bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential of Hyperspectral Imaging for Label‐free Tissue and Pathology Classification
Authors: Deal Joshua Andrew , Favreau Peter , Weber David , Rich Tom , Leavesley Silas
Published: November 2023

The ultimate goal of this project is to develop a novel imaging system that allows classification of both normal and pathogenic tissues based on fluorescence excitation spectra. Current imaging diagnostic techniques have limited capacity to classify normal tissue or detect pathogenic states. In vivo imaging suffers from poor signal to noise ratios and excessive data acquisition times while most alternative imaging techniques offer little molecular specificity. Our previous research has shown that excitation scanning hyperspectral imaging produces image data with high signal to noise ratios, fast acquisition times, and the potential to determine molecular composition. Here, we present data comparing characteristic spectral signatures for a range of tissue types. These data serve as a basis for establishing normal tissue spectra and characterizing molecular composition per tissue type. Tissues from Sprague Dawley rats were collected as 2 cm cubes and stored in cold PBS. Immediately following harvest, a custom inverted microscope (TE‐2000, Nikon Instruments) with a Xe arc lamp and an array of thin film tunable filters (VersaChrone, Semrock, Inc.) were used to collect hyperspectral image data from each sample. Scans utilized excitation wavelengths from 360nm to 600nm in 5nm increments. Three fields of view were recorded for each sample. Hyperspectral images were analyzed with custom Matlab scripts including linear spectral unmixing (LSU), principal component analysis (PCA), and Gaussian mixture modeling (GMM). Spectra were examined for potential characteristic features such as unique intensity peaks at specific wavelengths or ratios between intensity peaks. The resultant spectra vary among tissues types, which alludes to a unique spectral signature per tissue type. Additionally, excitation spectra appear to be a mixture of pure endmembers with commonalities in multiple tissue types, potentially identifiable through GMM. These results suggest that most tissues have common molecules and that intensity ratios of these molecules may serve as a signature for characterizing tissue composition. In addition, variations in signatures could indicate a change in molecular composition coincident with changes in pathology. Thus, excitation scanning hyperspectral imaging may be a potential diagnostic tool with the ability to distinguish tissues of varying pathology.

Support or Funding Information

This work is supported by P01HL066299 and the Abraham Mitchell Cancer Research Fund.
EXPEL: A Novel Non‐Destructive Method for Mining Soluble Tumor Biomarkers
Authors: Turtoi Andrei , Costanza Brunella , Peulen Olivier , Bellahcène Akeila , De Pauw Edwin , Detry Olivier , Delvenne Philippe , Castronovo Vincent
Published: November 2023

The search for biomarkers able to detect and evaluate disease such as cancer at an early stage, or to predict resistance and response to therapies, has been and remains a major challenge. Despite very important progresses in all fields of omics technologies, the success of discovery of clinically valuable biomarkers is surprisingly disappointing. Difficult mining of secreted proteins in biological fluids poses the first major hurdle, mainly because the concentration of interesting proteins in serum or urine is generally very low. The second key limitation in the field is the inaccessibility of tissue specimens from early lesions. Those are routinely required in their integrity for the complete histological evaluation in the clinical routine, leaving no residual material for research (e.g. colonic polyps). Here we present an innovative procedure that we have named EXPEL, which entirely overcomes these limitations. It makes any tissue, regardless of its size, available for both omics research and histological investigation. Our original device and approach extracts soluble tumor biomarkers and small metabolites within few minutes and without altering the tissue morphology. For this purpose a small tissue biopsy is incubated in a slightly hypertonic extraction buffer while subjected to alternating pressure. Upon extraction the tissue is fixed in formalin and can be used for histological analysis. The soluble extract is further prepared for proteomic and metabolomic analysis. In a proof of concept study we have extracted and analyzed soluble biomarkers from human colorectal carcinoma liver metastases (N=10) as well as primary colorectal tumors (N=10). Immunohistochemistry (IHC)‐based validation demonstrates that EXPEL procedure does not alter tissue morphology or any subsequent molecular and pathological tests. The comparison of proteins and metabolites identified in tumor lesions with those found in adjacent normal tissues revealed a promising group of novel and differentially expressed targets. Their potential usefulness as diagnostic or predictive markers is currently being explored in larger cohort of patients using IHC on tissue and ELISA on blood samples.

Support or Funding Information

The present work has been supported by FNRS Televie grant and funding from Mithra Pharma Co.
Single‐cell biomarker detection identifies heterogeneity within cancer populations
Authors: Weldon Don , Williams Yuko , Patel Amish
Published: November 2023

Understanding a complex biological system such as a cancerous tumor is already a difficult endeavor. Further, this complexity is compounded given the multiple cell subpopulations found in cancer tissue (e.g., cancer stem cells), broadly described as tumor heterogeneity. The significance of tumor heterogeneity is best understood when examined at the cellular level, where distinct differences in gene expression, signaling pathways, nutrient requirements can contribute to a diverse and dynamic microenvironment, which has already been implicated as a key factor in chemotherapy resistance. With so many distinct factors at play performing bulk measurements on a subset of cells will limit the ability to understand key differences which exist at the single cell level.

