bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using AAV9 to trace bulbospinal inputs to phrenic motoneurons
Authors: Nair Jayakrishnan , Mandel Ronald J , Fuller David D 
Published: November 2023

We used adeno associated virus (AAV) serotype 9 driving expression of green (AAV9‐cba‐GFP) or red (AAV9‐cba‐mCherry) fluorescent protein to examine the distribution of bulbospinal projections to the phrenic motor nucleus in the adult rat. Rats were anesthetized with isoflurane and focal injections of AAV9‐GFP (left medulla; titer: 1.19 × 10e13 vg/ml; volume: 0.25μl) and AAV9‐mCherry (right medulla; titer: 1.66 × 10e13 vg/ml; volume: 0.25μl) were targeted to the immediate region of medullary rostral ventral respiratory group (rVRG) as determined in separate neurophysiological recordings. In spinal intact rats, brainstem and spinal cord tissues were harvested 18‐wks following AAV injection. Separate animals received a cervical spinal cord hemisection injury (C2Hx) 4‐wks prior to the brainstem AAV injections. Phrenic motoneurons were retrogradely and bilaterally labeled 3‐days prior to tissue harvest using intrapleural delivery of cholera toxin‐beta (CT‐β, 0.2%, 5μl). When the rVRG showed robust transgene expression as indicated via fluorescence, a dense cluster of AAV9‐GFP or mCherry expressing terminal projections could also be observed in the phrenic nucleus bilaterally. In a few rats, injections were slightly lateral to the rVRG, and these produced minimal if any labeling in the region of the phrenic nucleus. Preliminary observation of medullary injected C2Hx cord (14‐wks) revealed robust AAV9‐GFP and mCherry expression in the phrenic nucleus contralateral to the lesion, and a dramatically reduced but even distribution of GFP and mCherry positive fibers along the ipsilateral phrenic nucleus. These initial results indicate that injection of AAV9 to the rVRG is an effective technique to label bulbospinal projections to the phrenic motor nucleus.Support or Funding Information1R01NS080180‐01A1 (DDF)
TrkB Agonist Treatment in Old Age Does Not Mitigate Diaphragm Neuromuscular Dysfunction and Sarcopenia
Authors: Vasdev Amrit Kaur , Greising Sarah M. , Sieck Gary C , Mantilla Carlos B 
Published: November 2023

Neurotrophic signaling is essential to the maintenance of diaphragm muscle function across the lifespan. With aging, there is an age‐related loss of neurotrophic signaling and a resultant increase in diaphragm muscle denervation and impairment in neuromuscular transmission. We hypothesized that enhancing neurotrophic signaling via the tropomyosin‐related kinase receptor subtype B (TrkB) using the small molecule TrkB agonist 7,8‐dihydroxyflavone (7,8‐DHF) would mitigate age‐related changes in diaphragm neuromuscular transmission and possibly sarcopenia (muscle atrophy and force loss). Adult male TrkBF616A mice (n=32) were randomized to receive 6‐month oral treatment with vehicle (control), 7,8‐DHF, or co‐treatment with 7,8‐DHF and 1NMPP1(a specific inhibitor of TrkB kinase activity in TrkBF616A mice) beginning at 18 and ending at 24 months of age. Mice were analyzed for neuromuscular transmission failure using diaphragm muscle‐phrenic nerve preparations, diaphragm muscle force, and morphologic characteristics of sarcopenia. Chronic 7,8‐DHF treatment did not improve diaphragm neuromuscular function or force (P≥0.25). Co‐treatment with 7,8‐DHF and 1NMPP1 decreased the ratio of the initial nerve stimulation‐derived to initial muscle stimulation‐derived force (~22%) compared to vehicle (p=0.01), consistent with a deleterious effect of inhibiting TrkB kinase activity on aging diaphragm muscle. With age, there was fiber type specific atrophy of type IIa and type IIx and/or IIb diaphragm muscle fibers. There was no evidence of a protective effect of 7,8‐DHF on muscle fiber cross‐sectional area. Taken together, these results support a role for BDNF/TrkB signaling in old age but do not support 7,8‐DHF as a therapeutic agent to mitigate age‐related effects on diaphragm muscle function.Support or Funding InformationSupported by R01‐AG044615, T32‐HL105355, and the Mayo Clinic.
Aging‐induced impairments in diaphragm isotonic contractile properties and modifications of proteomic and sphingolipid profile
Authors: Ferreira Leonardo F. , McDonagh Brian , Kelley Rachel C. , Coblentz Philip D. , Patel Nikhil 
Published: November 2023

