Radio-anatomical evaluation of clinical and radiomic profile of multi-parametric magnetic resonance imaging of de novo glioblastoma multiforme.

BACKGROUND: Glioblastoma (GBM) is a fatal, fast-growing, and aggressive brain tumor arising from glial cells or their progenitors. It is a primary malignancy with a poor prognosis. The current study aims at evaluating the neuroradiological parameters of de novo GBM by analyzing the brain multi-parametric magnetic resonance imaging (mpMRI) scans acquired from a publicly available database analysis of the scans. METHODS: The dataset used was the mpMRI scans for de novo glioblastoma (GBM) patients from the University of Pennsylvania Health System, called the UPENN-GBM dataset. This was a collection from The Cancer Imaging Archive (TCIA), a part of the National Cancer Institute. The MRIs were reviewed by a single diagnostic radiologist, and the tumor parameters were recorded, wherein all recorded data was corroborated with the clinical findings. RESULTS: The study included a total of 58 subjects who were predominantly male (male:female ratio of 1.07:1). The mean age with SD was 58.49 (11.39) years. Mean survival days with SD were 347 (416.21) days. The left parietal lobe was the most commonly found tumor location with 11 (18.96%) patients. The mean intensity for T1, T2, and FLAIR with SD was 1.45E + 02 (20.42), 1.11E + 02 (17.61), and 141.64 (30.67), respectively (p = < 0.001). The tumor dimensions of anteroposterior, transverse, and craniocaudal gave a z-score (significance level = 0.05) of - 2.53 (p = 0.01), - 3.89 (p < 0.001), and 1.53 (p = 0.12), respectively. CONCLUSION: The current study takes a third-party database and reduces physician bias from interfering with study findings. Further prospective and retrospective studies are needed to provide conclusive data.

ARF6 promotes Streptococcus suis suilysin induced apoptosis in HBMECs.

Streptococcus suis (S. suis) is a significant zoonotic microorganism that causes a severe illness in both pigs and humans and is characterized by severe meningitis and septicemia. Suilysin (SLY), which is secreted by S. suis, plays a crucial role as a virulence factor in the disease. To date, the interaction between SLY and host cells is not fully understood. In this study, we identified the interacting proteins between SLY and human brain microvascular endothelial cells (HBMECs) using the TurboID-mediated proximity labeling method. 251 unique proteins were identified in TurboID-SLY treated group, of which six plasma membrane proteins including ARF6, GRK6, EPB41L5, DSC1, TJP2, and PNN were identified. We found that the proteins capable of interacting with SLY are ARF6 and PNN. Subsequent investigations revealed that ARF6 substantially increased the invasive ability of S. suis in HBMECs. Furthermore, ARF6 promoted SLY-induced the activation of p38 MAPK signaling pathway in HBMECs. Moreover, ARF6 promoted the apoptosis in HBMECs through the activation of p38 MAPK signaling pathway induced by SLY. Finally, we confirmed that ARF6 could increase the virulence of SLY in C57BL/6 mice. These findings offer valuable insights that contribute to a deeper understanding of the pathogenic mechanism of SLY.

The Impact of Prevotella on Neurobiology in Aging: Deciphering Dendritic Cell Activity and Inflammatory Dynamics.

Prevotella species, notably Prevotella copri, significantly populate the human gut. In particular, P. copri is prevalent among non-Western populations with diets high in fiber. These species show complex relationships with diverse health aspects, associating with beneficial outcomes, including reduced visceral fat and improved glucose tolerance. Studies implicate various Prevotella species in specific diseases. Prevotella nigrescens and Porphyromonas gingivalis were linked to periodontal disease, promoting immune responses and influencing T helper type 17 (Th17) cells. Prevotella bivia was associated with bacterial vaginosis and a specific increase in activated cells in the vaginal mucosa. In contrast, they have shown substantial potential for inducing connective tissue degradation and alveolar bone resorption. Prevotella's role in neuroinflammatory disorders and autoinflammatory conditions such as Alzheimer's disease and Parkinson's disease has also been noted. The complex relationship between Prevotella and age-related conditions further extends to neurobiological changes in aging, with varying associations with Alzheimer's, Parkinson's, and other inflammatory conditions. Studies have also identified Prevotella to be implicated in cognitive decline in middle aged and the elderly. Future directions in this research area are anticipated to explore Prevotella-associated inflammatory mechanisms and therapeutic interventions. Investigating specific drug targets and immunomodulatory measures could lead to novel therapeutic strategies. Understanding how Prevotella-induced inflammation interacts with aging diseases would offer promising insights for treatments and interventions. This review urges ongoing research to discover therapeutic targets and mechanisms for moderating Prevotella-associated inflammation to further enhance our understanding and improve health outcomes.