Traditional methods tend to measure RNA expression globally, with cell lysis and fixation steps resulting in a loss of key information about individual cells, making it challenging to properly assay the genetic heterogeneity within cell populations. Analyzing the relationships between gene expression and biological processes involved in the development and progression of cancer requires analysis at single cell resolution. We have developed a single cell biomarker tool for sequence‐specific detection of gene expression in live cells without altering viability or inherent biology. In addition to detection of cellular heterogeneity within researchers’ samples, the live single cell compatibility enables enrichment and further characterization of cell subpopulations based on RNA expression through Fluorescent Activated Cell Sorting (FACS).

Here, we describe live single cell detection of cancer biomarkers within heterogeneous cell models. Breast cancer cell lines were co‐cultured in specific ratios to mimic heterogeneous breast cancer populations. Subsequent characterization of the populations was performed by both flow cytometry using fluorescent live‐cell RNA detection probes, and quantitative real‐time PCR. Additionally, we analyzed miR‐221 expression in a mixture of T47D and MDA‐MB‐231 breast cancer cell lines, which allowed us to sort the two cell types based on differential expression of this microRNA. Subsequently after culturing the sorted cells we were able to perform downstream IHC analysis of vimentin and E‐cadherin, two protein markers known to be associated with the epithelial‐to‐mesenchymal transition during tumor progression.

Single cell analysis of populations with varied gene expression allows a better understanding of the inherent differences that exist within the population. The ability to identify differences in gene expression within live cells allows scientists to formulate novel questions and design experiments that better address the importance of gene expression heterogeneity in normal and disease states. This is particularly true in cancer where alterations in gene expression within specific cell subpopulations can play a role in resistance to standard drug therapies.
Exploring Molecular and Morphological Relationships between Obesity and CtBP in Breast Cancer
Authors: Park Sam Sangil , Yi Dae Ik , Li Daniel , Crawford Lindsey , Liang Genqing , Kabbout Mohamed , Hernandez Roberto , Yan Tingfen , Ambs Stefan , Byun Jung S. , Gardner Kevin
Published: November 2023

In the United States, 69% of adults are overweight or obese. This epidemic is associated with grave consequences, including increased breast cancer morbidity and mortality. One possible mechanism accounting for this elevated risk is adipocyte hypertrophy, which induces hormonal and immune dysregulations that may contribute to abnormal growth of surrounding epithelial cells. In addition, several metabolic intermediates associated with high carbohydrate food intake may influence cellular gene expression. One of these intermediates is NADH, which is elevated under conditions of obesity, diabetes, and metabolic syndrome. NADH stabilizes and activates C‐terminal binding protein (CtBP), a nuclear protein that plays a substantial epigenetic role in modifying gene expression. In particular, CtBP drives Epithelial‐Mesenchymal Transition, genome instability, and stem cell like pathways to induce tumor invasion and metastasis. In this study, we explore a link between obesity and CtBP by examining cohorts of breast cancer patient samples and in vitro assays. Using digital analysis of histological sections and immunohistochemistry, we correlate patient median adipocyte cross‐sectional area and BMI, along with gene and protein expressions of CtBP and its regulatory targets. These characteristics are then assessed in combination with patient parameters including age, race/ethnicity, and hormone receptor status. Furthermore, we perform functional in vitro assays by manipulating the levels of CtBP and glucose in human breast mammary cell lines. The goal of this study is to begin to understand how aspects of lifestyle and personal traits interact with the molecular pathways of CtBP to influence breast cancer incidence and mortality.
Regulation of p65‐β‐catenin Complex And Its Targets in Liver Injury And Regeneration
Authors: Nejak‐Bowen Kari , Cornuet Pamela K , Monga Satdarshan P
Published: November 2023

We have previously reported the identification of a complex between β‐catenin and the p65 subunit of NF‐κB. Further, we have shown that β‐catenin sequesters p65 in the cytosol to prevent it from translocating to the nucleus, and that lack of p65‐β‐catenin complex in liver‐specific β‐catenin knockout (KO1) mice enhances survival due to enhanced p65 nuclear translocation and activation. To determine the signaling pathways regulating this complex during acute liver injury, we injected galactosamine (GalN) followed by lipopolysaccharide (LPS), which activates the TNF‐α pathway, into liver‐specific LRP5‐6 double KO mice (KO2) and wild‐type littermate controls (WT). Unlike KO1, KO2 phenocopy WT and show comparable morbidity, apoptosis, liver weight to body weight ratio, and alanine aminotransferase (ALT) levels. This is due to existence of the β‐catenin‐p65 complex in KO2 as opposed to its absence in KO1. These observations also suggest that the β‐catenin‐p65 association is autonomous of Wnt signaling since lack of LRP5‐6 in hepatocytes prevents Wnt communication to β‐catenin. Treatment of Hep3B hepatoma cells with TNF‐α, or of WT mice with GalN/LPS, induced dissociation of the β‐catenin‐p65 complex, implicating TNF‐α signaling in the regulation of this association. Since cyclin D1 is a target of both NF‐κB and β‐catenin, we next examined the role of the p65‐β‐catenin complex in hepatocyte proliferation. In hepatoma cells, TNF‐α induced p65 reporter activity; however, it had no effect on either TOPflash or cyclin D1 reporter. Further, while β‐catenin suppression decreased both cyclin D1 reporter activity and cell proliferation, these functions were unchanged in the presence of p65 siRNA. We then characterized the association and expression of NF‐κB and β‐catenin during liver regeneration and demonstrated translocation of these two proteins in the nucleus within hours after partial hepatectomy, which preceded a 2.5‐fold increase in cyclin‐D1 mRNA. However, using inducible NF‐κB lacZ reporter mice, we found p65 activity to be confined exclusively to the NPC compartment during liver regeneration. Thus we conclude that hepatocyte proliferation is independent of p65 but requires β‐catenin, and that p65 and β‐catenin activation are occurring in disparate cell types during early liver regeneration. The distinct roles of β‐catenin and p65 in proliferation and survival, respectively, offer opportunities for manipulation of this complex to optimize regenerative therapies.