The diaphragm is involved in ventilatory and non‐ventilatory (e.g., sneezing and coughing) activities that are essential for gas exchange and airway clearance. Inspiratory efforts for sneezing and coughing, or breathing during exercise, require rapid shortening and powerful diaphragm contractions. Thus, impairments in diaphragm contractile properties compromise airway clearance and contribute to inability to sustain ventilation during physical activity. Aging causes diaphragm atrophy and loss of isometric specific force. However, the effects of aging on diaphragm isotonic contractile properties and muscular factors associated with dysfunction are not fully understood. Our goal in the current study was to determine diaphragm isometric and isotonic contractile properties and the associated changes in the proteomic and sphingolipidomic profile of the diaphragm in ‘very old’ age. We studied adult (6 months, n = 6) and very old mice (30 months, n = 6) obtained from the National Institute on Aging. We assessed contractile function in vitro (force‐frequency and force‐velocity protocols) and used mass spectrometry for global label free proteomics and sphingolipid analyses in diaphragm samples. Aging decreased maximal isometric specific force (N/cm2) by 20% (P < 0.01) and maximal shortening velocity (Lo/s) by 15% (P = 0.098). We calculated power as force × velocity and determined that aging caused a 35% loss in peak power (W/kg) (P < 0.01). Our initial proteomic analysis revealed down regulation of glycolytic enzymes and calcium regulatory proteins, while cytoskeletal proteins were upregulated in diaphragm of old mice (P<0.01, false‐discovery rate 1%). Our sphingolipid analysis showed increases in diaphragm sphingosine‐1‐phosphate content (P<0.05) with no changes in ceramide levels. Overall, our findings suggest pronounced impairments in diaphragm isotonic contractile properties in the elderly. The disruption of the metabolic machinery and calcium regulation are putative factors causing abnormal diaphragm function with aging.Support or Funding InformationR03‐AG040400‐02
DHA is more potent than EPA in attenuating cardiometabolic risk in men and women: a randomized double‐blind, placebo‐controlled crossover trial
Authors: Allaire Janie , Couture Patrick , Charest Amélie , Leclerc Myriam , Marin Johanne , Lépine Marie‐Claude , Tchernof André , Lamarche Benoît 
Published: November 2023

BackgroundMost studies to date on the cardiometabolic effects of eicosapentaenoic (EPA) and docosahexaenoic (DHA) in humans have used a mixture of the two fatty acids in different forms and proportions. The objective of this study was to compare the individual effects of EPA vs. DHA supplementation (as re‐esterified triacylglycerol, 90% pure) on blood lipids and inflammatory markers in men and women at risk of cardiovascular diseases.MethodsUsing a double‐blind, placebo‐controlled crossover design, 48 men and 106 women with abdominal obesity were randomized to three treatment phases: 1‐EPA (3g/d), 2‐DHA (3g/d), 3‐corn oil (placebo, 3g/d). Treatments had durations of 10 weeks each and were separated by an 8‐week washout period. Blood lipids and inflammatory markers were measured before and after each treatment phase. Differences in study outcomes between treatments were assessed using the MIXED procedure for repeated measures with endpoint measures as primary outcomes. Potential confounders of the response to treatment, mainly obesity/body fat status, age, use of contraceptive agents (premenopausal women), menopausal status, treatment‐specific baseline values and sequence of treatments were considered.ResultsEPA vs. placebo decreased plasma TG concentrations (−11.1±2.4%, p<0.001). DHA vs. placebo decreased diastolic blood pressure (DBP, −2.2±0.9%, p<0.001), TG (−18.1±2.5%, p<0.001), cholesterol(C)/HDL‐C ratio (−2.5±1.4%, p=0.02), CRP (−8.4±5.0%, p=0.03), TNF‐α (−13.7±5.2%, p=0.02) and IL‐18 (−4.8±2.9%, p=0.01), and increased total C (+2.5±1.2%, p=0.001), HDL‐C (+6.1±1.2%, p<0.001) and LDL‐C (+5.0±1.9%, p<0.001). Changes in DBP (p=0.03), TG (p=0.02), total C (p<0.001), HDL‐C (p<0.001), LDL‐C (p=0.03), C/HDL‐C ratio (p=0.02), IL‐18 (p=0.007) and adiponectin (p<0.001) were greater with DHA than with EPA.ConclusionDHA is more effective than EPA in modulating blood lipids and inflammatory markers. Further studies are needed to determine the impact of a long term DHA supplementation on cardiovascular risk in men and women.Support or Funding InformationThis research was funded by the Instituts de recherche en santé du Canada (IRSC/CIHR). Janie Allaire is recipient of a scholarship from the Fonds de Recherche du Québec – Santé (FRQ‐S) for graduated students with a Professional Degree.
Managing the Growing Classroom: Opportunities for Postdoctoral Teaching Fellows
Authors: Nevins Julie E.H. , Wilkinson Amanda L. 
Published: November 2023

