Engineered three-dimensional scaffolds modulating fate of breast cancer cells using stiffness and morphology related cell adhesion

Goal: Artificially engineering the tumor microenvironment in vitro as a vital tool for understanding the mechanism of tumor progression. In this study, we developed three-dimensional cell scaffold systems with different topographical features and mechanical properties but similar surface chemistry. The cell behavior was modulated by the topography and mechanical properties of the scaffold. Adenocarcinoma (MCF7), triple-negative (MDA-MB-231) and premalignant (MCF10AneoT) breast cancer cells were seeded on the scaffold systems. The cell viability, cell-cell interaction and cell-matrix interactions were analyzed. The preferential growth and alignment of specific population of cells were demonstrated. Among the different scaffolds, triple-negative breast cancer cells preferred honeycomb scaffolds while adenocarcinoma cells favored mesh scaffolds and premalignant cells preferred the aligned scaffolds. The 3D model system developed here can be used to support growth of only specific cell populations or for the growth of tumors. This model can be used for understanding the topographical and mechanical features affecting tumorigenesis, cancer cell growth and migration behavior of malignant and metastatic cancer cells

Differential Impact of Blood Pressure Control Targets on Epicardial Coronary Flow After Transcatheter Aortic Valve Replacement

Background: The cause for the association between increased cardiovascular mortality rates and lower blood pressure (BP) after aortic valve replacement (AVR) is unclear. This study aims to assess how the epicardial coronary flow (ECF) after AVR varies as BP levels are changed in the presence of a right coronary lesion. Methods: The hemodynamics of a 3D printed aortic root model with a SAPIEN 3 26 deployed were evaluated in an in vitro left heart simulator under a range of varying systolic blood pressure (SBP) and diastolic blood pressure (DBP). ECF and the flow ratio index were calculated. Flow index value 0.9 for SBP ≥130 mmHg. However, at an SBP of 120 mmHg, the flow ratio was 0.63 (p ≤ 0.0055). With decreasing DBP, no BP condition yielded a flow ratio index that was less than 0.91. Conclusions: Reducing BP to the current recommended levels assigned for the general population after AVR in the presence of coronary artery disease may require reconsideration of levels and treatment priority. Additional studies are needed to fully understand the changes in ECF dynamics after AVR in the presence and absence of coronary artery disease

Association of Bovine Arch Anatomy With Incident Stroke After Transcatheter Aortic Valve Replacement

BACKGROUND: Acute ischemic stroke complicates 2 % to 3 % of transcatheter aortic valve replacements (TAVRs). This study aimed to identify the aortic anatomic correlates in patients after TAVR stroke. METHODS AND RESULTS: This is a single-center, retrospective study of patients who underwent TAVR at the Mayo Clinic between 2012 and 2022. The aortic arch morphology was determined via a manual review of the pre-TAVR computed tomography images. An a priori approach was used to select the covariates for the following: (1) the logistic regression model assessing the association between a bovine arch and periprocedural stroke (defined as stroke within 7 days after TAVR) and (2) the Cox proportional hazards regression model assessing the association between a bovine arch and long-term stroke after TAVR. A total of 2775 patients were included (59.6 % men, 97.8 % White race, mean ± SD age, 79.3 ± 8.4 years), of whom 495 (17.8 %) had a bovine arch morphology. Fifty-seven patients (1.7 %) experienced a periprocedural stroke. The incidence of acute stroke was significantly higher among patients with a bovine arch compared with those with a nonbovine arch (3.6% versus 1.7%; =0.01). After adjustment, a bovine arch was independently associated with increased periprocedural strokes (adjusted odds ratio, 2.16 [95 % CI, 1.22-3.83]). At a median follow-up of 2.7 years, the overall incidence of post-TAVR stroke was 6.0 % and was significantly higher in patients with a bovine arch even after adjusting for potential confounders (10.5 % versus 5.0 % adjusted hazard ratio, 2.11 [95 % CI, 1.51-2.93], \u3c 0.001). CONCLUSIONS: A bovine arch anatomy is associated with a significantly higher risk of periprocedural and long-term stroke after TAVR

Local staging of rectal cancer: the current role of MRI

With the advent of powerful gradient coil systems and high-resolution surface coils, magnetic resonance imaging (MRI) has recently extended its role in the staging of rectal cancer. MRI is superior to endorectal ultrasound, the most widely used staging modality in patients with rectal tumors, in that it visualizes not only the intestinal wall but also the surrounding pelvic anatomy. The crucial advantage of MRI is not that it enables exact T-staging but precise evaluation of the topographic relationship of a tumor to the mesorectal fascia. This fascia is the most important anatomic landmark for the feasibility of total mesorectal excision, which has evolved into the standard operative procedure for the resection of cancer located in the middle or lower third of the rectum. MRI is currently the only imaging modality that is highly accurate in predicting whether or not it is likely that a tumor-free margin can be achieved and thus provides important information for planning of an effective therapeutic strategy, especially in patients with advanced rectal cancer

Access to pain treatment as a human right

<p>Abstract</p> <p>Background</p> <p>Almost five decades ago, governments around the world adopted the 1961 Single Convention on Narcotic Drugs which, in addition to addressing the control of illicit narcotics, obligated countries to work towards universal access to the narcotic drugs necessary to alleviate pain and suffering. Yet, despite the existence of inexpensive and effective pain relief medicines, tens of millions of people around the world continue to suffer from moderate to severe pain each year without treatment.</p> <p>Discussion</p> <p>Significant barriers to effective pain treatment include: the failure of many governments to put in place functioning drug supply systems; the failure to enact policies on pain treatment and palliative care; poor training of healthcare workers; the existence of unnecessarily restrictive drug control regulations and practices; fear among healthcare workers of legal sanctions for legitimate medical practice; and the inflated cost of pain treatment. These barriers can be understood not only as a failure to provide essential medicines and relieve suffering but also as human rights abuses.</p> <p>Summary</p> <p>According to international human rights law, countries have to provide pain treatment medications as part of their core obligations under the right to health; failure to take reasonable steps to ensure that people who suffer pain have access to adequate pain treatment may result in the violation of the obligation to protect against cruel, inhuman and degrading treatment.</p

