer and is the second leading cause of cancer-related death worldwide . GloballFibrosis is characterized by abundant extracellular matrix deposition, especially collagen I, as a result of persistent inflammation and continuous injury to organs such as the liver, kidney, and lungs . HCC is Historically, fibrosis was considered an irreversible process until recently, where several animal studies have shown that reversal of fibrosis may occur when the liver insult is removed . FurtherIn a healthy liver, extracellular matrix turnover is precisely regulated by an intricate balancing act between a group of enzymes called matrix metalloproteinases (MMPs) in one side, and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs) on the other side . Upon daThe main cell type that is responsible for fibrosis development is the myofibroblast, which is absent in normal liver . MyofibrHSCs are located in between the hepatocytes and the sinusoidal endothelial cells (space of Disse), and constitute about 10% of all resident liver cells . In the HSCs are activated during chronic liver injury and, during this process, HSCs gradually lose their lipid droplets and become myofibroblasts as regard to their secretory and phenotypic profile . ActivatAlthough no direct relationship between liver fibrosis and hepatocellular carcinogenesis has been conclusively established, there is substantial evidence suggesting that HSCs may play a role in HCC initiation and progression . MyofibrPFs are quiescent spindle-shaped fibroblasts that are located in the peri-portal space. Because of the paucity of markers identifying PFs, it is hard to distinguish these cells from other mesenchymal cells . Elastin4-induced liver fibrosis [in vivo [Epithelial-mesenchymal transition (EMT) is a process characterized by epithelial cells gaining motility and mesenchymal features . EMT plafibrosis . FSP1 isfibrosis . Meanwhi[in vivo . Similar[in vivo .Myofibroblasts in HCC may be originated from HCC cells undergoing EMT. Hypoxia induces increased expression FAP, which is a typical marker for CAFs, in HCC cells through HIF-1α . In anotet al. have shown that HPCs isolated from mice injured liver can differentiate into myofibroblasts, as a third distinct cell type, in addition to hepatocyte and cholangiocyte differentiation. They also have proposed that HPCs can contribute to the formation of the premalignant niche by abundant production of myofibroblasts [HPCs are bipotent progenitor cells that give rise to hepatocytes and cholangiocytes in response to liver injury . In a reroblasts .Fibrocytes are bone marrow-derived cells that express both hematopoietic  as well as mesenchymal  markers . In respOnly a small number of fibrocytes can be detected in the peripheral blood from healthy individuals . NonetheMCs are simple squamous cells lining the surface of visceral organs and body cavities . They secrete lubricating fluid to decrease the friction during organ movement. MCs exhibit both epithelial and mesenchymal features . StudiesSince HSCs are the main cell type contributing to liver fibrosis, most published literature is focused on HSC activation as the main triggering factor leading to liver fibrogenesis. The activation of HSCs encompasses a complex process that includes cellular and molecular interactions . Brieflyin vitro experiments  and non-structural  proteins via proteolytic cleavage . These pHCV can directly infect human skin fibroblasts and induce the expression of pro-fibrotic proteins such as vimentin, collagen, and α-SMA by activating GLI2 (glioma-associated oncogene family zinc finger 2), which has been previously linked to organ fibrosis , 54. SinFibrocytes are another cell type that may contribute to HCV-mediated liver fibrosis. Patients who are infected with HCV have higher levels of circulating fibrocytes in their peripheral blood than healthy people . AlthougThe HBV has a partially double-stranded DNA encoding the C, S and X proteins, reverse transcriptase, and polymerase . AlthougMacrophages constitute the largest part of the non-parenchymal cellular compartment of the liver and important for liver fibrosis . There aKCs get activated following the liver injury and secrete many chemotactic stimuli (e. g. CCL2) for inflammatory cells. This results in the infiltration of a large number of MoMFs into the liver. These macrophages secrete pro-inflammatory cytokines and chemokines resulting in the activation of HSCs to fibrogenic phenotype .Liver macrophages perform diverse functions in different stages of liver fibrosis. Impaired monocyte recruitment in liver results in reduced HSC activation and liver fibrosis , 66. HowAs liver macrophages have important functions in liver fibrosis and are abundant in the liver, they have been seen as a potential target for treating liver fibrosis . PotentiTumors are believed as ‘’wounds that not heals’’ as chronic inflammation and fibrosis is generally precedes with tumor initiation. Several types of cells in the tumor microenvironment  support this process , 75. FibActivated HSCs signature is associated with earlier recurrence of HCC after resection . HSCs maThere is a continuous crosstalk between stromal cells such as fibroblasts and immune cells in tumor microenvironment . This crA study by Zhao et al., has shown that HSCs inhibit T-cell proliferation. Co-transplantation of HSCs and H22 (murine hepatic cancer cell line) results in less immune cell infiltration in the tumor tissue, more regulatory T cells and myeloid derived suppressor cells (MDSCs) in the spleen and bone marrow, and more apoptotic mononuclear cells in the tumor tissue than transplantation of H22 cells alone in orthotopic liver tumor mouse models , 79.Deng et al., have shown that tumor associated fibroblasts (TAFs) isolated from HCC tissues recruit monocytes via the stromal cell-derived factor (SDF)-1/CXCR4 pathway and differentiate them into myeloid-derived suppressor cells (MDSCs) through the IL-6/STAT3 axis. Furthermore, in human HCC tissue samples, CD11-positive myeloid cells, which resemble TAF-educated monocytes are found to have a positive association with TAFs .Regulatory dendritic cells (DCs) exhibit an immune suppressive phenotype by inhibiting T-cell proliferation through indoleamine 2,3-dioxygenase (IDO) production in tumor tissues . Cheng eNatural killer (NK) cells are another important innate immune cell type that kill tumor cells. Fibroblasts isolated from human HCC tissue disrupt NK cell functions. NK cells co-cultured with HCC fibroblasts have shown decreased expression of cytotoxic molecules and surface markers for cell activation through prostaglandin E2 (PGE2) and IDO . HSCs-deIdentification of oncogenic addiction pathways in different tumor types has led to revolutionary therapeutic approaches in many cancers, such as imatinib for treatment of chronic myeloid leukemia . Unlike Interestingly, some recent studies challenge the idea that stromal cells merely exert pro-tumorigenic functions. For example, targeting CAFs in mouse models of pancreatic ductal adenocarcinoma enhances tumor growth instead of inhibiting it . SimilarBiomarkers found in serum, tissue or other body fluids are important tools for screening, prognosis, prediction, and monitoring response to therapy in cancer. α-fetoprotein (AFP) is the most widely used diagnostic and prognostic serum biomarker in HCC, but most small HCC do not secrete AFP. In fact, AFP sensitivity drops to 25% if the tumor is smaller than 3 cm in diameter . TherefoPersisting chronic liver injury induces a continuous cycle of inflammation, regeneration and proliferation of hepatocytes that results in accumulation of pathophysiologic aberrancies that lead to fibrosis, cirrhosis, and HCC initiation, as discussed above in detail . HoweverEntrenched within this framework of viral infection and transformation of resident liver cells into fibrogenic cells and/or cells with genomic instability is an environment that is permissive for initiation and progression of HCC. A key component of this permissive environment is the crosstalk between resident cells, migratory cells, and freshly recruited cells that is mediated by cytokines, which are important molecules for cellular interactions and especially in mediating the immune response to alterations in integrity of the liver structure and physiology. Since inflammation is a major response to viral hepatitis and possibly fibrosis and HCC development, cytokines in the liver and in the blood maybe used as a biomarker for disease progression. For example, Hsia et al. showed that the serum levels of IL-6 and IL-10 are frequently elevated in patients with HCC . In the This review provides a summary of recent literature on the pathogenesis of liver fibrosis that is often a prelude to HCC development in the setting of chronic viral hepatitis. A preponderance of studies suggest that HSCs are precursors to myofibroblasts, the cells responsible for ECM deposition that is the hallmark of fibrosis. Nevertheless, there are other possible routes to myofibroblast development and recruitment that implicate PFs, hepatocytes, fibrocytes, and MCs. It also appears that the exact cell of origin of HSCs is possibly being dictated by the nature of liver injury. Furthermore, the molecular signaling pathways that transform these cells, HSCs in particular, into mediators of fibrogenesis are varied and highly context dependent. Convergence of multiple factors related to direct transformation of cells into cancer cells, paracrine effects of other stromal cells, and immune system alterations contribute to hepatocellular carcinogenesis and treatment resistance within the microenvironment of chronic liver injury. Relevant observations addressed in this review carry significant importance considering recent emergence of immune modulatory-based therapies as a legitimate approach to treat HCC .