Increasing undergraduate class sizes place high demands on professors in the field of nutrition. Postdoctoral teaching fellows can absorb some of the teaching workload and elevate the quality of undergraduate education. These positions are mutually beneficial to professors, undergraduate and graduate students, and postdoctoral scholars.Teaching fellows advance undergraduate learning by promoting evidence‐based teaching practices, as well as innovative and engaging learning activities. Further, undergraduates gain the opportunity to interact with an additional doctoral‐level scientist in the field of nutrition. Graduate and undergraduate teaching assistants benefit from direct mentoring from both professors and postdoctoral teaching fellows. This mentorship can enhance the larger teaching and learning environment to improve the educational experience in courses across the department.The teaching‐oriented fellowship provides postdoctoral scholars with experiential training in effective undergraduate education within their discipline, a skill‐set that is not often developed in a traditional postdoctoral position. The professor serves as a mentor, role model, and collaborator in both teaching and research to the teaching fellow. As a nutrition scientist, the teaching fellow can manage day‐to‐day activities and teaching personnel, help link research to the classroom, and serve as an intermediary between professor and students.We will discuss our experiences as teaching fellows including the benefits and challenges of the position, the projects we have contributed to, and ideas for the future. We provide examples of evidence‐based teaching that we have incorporated into the classroom, and will also share perspectives from undergraduates in the courses we support.Postdoctoral teaching fellowships can address the increased teaching demands due to larger class sizes, and heighten the quality of undergraduate nutrition education. These positions are advantageous for professors, students, and postdoctoral scholars alike.
Novel Tool for Discrimination of Feeding Intolerance and Necrotizing Enterocolitis Risk in the Preterm Infant
Authors: Naberhuis Jane , Wetzel Chris , Tappenden Kelly 
Published: November 2023

BackgroundPreterm infants are at increased risk of developing feeding intolerance and necrotizing enterocolitis (NEC). Comprehensive nursing assessments can improve infant outcomes through early identification of these conditions.ObjectiveTo validate a novel nursing tool for assessment of neonatal feeding intolerance and NEC risk.MethodsThe tool was developed based on published literature and implemented in a University of Illinois‐affiliated 48‐ bed level III neonatal intensive care unit following Institutional Review Board approval. Data were collected from the electronic medical record of all preterm infants with parental consent during the study period. Tool error rate, consistency (Cronbach's alpha), and inter‐rater reliability (intraclass correlation coefficient [ICC] and Fleiss’ kappa) were assessed. Risk factors significant to the development of feeding intolerance (days with emesis, abdominal distention, or gastric residuals > 50% of previous feeding volume) and NEC (ICD‐9 557.0, 777.50, 777.51, 777.52, or 777.53) were identified through χ2 testing. Tool discrimination was evaluated via receiver operating characteristic (ROC) curve. Pearson correlation coefficient and independent t‐test were used to assess construct validity. Following these assessments, the tool was optimized and reassessed. Optimization was achieved by removing factors not significant to ≥ 2 outcomes of interest and weighting point values assigned to each factor.ResultsFrom August 2013 to December 2014, 49 nurses scored 499 tools on the 133 enrolled infants. Cronbach's alpha (0.71), ICC (0.99), and Fleiss’ kappa (1.00) were in acceptable ranges. Scoring error rate was 9.2%, and inversely related to the number of tools a given nurse scored (R2 = 0.53, P = 0.01). Total optimized tool score was associated with all outcome measures (area under the ROC curve; diagnostic odds ratio [95% CI]) for the number of days with emesis (0.67; 1.12 [1.05, 1.21]), abdominal distention (0.81; 1.27 [1.17, 1.41]), or gastric residuals > 50% of previous feeding volume (0.62; 1.10 [1.03, 1.18]), and NEC (0.91; 1.30 [1.13, 1.59]). Correlation coefficients for each of these outcomes were 0.50, 0.60, 0.49, and 0.36, respectively. Optimized tool scores of infants who did and did not develop each of the outcome measures were significantly different (P < 0.05).ConclusionsThe tool is a clinically efficacious means to discriminate infants at risk of feeding intolerance and NEC. Implementation at additional institutions and further refinement will improve its clinical utility.Support or Funding InformationInternally funded.
Aortic Depressor Nerve Morphology in Developing Spontaneously Hypertenvie Rats
Authors: Amorim Milena Menezes , Castania Jaci A , Salgado Helio Cesar , Fazan Valeria Paula Sassoli 
Published: November 2023

