bluuebunny/crossref_metadata_2025_split huggingface dataset:
MUSE: A New, Fast, Simple Microscopy Method for Slide‐Free Histology and Surface Topography
Authors: Levenson Richard M , Fereidouni Farzad 
Published: November 2023

IntroductionConventional brightfield or fluorescence microscopy works best with thin, stained specimens mounted on glass slides, but to prepare these requires hours of processing and the help of highly skilled technical personnel. We describe a new, inexpensive form of light microscopy that can generate high‐quality histology and histopathology images directly from cut surfaces of fresh (or fixed) tissue samples of any thickness, with less than 1 minute of preparation.BackgroundWhile alternative microscopy‐scale methods, such as confocal or two‐photon, or optical coherence tomography approaches, can generate reasonable images from thick tissues, the instrumentation is typically complex, expensive and not widely available. We are developing an alternative technique, MUSE (Microscopy with UV Surface Excitation), that relies on simple properties of light, tissue, and fluorescent stains, and can be implemented at relatively low cost. Thick pieces of tissue obtained by biopsy, surgery or necropsy can be imaged directly. The method is non‐destructive, and eliminates requirement for conventional histology processing, formalin fixation, paraffin‐embedding, or thin‐sectioning.MethodUltraviolet light at about 280 nm from an LED arranged to provide oblique illumination, is used to excite just the surface layer of tissue that has been briefly (~10 seconds) stained with common and inexpensive fluorescent dyes. Unlike light of longer wavelength, 280‐nm light only penetrates to a depth of 10 microns or less, and thus excites fluorescent signals, conveniently in the visible range, only from the cut specimen surface. The images, which can be diffraction‐limited, are captured using conventional microscope optics and a standard color cameraResultsMUSE samples from fresh (or fixed) tissues stained with general tissue stains such as rhodamine and Hoechst generate high‐resolution fluorescence images that can be converted in real time from fluorescence to H&E‐like brightfield appearance, for ease of interpretation. However, fluorescence display mode preserves surface shading and depth cues that allow for appreciation of surface profiles important in understanding 3D organization of complex specimens. We have obtained high‐quality MUSE images from normal and diseased tissues from multiple organisms, as well as from plants, and manufactured materials. Moreover, surface profile information provides views beyond what can be seen with in standard thin‐sectioned material, generating results that can resemble those obtainable with scanning electron microscopy (SEM).ConclusionWe have developed a new form of optical microscopy that generates diagnostic‐quality histological images, with enhanced content, from fresh or fixed, but unsectioned tissue, rapidly, with high resolution, simply and inexpensively. We anticipate that there could be widespread adoption in preclinical and clinical research facilities, as well as hospital‐based and stand‐alone medical settings.
Lack of β‐catenin in Hepatocytes Impairs Proliferation and Leads to Increased Morbidity in Response to a Choline‐Deficient Ethionine‐Supplemented Diet
Authors: Russell Jacquelyn Olivia , Okabe Hirohisa , Singh Sucha , Poddar Minakshi , Monga Satdarshan Paul 
Published: November 2023