Assessment of Bacterial Load and Post-Endodontic Pain after One-Visit Root Canal Treatment Using Two Types of Endodontic Access Openings: A Randomized Controlled Clinical Trial.

The need for controlling bacteria and pain during root canal therapy is undeniable. This clinical trial aimed to assess whether there is a difference in colony-forming unit (CFU) reduction after instrumentation and post-endodontic pain after root canal treatment (RCT) using a traditional endodontic cavity (TEC) versus a conservative endodontic cavity (CEC). This clinical study was conducted on 89 patients designated for a single-visit RCT. Patients were allocated randomly (TEC n = 45 and CEC n = 44). The access opening was gained accordingly in each group by a single operator. A pre-instrumentation sample of root canal dentin was collected using an endodontic file; the second sample was collected similarly, right after shaping and cleaning the root canal. The CFU was calculated based on the samples collected. The pain level was recorded preoperatively and at 1, 7, and 21 days postoperatively utilizing a visual analog scale (VAS). There were no statistically significant differences in the CFU reduction between the TEC and CEC groups (p > 0.05). Additionally, there were no statistically significant differences found in postoperative pain levels between the TEC and CEC at 1, 7, and 21 days (p > 0.05). Despite the limitations of this study, both the CEC and TEC demonstrate a decrease in bacteria within the root canals and alleviate postoperative pain with no difference between them.

Functional gastrointestinal disorders in Jordanian infants: a pilot study.

Introduction: Functional gastrointestinal disorders (FGIDs) encompass a wide spectrum of disorders that may be diagnosed using the Rome criteria. Aim: To identify the prevalence and risk factors for the development of FGIDs in Jordanian infants. Material and methods: We conducted a cross-sectional study to investigate the prevalence of FGIDs among infants and characterise any possible risk factors. Between 1 January 2020, and 30 December 2020, patients who presented to the paediatric follow-up clinic at King Abdullah University Hospital were recruited. Parents were interviewed and asked to complete an Arabic version of the Rome IV diagnostic questionnaire for pediatric gastrointestinal disorders for neonates and toddlers. Data regarding the parents' gastrointestinal symptoms and children's medical history were collected. Children's electronic medical files were also reviewed. Results: The study included 127 children, 78 (61%) were males. The median age was 40 days. According to the Rome IV criteria eighty-two (64%) of the infants fit the diagnosis for at least one disorder. The most prevalent disorder was functional constipation (n = 78, 95%) followed by infant dyschezia (n = 11, 13%). Compared to infants who did not meet the diagnostic criteria, herb intake and circumcision rates were significantly higher among those who did. Univariate analyses revealed that Infants with FGIDs were more likely to ingest herbs. Conclusions: FGIDs were common among young infants. Functional constipation was the most commonly diagnosed FGID. Infants with with FGIDs were more likely to intake herbs to ease the symtpoms.

Clinical Practice of High-Flow Nasal Cannula Therapy in ARDS Patients: A Cross-Sectional Survey of Respiratory Therapists.

Background: High-flow nasal cannula (HFNC) is an essential non-invasive oxygen therapy in acute respiratory distress syndrome (ARDS) patients. Despite its wide use, research assessing the knowledge, practice, and barriers to using HFNC among respiratory therapists (RT) is lacking. Methods: A cross-sectional questionnaire was conducted among RTs in Saudi Arabia between December 19, 2022, and July 15, 2023. Data were analyzed as means and standard deviation or frequency and percentages. A Chi-square test was used to compare the differences between groups. Results: A total of 1001 RTs completed the online survey. Two-thirds of the respondents 659 (65.8%) had received training in using HFNC and 785 (78.4%) had used HFNC in clinical settings. The top conditions for HFNC indication were COVID-19 (78%), post-extubation (65%), and do-not-intubate patients (64%). Participants strongly agreed that helping maintain conversation and eating abilities (32.95%) and improving shortness of breath (34.1%) were advantages of HFNC. Surprisingly, 568 (57%) of RT staff did not follow a protocol for HFNC with ARDS patients. When starting HFNC, 40.2% of the participants started with FiO2 of 61% to 80%. Additionally, high percentages of RT staff started with a flow rate between 30 L/minute and 40 L/minute (40.6%) and a temperature of 37°C (57.7%). When weaning ARDS patients, 482 (48.1%) recommended first reducing gas flow by 5-10 L/minute every two to four hours. Moreover, 549 (54.8%) believed that ARDS patients could be disconnected from HFNC if they achieved a flow rate of <20 L/minute and FiO2 of <35%. Lack of knowledge was the most common challenge concerning HFNC implementation. Conclusion: The findings revealed nuanced applications marked by significant endorsement in certain clinical scenarios and a lack of protocol adherence, underscoring the need for uniform, evidence-based guidelines and enhanced training for RTs. Addressing these challenges is pivotal to optimizing the benefits of HFNC across varied clinical contexts.