Aortic Depressor Nerve (ADN) is an aferent nerve that originates on the aortic arch. Its major function is providing constant information about the body hemodynamics (beat by beat) to the Central Nervous System (NCS) in order to maintain cardiovascular homeostasis. This nerve is constituted by myelinated fibers (A‐type) and unmyelinated fibers (C‐type). In this study, we analyzed the myelinated fiber's morphology and morphometry in Spotaneously hypertensive rats (SHR) in different ages. We used SHR at 5 weeks (8 female, 5 male), 20 weeks (5 female, 8 male), 50 weeks (8 female, 9 male) of age and normotensive controls Wistar Kyoto rats (WKY) 20 weeks‐old (7 female, 6 male). All animals had their left ADN recorded for spontaneous activity associated with the arterial pressure pulse. After the electroneurographic recordings, proximal (close to nodose ganglion) and distal (at clavicle level) segments were prepared for epoxy resin embedding. Semithin cross sections of ADN segments were stained with 1% toluidine blue and analyzed by light microscopy. The morphometric study of the myelinated fibers was performed with the aid of computer software and took into consideration the myelinated fiber and respective axons area, diameter and the G ratio (axon diameter/fiber diameter). Comparison between proximal and distal segments made for the same strain, gender and age showed no morphometric differences. At 20 weeks of age, male WKY presented significantly larger number of fibers than male SHR, while comparisons between females showed no significant differences. The aging SHR morphometric data indicated that the nerve growth stopped at 20 weeks of age in both genders, suggesting that the 5 week old animals myelinated fibers are not fully developed for the best conduction velocity. Also, in elderly male SHR, the reduction of G ratio points to an axonal atrophy, that could explain, at least in part, the fact that males have higher blood pressure than females.Support or Funding InformationFAPESP, CNPq, CAPES and FAEPA
Non‐invasive evaluation of anomalous aortic origin of coronary arteries and surgical management
Authors: Ashwath Ravi , Prasad Deepa 
Published: November 2023

Advances in imaging of the coronary arteries allow more detailed and accurate information to be assessed to detect anomalies that might prevent a young athlete dying on the field. Normal coronary anatomy includes origin of left coronary artery from left sinus of Valsava, which then divides into left anterior descending artery and left circumflex coronary artery and origin of right coronary artery from the right sinus. Anomalous aortic origin of coronary arteries (AAOCA) is when the coronary arteries arise from opposite sinus or wrong sinus or as single right or left coronary artery. AAOCA is rare with an incidence of about 0.2%. However, it is the second most common cause of sudden cardiac death in young athletes.Most patients are asymptomatic and sudden death could be the initial presentation, which is provoked by myocardial ischemia leading to myocardial infarction and lethal arrhythmia's. The pathological mechanisms attributed to the coronary compression include, intramural/interarterial course, slit‐like orifice, acute angle take‐off, hypoplastic coronary arteries and coronary artery dominance. Anomalous left coronary artery from right sinus is thought to carry a higher risk of sudden death than anomalous right coronary artery.Echocardiography is a useful tool in the initial evaluation of AAOCA but generally needs to be complemented and confirmed by advanced imaging such as computed tomographic angiography (CTA) or magnetic resonance imaging (MRI). The intramural and interarterial course can be easily determined by CTA and in most cases by MRI. A slit like orifice can be visualized by CTA, however with technological advancements in CT, it is possible to obtain dynamic images of the coronary artery origin, which has enabled us to determine the slit like orifice more accurately. MRI has enabled us to identify myocardial viability by using stress perfusion and late Gadolinium enhancement imaging.Accurate delineation of the coronary anatomy and viability is important in the decision making for management and pre‐operative evaluation. There are various surgical options depending on the type of coronary anomaly and presence of additional risk factors.Support or Funding InformationDeepa Prasad M.D. is funded by AAA
Imaging the Role of Macrophage in Infection and Sterile Injury in Liver
Authors: Kubes Paul , Zeng Zhutian , Jenne Craig 
Published: November 2023