Despite the liver's capacity for regeneration, liver disease is the 12th leading cause of death in the United States. Treatments for chronic liver disease are limited due to incomplete understanding of liver regeneration mechanisms. Although activation of liver stem cells (LSCs) is thought to contribute to liver regeneration when hepatocyte proliferation is impaired, the role and origin of these cells is still controversial. The choline‐deficient ethionine‐supplemented (CDE) diet model of liver injury is known to induce proliferation of LSCs. However, recent evidence has supported repair primarily driven by hepatocyte self‐duplication in the CDE diet model. As a member of the WNT signaling pathway, β‐catenin plays an important role in liver regeneration by promoting hepatocyte proliferation. However, the role of β‐catenin in liver regeneration after injury from the CDE diet has not been previously characterized. We show that lack of β‐catenin‐driven WNT signaling in mouse livers leads to a defect in hepatocyte proliferation and increased morbidity in response to the CDE diet. Mice with liver‐specific deletion of β‐catenin (β‐catenin KO) and control wild‐type littermates (WT) on the CDE diet showed comparable initial levels of liver injury and inflammation. After 14 days on the CDE diet, WT mice demonstrated significant hepatocyte proliferation and reduced liver injury markers. In contrast, β‐catenin KO mice displayed a lack of hepatocyte proliferation, sustained liver injury, and increased fibrosis. Mice lacking WNT signaling via liver‐specific deletion of co‐receptors LRP5 and LRP6 (LRP5‐6 DKO) also displayed sustained liver injury after 14 days on the CDE diet. Interestingly, we observed proliferation of LSCs in WT, β‐catenin KO, and LRP5‐6 DKO mice, suggesting liver regeneration occurs independently from LSC activation. Therefore our results indicate a role of β‐catenin in liver regeneration through hepatocyte proliferation and provide additional evidence to support a model of regeneration driven by hepatocyte self‐duplication rather than LSC amplification.Support or Funding InformationThis research was funded by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under award number T32EB0010216. Support was provided by the Cellular and Molecular Pathology Graduate Training Program of the University of Pittsburgh.
Hippo/YAP Signaling Induced by Endotoxin Promotes Kupffer Cell Activation and Hepatic Inflammation in Non‐Alcoholic Fatty Liver Disease (NFALD)
Authors: Song Kyoungsub , Kwon Hyunjoo , Han Chang , Zhang Jinqiang , Yao Lu , Ungerleider Nathan , Wu Tong 
Published: November 2023

Recent studies show that the Hippo pathway and its downstream effector YAP play important roles in organ size control, liver fibrosis and hepatocarcinogenesis. However, it remains unknown whether Hippo/YAP signaling is implicated in the pathogenesis of non‐alcoholic fatty liver disease (NAFLD). This study was designed to investigate the potential role of Hippo/YAP signaling in a mouse model of high‐fat diet (HFD)‐induced NAFLD. Male C57BL/6 mice were fed a normal chow diet (NCD) or HFD (60% kcal fat) for 12 wks. Intraperitoneal injections of low‐dose lipopolysaccharide (LPS: 0.25mg/kg) were administered daily for 3 wks to NCD‐fed mice. Upregulation of YAP in Kupffer cells was observed in HFD‐fed mice and LPS‐treated mice. Our data indicated that LPS induced AP‐1 binding to their consensus site in the YAP gene promoter which leads to enhanced YAP gene transcription. In contrast, the protein level of MST1, an upstream kinase that inactivates YAP, was decreased by LPS treatment. We observed that overexpression of YAP significantly induced the expression of pro‐inflammatory cytokines (TNF‐α, IL‐6, MCP‐1, and IL‐1β) in primary Kupffer cells and in Raw264.7 cells (murine macrophage cell line). Pharmacological inhibition of YAP‐TEAD with vertepofin attenuated both YAP‐ and LPS‐induced pro‐inflammatory cytokine expressions. Moreover, the expression of pro‐inflammatory cytokines was markedly reduced in Kupffer cells isolated from vertepofin‐treated HFD‐fed mice compared to vehicle‐treated HFD‐fed mice. These results demonstrate a novel role of Kupffer cell Hippo/YAP signaling in endotoxin‐induced hepatic inflammation in NAFLD. Therefore, inhibition of YAP activation may represent a novel therapeutic approach for the treatment non‐alcoholic steatohepatitis.Support or Funding InformationNIH R01 CA1023252 and R56DK077776
Giardia muris Protection against Citrobacter rodentium Colitis is Associated with Inflammasome Activation and Increased Release of Antimicrobial Peptides in the Gut
Authors: Manko Anna , Motta Jean‐Paul , Cotton James A , Oyeyemi Ayodele , Vallance Bruce A , Wallace John L , Buret Andre G 
Published: November 2023