Mental health in genocide: Balancing between posttraumatic distress and growth among displaced Yazidi mothers.

Background. The Islamic State of Iraq and Syria (ISIS) committed genocide of the Yazidis in Sinjar 2014, resulting in dispersion and enslavement. Research shows severe mental health problems, such as posttraumatic stress disorder (PTSD) among survivors, but less is known about their resources and strengths, conceptualized as posttraumatic growth (PTG). Aims. are to examine the balance between symptoms and strengths among Yazidi women caring for their infants by identifying groups differing in PTSD and PTG, and analyze how demographic, obstetric, and infant-related factors associate with the groups. Method. Participants were 283 Yazidi mothers with their 1-18-month-old infants displaced in Kurdish Region of North Iraq. PTSD symptoms were measured by Harvard Trauma Questionnaire and PTG by the Posttraumatic Growth Inventory. Results. identified four groups: "Severe symptoms and low growth" (39%), "Low symptoms and moderate growth" (38%), "Moderate symptoms and very high growth" (13%), and "Moderate symptoms and low growth" (10%). Low education, economic difficulties and obstetric problems related to the "Severe symptoms and low growth" group, whereas newborn and infant health problems did not have an impact. Conclusion. Effective help for genocide survivors should both alleviate suffering and encourage resources through tools of recreating a sense of cultural security and pride.

Secondary Syphilis Presents as Palmoplantar Hyperpigmented Maculopapules: A Case Report.

Syphilis is a worldwide chronic systemic sexually transmitted infection caused by the spirochete bacterium Treponema pallidum. Here, we report a 28-year-old homosexual male who presented to the dermatology clinic with a six-month history of asymptomatic persistent skin lesions. A review of systems revealed unintentional weight loss of about 40 kg within one year. Skin examination revealed multiple scaly and non-scaly hyperpigmented macules and patches on the palms and soles. Hair, nail, and mucus membrane examinations were normal. There was no lymphadenopathy. A skin biopsy revealed psoriasiform acanthosis, lichenoid infiltrates with moderately dense mononuclear lymphohistiocytic cells, few plasma cells, and eosinophils. Laboratory investigations revealed positive rapid plasma reagin (RPR) with a titer of 1:128. Treponema pallidum hemagglutination test (TPHA) was positive. The HIV test by western blot was positive. Based on the above clinicopathological and laboratory findings, a diagnosis of secondary syphilis was made in this patient, who also tested positive for HIV. He was given a single dose of penicillin G benzathine (2.4 units) intramuscularly. He was also started on Dolutegravir 50 mg tablet once daily and Tenofovir alafenamide fumarate + Emtricitabine tablet once daily. Three months after penicillin G benzathine treatment, the RPR test turned negative, and the skin lesions disappeared.

HbA1c or fructosamine on evaluating glucose intolerance in children with beta- thalassemia.