We will then discuss how these tools can be used to reveal the functional roles of these cell-type specific connections in governing sensory information processing, and learning and memory in the visual cortex, somatosensory cortex, and motor cortex. Finally, we will discuss the prospect of new optogenetic tools and how their application can further advance modern neuroscience. In summary, this review serves as a primer to exemplify how optogenetics can be used in sophisticated modern circuit analyses at the levels of synapses, cells, network connectivity and behaviors.The exquisite intricacies of neural circuits are fundamental to an animal’s diverse and complex repertoire of sensory and motor functions. The ability to precisely map neural circuits and to selectively manipulate neural activity is critical to understanding brain function and has, therefore been a long-standing goal for neuroscientists. The recent development of optogenetic tools, combined with transgenic mouse lines, has endowed us with unprecedented spatiotemporal precision in circuit analysis. These advances greatly expand the scope of tractable experimental investigations. Here, in the first half of the review, we will present applications of optogenetics in identifying connectivity between different local neuronal cell types and of long-range projections with both  Lox recombinase system, it provides a spatiotemporally precise method to reversibly turn on and off the activity of genetically defined or projection-specific groups of neurons. In this review, we will first highlight the use of optogenetics in the investigation of neural connectivity, both within and between brain regions, and then its applications in identifying the functional roles of specific neural circuit components in behavior and physiology. Finally, we will discuss some of the limitations and future directions of optogenetics. Although most of the examples in this review come from studies of sensory and motor systems, their diverse experimental designs and underlying principles are potentially useful for advancing our understanding of the structure and function of other brain circuits.In the past decades, numerous newly developed techniques have greatly assisted in dissecting connectivity and function of the brain. However, only a handful of them have influenced and advanced modern neuroscience as heavily as optogenetics. This state-of-the-art technique utilizes light-sensitive channels or pumps, known as opsins, to manipulate the activity of neurons. In addition, when it is combined with the Cre-Opsins used in optogenetics were first discovered in microbes  and lateLox recombinase system, provides a cell-type specific and high-throughput method for dissecting circuit connectivity.Neural circuits consist of heterogeneous cell-types receiving distinct inputs from both local and long-range sources. Dissecting the intricate connections of these neural circuits has been a long-standing challenge for neuroscientists, largely due to technical limitations in identifying and targeting specific neuronal cell-types. Although traditional methods of circuit analysis have been useful in gaining a gross understanding of macroscale and mesoscale features of brain connectivity, these techniques are limited. For example, anatomical circuit tracing with anterograde or retrograde reagents can only suggest potential innervations, without confirming the presence of functional synaptic contacts ; electroNeural circuits are characterized by entangled connections between various types of neurons within the network, making detailed dissection of local circuit connectivity extremely difficult. Optogenetics has simplified experimental designs for analysis of local connectivity and has greatly boosted the efficiency of data collection. For example, by selectively expressing ChR2 in a specific population of neurons, one can study the connectivity from those ChR2-expressing neurons onto other non-ChR2 expressing neurons with ease and speed . In thisWhen combined with cell-type specific Cre mouse lines, optogenetics can also be used to study the connectivity of genetically-defined populations within local circuits. For instance, in the visual cortex, NTSR1)-Cre, they optogenetically stimulated L6 neurons and identified the recruitment of unique L6 fast-spiking interneurons with massive translaminar axons whose activation suppresses neurons across laminar layers.Local connectivity can also be investigated between layers of the cortex. For instance, lox system enables cell-type specificity; and the range of the light illumination provides a final level of specificity. For example, this method was successfully applied to explore the differential connectivity of thalamocortical and corticothalamic pathways that are entwined with each other  and/or indirectly via recurrent connections from other neurons in the network (polysynaptic input). To establish monosynaptic connectivity, one can pair ChR2 assisted optogenetic stimulation with pharmacology. By blocking voltage-gated sodium channels with tetrodotoxin (TTX) and potassium channels with 4-Aminopyridine (4AP), action potentials and thereby polysynaptic inputs will be prevented. Consequently, any remaining light-evoked response in recorded neurons must come directly from the activation of axon terminals that express ChR2. For instance, the long-range connectivity between the visual cortex and the brainstem accessory optic nuclei (AOS) was investigated by Slc6a3-IRES-Cre mouse line, in dopaminergic neurons to specifically activate dopaminergic neurons in the substantia nigra pars compacta (SNc) and pharmacologically isolated currents mediated by different neurostransmitters. Surprisingly, when they activated these neurons in the SNc and recorded from neurons in the dorsal striatum, they found both glutamatergic excitatory post-synaptic current and GABAergic inhibitory post-synaptic current, as well as amperometric dopamine transients. By combining cell-type specific optogenetics with pharmacology, they were able to definitively identify co-release of dopamine, glutamate and GABA  in GABAergic interneurons, these researchers introduced plasmid DNA encoding ChR2 into a single L2/3 pyramidal cell with electroporation and elicited one action potential per stimulus with very brief light pulses. In particular, they compared the uEPSPs response between Pvalb and Sst inhibitory neurons, finding that each inhibitory population differed in the probability, time course, strength, reliability, and short-term synaptic plasticity of their response to excitatory stimulation. This finding largely agrees with previous in vitro results , ex vivo to target superficial layers of S1 without affecting activity at the soma of L5 pyramidal neurons located deeper in the cortex. Silencing the L5 pyramidal neuron dendrites shifted the detection probability curve to higher intensity values when compared to light-off trials, implying mice had impaired detection ability. Second, to further understand the local microcircuit, the authors expressed ChR2 in Sst interneurons, which preferentially inhibit apical dendrites of pyramidal neurons. Activating Sst interneurons also significantly shifted the detection probability to higher intensities. Finally, activation of ChR2 expressed in L5 pyramidal neurons shifted the