BackgroundPolymicrobial gastrointestinal (GI) infections are common in individuals living in areas with poor sanitation. In areas where Giardia sp. infections are found in association with enteropathogens causing diarrhea via gut inflammation, Giardia sp. appears to protect against diarrhea via mechanisms that remain unlcear. Intestinal epithelial anti‐microbial peptides (AMPs) and the canonical and non‐canonical inflammasome pathways are essential to host defense.ObjectivesThe aim of this study was to determine whether Giardia muris infection may protect against Citrobacter rodentium colitis, and whether this involves inflammasome activation and/or enhanced AMP production.MethodsMale C57BL/6 mice were co‐infected with G. muris trophozoites and GFP‐labeled C. rodentium. Animals were assessed for weight gain, fecal blood, histopathology, myeloperoxidase (MPO) assays, bacterial loads, immunofluorescence for microbial‐tissue interactions, as well as Western blotting and qPCR for caspase‐1 and ‐11 (markers of inflammasome activation), β‐Defensin‐2 and Trefoil‐Factor (TFF) 3.ResultsAt 14 days post‐infection, mice infected with C. rodentium had increased macroscopic damage in colon, lost weight and rectal bleeding; G. muris co‐infection significantly inhibited these effects. Microscopic damage score and MPO levels were reduced in co‐infected animals at 14 days post‐infection. In the colon of C. rodentium‐infected mice, we observed attachment of bacteria to the intestinal epithelium and translocation into the lamina propria. In Giardia co‐infected animals, mucosal adhesion and translocation of C. rodentium was reduced and associated with lower tissue C. rodentium counts. Colonic caspase‐1 and ‐11 protein levels were increased in the co‐infected group compared to animals given C. rodentium alone. In colonic tissues of mice co‐infected with G. muris, mRNA and protein levels of the AMPs β‐Defensin‐2 and TFF3 proteins were significantly increased compared to animals given C. rodentium alone. Immunofluorescence of colonic tissues revealed increased intensity of TFF3 and β‐Defensin‐2 in co‐infected animals, particularly in the lumen and intestinal epithelium.ConclusionThe data indicate that G. muris infection protects against C. rodentium‐‐induced colitis, in association with upregulation of intestinal AMPs and activation of inflammasome pathways. Our data shed new light on how microbial‐microbial interactions may protect against bacterial enteritis in zones endemic for giardiasis.Support or Funding InformationThis work was supported by Canadian Institutes of Health Research
The Biophysical Determinants of Prion Neuroinvasion
Authors: Sigurdson Christina , Lawrence Jessica , Bett Cyrus , Kurt Tim , Wu Chengbiao , Surewicz Witold , Nilsson K. Peter R. 
Published: November 2023

Prions naturally transmit to other individuals as infectious pathogens and have led to large scale epidemics, for example, as occurred during the bovine spongiform encephalopathy (BSE) epidemic. In humans, prions have been transmitted iatrogenically through the transplantation of dura mater grafts and cornea from prion‐infected donors. Most cases of natural prion transmission follow a peripheral exposure and prions spread into the CNS in a process known as neuroinvasion. This ability of most prions to shuttle in and out of the CNS is remarkable and not described for other amyloidogenic proteins. Using mouse models, we have found that certain prion aggregates rarely invade the CNS following intraperitoneal or intra‐tongue inoculation, yet accumulate in extraneural organs, leading to lifelong subclinical carriers of infectious prions. Intriguingly, these poorly neuroinvasive prions are fibrillar, which are uncommon structures in prion disease, as most prions form oligomers. We found that reducing the prion aggregate size markedly impacts the neuroinvasive ability of fibrillar prions, suggesting that size plays an important role in prion neuroinvasion. Additionally, we have found that the intravenous route is surprisingly efficient for fibrillar prion entry into the CNS, which may help explain how human‐to‐human transmission of variant‐Creutzfeldt‐Jakob disease prions occurred following blood transfusion. Taken together, these results indicate that aggregate size and route of exposure are major determinants that impact the ability of a prion to neuroinvade.Support or Funding InformationNIH R01NS076896
Changes in plasma and urine docosahexaenoic acid levels in Alzheimer's disease
Authors: Fonteh Alfred N. , Castor Katherine , Chung Eun , Applegate Sarah , Harrington Michael 
Published: November 2023