BACKGROUND: Beta-thalassemia major (ß-TM) patients are more likely to experience blood glucose intolerance and to date; the blood markers that could evaluate this are debatable. So, this study aimed to assess the roles of glycated hemoglobin A1c (HbA1c) and fructosamine in evaluating glucose intolerance in children with ß-TM and figuring out role of insulin resistance in these patients. METHODS: One hundred children diagnosed with ß-TM and 100 age and sex-matched controls were enrolled. Fasting plasma glucose (FPG), 2-h post-prandial blood glucose (2-h PG), HbA1c, fructosamine, fasting insulin level (FINS), insulin resistance index (HOMA-IR), and insulin sensitivity index (HOMA-IS) were evaluated. RESULTS: FPG and 2-h PG revealed glucose intolerance in 51 patients (51%), 19 of them had diabetes mellitus. HbA1c, fructosamine, FINS, and HOMA-IR showed a high statistically significant increase in patients compared to controls, (P < 0.001). Results revealed fructosamine was more specific in detecting prediabetes state and more sensitive in identifying diabetes mellitus in our patients when compared to HbA1c. CONCLUSIONS: Despite controversies on HbA1c in children with ß-TM, it is still valuable in glucose intolerance detection. Fructosamine showed more sensitivity and specificity. Furthermore, insulin resistance was prevalent in children with ß-TM highlighting the necessity of regular glycemic state evaluation. IMPACT: Glucose intolerance is a common complication in beta thalassemia patients. Conflicting data was reported about the role of HbA1c and fructosamine in evaluating glucose intolerance in thalassemic patients. Fructosamine does not yet have a threshold that may be used to distinguish between patients who have diabetes mellitus and those who do not. Fructosamine was more specific in detecting blood glucose intolerance compared to HbA1c and was more sensitive for diagnosing diabetes mellitus. Insulin resistance was common in patients with beta-thalassemia and often present before the onset of overt diabetes.

Protoplast-mediated transformation of Madurella mycetomatis using hygromycin resistance as a selection marker.

Madurella mycetomatis is the main cause of mycetoma, a chronic granulomatous infection for which currently no adequate therapy is available. To improve therapy, more knowledge on a molecular level is required to understand how M. mycetomatis is able to cause this disease. However, the genetic toolbox for M. mycetomatis is limited. To date, no method is available to genetically modify M. mycetomatis. In this paper, a protoplast-mediated transformation protocol was successfully developed for this fungal species, using hygromycin as a selection marker. Furthermore, using this method, a cytoplasmic-GFP-expressing M. mycetomatis strain was created. The reported methodology will be invaluable to explore the pathogenicity of M. mycetomatis and to develop reporter strains which can be useful in drug discovery as well as in genetic studies.

Impacts of preoperative anxiety and depression on pain and range of motion after arthroscopic frozen shoulder release: a cohort study.

PURPOSE: We aimed to evaluate the impact of preoperative anxiety and depression levels on baseline and postoperative pain in patients who underwent arthroscopic frozen shoulder release. METHODS: The study included 59 patients with more than three months of idiopathic frozen shoulder. All patients had arthroscopic frozen shoulder release. Two patients were excluded from statistical analysis. Therefore, the statistical analysis was performed on the remaining 57 patients. The patients were divided into two groups according to HADS scores: group 1 which included 28 patients with a healthy psychological status (anxiety ≤ 7 and depression ≤ 7), and Group 2, which included 29 patients with psychological distress ( anxiety ≥ 8 or depression ≥ 8). RESULTS: The hallmark finding of this study is that patients complaining of frozen shoulder symptoms and having psychological distress (HADS ≥ 8) experienced higher pain scores preoperatively and at one-year follow-up after arthroscopic release. All patients showed significant improvement between the preoperative period and the one year follow-up regarding the abduction, forward flexion, external rotation at the side and the VAS pain score with a P value of 0.001. CONCLUSIONS: Arthroscopic frozen shoulder release significantly lowers the VAS pain score over the 12-month.

Cardiovascular risk reduction in older people with type 2 diabetes mellitus-a comprehensive narrative review.

Metabolic targets are controversial in older people with type 2 diabetes due to functional heterogeneity and morbidity burden. Tight blood pressure and metabolic control appears beneficial in fit individuals who are newly diagnosed with type 2 diabetes and have fewer comorbidities. The benefits of low blood pressure and tight metabolic control is attenuated with the development of comorbidities, especially frailty. Guidelines consider frail older people as one category and recommend relaxed targets. However, sarcopenic obese frail individuals may benefit from tight targets and intensification of therapy due to their unfavourable metabolic profile, accelerated diabetes trajectory and high cardiovascular risk. In addition, the early use of sodium glucose transporter-2 inhibitors and glucagon like peptide-1 receptor agonists may be beneficial in this frailty phenotype due to their cardio-renal protection, which is independent of glycaemic control, provided they are able to engage in resistance exercise training to avoid loss of muscle mass. In the anorexic malnourished frail individual, early use of insulin, due to its weight gain and anabolic properties, is appropriate. In this phenotype, targets should be relaxed with deintensification of therapy due to significant weight loss, decelerated diabetes trajectory and increased risk of medication side effects.

Enhanced intramolecular charge transfer and near-infrared fluorescence in 4-dimethylamino-chalcone analogues through extended conjugation: synthesis, photophysical properties, and theoretical modelling.