detection probability to significantly lower detection probabilities and caused a substantial increase in false detection rates. The use of optogenetics enables a reversible approach for within animal and within session comparisons between light on and light off trials.Another study used optogenetics in S1 to reveal the importance of dendritic activity in layer 5 (L5) pyramidal neurons in sensory perception . The autThe motor cortex is unique among primary cortical areas in that its primary function is to activate muscles and execute movements. Inactivation techniques such as pharmacological inactivation or lesions lack the temporal resolution needed to dissect circuit contributions to specific aspects or components of a movement, such as an arm movement versus digit movement in a reaching task. Additionally, motor cortex lesions impair movement but do not result in the complete loss of movement  due to cThe ultra-fine temporal precision of optogenetics makes it an ideal tool for addressing these open questions regarding the motor cortex. In recent years, the use of optogenetics in the motor cortex has elicited a range of results, some of which do not support previous findings in lesion studies, further demonstrating how lesion and pharmacological studies can be limiting when probing complex systems conveying multiplexed information. To test the role of the motor cortex in learned behaviors, Furthermore, learning a new movement has been shown to be associated with the emergence of a reproducible neuronal activation pattern in the motor cortex that is specific to the learned movement . SubcellThe contribution of long-range input to motor function has also been examined using optogenetics. To understand the role of thalamus and the anterior motor lateral area (ALM), two main sources of inputs to the primary motor cortex, in movement, Optogenetic activation of GABAergic inhibitory neurons in the visual cortex or in the thalamic reticular nucleus has also been used to shut down local recurrent excitation or long-range thalamocortical excitation respectively, in order to elucidate their contribution to cortical visual processing .Tyrosine hydroxylase (Th):Cre transgenic rats to drive the expression of the Cre recombinase under the dopaminergic specific Th promoter. By injecting Cre-dependent ChR2 virus in the VTA, the expression of ChR2 was restricted to dopaminergic neurons in the VTA. With this model, they investigated cell-type specific circuitry driving positive reinforcement during intracranial self-stimulation (ICSS). During a freely moving ICSS task, optogenetic stimulation of dopaminergic neurons in the VTA occurred when rats nosepoked one of the two identical ports, but not when they poked the other one. This simple optogenetic activation of dopaminergic system during behavior strongly biased rats to the port associated with optogenetic stimulation, but not the other port, thus demonstrating that activation of dopaminergic cells in the VTA is sufficient to drive ICSS.This review has primarily focused on the use of optogenetics in mice because of the extensive availability of transgenic mouse lines that permit cell-type specific circuit dissection. However, it is important to note that optogenetics can also be used in other animal models. In particular, rats present a desirable animal model, because they can learn more complex tasks, and because their larger size, relative to mice, enables them to tolerate implants more easily. Recently, more and more transgenic rat lines have become available, which makes the aforementioned cell-type specific experimental designs feasible for this animal model. For example, Optogenetics has also been used in rats to investigate projection-specific contributions to motivation. For instance, Th promoter to express Cre recombinase alongside a cre-dependent ChR2 virus, thus restricting ChR2 expression to dopaminergic neurons in the midbrain. They then demonstrated that the activation of this dopaminergic population promotes reward-related learning at both cellular and behavioral levels. Similarly, the Purkinje cell specific promotor L7/Pcp2 has been used to selectively drive ChR2 expression in Purkinje cells in the cerebellum occulomotor vermis  of the tract of presynaptic axons, which is not feasible for in vivo experiments. However, the ultra fast opsins which support reliable optogentic stimulation up to 100 Hz provide an opportunity. in vivo field recordings to confirm the induction of LTP. When this optical stimulus used to induce LTP, was paired with a foot shock in a cued fear conditioning paradigm, the rats performed the conditioned fear response. In contrast, when the optical stimulus and the shock were unpaired, the rats did not perform the conditioned fear response, suggesting they had not formed the cued-fear memory. In this experiment, the reliable high frequency optogenetic stimulation of axon terminals depends on several desirable properties of oChIEF, such as fast opening and closing rates, high light sensitivity and the low channel inactivation (One advantage of these ultra fast opsins was demonstrated when studying the importance of long-term potentiation (LTP) for memory formation . Althougtivation .in vivo investigations since complex animal behaviors typically occur on the timescale of minutes. In addition, SSFO can also be useful when optogenetics is paired with two-photon calcium imaging, since it solves the issue of visible light from optogentic stimulation interferring with GCaMP based calcium imaging. For example, SSFO gene to conditionally express SSFO in Sst inhibitory neurons of Sst-Cre mice, and expressed GCaMP6f in pyramidal neurons. With this design, the researchers optogenetically turned Sst interneuron activity on (using blue light) and off (using amber light), while performing calcium imaging of mostly pyramidal neurons. The use of SSFO in this study enabled cell-type specific optogenetic manipulation throughout the entire course of a complex behavioral task with simultaneous calcium imaging. This study also exemplifies the flexibility of optogenetics, enabling within animal and within session controls.In addition to ChR2 variants with faster kinetics, step function opsin (SFO)  and stab3 signaling in HEK cells. When this chimeric opsin-receptor was expressed in the nucleus accumbens of mice and photoactivated during a place preference task, mice spent significantly more time in the conditioned area in the subsequent session than control mice without the optical stimulation, indicating that opto-α1-AR can alter cell signaling in vivo and affect animal behavior  and their corresponding Pharmacologically Selective Effector Modules (PSEMs)  injection  . PSAMs anjection . Designenjection . hM3Dq anjection . For in tivation  or silentivation  of axon tivation . These sin vitro and in vivo. Among these techniques optogenetics provides numerous powerful advantages for modern circuit dissection.Other less prevalent solutions to the invasiveness of optogenetics also exist. Transcranial near-infrared optogenetics utilizes synthesized Lanthanide-doped upconversion nanoparticles (UCNPs), which convert near infrared photons into high energy visible light sufficient to activate opsins . For exaAll authors contributed to writing the review.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.