ObjectivesTo test the hypothesis that the major brain omega‐3 fatty acid (docosahexaenoic acid, DHA, 22:6n‐3), is excreted at a faster rate from study participants with Alzheimer's disease (AD) compared with cognitively normal study participants.MethodsWe recruited and collected cerebrospinal fluid (CSF), plasma, and urine from cognitively normal study participants with normal amyloid beta 42 (Aβ42) to total tau (CN‐nAT, n= 36), pathological Aβ42/tau (CN‐pAT, n=34), mild cognitive impairment (MCI) with normal (MCI‐nAT, n= 28) or pathological Aβ42/tau (MCI‐pAT, n=10), and AD (n=29). Lipids were extracted from pooled plasma and urine samples and DHA levels measured using gas chromatography/negative ion chemical ionization/mass spectrometry.ResultsPlasma free DHA and total DHA levels were lower in AD compared with CN and MCI. In contrast, free and total DHA levels in urine were higher in AD compared with CN and MCI. CN and MCI subjects with normal Aβ42/tau had higher plasma DHA than those with pathological Aβ42/tau.ConclusionsDysfunctional regulation of DHA metabolism may account for reduced resolution of inflammation in AD study participants. Measurement of plasma and urine DHA levels may be viable approaches for monitoring metabolic pathways associated with dementia in an aging population.Support or Funding InformationL.K. Whittier and the Helen Posthuma Foundations
Clinical Simulations: Engaging Medical Students in Problem‐Based Learning
Authors: Li Andrew , Carvalho Helena 
Published: November 2023

IntroductionProblem‐Based Learning (PBL) curricula allow for medical students to learn preclinical material by teaching each other through presentations based on real patient cases. A benefit to PBL is the development of individual student teaching styles. Traditional, lecture‐format presentations are effective for a certain portion of medical students. It is important to develop novel teaching methods that engage the student audience and facilitate learning and retention.GoalDesign and implement PBL learning activities for “Chest Pain Differentials” and “Cardiac Rehabilitation” that involve students in interactive scenarios to capture their attention and encourage learning through participation.MethodsChest Pain Differentials: Six systems were addressed (Musculoskeletal, Cardiovascular, Pulmonary, Gastrointestinal, Endocrine/Neurological, and Psychiatric) with six clinical vignettes. Pairs of students were instructed to act as a physician or patient: the “physician” student was tasked with diagnosing underlying etiology of chest pain; the “patient” student was tasked with simulating the clinical vignette containing patient identifier, HPI, and key buzzwords. The scenarios were debriefed with slides containing images of the vignette along with basic information on other differentials in that system. Cardiac Rehabilitation: A simulation of a cardiac rehabilitation orientation was done where students were the incoming admissions. It introduced patient demographics, indications, health assessments, physical activity regimen, diet plan, reducing risk factors, emotional/sexual counseling, risks and benefits.ResultsVoluntary and anonymous survey to students on presentation effectiveness scored 4.17 ± 0.75 (mean ± SD) for Chest Pain Differentials and 3.83 ± 0.98 (mean ± SD) for Cardiac Rehabilitation (with 1 being the least effective and 5 being the most effective).DiscussionFeedback was generally positive for both presentations. It is interesting that Chest Pain Differentials, which included student interaction in scenarios, scored higher than Cardiac Rehabilitation, which was presenter‐driven. Students favored the engaging component of both presentations, which helped with their learning. Limitations include the short time available (15 minutes) that prevented further discussions on differentials. Opportunities for improvement are to expand the differential scope and give better direction for each scenario.
Race Influences Student Experience in STEM Courses
Authors: Johnson Kathryn M.S. , Mantina Namoonga 
Published: November 2023

