bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unbiased Proteomics Supports a Key Role for Mitochondria in Skeletal Muscle of Highly Functioning Octogenarians
Authors: Ubaida-Mohien Ceereena , Lyashkov Alexey , Spendiff Sally , Taivassalo Tanja , Hepple Russell T. 
Published: April 2020

IntroductionSkeletal muscle mass and function decline with aging, and more precipitously after the age 75 y. To help provide insights into biologically relevant mechanisms for preserving muscle mass and function in advanced age, in this study we performed proteomics on skeletal muscle of world class octogenarian track and field athletes in comparison to healthy octogenarian non‐athletes.MethodsMuscle cross‐sectional area by MRI and a vastus lateralis muscle biopsy were performed in 15 octogenarian world class track and field athletes (8 of whom were world record holders in their discipline at the time of testing) and 14 non‐athlete age‐ and sex‐matched non‐athlete controls. From these subjects, a portion of muscle from a subset of 12 master athletes (MA mean age 81.19 ± 5.1 y) and 12 non‐athlete controls (NA mean age 80.94 ± 4.5 y) was used for liquid‐chromatography mass spectrometry to generate quantitative tandem mass tag proteomics data. In addition, we measured mtDNA copy number, COX/SDH histochemistry to identify respiratory compromised fibers, and Western blot of mitochondrial inner and outer membrane proteins.ResultsMuscle cross‐sectional area was higher in MA. Tandem mass spectrometry identified over 6000 proteins, and significant differences in abundance were found between NA controls and MA for more than 800 proteins. A pathway analysis revealed that pathways involved in mitochondria (e.g., TCA cycle, respiratory electron transport, cristae formation, sirtuins) were higher in MA, while proteins in pathways involved in the spliceosome and nuclear pore were downregulated in MA. Finally, 8 mtDNA‐encoded proteins that were included in the analysis were elevated in MA versus NA. These proteomics data are consistent with phenotypic data showing MA have higher mtDNA copy number, fewer respiratory chain compromised muscle fibers, and an increased ratio of ETC subunits (inner mitochondrial membrane proteins) relative to VDAC (outer mitochondrial membrane protein), suggesting an increase in cristae formation.ConclusionOur data underscore that mitochondrial pathways are key to maintaining a high level of physical function in advanced age. With the current study design we cannot determine the degree to which these differences are attributable to the physical activity habits of MA, but it is likely to play a role.Support or Funding InformationCIHR (MOP 125986 to RTH)NIA Intramural Research program
Optimizing Kinetic Assay Conditions to Study Bacterial Protein Lysine Acetyltransferases in Escherichia coli
Authors: Jew Kristen , Kho Ellen , Kuhn Misty L. 
Published: April 2020

Protein acetylation is a widespread post translational modification that can be observed in prokaryotes. Recent studies have shown that a multitude of bacterial proteins undergo two types of lysine acetylation: non‐enzymatic and enzymatic. Non‐enzymatic acetylation via the small molecule acetyl‐phosphate (AcP) has been the predominant focus of prior studies. However, recent work indicates that enzymatic protein acetylation by a set of Ne‐lysine acetyltransferases (KATs) in Escherichia coli is extensive and offers new opportunities to more deeply study the role of enzymatic protein acetylation in bacteria. One of the barriers to studying KAT acetylation is that current enzymatic acetylation methods do not appear to consider self‐acetylation properties of some KATs, which can lead to inconclusive results. Thus, finding optimal conditions for controlling or accounting for KAT self‐acetylation is vital to understand its role in enzymatic acetylation of substrate proteins. Therefore, we have examined the self‐acetylation properties of YfiQ and its effect on acetylating a previously uncharacterized protein substrate. We found YfiQ is already acetylated after heterologous expression and purification, which complicates interpretation of enzymatic assay results. Therefore, we are currently optimizing our system to account for this characteristic and are exploring different reaction conditions to study the enzymatic acetylation of the previously uncharacterized protein more deeply.Support or Funding InformationResearch reported in this work was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R35GM133506 (to MLK).
To what extent have Disability Resource Centers evolved to accommodate the challenges of active learning in large enrollment STEM courses?
Authors: Guerrero Frank Anthony , Gin Logan E. , Brownell Sara 
Published: April 2020

While active learning teaching methods have been shown to improve student achievement in science, technology, engineering, and math (STEM), the increased interactions among students can also present unique challenges for students from underrepresented social identities. One proposed underrepresented group of individuals who may face challenges with active learning are students with disabilities who request academic accommodations from Disability Resource Centers (DRCs). DRCs are offices on university campuses that provide academic and social services for students with disabilities and other diagnosed medical conditions. Academic accommodations often include note‐taking services, preferential seating, extended time for exams, closed captioning of videos, and interpreters. However, as more and more classes are moving away from traditional lectures to adopting active learning methods, are we providing the right accommodations for students? Could we be disadvantaging students who normally would be receiving accommodations in traditional lectures? In this exploratory study, we identified commonly implemented active learning strategies and reviewed the literature on what reported disadvantages these activities may present for students. We then contacted directors of DRCs from 305 universities with large undergraduate student populations and large enrollment science courses based on the Carnegie Classification of Institutions of Higher Education. We interviewed directors to identify how familiar they are with the term of active learning and what accommodations, if any, they currently have for students in active learning science classrooms along with any challenges they have experienced when accommodating students with disabilities in active learning science courses. Our data suggest that directors are generally aware of “active learning” and have encountered it in their position when talking with students and faculty. However, few DRCs have policies or protocols in place to specifically address accommodations needed for active learning courses. Thus, accommodations for active learning are generally determined retroactively or on a “case‐by‐case basis”, which requires students to be the ones responsible for identifying aspects of active learning courses that they struggle with and report these challenges to the DRC in order to receive appropriate accommodations. With this study, we hope to provide a foundation for creating more inclusive active learning classrooms for students with disabilities.Support or Funding InformationNational Science Foundation
Static Muscle Stretching Enhances Vascular Responsiveness of the Tibial Nutrient Artery
Authors: Reid-Foley Emily Carole , Caldwell Jacob , Dewell Isabella , Monroe Richard , Naganoma Naomi , Makadia Ruchickumar Anilkumar , Eazer Julia , Perez Adrioano , Griesheimer Jessica , Sadowsky Dylan , Bedwell Kristin , Park Hyerim , Hotta Kazuki , Delp Michael , Muller-Delp Judy 
Published: April 2020