Upper gastrointestinal (GI) carcinomas are characterized as one of the deadliest cancer types with the highest recurrence rates. Their treatment is challenging due to late diagnosis, early metastasis formation, resistance to systemic therapy and complicated surgeries performed in poorly accessible locations. Current cancer medication face deficiencies such as high toxicity and systemic side-effects due to the non-specific distribution of the drug agent. Nanomedicine has the potential to offer sophisticated therapeutic possibilities through adjusted delivery systems. This review aims to provide an overview of novel approaches and perspectives on nanoparticle (NP) drug delivery systems for gastrointestinal carcinomas. Present regimen for the treatment of upper GI carcinomas are described prior to detailing various NP drug delivery formulations and their current and potential role in GI cancer theranostics with a specific emphasis on targeted nanodelivery systems. To date, only a handful of NP systems have met the standard of care requirements for GI carcinoma patients. However, an increasing number of studies provide evidence supporting NP-based diagnostic and therapeutic tools. Future development and strategic use of NP-based drug formulations will be a hallmark in the treatment of various cancers. This article seeks to highlight the exciting potential of novel NPs for targeted cancer therapy in GI carcinomas and thus provide motivation for further research in this field. The upper digestive tract refers to a system of organs that includes, but is not limited to, the esophagus, stomach, bile duct, gallbladder and pancreas. Upper gastrointestinal (GI) cancer is one of the leading causes of cancer death worldwide . In 2017Integrating the challenges related to diagnosis, aggressive metastasis, impeded drug penetration, and high recurrence rates marks GI cancers as some of the deadliest tumor types. Local and distant recurrences remain the rule rather than the exception, suggesting that cancer cells remain present, even after aggressive surgical removal of gross evidence of the disease. Ultimately, therapeutic advancements will identify and address the unique biochemical, physiological and genetic processes which promote the lethality of this disease. Indeed, a one-treatment cure seems unlikely, rather, improved survival may more likely result as multiple agents and modalities address particular difficulties. For example, in colorectal cancers, survival rates have improved as effective targeted therapy, immunotherapy, cytotoxic chemotherapy and radiation therapy more effectively control microscopic and locally invasive disease, allowing for durable disease-free intervals even in advanced cases. However, during the same period, novel treatments for upper GI cancers have led to only limited improvements in survival. Thus, emerging therapies should pursue the incorporation of intelligent tools that minimize toxicity and unwanted side effects via targeted approaches to a given tumor, with future success resting in the cooperative and additive application of innovative multimodality treatments.Pancreatic cancer (PC) accounts for approximately 7% of all cancer deaths worldwide and 3% for cancer deaths within the United States , making n Europe . Other cThough some of these newer agents and regimens have improved survival, this has been on the order of only a few months and progression of the disease occurs in more than 90% of patients. Thus, it is necessary to explore alternative treatments such as NP-based therapies that are able to more effectively target and treat complex cancerous tissues. Targeted therapies are in development which could address the unique challenges presented by pancreatic adenocarcinoma (PA). Novel agents are being designed which modify various processes thought to be responsible for PA virulence. The targeted mechanisms include signaling pathways such as the ones mediated through phosphoinositide 3-kinases (PIK3), supportive processes such as angiogenesis and the desmoplastic environment, immune response augmentation, and agents which may work towards interrupting the epithelial to mesenchymal transition.To date, only a handful of NP-based therapies have been approved for clinical use. One such example is the nanoliposomal irinotecan, a topoisomerase inhibitor, which acts as a second line of treatment following GEM-based chemotherapy for advanced PC –13. FurtCholangiocarcinoma is a malignancy originating from the biliary epithelium and develops anywhere along the biliary tree. The overall prognosis for cholangiocarcinoma remains poor with a 5-year survival rate ranging between 8 and 24% , dependinced BDC . CurrentGastro-esophageal cancer (GC) is the third leading cause of cancer-related deaths worldwide  and is cPre-surgical treatment for non-metastatic gastric and esophageal cancer is performed to optimize therapy by controlling the micrometastasis, decrease the size of the tumor and test its aggressiveness. These actions allow treatment tailored to patient-specific needs, as well as mitigate post-operative complications while increasing the likelihood of complete tumor removal. Though surgical interventions have improved, the parallel application of chemotherapy or radiochemotherapy provides better clinical outcomes. Gastric cancer treatments employ a recently developed neoadjuvant chemotherapy regimen consisting of synergetic medications using the FLOT scheme: docetaxel anced GC , 20.Meanwhile, surgical prospects such as minimally invasive esophageal resection has led to decreased postoperative morbidity . For unrConventional chemo-treatment of cancer is impeded by limited circulation time, low concentrations within the intended treatment area, reduced water solubility, and toxic side effects due to disparate biodistribution, all of which reduce the overall efficacy of the treatment, as well as negatively impact patient morale. Therefore, drug systems operating at nanoscales have emerged as an improved pharmacokinetic approach to overcoming the deficiencies of current combination therapies. Nanoparticles (NP) are colloidal carriers varying between 1 and 1000 nm in size with natural or synthetic origins. The primary advantages of using NPs in the delivery of cancer therapy drugs are high specificity, increased efficiency, excellent stability and low overall toxicity for the patient . There ico-glycolic acid)(PLGA)-microspheres [Metal nanoparticles have gained considerable attention due to their promising properties and therapeutic applications in cancer treatment. Materials such as gold or iron oxides have revolutionized the approach to cancer therapy. Gold nanoparticles (GNPs) are established nanostructures that strongly absorb light, allowing them to generate thermal energy often resulting in the photothermal destruction of cancerous tissue . Photothospheres . Furtherospheres . Upon raAdditionally, iron oxides such as magnetite , which is constructed to perform a variety of functions . MOFs arInorganic NPs, such as the ones described above may offer advantages over polymeric particles with respect to size and shape control, as well as the simplified preparation and functionalization of NPs. Additionally, these particles may be tracked more easily via magnetic resonance imaging (MRI), analytical techniques such as mass spectrometry, or optical techniques performed at the cellular level . Yet, inViruses may also be used to develop technologies in the fields of biomedicine and nanoparticles, particularly in tissue targeting and drug delivery. Viral nanoparticles (VNPs) are robust in their protection of nucleic acids due to the stability of the capsid. This increases the resistance of VNPs to both temperature and pH levels while allowing the VNPs to remain stable in a variety of solvents. Additionally, VNPs are often considered symmetrical, polyvalent, and monodisperse. Numerous VNP platforms have been developed, including icosaherdral plant viruses and bacteriophages, as well as rod-shaped plant viruses and filamentous phages . The adaCargo molecules may be encapsulated through interactions with the interior architecture of the capsid, whose highly symmetric and repetitive surface provides multiple sites for the covalent attachment of site-specific residues . TherapeViruses may also present molecules exposed on their surface that allow for host recognition, implying that the virus may avoid host defense mechanisms. Additionally, viruses can also have an affinity for receptors of biomolecules that are up-regulated in tumor cells . To combPolymers are large molecules consisting of recurring structural units (known as monomers) that are joined with covalent bonds and can also be utilized as a vehicle for drug delivery to treat cancer. Polymers have several beneficial qualities with regard to drug delivery, patient safety and manufacturing.During preparation of polymer-based systems for drug delivery, the drug is either entrapped or covalently bound to the matrix of the polymer . Thus, tPolymeric nanoparticles are defined as colloidal carriers that must be less than 1  in size . When se in size .Natural polymers are ideal candidates for the delivery of drugs due to their ability to enhance drug availability to the target tissue . AdditioSynthetic NPs are prepared