In the liver, populations of resident macrophage and recruited monocytes play key roles in both the clearance of infection and tissue repair.Kupffer cells are liver macrophage that reside directly within the bloodstream, adherent to the sinusoid walls, ideally positioned to detect and capture pathogens. Using intravital microscopy (IVM), we are able to directly visualize Kupffer cells in the liver of live mice and to study how these cells bind, and clear bacteria from the bloodstream. IVM has revealed a number of unique aspects of pathogen recognition including antibody‐dependent, complement‐dependent and antibody/complement‐independent mechanisms of pathogen capture. The specific mechanism used by the Kupffer cell appears to vary according to the pathogen involved and these findings provide great insight into the development of vaccination strategies and new antibody‐based therapies designed to target specific pathogens.In contrast to infectious disease, tissue repair following sterile injury in the liver does not depend on the resident Kupffer cells, but rather, is dependent on the recruitment of inflammatory monocytes. Using IVM and mice with fluorescent reporter genes for various monocyte populations, we have identified that these recruited monocytes clear cellular debris from the site of injury and then transition, in situ, from classic CCR2high (Cx3CR1low) monocytes to reparative Cx3CR1high (CCR2low) alternative monocytes that support tissue repair and wound healing. This transition of CCR2high cells to Cx3CR1high monocytes is driven by the presence specific cytokines including IL‐4 and IL‐10. Failure to recruit to the initial CCR2high cells or inhibition of the CCR2high to Cx3CR1high phenotype transition results in abnormal tissue repair including defects in collagen deposition and delayed wound healing.
Illuminating biology at the nanoscale with single‐molecule and super‐resolution imaging
Authors: Zhuang Xiaowei 
Published: November 2023

Dissecting the inner workings of a cell requires imaging methods with molecular specificity, molecular‐scale resolution, and dynamic imaging capability such that molecular interactions inside the cell can be directly visualized. Fluorescence microscopy is a powerful imaging modality for investigating biological systems largely owning to its molecular specificity and dynamic imaging capability. However, the diffraction‐limited resolution of light microscopy is substantially larger than molecular length scales in cells, making many sub‐cellular structures difficult to resolve. We developed a super‐resolution fluorescence microscopy method, stochastic optical reconstruction microscopy (STORM), which overcomes the diffraction limit by using photo‐switchable fluorescent probes to temporally separate the spatially overlapping images of individual molecules. This approach has allowed multicolor and three‐dimensional imaging of living cells with nanometer‐scale resolution and enabled discoveries of novel sub‐cellular structures. In this talk, I will discuss the technological advances and applications of STORM, with the focus on the recent biological discoveries enabled by STORM.I will also describe a recently developed single‐cell transcriptome imaging method. In situ transcriptomic analyses of single cells promise to transform our understanding in many areas of biology, such as the mechanism of gene regulation, the heterogeneous behavior of cells, and the development and maintenance of cell fate. Single‐molecule imaging allows for counting and mapping of RNA molecules in individual cells; however, the number of RNA species that can be simultaneously imaged has been limited. To overcome this challenge, we developed a new imaging approach, multiplexed error‐robust fluorescent in situ hybridization (MERFISH), which allows numerous RNA species to be quantified in a spatially resolved manner in single cells in situ. This approach enables unique analyses based on the variation and correlation of copy numbers and spatial distributions of many RNA species within single cells, facilitating the delineation of gene regulatory networks and in situ identification of cell types. In this talk, I will also discuss the technology development and applications of MERFISH.