The rapid diversification of student populations necessitates assessment of teaching practices to ensure success and equity for all students. At a small residential liberal arts college in the Midwest, persistence in science, technology, engineering, and mathematics (STEM) courses is >90%, with no difference in all‐college STEM persistence and persistence in STEM of students from traditionally underrepresented (UR) groups. However, although there is no significant difference in student persistence through STEM courses, it is unclear if students belonging to UR groups and White students are having similar and equitable experiences of inclusion and success inside and beyond the STEM classroom. To assess the effect of race on student experience in STEM courses, current students (n=20, 10 UR, 10 White) were grouped by race (UR or White) and number of STEM courses completed at the institution (1 or 4+), and participated in one of four student‐facilitated student focus groups (UR1, UR4+, White1, White4+). During the focus groups, trained and experienced student facilitators asked a series of questions relating to students’ strategies for success when struggling in STEM courses, perception of support from STEM faculty and other students, how aspects of a student's social identity have affected their experiences, and ideas for an inclusive and equitable STEM environment. Upon analysis of the responses, clear differences emerged between White and UR students. While White students who had completed only one STEM course indicated that they had never contemplated dropping the course, students belonging to UR groups reported having strongly considered dropping their STEM course. When students who had completed at least four STEM courses were asked, “What do you do when you are struggling in a STEM course?”, White students had a variety of responses, but most replied that they would form study groups. Students from UR groups indicated that if they do ask for help, they are most likely to go to the professor for assistance. However, when the same group of UR students were asked if they ever felt unwelcome or unsupported in a STEM course, their responses focused on difficulties communicating with professors. Although students belonging to UR groups are persisting at a similar rate as all students, the results of these focus groups provide evidence of important differences in those students’ STEM experiences.Support or Funding InformationThis research was supported by the Beloit College Office of the Provost and Dean of the College.
Trichloroethylene Produced Defects in the Developing Heart Involve the Transcription Factor, HNF4a
Authors: Chen Sheri , Nunez Martha , Ismail Kareem , Selmin Ornella , Runyan Raymond Bruce 
Published: November 2023

Trichloroethylene, TCE, is an organic solvent known to cause congenital heart disease in animals. Prior studies showed that TCE alters calcium homeostasis and myocyte contraction and transcription of more than 4000 genes. Bioinformatic analysis of altered gene transcription suggested that Hepatocyte nuclear factor 4, alpha (HNF4α) may be a central target for TCE. HNF4a was linked to 75% of the nodes in a TCE interactome. HNF4α is transcription factor that plays a significant role in developing liver, kidney, and intestines. Though not previously reported, it can be found in the embryonic heart by PCR and western blot. To explore the connection between TCE and HNF4a, we exposed pregnant mice to TCE (11μM) or the HNF4a agonists/anatagonists Bi6015 and Benfluorex (10 μM) in maternal drinking water. Embryos were collected on day 10.5 and hearts were dissected and pooled for each litter. RNA was isolated and synthesized into cDNA for quantitative PCR analysis of marker gene expression. Fourteen markers were selected from previous microarray studies in mouse or chick embryo models as being significantly altered by TCE exposure during development. TCE inhibited expression of each the selected marker genes while Benfluorex and Bi6015 were agonists of their expression. The overlap between HNF4a and TCE regulation of the selected markers was complete. Bi6015 activity varied as an agonist or antagonist in culture depending on concentration. The data support the hypothesis that HNF4a is a direct target of TCE exposure during heart development. Further studies will explore the direct binding of TCE and Benfluorex to HNF4a.Support or Funding InformationNIEHS P30 ES006694
Morphometric parameters to evaluate zebrafish heart: a model to study cardiovascular function.
Authors: Vargas Rafael A , Vásquez Isabel Cristina 
Published: November 2023

Cardiovascular diseases are a worldwide public health problem. To date, extensive research has been conducted to elucidate the pathophysiological mechanisms that trigger cardiovascular diseases and to evaluate therapeutic options. Animal models are widely used to achieve these goals, and zebrafish have emerged as a low‐cost model that produces rapid results. Currently, a large body of research is devoted to the cardiovascular development and diverse cardiovascular disorders of zebrafish embryos and larvae. However, less research has been conducted on adult zebrafish specimens and, there is insufficient information about cardiosomatic parameters in healthy adult zebrafish. Although various somatic and cardiac morphometric parameters are widely used to assess the developmental conditions of commercial and wild fish species, to evaluate growth, maturation, nutrition, reproduction and overall health status for individuals and populations, we found that surprisingly, these parameters have not previously been fully examined in adult zebrafish. In this study, we describe a method to obtain and to evaluate morphometric parameters (of both the entire animal and the heart) of adult zebrafish. We used these data to calculate additional parameters, such as body mass index, condition factor and cardiac somatic index. This method and its results can be used as reference for researchers who are interested in future studies that aim to evaluate the pathophysiological aspects of the zebrafish cardiovascular system.Support or Funding Information This work was supported by Research Grant from the Pontificia Universidad Javeriana, Bogotá, Colombia. Project: 5605, budget code 120112Z0401200.