from polymeric materials such as poly(ethyle-nimine) (PEI) , poly (PCL) , PLGA [8e) (PCL) –83, or (e) (PCL) . These ce) (PCL) . Other ce) (PCL) –88. DespThe second polymer-based drug delivery system are polymeric micelles, whose functional properties are based on amphiphilic block copolymers . When asOnly few micelles for cancer therapy have reached clinical practice. Presently, polymeric micelle delivery systems are faced with drawbacks such as non-targeted delivery, difficulties in creating multidrug systems and reduced drug resistances. However, micellar drug formulations have potential for future clinical use with emergence of one of the most successful nanocarriers: PEG–PLA micelles . FunctioDendrimers are synthetic polymeric macromolecules, composed of branched monomers that radially extrude from a central core. Their structure allows for a more modifiable surface functionalization, increased solubility, and an internal cavity for drug delivery . This pePresently, researchers are exploring the concept of dendrimers as radiopharmaceuticals, which combine radiotherapy and gene or antibody delivery . These aLiposomes are closed colloidal structures capable of self-assembly. Their structure is composed of lipid bilayers that produce a spherical shape surrounding an aqueous center. Thus, it is possible to encapsulate both hydrophilic and lipophilic drugs , 108. SoDespite the advantages of liposomes, poor stability and reduced availability during oral administration are considered general limitations of the method. Recent work has sought to increase drug adsorption through surface modifications such that liposomal nanocarriers could withstand the harsh acidic conditions in the GI tract . MeanwhiGiven the advantages of tailored drug delivery, targeted NPs has the potential to be more effective and a lesser toxic treatment option. Not only do these drug delivery systems have prolonged circulation and protection against premature drug degradation, they also facilitate drug penetration, targeted delivery, and an increased concentration of the drug in the specified cancerous tissues. NPs provide an innovative platform for drug delivery since the structures allow for a range of sizes, shapes, chemistries, and surface charges. By modifying these elements, there is improved control over their stability of the drug, as well as the timing and location at which the therapeutics are released. A summary of key NPs in targeted cancer nanomedicine can be found in Table Chemotherapy is a prominent method of medication used in a significant portion of metastasized tumor treatments. However, the non-specificity of the treatment can cause serious toxic side effects and increase the resistance of the tumor to multiple drugs. Current research seeks to apply NPs in conjunction with an expanding knowledge of cancer development to more quickly and effectively address the diseases. Several studies have discovered that there is a correlation between chronic inflammation sites and tumor genesis , 125. CoWhereas the opposite event of an immuno-suppressed tumor environment stimulates cancer angiogenesis. Other treatments seek to trigger the innate and adaptive immune system and boost its activity against cancer cells. Treatment procedures like T-cell based immunotherapeutic strategies are grounded in tumor-specific antigen delivery or the removal of inhibitory signals, resulting in the activation of T-cells . NanodelFurther research is being performed to determine how NPs might be used to disrupt the dense, fibrous stromas of GI tumors and their hypoxic microenvironments using hyaluronidase and/or collagenase –136. MorTripterygium wilfordii. Celastrol displays anti-inflammatory properties by inhibiting the activation of nuclear factor Due to a limited number of treatment options with low treatment efficacy, PC remains one of the most fatal cancer, resulting in a patient 5-year survival rate of less than 5%. Therefore, significant emphasis has be placed on developing more targeted and efficient therapies. Nanosystems have demonstrated enhanced bioavailability by promoting prolonged drug circulation without degradation . Moreovese model . The bioFurther enhancements in chemotherapeutics have been exhibited through the application of cationic albumin NPs loaded with hydrophobic celastrol and hydrophilic 1-methyltryptophan as a combination therapy with an indoleamine-2,3-dioxygenase (IDO) inhibitor . Recent Helicobacter pylori-associated GC, which constitutes the root cause of approximately 60% of all GC [As with other upper GI carcinomas, gastric cancer develops asymptomatically and is a significant cause of cancer-associated deaths. However, NPs can be effectively employed in the early detection of GI cancer. GNPs-RNA conjugates are used in the coloriometric detection of biomarker micro-RNA in GC . In the f all GC . Additiof all GC . As overf all GC . Others f all GC . As for f all GC . AlginatC models –157. FigNPs offer a promising route to deliver drugs that can be used in various stages of GI cancer. Over the past decade, nanotechnology has proven to be an important tool for the enhancement of novel chemo-immunotherapy for the treatment of various upper GI carcinoma. In future clinical practice, treatment of the tumor microenvironment, mitigating inflammation, and further activating the patient’s immune system will significantly affect the outcome of treatments. Presently, there is an urgent need for multifunctional tools capable of supporting and stimulating the immune response. Future efforts could focus on engineering anti-cancer immunity to minimize the toxic effects of chemotherapy drugs. While studies have identified multiple mutations, such as the oncogene K-rat sarcoma (KRAS), that are common in foregut cancers, attempts to interfere at the point of the gene product have not produced effective therapy. This has led researchers to increasingly focus on down stream molecular targets. Multiple such targets are now increasingly identified within the tumoral environment, including the stroma, angiogenic milieu and immune system. Other investigations have led to novel combinations of traditional cytotoxic drugs and have shown some promise. Given the multiple aberrant, virulence producing mechanisms that make foregut cancer among the most lethal, a single agent cure seems unlikely. Future inroads are best anticipated via mutimodality and multi-pathway interventions.Several polymeric NPs have been used to simultaneously deliver tumor antigens and cell-specific adjuvants resulting in an effective stimulation of the immune system . MeanwhiAs the approach to cancer treatment shifts towards personalized medicine, individualized gene therapy could play a major role in the treatment of cancerous tumors with NPs delivering nucleic acids to targeted locations. Drug resistance is another obstacle that must be overcome to truly improve the survival outlook of patients with GI cancer. Since drug resistances are related to modified lipid biosynthesis, researchers are working on engineering effective NPs that can interact with lipid membranes to allow for enhanced uptake. However, these approaches still require further developments to efficiently target cancerous tissue. In conjunction, these novel strategies suggest an exciting potential for furthering the efforts of drug delivery systems used in the treatment of GI cancer.Pharmacokinetic shortcomings of current drug delivery techniques such as short retention time, non-targeted delivery, poor penetration into deep tumor tissues, lack of co-formulating agents, and high toxicity drive the development of novel drug delivery platforms such as nanoparticles. A wide variety of NPs are currently being researched with applications in chemotherapeutics, as well as photothermal therapy. The positive in vivo performance of nanomaterials relates to their unique properties that allow for controlled drug release, as well as both surface and cellular compatibility modifications. Presently, several NP-based systems, such as liposomes and protein-based NPs, are being applied in clinical practice for the treatment of GI carcinomas. These studies present evidence of an increase in patient survival. The use of NP-bound albumin loaded with paxlitaxel, nanoliposomal irinotecan as well as gold nanorods for photothermal ablation have been shown to be effective in targeting cancerous tissues and are applied in clinics at present. However, the field of nanomedicine still lacks standardization that would allow these therapies to become front line treatment options. Often, implementation of nano-based cancer therapies is impeded by uncontrolled toxicity and unforeseeable cellular interactions. Optimization of the structure and composition of NPs has yet to be performed to allow for a drug delivery system that is both non-toxic and programmable. This has proven to be a challenging proposition, as well as an opportunity for growth within the field. Furthermore, FDA approval rests upon novel drug formulations outperforming current treatment methods. Although several in vitro studies have been evaluated for the delivery of chemotherapeutics, clinical evaluations and deeper analyses of immunotherapies and combination therapies must be conducted before they can be adopted as standard treatment options.