Support or Funding Information

This study was funded by NIH grants 1R01DK62277 to SPSM and by the American Liver Foundation's Thomas E. Starzl, MD Postdoctoral Research Fellowship to KNB.
Synonymous Codon Changes in Measles (HMV) and Canine Distemper (CDV) Viral Nucleic Acid Sequences Result in Gene‐Specific Changes in Levels of Viral Protein Expression
Authors: Uhl Elizabeth W , Osborn Michelle L , Michel Frank J , Hogan Robert J
Published: November 2023

The purpose of this study was to characterize the effects of human and canine codon optimization on expression of viral proteins from HMV and CDV nucleic acid sequences. All the codon changes made were synonymous in that the amino acid coded for was unchanged. The human and canine CUB optimized HMV and CDV sequences had increased nucleic acid and codon identity as compared to the WT sequences. Protein expression from human and canine CUB optimized and sub‐optimized constructs of the N, F, M, H and P/C proteins was assessed in transfected human (293 HEK) and canine (A‐72) cells using fluorescence, Cellomic and, for proteins for which antibodies were available, western analysis.

Results

1) codon optimization increased protein expression of HMV and CDV N and F proteins in both cell lines; 2) synonymous codon changes did not affect expression of the HMV and CDV P and C and the HMV M proteins, but both optimization and sub‐optimization to canine CUB increased expression of the CDV M protein in human cells; 3) synonymous codon changes increased expression of the HMV H protein in both cell lines, but did not significantly affect CDV H protein expression. Overall both CUB optimization and sub‐optimization affected protein expression independent of viral infection in ways that varied with the gene and cell type, and differed between HMV and CDV. These results indicate that synonymous codon changes in viral nucleic acid sequences can alter protein expression in a variety of ways, some of which are likely to impact viral pathogenicity.

Support or Funding Information

This project was sponsored by the Department of Defense Threat Reduction Agency. The content of the information does not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred.
Brainstem pathology induces peripheral changes correlating with hippocampal markers of Alzheimer's disease in animal model
Authors: Filipcik Peter , Cente Martin , Zorad Stefan , Fecik Miroslav , Novak Michal
Published: November 2023

Alzheimer's disease (AD) and related tauopathies are difficult to diagnose in early phase and their diseases modifying treatment is still missing. Epidemiological studies indicate relationships between AD and level of leptin in blood. However, the mechanistic link behind this association is not yet defined. Here, we investigated the link between selected metabolic parameters including leptin and pathogenic markers of neurodegeneration in a transgenic rat model of AD.

Brains of transgenic rats expressing human truncated tau protein, whose primary sequence was designed according to AD‐core tau protein, were analysed in pre‐symptomatic and terminal phase of disease. The data were correlated with biochemical parameters such as glucose, insulin and lipids in plasma. We found that development of AD pathology leads to reduction of body weight accompanied with significant decrease in level of plasma leptin in transgenic animal model of sporadic AD. The plasma leptin inversely and significantly correlates with amount of hippocampal tau proteins hyperphosphorylated on several AD‐specific epitopes. Moreover, the strong inverse correlation between the load of neurofibrillary pathology and peripheral levels of leptin was observed.

We provide a molecular evidence and experimental confirmation for association of circulating leptin and early stage of neurofibrillary degeneration in hippocampus, thus leptin could serve as a convenient peripheral biomarker, which can help to recognize an early phase of neurodegeneration.