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

Topographical ues overlaid with fructose-like molecules to assess breast cancer recruitment in nanofiber scaffolds

Tumorigenesis is a complex process involving numerous cellular signaling cascades and environmental factors. While 2D cultures for stiffness measurements and more recently 3D cultures to demonstrate differences in cell structures have been reported, very little is known about the impact of sugars in cell recruitment. In this study, we report the fabrication of 3D-scaffolds with different morphologies obtained by electrospinning with fluorescent fructose-like molecular probes to study cancer cell proliferation and migration. Using a FDA approved, biocompatible and biodegradable polymer Polycaprolactone (PCL), we electrospun nanofiber scaffolds having random, aligned, and honeycomb morphologies. Scaffolds with similar morphology without the fructose mimicking analogs were fabricated and used as controls. The degradation rate of the scaffolds was also characterized to ensure long-term availability of probes and mechanical stability of PCL. Cell viability, cell morphology, formation of colonies with changes in morphology were investigated. The changes in biophysical properties of tumor microenvironment with change in morphology of the scaffolds were investigated. In vitro tests for proliferation, alignment and migration of normal breast epithelial cells (184B5), adenocarcinoma (MCF-7), pre-malignant (MCF10AneoT) and triple-negative (MDAMB231 on the scaffolds on days 1, 2, and 3 were carried out. The morphology of the scaffolds was characterized using FE-SEM; cell proliferation was assessed using CellTiter-Blue® Viability Assay; migration and cell-scaffold interactions were investigated using phalloidin for F-Actin and fructose response was determined by immunostaining for facilitative fructose transporter GLUT-5. Our data indicates that while topographical features affected cell adhesion and proliferation, cell lines that responded to the fructose-like probes tended to be more invasive. Furthermore, the preference to a specific scaffold was greatly altered by the presence of the probes with MDAMB231 showing least preference after 72 hours and pre-malignant AneoT showing highest preference. However, there was no significant difference in the cell numbers between scaffolds with probes and those without for the pre-malignant cells while this difference was noticeable in the control cell lines. Further investigation into specific response to glucose and fructose uptake through their major transporters GLUT2 and GLUT5 are currently ongoing

Flow dynamics in the sinus and downstream of third and fourth generation balloon expandable transcatheter aortic valves

Objective: The early success of transcatheter aortic valve (TAV) replacement (TAVR) has fueled further innovations in the field leading to the emergence multiple iterations of TAV designs. Whether these newer designs are associated with similar hemodynamic outcomes remains unknown. Recently, the SAPIEN 3 Ultra valve received FDA approval for use in patients with published clinical outcomes. The aim of this study is (1) to evaluate and compare the flow dynamics downstream of the SAPIEN 3 Ultra and a SAPIEN 3 (2) and to evaluate and compare the resulting sinus hemodynamics and washout characteristics for a complete hemodynamic characterization. Methods: The hemodynamic assessment was performed in a pulse duplicating system and particle image velocimetry was used to assess the flow dynamics. Pressure gradient (ΔP), effective orifice area (EOA), leakage fraction (LF), velocity in the flow downstream and the sinus, viscous shear stress (VSS) downstream and adjacent to the leaflet in the sinus, and sinus washout were calculated. Results: EOA for the SAPIEN 3 Ultra was 1.81 ± 0.05 cm2 and 1.86 ± 0.05 cm2 with the SAPIEN 3, ΔP with the SAPIEN 3 Ultra was 10.56 ± 0.62 mmHg and 14.73 ± 0.79 mmHg with the SAPIEN 3, and LF with the SAPIEN 3 Ultra was 10.4 ± 0.5% and 9.7 ± 0.4% with the SAPIEN 3 (p \u3c 0.05). The instantaneous VSS for both valves ≤ 15 Pa, which is not sufficient to induce hemolysis, but may lead to platelet activation. RSS — an indicator of blood damage — exceeded 100 Pa at peak systole with both TAVs. The sinus velocity at peak systole was 0.24 ± 0.08 m/s with the SAPIEN 3 Ultra and 0.22 ± 0.10 m/s with the SAPIEN 3. VSS range reached 3.9 Pa with the SAPIEN 3 Ultra and 4.0 Pa with the SAPIEN 3. Complete sinus washout was achieved in ∼1.5 and ∼2.4 cardiac cycles for the SAPIEN 3 Ultra and SAPIEN 3, respectively. Conclusion: Compared to its predecessor, the hemodynamic performance and sinus hemodynamics of SAPIEN 3 Ultra are comparable

Impact of calcific aortic valve disease on valve mechanics

The aortic valve is a highly dynamic structure characterized by a transvalvular flow that is unsteady, pulsatile, and characterized by episodes of forward and reverse flow patterns. Calcific aortic valve disease (CAVD) resulting in compromised valve function and increased pressure overload on the ventricle potentially leading to heart failure if untreated, is the most predominant valve disease. CAVD is a multi-factorial disease involving molecular, tissue and mechanical interactions. In this review, we aim at recapitulating the biomechanical loads on the aortic valve, summarizing the current and most recent research in the field in vitro, in-silico, and in vivo, and offering a clinical perspective on current strategies adopted to mitigate or approach CAVD