The distinctive characteristics of near-infrared fluorescent organic molecules render them indispensable across diverse applications, from energy harvesting to bioimaging and sensing technologies. In this work, we continue our investigation on the chalcone derivative, 4-dimethylamino-2'-hydroxychalcone (nDHC, n = 1; where n is the number of olefinic bonds), by expanding the number of central double bonds (n = 2 (2DHC) and n = 3 (3DHC)). Additionally, we also synthesized the structurally related chalcones lacking the OH group (DC, 2DC, 3DC) in order to obtain a comprehensive understanding of their effects on the intramolecular charge transfer (ICT). The results show remarkable bathochromic shifts in absorption and fluorescence peaks in solution as n increases. These shifts, 20 nm and 35 nm for absorption and 100 nm and 200 nm for fluorescence in 2DHC and 3DHC, respectively, signify enhanced ICT and a significant increase in the excited state's dipole moment. The presence of OH groups notably amplifies these shifts due to additional electron donation, influencing solute-solvent interactions in solution. Femtosecond fluorescence upconversion and transient absoprtion techniques unraveled distinct dynamics in these derivatives, exhibiting the dominance of vibrational cooling, solvation, and intramolecular motions, particularly in the larger conjugated systems 3DHC and 3DC. The observed changes in the femtosecond transinet absorption spectra suggest the existence of new active states in extended conjugation systems, indicating diverse intramolecular conformational states contributing to their relaxation dynamics. The results of this study provide invaluable insights into excited-state spectroscopy, offering a roadmap for tailoring chalcone derivatives for specific applications.

Synthesis of novel bioactive pyrido[2,3-d]pyrimidine derivatives with potent cytotoxicity through apoptosis as PIM-1 kinase inhibitors.

Direct synthesis and cytotoxicity activity of new series of pyrido[2,3-d]pyrimidine was described. Nicotinamide 2 was synthesized via cyclization of N-cyclohexyl derivative with cyanoacetamide. The o-aminonicotinonitrile 2 was subjected to acylation or thio acylation process followed by intramolecular heterocyclization to afford the desired pyrido[2,3-d]pyrimidine (3-10) and pyrido triazine 11. Compounds 4 and 11 exhibited remarkable cytotoxicity against MCF-7 cells with IC50 values of 0.57 µM and 1.31 µM and IC50 values of 1.13 µM and 0.99 µM against HepG2 cells. Interestingly, compounds 4 and 10 had potent PIM-1 kinase inhibition with IC50 values of 11.4 and 17.2 nM, respectively, with inhibition of 97.8% and 94.6% compared to staurosporine (IC50 = 16.7 nM, with 95.6% inhibition). Moreover, compound 4 significantly activated apoptosis in MCF-7 cells, increasing the cell apoptosis by 58.29-fold by having 36.14% total apoptosis in treated cells compared to 0.62% for control. Moreover, it arrested the cell cycle at the G1 phase. PIM-1 kinase inhibition was virtually elucidated by the molecular docking study, highlighting binding interactions of the lead compound 4 towards the PIM-1 protein. Accordingly, compound 4 was validated as a promising PIM-1 targeted chemotherapeutic agent to treat breast cancer.

Three-Dimensional Measurement of Obturation Quality of Bioceramic Materials in Filling Artificial Internal Root Resorption Cavities Using Different Obturation Techniques: (An In Vitro Comparative Study).

INTRODUCTION: Pathological conditions such as internal root resorption (IRR) may complicate root canal filling. This study aimed to evaluate and compare the obturation quality by measuring the percentage of obturation volume (POV) in root canals with artificial IRR obturated with different materials and techniques using cone beam computed tomography (CBCT). METHODS: Forty single canal extracted mandibular premolars were decoronated to standardize their length to 14mm. Following instrumentation, the roots were cut horizontally, and artificial IRR cavities were made at the level of 7mm from the apex. The root halves were joined using cyanoacrylate adhesive. The samples were randomly assigned to four groups (n = 10), and the canals were filled as follows: Single-cone technique (SC), bulk-fill Bio-C Sealer (BF), Bio-C Repair for the coronal and middle third (BCR) +cold lateral condensation technique (CLC) for the apical third and continuous wave compaction technique (CWC). The pre-and post-obturation volumes and the POV were measured in the total canal and for the apical, middle, and coronal thirds separately using CBCT and Mimics Medical software. The results were analyzed statistically using one-way ANOVA and Tukey HSD test, and statistical significance was set at p<0.05. RESULTS: BF group resulted in significantly lower total, coronal, middle and apical POV values compared to SC, BCR+ CLC, and CWC groups (p < 0.05), respectively. Also, at the apical third, the BCR+ CLC group showed significantly lower POV than the SC and CWC groups (P<0.05), respectively. The intra-group comparison showed that BF and BCR+ CLC groups had a significantly lower POV in the apical third compared to the middle third (p<0.05). Conversely, the CWC group had a significantly higher apical POV than the middle third (p<0.05). CONCLUSIONS: The maximum POV was obtained using the CWC technique, Bio-C Repair, and SC technique with Bio-C Sealer, making their application in IRR more preferable than the BF Bio-C Sealer.