Given the growing concerns of problematic Internet use and online safety, it is critical to address parental self-efficacy in managing adolescent Internet use and to examine associated factors, especially in parents of adolescents with attention-deficit/hyperactivity disorder (ADHD). We examined the roles of adolescents’ hyperactivity/impulsivity, inattention and oppositional defiant disorder (ODD) symptoms, parents’ depressive symptoms, parenting behavior , and child behavior (Internet addiction) in relation to parental self-efficacy in managing adolescent Internet use. We recruited 237 Taiwanese parents of adolescents with ADHD (ages 11–18). Hierarchical linear regression was performed in four steps to test the study hypotheses. The results indicated that child’s age, ODD symptoms, and Internet addiction of adolescents were negatively associated, and parental care was positively associated with parental self-efficacy in managing adolescent Internet use. The final model was significant and explained 43% of the variance. The present study demonstrated that parenting and child behaviors contribute to parental self-efficacy in managing adolescent Internet use. Moreover, children’s ODD symptoms were identified as the risk factor for reduced parental self-efficacy. Self-efficacy refers to an individual’s belief in their capacity to perform behaviors necessary to produce specific performance attainments ,2,3. ParAttention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent DSM-5 mental disorders among children and adolescents in Taiwan 8.7%) [.7% [8]. The Swanson, Nolan, and Pelham version IV Scale (SNAP-IV) is a widely used rating scale that measures the ADHD symptoms of hyperactivity/impulsivity and inattention and oppositional defiant disorder (ODD) symptoms. Hyperactivity/impulsivity is characterized by symptoms of impulsivity and hyperactivity. Inattention is characterized by distractibility, limited attention span, forgetfulness, and procrastination. ADHD children with inattention symptoms have difficulty in following detailed instructions, remaining focused, and organizing tasks. ODD is a common disorder in children marked by hostile and defiant behavior . ParentsIn addition to children’s mental health, parental depression has been negatively associated with parental self-efficacy  and posiParents who reported more positive parent–adolescent communication perceived higher parental self-efficacy than did those who reported less positive communication . ParentaBy contrast, parental indifference to children’s emotions may be considered a form of emotional invalidation  as well Previous research has documented that parental behaviors play a vital role in predicting children’s and adolescents’ psychological and behavioral adjustment . For exaGiven the growing concerns of adolescents’ problematic Internet use, it is vital to examine and address parental self-efficacy in managing it and factors associated with it. The present study examined the roles of adolescents’ and parents’ mental health (ADHD and ODD symptoms in adolescents and parents’ depressive symptoms), parenting behavior , and adolescent behavior (Internet addiction) in relation to parental self-efficacy in managing adolescent Internet use after controlling for demographic factors . We hypothesized that higher levels of ADHD and ODD symptoms, parents’ depressive symptom, parental indifference, and adolescent Internet addiction are associated with lower parental self-efficacy levels in managing adolescent Internet use, whereas parental care is associated with higher parental self-efficacy levels in managing adolescent Internet use.Parents of adolescents aged 11–18 years who had been diagnosed as having ADHD, according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) , were coIn total, 237 parents of adolescents with ADHD were invited; of them, 231 (97.5%) agreed to participate (83% mothers). In all, 86% of the adolescents with ADHD were male, and 82% of participants were in a two-parent family. Only one parent per household answered the questionnaire. Informed consent was obtained from all the participants prior to the assessment. The participants could seek help from the research assistants if they had problems in completing the questionnaires.We used the PSMIS  to measuThe 26-item SNAP-IV—Chinese version was used for assessing the severities of DSM-IV-derived ADHD and ODD symptoms in the previous month ,36. EachThe Mandarin Chinese version  of the CWe used the Chinese version of the PBI ,21,40 toThe 26-item CIAS  was used2 was included in determining the percentage of variance explained by each step and the overall model.Data analysis was performed using SPSS software v25 . Descriptive statistics and Pearson correlation analyses were first conducted to provide information about the sample and relations among the key variables. Hierarchical linear regression was performed in four steps to test the hypotheses of examining the multidimensional correlates of parental self-efficacy in managing adolescent Internet use and to ascertain the significance of potential predictors and the percentage of variance explained. Four sets of independent variables included demographics , mental health (adolescent ADHD and ODD symptoms and parents’ depressive symptoms), parenting behavior , and adolescent behavior (Internet addiction). Adjusted RThe research proposal was approved by the Institutional Review Boards of Kaohsiung Medical University Hospital (KMUHIRB-20130131). The purpose and processes of the study, privacy and confidentiality of data, and freedom of participation were fully explained to all potential participants. All participants signed written informed consent.The results of descriptive statistics and correlation coefficients for study variables are presented in The results of hierarchical linear regression revealed that adolescents’ age, ODD symptoms, and Internet addiction were negatively associated with parental self-efficacy in managing adolescent Internet use, whereas parental care was positively associated . SpecifiIn the final model, parents of older adolescents with higher levels of ODD symptoms and Internet addiction were more likely to report lower parental self-efficacy levels in managing adolescent Internet use. By contrast, parents with higher levels of parental care were more likely to report higher levels of parental self-efficacy in managing adolescent Internet use. We did not observe significant associations between parental self-efficacy and variables such as adolescents’ sex, parents’ years of education, hyperactivity/impulsivity, inattention, parents’ depressive symptoms, and parental indifference. The final model explained 42% of the variance.The present study examined the extent to which particular dimensions of mental health, parenting, and adolescent behaviors affected parental self-efficacy in managing Internet use among adolescents with ADHD. The results of the final model indicated that high levels of adolescent ODD symptoms and Internet addiction were associated with decreased levels of parental self-efficacy in managing adolescent Internet use, after controlling for other covariates. By contrast, a high level of parental care was associated with an increased parental self-efficacy level.In the mental health dimension, only adolescent ODD symptoms and not core ADHD symptoms and parental depressive symptoms were significantly associated with parental self-efficacy in managing adolescents’ Internet use. Although both ADHD and ODD of adolescents may increase parental stress and challenges in raising and disciplining their children, ODD seems to have a stronger influence than hyperactivity/impulsivity and inattention on parental self-efficacy in managing adolescent Internet use. ADHD adolescents with ODD often display a pattern of hostile, disobedient, and defiant behaviors directed at parents or other authority figures ,45. ThesAlthough parental depressive symptoms may reduce parental self-efficacy , we did In the parenting dimension, we found that parental care was positively associated with parental self-efficacy in managing adolescent Internet use, consistent with a previous study in Korea . How parIn the adolescent behavior dimension, adolescent Internet addiction was negatively associated with parental self-efficacy in managing adolescent Internet use. Given the interactive nature of the parent–child relationship, parents and children may influence each other’s behaviors. According to transactional theory , a set oThis study seems to be the first, to our knowledge, to address parental self-efficacy, specifically in managing adolescent Internet use. In the digital age, parents are concerned about adolescents’ problematic Internet use and online safety, and managing it has been a major challenge in parenting, focusing on how