This study was supported by research grants:

Slovak research and development agency APVV‐0677‐12 and VEGA 2/0147/16
Utilizing Interdisciplinary Research Experiences and Learning Communities To Engage Students in the Natural Sciences and Mathematics
Authors: Kruchten Anne
Published: November 2023

Faculty in the biology, chemistry, math, and physics departments at Linfield College have developed an interdisciplinary STEM community through an annual iFOCUS camp for incoming students and student‐led learning communities. In August 2012, iFOCUS (Interdisciplinary First‐Year Orientation Camp for Undergraduate Sciences) engaged ten new Linfield students in collaborative research projects with Linfield faculty for a week before classes began in the fall. Primary goals for this pilot program included increasing the recruiting and retention of STEM majors, developing interdisciplinary problem solving skills through modeling and practice, and enhancing the intellectual opportunities for STEM faculty. In the fall of 2013, the first learning community was led by students interested in the field of genomics. We now report on the successes of four years of iFOCUS camp and three years of learning communities, including an increase of iFOCUS students registering for multiple STEM courses and an increase in the involvement of first year students in our research programs. We will also discuss plans for the future development of interdisciplinary science at Linfield.

Support or Funding Information

Funding for this program was provided by the Hearst Foundations, Inc., and the Rose E Tucker Charitable Trust.
Geometry in Cell Biology
Authors: Lin Danielle , West Lori
Published: November 2023

A goal of our research is to demonstrate to students the integration of geometry in biology. In order to do so, we developed an activity where elementary students can apply mathematical concepts in their biology laboratory sessions. In these activities, students first view cells using a compound light microscope. The cells are onion root tip mitosis cells. Then, using Geometer's SketchPad, they survey parallel and perpendicular lines as well as angles. In another activity, they consider a single cell and consider whether the cell is symmetrical. We demonstrated these activities to 4th and 5th grade elementary teachers. The teachers’ response was very positive. Although this experiment was developed with elementary teachers in mind, we feel that extensions of this exercise would be well suited in secondary and higher education.

Support or Funding Information

These activities were funded by the Tennessee Higher Education Commission Improving Teacher Quality program.
A PhUn week Incursion in Australia Teaches 3–4 and 5–6 Graders Exercise Physiology
Authors: Halpin Patricia A.
Published: November 2023

PhUn Week is an annual science outreach program in which K‐12 students learn about physiology through meeting a physiologist and performing an experiment. By performing PhUn week in Australia the previous year I was able to demonstrate this was a project worth funding and received a Summer Graduate School Fellowship to return. In Australia, primary schools grades 3 and 4 are combined in one class (3–4), as is grades 5 and 6 (5–6). To set up the outreach I made direct contact via email with the Assistant Principal. She connected me with the physical education (PE) teacher. Together, the PE teacher and I planned the event. Over the course of two days, I taught four classes of 3–4 graders, and four classes of 5–6 graders for a total of 177 students. All classes were held in the gymnasium and on the playground track. I started each lesson with asking “Does anyone know what a physiologist is”? The most common answer was “A Physiotherapist” which is called a physical therapist in the US. The Scientific Method was described and explained. A hypothesis was designed, “Exercise Increases Heart Rate”‐ and a testing method in which students would measure their heart rates, run for two laps, and measure their heart rates again. After data collection, students were urged to report their data using the format “My resting heart rate was # beats per minute and my post exercise heart rate was # beats per minute”. The students all agreed they had proved their hypothesis. We discussed heart function and explained why heart rate increases with exercise. Students then were given pedometers and calibrated them by walking 20 paces. The students performed their next experiment by estimating how many steps it would take to walk around the track. After completing the walk they then made predictions of the number of steps running around the track would be higher or lower. They performed this experiment successfully and understood why fewer steps were needed when running due to a longer stride. PhUn Week forms beneficial partnerships among educators and inspires K‐12 students to think about becoming scientists. I recommend that all physiologists participate in PhUn week both locally and while traveling outside the U.S.
Comparison of High Fidelity Patient Simulation on the Retention of Physiology Concepts Over Summer Break
Authors: Jones Adriana , Harris David
Published: November 2023

It is well known that medical students experience significant knowledge loss over long breaks such as summer. Likewise, active learning methods, where students are involved in doing things and thinking about things, have been shown to improve retention of material versus passive learning. Therefore, high fidelity patient simulations (HFPS) which are an engaging, active learning activity, may promote better long term retention of physiology covered. The purpose of this study is to determine if medical students’ long‐term retention of physiology concepts is enhanced through the use of HFPS.

Methods

Questions from the midterm of the physiology module were selected from topics covered by HFPS or other methods (lecture or computer based instruction) with similar averages and difficulties. 2nd year medical students were recruited to take a formative set of different questions comparing physiology topics covered in HFPS vs other teaching methods about 6 months later. Student scores from the formative questions were compared with performance on the midterm to determine knowledge loss.

Results

Forty of about 120 students participated in the formative test in Year 2 six months later.