Relationship Between Alexithymia, Smartphone Addiction, and Psychological Distress Among University Students: A Multi-country Study.

Objectives: Increasing dependence on smartphones results in the appearance of psychological problems, especially among young people. This study aims to determine the rates of alexithymia and its relationship with smartphone addiction and psychological distress in university students. Methods: A total of 2616 students (mean age = 22.5±3.5 years; 73.1% female) from universities in Egypt, Oman, and Pakistan were included in a cross-sectional and comparative study conducted through a web survey during the COVID-19 pandemic from October to December 2021. The following scales were used: Toronto Alexithymia Scale (TAS-20), Depression Anxiety Stress Scale (DASS-21), and Smartphone Addiction Scale-Short Version (SAS-SV). The survey also included questions related to sociodemographic and smartphone usage patterns.

Cellulose acetate nanofiber modified with polydopamine polymerized MOFs for efficient removal of noxious organic dyes.

The need to effectively remove toxic organic dyes from aquatic systems has become an increasingly critical issue in the recent years. In pursuit of this objective, polydopamine (PDA)-binary ZIF-8/UiO-66 (MOFs) was synthesized and incorporated into cellulose acetate (CA), producing ZIF-8/UiO-66/PDA@CA composite nanofibers under meticulously optimized conditions. The potential of fabricated nanofibers to remove cationic methylene blue (MB) dye was investigated. Various analysis tools including FTIR, XRD, SEM, zeta potential, BET, tensile strength testing, and XPS were employed. Results revealed a substantial leap in tensile strength, with ZIF-8/UiO-66/PDA@CA registering an impressive 2.8 MPa, as a marked improvement over the neat CA nanofibers (1.1 MPa). ZIF-8/UiO-66/PDA@CA nanofibers exhibit an outstanding adsorption capacity of 82 mg/g, notably outperforming the 22.4 mg/g capacity of neat CA nanofibers. In binary dye systems, these nanofibers exhibit a striking maximum adsorption capacity of 108 mg/g, establishing their eminence in addressing the complexities of wastewater treatment. Furthermore, the adsorption data fitted to the Langmuir isotherm, and the pseudo-second-order kinetic model. The fabricated nanofiber demonstrates good reproducibility and durability, consistently upholding its performance over five cycles. This suite of remarkable attributes collectively underscores its potential as a robust, durable, and highly promising solution for the effective and efficient removal of pernicious MB dye, in the context of both water quality improvement and environmental preservation.

Do dielectric bilayer metasurfaces behave as a stack of decoupled single-layer metasurfaces?

Flat optics or metasurfaces have opened new frontiers in wavefront shaping and its applications. Polarization optics is one prominent area which has greatly benefited from the shape-birefringence of metasurfaces. However, flat optics comprising a single layer of meta-atoms can only perform a subset of polarization transformations, constrained by a symmetric Jones matrix. This limitation can be tackled using metasurfaces composed of bilayer meta-atoms but exhausting all possible combinations of geometries to build a bilayer metasurface library is a very daunting task. Consequently, bilayer metasurfaces have been widely treated as a cascade (product) of two decoupled single-layer metasurfaces. Here, we test the validity of this assumption for dielectric metasurfaces by considering a metasurface made of titanium dioxide on fused silica substrate at a design wavelength of 532 nm. We explore regions in the design space where the coupling between the top and bottom layers can be neglected, i.e., producing a far-field response which approximates that of two decoupled single-layer metasurfaces. We complement this picture with the near-field analysis to explore the underlying physics in regions where both layers are strongly coupled. We also show the generality of our analysis by applying it to silicon metasurfaces at telecom wavelengths. Our unified approach allows the designer to efficiently build a multi-layer dielectric metasurface, either in transmission or reflection, by only running one full-wave simulation for a single-layer metasurface.