parents perceive themselves as competent in handling these new parenting challenges in which they may not have any background knowledge and reference point linked to their generations. This study extends the literature and examines how multidimensional aspects of mental health, parenting, and child addictive behavior on the Internet contribute to parental efficacy in managing Internet use among adolescents with ADHD.This study has several implications for practice. On the basis of the findings, ODD symptoms were the strongest and only significant mental health factor contributing to parental self-efficacy. The findings highlight the need for family-based interventions that address the associations between adolescents’ ODD symptoms and parental self-efficacy in the negative cognitive process, which in turn may influence parenting behaviors and their interactions with their children. Moreover, when planning a family-based intervention in adolescents with ADHD, health care professionals need to be aware of adolescent Internet addiction, as this may intensify the challenges of parenting and heavily reduce parental self-efficacy. In addition to ADHD treatment, thus, it is crucial to recognize signs and symptoms of Internet addiction, empower and provide parents with parenting resources and tools, and suggest measures to improve parent–child relationships and parental self-efficacy. Given the importance of contextual factors, intervention may include parenting training that addresses the positive effects of parental care, which Asian parents do not often overtly express and the power and effectiveness of which they may not recognize , and proAlthough the present study provides insights into the multidimensional correlates of parental self-efficacy in managing adolescent Internet use, the study has some limitations. First, because self-report questionnaires were used to collect data one time from one source—parents of adolescents with ADHD—the results might be influenced by shared method variance (common method bias). Future studies could collect data from both parents and adolescents to reduce the shared method variance. Second, the cross-sectional design precluded the assessment of causal relationships between variables. Given the interactive nature of parent–child relationships, future studies could further investigate bidirectional relationships between parent and child behaviors through a longitudinal design. Third, the present study was conducted in a clinical sample, and the results may not be generalized to the general public. Further research should test the model in other populations.In summary, the present study addressed the importance of parental self-efficacy in managing adolescent Internet use in the digital age and identified multidimensional correlates at both the individual and contextual levels. We found that adolescents’ ODD symptoms and Internet addiction were negatively associated with parental efficacy, whereas parental care was positively associated with parental self-efficacy in managing adolescent Internet use after accounting for several covariates. Our findings are consistent with transactional theory , which h


Bioengineering special issue on Advances in Biological Tissue Biomechanics, therefore, focuses on research dealing with cutting-edge experimental and computational methodologies for biomechanical investigations of tissues in the human body system across multiple spatial and temporal scales.Advanced experimental and computational biomechanics have become essential components to better understand the physiological and pathological conditions of biological tissues in the human body. Recent advances in medical imaging modalities, image segmentation, tissue characterization experiments, and predictive computer simulations have made major contributions to transforming current therapeutic paradigms towards the facilitation of patient-specific diagnostics and individualized surgery planning. This Valvular heart disease (VHD) encompasses a number of common cardiovascular conditions that account for 10 to 20% of all cardiac surgical procedures in the United States [Lee et al. (2019)  providedNovel multiscale characterizations for the three TV leaflets were presented by Hudson et al. (2020) . In thisIn soft tissue biomechanics, characterizations of a tissue’s mechanical properties have traditionally been facilitated through bench-top experiments, such as uniaxial or biaxial tensile extension tests, in which tissue samples are immersed in a buffer solution ). Salinas et al. (2019)  conducteNext, Ross et al. (2020)  reviewedThe progression of calcific aortic valve disease (CAVD) is the consequence of extracellular matrix (ECM) remodeling, leading to structural abnormalities and improper valve function. Tesfamariam et al. (2019)  providedArtificial heart valves may become dysfunctional, leading to thrombus and/or pannus formations. Computational fluid dynamics (CFD) is a promising tool for improved understanding of heart valve hemodynamics, allowing quantification of detailed flow velocities and turbulent stresses to complement in-vivo clinical Doppler measurements. Khalili et al. (2018)  investigThe etiology of abdominal aortic aneurysm (AAA) development is believed to be multi-factorial, in that the pathology is initiated at the molecular level (protease- and enzyme-related), builds up to the tissue level through extracellular matrix (ECM) and structural changes, and manifests as geometrical-, biomechanical-, and blood-flow-related alterations in the abdominal aorta. Of the numerous etiological theories of AAA pathology, the degraded ECM theory is most widely accepted, as human AAA specimens usually exhibit a reduction in elastin content and an increase in collagen cross-linking . AAA porDespite the advances in modern clinical management, heart failure (HF) maintains a high mortality and morbidity in the United States. More than 5 million Americans have HF, and around 550,000 new cases occur every year . Liu andTraumatic brain injury (TBI), primarily induced by mechanical impact to the head, is a leading cause of death and life-long disability in the United States. Around 5.3 million Americans currently have long-term disabilities after sustaining a TBI . DesigniIn automobile accidents, abdominal injuries are often life-threatening yet not apparent at the time of initial injury. The liver is the most commonly injured abdominal organ from this type of trauma owing to its fragile material properties. Efforts to determine the optimal safety measures for automobile-related accidents have largely relied on crash dummies, which exhibit significant limitations in recapitulating injury impact to humans. Since the 1970s, there have been no substantial changes in assessing injury. In this study, Chen et al.  utilizedJugular venous valve incompetence has no long-term remedy and symptoms of transient global amnesia and/or intracranial hypertension continue to discomfort patients. Benson and Huang  examinedSeveral nonlinear and anisotropic constitutive models have been proposed to describe the biomechanical properties of soft tissues, and reliably estimating the unknown parameters in these models using experimental data is an important step towards developing predictive capabilities. However, the effect of parameter estimation techniques on the resulting biomechanical parameters remains under-analyzed. Aggarwal  conducteAdvances in Biological Tissue Biomechanics reflect the importance of experimental and computational biomechanics for improving the fundamental understanding of the function and properties of biological tissues in human body systems. These essential research investigations and technological developments will serve as a foundation for future advances in precision medicine for accurate diagnosis and effective prophylactic management. Finally, the guest editors would like to thank all the authors for their appreciated contributions.Altogether, the 12 research papers/reviews in this Special Issue on