Discussion

Developing ways to prevent knowledge loss and facilitate retention of material in students should become part of a “best practices” approach for faculty. Active learning methods such as HFPS may be an avenue to facilitate better and more efficient learning of physiology material.
Quantitative and Qualitative Analysis of Medical Students’ Research Output in Six Developing Countries
Authors: Obad Adam S. , Albarqawi Haneen T. , Eshaq Abdulaziz M. , Hoilat Hudie N. , Al‐Khateeb Abdulrahman A. , Fothan Ahmed M. , AlSaffar Alaa H. , Al‐Najjar Wedad M. , Bakather Abdulrahman M. , Shareef Mohammad A. , Khan Tehreem A. , AlAmodi Abdulhadi A.
Published: November 2023

Background

Publishing in peer‐review journals is among the useful outcomes resulting from participating in medical research. In particular, medical students perceive it as important aspect of improving employment chances and associated with long term academic career success. There is lack in studies with objective measure assessing the medical students’ research output in developing countries. This study aims to investigate the quantity and quality of medical students’ research output in the Gulf Cooperation Council countries (GCC).

Methods

abstracts presented by medical students in the medical students GCC conference were subject to analysis. Abstracts which propagated into full‐length articles were subject to further demographic analysis in which information in regard to type of study, field of study, country of origin, mode of presentation and journal's impact factor were collected.

Results

798 abstracts were studies, and 19% (n=155) were found to be published for all the GCC countries with average impact factor of 1.85 ± 0.26 (SE). Countries which recorded the highest conversion rats in descending order were Saudi Arabia, United Arab of Emirates, Oman, Bahrain and Kuwait. Moreover, basic biomedical and clinical research topics were to be likely more publishable than community oriented and medical education related topics.

Conclusion

effective efforts should be promoted to encourage more medical students” research output in the GCC countries with focusing on qualitative aspects too to reach the numbers reported by developed countries.
Can Visual Memory Devices Aid Retention and Short‐term Recall of Pre‐clinical Science Knowledge?
Authors: Hawkins Anthony Louis
Published: November 2023

Visual mnemonics, such as the Loci method, have been shown to be effective in learning new information and later recalling it. Retention and recall is critical for medical students, and atrophy of knowledge over time following examinations is an established problem in medical education. This study attempted to determine if visual mnemonics are an effective means of learning complex concepts, such as pre‐clinical medical science curriculum. This randomized controlled trial was designed as a pre‐test, learning phase, and post‐test, followed by a one week delayed post‐test 2. The learning phase was two hours long, during which participants studied information from four Picmonic© visual mnemonics covering gastrointestinal pathology. Thirty‐two participants were assigned to one of four groups. A text group received only a paragraph summarizing the topics, and was instructed to use traditional study techniques (e.g., outlining). An image group used the Picmonic© image and summary text, and the Loci group studied the Picmonic© image and text using the Loci method. A control group took all three tests without going through the learning phase in order to measure the equivalency of the exams. Results show a significant increase in mean correct answers for all three interventions from pre‐test to post‐test 1 [Text: t(6)=9.260, p<0.001; Image: t(8)=12.336, p<0.001; Loci: t(8)=6.615, p<0.001], as well as a decrease from post‐test 1 to post‐test 2 [Text: t(6)=4.399, p=0.005; Image: t(8)=4.608, p=0.002; Loci: t(8)=4.667, p=0.002]. ANOVA found no significant difference between the three interventions on both post‐test 1 and post‐test 2 [Post‐test 1: F(2,21)=0.176, p=0.840; Post‐test 2: F(2, 21)=0.866, p=0.435]. This indicates that visual mnemonics are as effective in learning, retaining and recalling complex pre‐clinical medical science concepts as traditional study techniques.
Humanizing Science and Engineering to Reduce Health Care Delivery Inequalities
Authors: Cabrales Pedro , Jani Vivek
Published: November 2023

We have developed an experiential learning program that integrates modern non‐invasive medical sensors with basic physiological principles, and modern medical practices in order to introduce the importance of understanding our own human physiology and its relationship to enriching human life and society. This experimental, multi‐disciplinary, experiential learning program introduces physiology to undergraduate students in science, technology, engineering, and math (STEM). The program allows students to learn physiology by applying science and engineering within the context of their bodily functions. This personalized program to learn physiology utilizes an engineering approach via dynamic models and modern sensors. Additionally, the experiential learning program integrates the social problems that influence modern healthcare, giving students a broader approach to not only basic physiological principles that affect health, life at extreme environments, and how modern medicine influences society. This program includes an outreach component targeted to high school students of the greater San Diego area, with the objetive of increase interest in physiology and STEM fields. Understanding physiological principles also allows students to learn the importance of both healthy living and healthcare, and their implications on both human life and society.

Support or Funding Information

UCSD Frontiers of Innovation Scholars Program (FISP) Program
Successful Inquiry Based Activities in High School Physiology
Authors: Anjur Sowmya
Published: November 2023

Physiology and Disease students at the Illinois Mathematics and Science Academy in Aurora employ inquiry driven activities to improve their understanding and articulation of the discipline. Students make heart models to understand structure function relationships within the cardiovascular system. This model building is supplemented with correlation to lab activities such as measurement of heart rate, lung capacity and blood pressure. Student scores on the heart unit assessment were evaluated using a combination of their lab reflections, heart models and also individual heart reflections where students explained the principles of biophysics involved in the pumping of the heart. Students also correlated their body measurements with changed heart physiology. Students seemed to gain a better understanding of the cardiovascular unit when they performed everyday activities and this allowed them to reflect better on cardiovascular physiology, as reflected in their heart unit assessment scores.
Double Superior Vena Cava: A Case Report
Authors: Rosenthal Oana , Lobo Stany , Sandhaus Henya , Kopelman Hannah , Zarkar Satin , Menezes Ritesh
Published: November 2023

During routine dissection, a double superior vena cava, which is commonly known as persistent left superior vena cava (PLSVC) was observed in a 75‐ year‐old female cadaver. PLSVC drained into the right atrium through the coronary sinus. Coronary sinus was abnormally dilated to accommodate the large volume of venous blood reaching it through the PLSVC. Three sets of veins; common cardinal, anterior cardinal and posterior cardinal veins are involved in the normal development of the vena cavae. Embryological basis of PLSVC and its clinical significance in heart diseases will be discussed.
An Explanatory Computational Simulation of Contiguous Capillary Occlusion in Diabetic Retinopathy based on Patient‐derived Vasculature
Authors: Fu Xiao , Gens John Scott , Glazier James A. , Burns Stephen , Gast Thomas J.
Published: November 2023

Early stages of diabetic retinopathy often feature contiguous areas of capillary occlusion in both perifoveal and peripheral areas. While leukocyte‐endothelium interactions appear to cause individual capillary occlusions, the underlying mechanisms by which multiple occlusions create large ischemic areas are not clear. To explain the observed pattern of contiguous capillary blockage seen in diabetics using fluorescein angiography, we developed a computational simulation based on a hypoxia‐driven vascular endothelial growth factor (VEGF)‐mediated adverse feedback mechanism. We constructed an in silico network of retinal capillaries in the perifovea (with an architecture derived from an actual human perifoveal arteriovenous sector capillary map obtained using adaptive‐optics scanning laser ophthalmoscopy (AOSLO) imaging) and in the retinal periphery. A hemodynamic model calculates blood flow rates in the simulated capillary network and submodels simulate advection, diffusion and metabolism of oxygen and synthesis, diffusion and decay of VEGF. Our main hypothesis is that hypoxic retinal tissue produces VEGF, which diffuses to adjacent capillaries and increases their probability of occlusion. Our simulations reproduce the experimentally observed pattern of contiguous areas of capillary occlusion. Furthermore, the simulated temporal evolution of blood flow agrees quantitatively with experiment, and the simulated venous oxygenation agrees qualitatively. We used multiple replica simulations to generate a vulnerability map for the capillary network, which showed that only a few capillary segments have a high probability of triggering large areas of derived occlusions. We then simulated the effects of specific patterns of pan‐retinal photocoagulation therapy using patterned alterations of tissue oxygen consumption to explore alternative therapeutic approaches to inhibiting progressive tissue ischemia. Future versions of this simulation framework may increase our ability to intervene early, using patient‐specific photocoagulation or anti‐VEGF treatments, to prevent large ischemic areas from developing and thereby prevent blindness from diabetic retinopathy.

Support or Funding Information

This work was sponsored by National Institutes of Health/National Institute of General Medical Sciences grants R01 GM076692, R01 GM077138, and U01 GM111243 and National Institutes of Health/National Eye Institute R01 EY024315. We have received support from the College of Arts and Sciences, the Office of the Vice President for Research under their IU Collaborative Research Grant Program at Indiana University, Bloomington.
Loss of Axin2 leads to Myxomatous Valve Disease
Authors: Hulin Alexia , Yutzey Katherine
Published: November 2023

In the older population, myxomatous valve disease (MVD) is the second most common heart valve disease and the leading cause of mitral regurgitation. Myxomatous valves display thickened leaflets with glycosaminoglycan (GAG) accumulation and increased chondrogenic markers, such as Sox9 and aggrecan. Recent human microarray data suggest activation of Wnt/β‐catenin signaling in MVD. However, the role of Wnt/β‐catenin signaling in the pathogenesis of MVD is still poorly understood.

To further investigate the role of Wnt/β‐catenin signaling, we analyzed heart valves from mice deficient in Axin2, a negative regulator of Wnt/β‐catenin signaling.

Axin2 is expressed in endothelial and interstitial cells in adult heart valves as indicated by X‐gal staining of Axin2‐lacZ heterozygous mice. Homozygous loss of Axin2 (KO) does not impair early heart valve development. However, at birth and in adult mice, KO mice demonstrate thickened GAG‐rich aortic valves with increased cell proliferation and nuclear Sox9. At 4 months, focal aggrecan‐rich areas are observed along with increased TGF‐β and BMP signaling, as indicated by increased phosphorylation of Smad2/3 and Smad1/5/9 respectively. These features are consistent with human myxomatous mitral valves. Moreover, thickened aortic valves do not calcify as indicated by lack of alizarin red staining in 1 year old KO mice. Interestingly, melanocyte accumulation is also observed in thickened aortic valves, suggesting that Axin2 may influence neural crest cell contributions to heart valves. Ongoing in vivo and in vitro studies are investigating the specific functions of Axin2 in valve disease mechanisms.