Moyamoya disease (MMD) is a chronic cerebrovascular disease that frequently results in intracranial ischemia or hemorrhage. Its concurrence with varying ophthalmic findings is relatively rare yet may lead to irreversible blindness. We performed a search and review of the literature to characterize the relevance of MMD (excluding moyamoya syndrome) and ophthalmic findings. As a result, a total of 38 articles identified from PubMed and Web of Science were included in this mini-review. Patients with MMD sometimes present with decreased visual acuity or visual field defects before the onset of symptomatic cerebrovascular dysfunction. The most predominant ophthalmic condition in MMD patients is the morning glory disc anomaly (MGDA). Deficiency during neuroectodermal genesis and subsequent mesodermal changes may be responsible for the association between these two diseases. Thus, it may be beneficial for patients with MGDA to receive cerebral vascular examinations as the precaution against life-threatening intracranial angiopathy. Other ophthalmic findings reported in cases of MMD include retinal vascular occlusion, optic disc pallor, cortical blindness, etc. For most of the patients with MMD, retinal examinations would be recommended to prevent potential loss of vision. It is essential for both neurologists and ophthalmologists to be aware of the correlation between cerebrovascular diseases such as MMD and ocular manifestations to achieve a comprehensive diagnosis. Moyamoya disease (MMD) is a life-threatening cerebrovascular disease that sometimes may also lead to irreversible vision loss. The disease is characterized as progressive steno-occlusive changes occurring at the terminal portion of the internal carotid artery (ICA), initial middle cerebral artery (MCA), and anterior cerebral artery (ACA) . Its typPrevious epidemiological studies show that the areas with high morbidity incidence of MMD are mainly East Asian countries, such as Japan, China, and Korea. According to one study in Taiwan, the prevalence of MMD in 2011 was 1.61  . There aIndependent ophthalmic presentations are uncommon in MMD. However, several cases of morning glory disc anomaly (MGDA) have been reported in pediatric MMD patients. The typical intracranial vascular and retinovascular anomalies suggest that there may be a common denominator between these two diseases . CentralPatients who complain of visual dysfunction may be unlikely to get initially diagnosed as having potential cerebral vascular disease. Since ocular findings are usually neglected in MMD, none of those cases have been reviewed systematically. Herein, we conduct a mini-review on MMD-associated ophthalmic manifestations to provide an overall insight into its possible clinical relevance and investigate hypotheses regarding its mechanism. Since moyamoya syndrome is defined as being accompanied by correlative conditions and it would be controversial to distinguish the direct effect of this intracranial angiopathy on ophthalmic changes, we have not included any of the literature on moyamoya syndrome in this study.We performed a search of the literature in the PubMed and Web of Science databases to identify articles related to MMD and ophthalmic findings on September 15th, 2019. The titles and abstracts of those articles were reviewed by two reviewers to confirm their quality and eligibility for further examination. The inclusion criteria were as follows: (1) MMD and ocular manifestations were simultaneously mentioned in the title or abstract, and (2) original studies or case reports. The exclusion criteria were as follows: (1) without a definite diagnosis of MMD; (2) non-English article; (3) Moyamoya syndrome; and (4) with a non-ophthalmic disease, which could probably affect visual function and not conforming to the diagnostic criteria of moyamoya syndrome. MMD was diagnosed when there was no specific underlying disease, including genetic, hereditary disorders, hematological disorders, connective-tissue diseases, infectious or chronic inflammatory conditions, metabolic diseases, and vascular injury in this study. Based on the inclusion and exclusion criteria, a total of 38 eligible articles were identified and reviewed, and the year of publication ranged from 1981 to 2019.All articles were classified according to the ophthalmic diagnosis. The various ophthalmic findings associated with MMD in these articles included MGDA, retinal vascular occlusion, nystagmus, amaurosis fugax, hypertropia, diplopia, decreased vision, visual field defect, iris hypoplasia, retinal artery tortuosity, ocular ischemia, retinochoroidal atrophy or coloboma, anterior ischemic optic neuropathy, optic nerve coloboma, optic nerve pallor, optic glioma, congenital cataract, and congenital glaucoma.According to our review, MGDA is the most frequent ophthalmic manifestation in all MMD patients included. MGDA is a rare congenital deficiency of the optic disc characterized by an enlarged, funnel-shaped excavation of the posterior pole involving the hypogenetic optic disc, which resembles a morning glory flower. Generally, this malformation is considered to be unilateral, while bilateral involvements were occasionally reported. Patients of MGDA mainly present with decreased visual acuity at the onset due to dysplasia of the optic disc. This disease is associated with various conditions, including intracranial vascular abnormalities; mid-line facial abnormalities; 47, XYY syndrome; Down syndrome; etc. .JAMA Ophthalmology in 2015 showed fundus and ultrasonography of an MGDA patient. The compensatory collateralization of chorioretinal anastomoses in this patient also imparted a “moyamoya” bypass system, indicating that MGDA may have pathological correlations with MMD .–29.24–29Retinal vascular occlusion can be recurrent in MMD patients. The patient in case 12 was diagnosed with bilateral MMD and received encephalo-myo-synangiosis as a surgical intervention. Six years after the surgery, the patient complained of decreased vision in the right eye, and branch retinal vein occlusion was found in this eye. Recurrence occurred in his contralateral eye 12 years later . Case 13The steno-occlusive changes of MMD usually occur at the supraclinoidal portion of the ICA and its two main branches. In some circumstances, the slow progression of MMD allows collateral circulation from the external carotid artery to develop and supply the central retinal artery . Aside fDiverse ocular manifestations are sometimes consequences of ischemia or hemorrhage in MMD and may differ from the regions involved. A total of 10 cases from eight articles referring to ischemia- or hemorrhage-related ocular manifestations are summarized and reviewed, five of which are from case series  31–38).–38.31–38Decreased cerebral blood flow is a prevalent pathological change in MMD with a tendency to cause cerebral hypoperfusion. Severe hypoperfusion may lead to cognitive impairment and intellectual disability . Case 19Hemorrhage may be a result of aberrant angiogenesis, such as fragile microaneurysms or false aneurysms, especially those occurring in collateral vessels of MMD . Case 20Although posterior circulation is rarely involved in MMD, it should still be regarded as an alternative cause of acute vision decrease. The possible mechanism of posterior circulation involvement in MMD is similar to that of anterior circulation besides an isolated pathological change, the unstable hemodynamic state of the posterior cerebral artery (PCA) . PatientOther uncommon ocular findings in MMD patients are referred to in this section from 12 articles, including optic nerve involvement, congenital cataract, and retinochoroidal anomaly  34, 38,–51. In CRetinal vasculature is a microcirculation that can be non-invasively observed by fundus photography. It could also be considered as a reflection of the systemic circulation. Case 27 reported a 30-year-old female with headache and blurred vision who was diagnosed with retinal arterial tortuosity and bilateral MMD. Proangiogenic factor levels increase as compensation and lead to neovascularization, which is hypothesized as an underlying explanation for the formation of retinal vascular tortuosity in this case . Case 28MMD is associated with varying ophthalmic findings, particularly MGDA, according to previous studies. The risk of having MMD in patients of MGDA is higher than in the general population. Deficiency during neuroectodermal genesis and the subsequent mesodermal changes may be responsible for this association. Cerebral vascular examinations are recommended for MGDA patients to exclude any potential life-threatening intracranial vascular diseases. Other ophthalmic findings related to MMD include retinal vascular occlusion, visual field defects caused by ischemia or hemorrhage, optic disc abnormalities, etc. Retinal examinations would be beneficial for MMD patients to prevent severe loss of vision. Posterior circulation involvement in MMD is rare but should not be underestimated, for sometimes it is responsible for acute or transient vision loss. Both neurologists and ophthalmologists should recognize the correlation between ocular manifestations and cerebrovascular diseases such as MMD, in order to achieve a comprehensive diagnosis.KY, JC, and YW designed this review. YW and KZ drafted the manuscript and searched and reviewed the database and all included articles. YY and FS reviewed the articles based on inclusion and exclusion criteria. YW, KZ, YY, FS, JY, JC, and KY provided comments and revised the manuscript. All authors have approved the final version of the manuscript.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.