Altogether these data indicate a role for Axin2 in heart valve homeostasis and in myxomatous disease. In addition, the Axin2‐deficient mouse is a new model for myxomatous valve disease that will be used to decipher molecular pathway interactions and identify therapeutic targets in valve pathogenesis.
Bilateral Intra‐individual Comparison of Vascular Structure Following Eight Weeks of Unilateral Maximal Interval Handgrip Training in Post‐Menopausal Women
Authors: Bentley Danielle C , Thomas Scott G
Published: November 2023

There is a growing body of literature, both primary and review, that supports the use of handgrip exercise training for resting blood pressure reduction. In further investigating the causative mechanisms responsible for this blood pressure improvement researchers have identified that handgrip exercise of sustained grip contractions held for upwards of two minutes can result in working‐limb specific improvements to both vascular structure and vascular function. Training with a more dynamic handgrip exercise protocol (32 × 5sec @ maximal force with 5sec of rest between sets) was therefore expected to produce more of a local vascular stimulus and potentially result in a greater influence on vascular measures. This research presents a component of an at‐home training study where post‐menopausal women completed unilateral maximal interval handgrip exercise. Bilateral vascular assessments were completed at the onset (week0), midway (week4), and the end (week8) of training. Based on previous research, it was hypothesized that working‐limb specific changes to carotid‐radial Pulse Wave Velocity (crPWV) would be presented while measures of Augmentation Index (AIx) would remain the same. Seventeen older (61.1±4.0yrs), women without hypertension (SBP: 127.5±13.6mmHg, DBP: 77.7±8.1mmHg) completed this eight‐week unilateral (non‐dominant, left for all) training study. Women self‐reported high at‐home exercise adherence (96.9%) over the full eight weeks. Although maximal interval handgrip exercise training resulted in significant reductions to resting systolic blood pressure at both week4 (−5.7±7.7mmHg, p<0.05) and week8 (−5.1±7.7mmHg, p<0.05), vascular measures remained unchanged. Specifically, crPWV was unchanged for both the working (7.2±0.7 to 7.2±1.0) and non‐working (7.3±0.6 to 7.2±0.6) limbs. Also AIx was unchanged for both the working (32.4±6.2 to 33.1±6.6) and nonworking (33.7±5.9 to 33.0±6.9) limbs. In conclusion, post‐menopausal women completing eight weeks of maximal interval handgrip exercise training reduce their resting systolic blood pressure in the absence of alterations to local vasculature, ultimately suggesting that other mechanistic avenues may be more influential. Future research should confirm this speculation using alternative assessments of the vasculature including flow mediated dilation and ultrasound imaging of the vascular wall.

Support or Funding Information

Canadian Institutes of Health Research, CGS Doctoral Research Award
Morphological Analyses of the Arterial Supply to the Brain
Authors: Kyle Emily G M , Hachinski Vladimir , Ramsay David A , Rogers Kem A
Published: November 2023

Introduction

Stroke is one of the leading causes of mortality and morbidity in North America. Specifically, lacunar infarcts – occurring within deeper cortical regions of the brain – account for up to 25% of all stroke incidence. These regions of the brain are supplied by short penetrating arteries (SPAs) that arise perpendicularly from their main arterial supply, such as the lateral lenticulostriate arteries which supply part of the basal ganglia. The penetrating arteries travel only a short distance before their systolic pressure must be reduced to capillary pressure. In contrast, the long circumferential arteries (LCAs) that supply the superficial cerebral cortex have a long course and oblique branching pattern, which permits a more gradual reduction in intraluminal pressure as the capillary bed is approached. This study compares the morphological design of the short vessels and the longer circumferential vessels to determine whether their structure reflects their different vascular pressure dynamics.

Objective

The objective of this study is to quantitatively assess the morphology of the SPAs and LCAs.

Methods

Histological sections from the cortex, mammillary bodies and brainstem were stained with Masson's trichrome and scanned with an Aperio ScanScope AT Turbo at 40x. Using Aperio ImageScope, four arterial measurements were obtained from an average of 40 vessels per section: thickness of the tunica adventitia; combined breadth of the tunica intima and media; luminal diameter; and the arterial luminal circumference.

Results

The preliminary results indicate that, in general, arteries at the brain base and adjacent to the brainstem (i.e., the SPAs) have a thicker tunica adventitia and a wider lumen as compared to the LCAs that supply the cortex. The ratio of tunica adventitia: tunica intima + tunica media is approximately 1.6 times higher for the basilar and rhombencephalic SPAs than the cortical LCAs. The ratio of luminal diameter: tunica intima + media is approximately 1.5 times higher for SPAs as compared to LCAs.

Conclusion

We have demonstrated a reliable quantitative method to assess cerebral arteries and have shown clear differences between the morphology of the SPAs and LCAs. This method is now being used to investigate age‐related arterial changes and the relationship between vessel morphology and various diseases, including hypertension and whether or not there are lacunar infarcts.
Variation of the Common Carotid Artery Diameter Related to Age
Authors: Tracy‐Bee Mary , Barton Scott T. , Zurke Jordan , Hamka Noor
Published: November 2023

In multi‐campus, multi‐year study we investigated the relationship of the size of the common carotid artery versus age of death. A significant and positive correlation was identified bilaterally in the diameter of the common carotid arteries in relationship to age of death in human cadavers ranging from 24 to 101 years old (p=0.013). The diameter of the common carotid artery has been associated with the occurrence and severity of strokes. This may provide insight into circulatory‐related procedures in the cervical region or may be indicative of a related genetic predisposition to a higher vascular flow.
Dysregulation of miRNA regulatory networks by chronic ethanol consumption impairs liver regeneration
Authors: Parrish Austin , Juskeviciute Egle , Hoek Jan B. , Vadigepalli Rajanikanth
Published: November 2023

microRNAs are a class of small, non‐coding RNAs ~21 nucleotides long that regulate numerous cellular processes in a post‐transcriptional manner. Previous research has identified several microRNAs of interest involved in liver regeneration and hepatocellular carcinoma, including miR‐21, which has been shown by our lab and others to be significantly upregulated following liver damage by 70% partial hepatectomy (PHx); miR‐21 is further increased in animals undergoing PHx following ethanol adaptation. Given that different microRNAs can regulate multiple targets in any given pathway, we sought to identify additional microRNAs involved in liver regeneration alongside miR‐21. In order to accomplish this, we knocked down miR‐21 in vivo using a locked nucleic acid (LNA) probe containing a complementary sequence to miR‐21. Whole liver tissue samples were collected from both control‐ and ethanol‐fed Sprague‐Dawley rats at baseline conditions and 24 hours post‐partial hepatectomy. These samples were analyzed for microRNA expression using the NanoString microRNA microarray platform. Analysis of the expression data reveals seven microRNAs that show differential expression in response to miR‐21 knockdown. Of these genes, three show positive correlations with miR‐21 expression while four are negatively correlated. Using target prediction software, we developed a network of putative microRNA‐gene interactions and compared the predicted targets to genes identified as differentially expressed based on Affymetrix microarray analysis. This network of putative targets identifies a number of genes that are potentially regulated by these differentially expressed microRNAs. Gene ontology and pathway analysis reveals that multiple predicted targets are involved in processes relating to cell cycle progression. In conclusion, these studies identified a set of candidate co‐regulatory microRNAs whose dysregulation by chronic ethanol consumption may lead to impaired liver regeneration.

Support or Funding Information

Research was supported by the National Institutes of Health grants from National Institute on Alcohol Abuse and Alcoholism R01 AA018873, R21 AA022417, and T32 AA007463.
Epigenetic silencing of microRNA‐34a in human cholangiocarcinoma cells via DNA methylation and EZH2: Impact on regulation of Notch pathway
Authors: Kwon Hyunjoo , Song Kyoungsub , Han Chang , Zhang Jinqing , Ungerleider Nathan , Yao Lu , Wu Tong
Published: November 2023

Aberrant expression and regulation of microRNAs (miRNAs) have been found in multiple cancers and their dysregulation importantly contribute to the tumorigenic processes. Among these miRNAs, miRNA‐34a (miR‐34a) functions as a tumor suppressor and its dysregulation has been reported in several cancers. In this study, we investigated epigenetic regulation and biological function of miR‐34a in human cholangiocarcinoma cells. Our data indicate that miR‐ 34a expression is epigenetically silenced in human cholangiocarcinoma cells (CCLP1, SG231, Hucct1 and TFK1) compared to the nonmalignant biliary epithelial cells (H69). Treatment of human cholangiocarcinoma cells with the DNA methylation inhibitor, 5′aza‐2′deoxycytidine (5‐ Aza‐CdR), or the EZH2 (enhancer of zeste 2 polycomb repressive complex 2) inhibitor, GSK126, enhanced the expression of miR‐34a. In parallel, knockdown of EZH2 by shRNA also significantly decreased miR‐34a expression in human cholangiocarcinoma cells. We further showed that DNA methylation and EZH2‐mediated histone H3 lysine 27 trimethylation (H3K27Me3) repressed miR‐34a gene expression, as determined by methylation‐specific PCR and chromatin immunoprecipitation, respectively. Functional analyses revealed that miR‐34a mimic decreased cholangiocarcinoma cell proliferation, colony formation and migration, in vitro. Moreover, we identified Notch1, Notch2 and Jagged 1, which are the major receptors and ligands of the Notch pathway, as miR‐34a target genes in cholangiocarcinoma cells. Accordingly, forced overexpression of miR‐34a significantly decreased the expression of Notch1, Notch2 and Jagged1, as determined by Western blotting and qRT‐PCR analyses. Our results provide novel evidence that miR‐34a expression is epigenetically silenced by DNA methylation and EZH2 in human cholangiocarcinoma cells. Thus, epigenetic induction of miR‐34a or miR‐34a replacement therapy may represent a novel therapeutic approach for the treatment of cholangiocarcinoma.

Support or Funding Information

NIH R01 CA1023252 and R56DK077776