The magnitude of bone formation and remodeling is linked to both the magnitude of strain placed on the bone and the perfusion of bone. We have previously shown that daily static stretching of the ankle flexor muscles in aged rats results in increased blood flow to the stretched muscles and to the proximal tibial metaphasis during walking exercise. The purpose of this study was to determine the effects of daily static muscle stretching on vasoreactivity of the nutrient artery that perfuses the proximal tibial metaphasis. Static stretching of ankle flexor muscles was performed in aged male Fischer 344 rats (20 months) by placement of a dorsiflexion splint on the left ankle for 30 min/day, 5d/wk for 4wks. The right hindlimb served as a contralateral control (unstretched) limb. After the 4 wk stretching intervention, the tibial nutrient artery was isolated from both the stretched and unstretched limb. Vasoconstrictor responses to the adrenergic agonist, phenylephrine (10‐9‐10‐4M) and vasodilatory responses to acetylcholine (10‐9‐10‐4M) and Dea‐NONO‐ate (10‐9‐10‐4M) were evaluated. Vasoconstrictor responses to phenylephrine were significantly increased in the tibial nutrient artery from the stretched limb as compared to those from the unstretched limb (maximal constriction, stretched limb = 54±4%, maximal constriction, unstretched limb = 42±6%; P<0.05 stretched vs. unstretched). Endothelium‐dependent vasodilation to acetylcholine was also significantly increased in the tibial nutrient artery from the stretched limb (maximal dilation = 62±5%) as compared to the unstretched limb (maximal dilation = 41±5%); P<0.01, stretched vs. unstretched). Endothelium‐independent dilation to the NO donor, Dea‐NONO‐ate was not different in the tibial nutrient arteries from the stretched and unstretched limbs. These data indicate that static muscle stretching alters the reactivity of both the smooth muscle and the endothelium of the tibial nutrient artery, leading to enhanced vasoconstrictor and vasodilatory responsiveness of the artery. This enhancement of vascular function in the nutrient artery may contribute to increased perfusion of the tibia during walking exercise following 4 weeks of daily static stretching.Support or Funding InformationSupported By: NIH R15AG055029
An Osteo‐Developmental Baseline for Cranial Casque Anatomy of Southern Cassowaries Better Informs Functional Interpretations
Authors: Green Todd L. , Watanabe Akinobu , Gignac Paul M. 
Published: April 2020

Seemingly bizarre cranial ornaments can be found among most major tetrapod groups. The casques (i.e., dorsal skull projections of bone surrounded by keratin sheathing) of modern cassowaries (Casuarius) are perhaps the most enigmatic of modern Aves. Both the biological role(s) and anatomical configuration of this headgear has been debated for the past 150 years, limiting our understanding of the life history of these unique birds as well as the selective conditions under which cranial elaborations appear in archosaurs. Because these structures are poorly understood, it is essential to set an osteo‐developmental foundation from which biomechanical, behavioral, physiological, and functional studies can radiate from. To address the commonly proposed roles of cassowary casques (e.g., ramming, vocalization, thermoregulation, display), we conducted μCT analyses of cranial anatomy in a developmental series of southern cassowaries (C. casuarius). This allowed us to describe details of both external and internal anatomy as well as timings of sutural fusions and inflations of casque elements. We compared the developmental timing of casques to physical, behavioral, and reproductive maturity to determine the plausibility of each function. Our sample (n = 130) indicates the majority of casque growth occurs prior to sexual maturity; although, casque morphology changes substantially throughout adulthood. Deviation from midline is particularly common in the casques of C. casuarius and such asymmetries appear to be primarily dextral. Form does not support functions for either physical ramming or vocalization; however, thermoregulation and display are not refuted by ontogeny nor adult phenotype, necessitating more focused future study.Support or Funding Information2019 New York Institute of Technology College of Osteopathic Medicine (Akinobu Watanabe)2019 Western Interior Paleontological Society ‐ Karl Hirsch Memorial Grant (Todd L. Green)2018 American Association of Anatomists ‐ Visiting Scholarship (Todd L. Green)2017 National Science Foundation ‐ Major Research Instrumentation Grant (Paul M. Gignac)2016 Western Interior Paleontological Society ‐ Karl Hirsch Memorial Grant (Todd L. Green)2015 National Science Foundation ‐ Early‐concept Grant for Exploratory Research (Paul M. Gignac)2015 National Science Foundation ‐ Division of Environmental Biology (Paul M. Gignac)
Obesity‐Induced Sympathoexcitation is Associated with Glial Senescence in the Brainstem
Authors: Monteiro Raisa , Sivasubramanian Mahesh Kumar , Balasubramanian Priya , Subramanian Madhan 
Published: April 2020

Previous studies from our laboratory showed that high fat diet‐induced obesity causes cellular senescence in the key brainstem region, the rostral ventrolateral medulla which is critical for the tonic and reflex control of sympathetic nervous system. Cellular senescence is characterized by a state of irreversible growth arrest and senescence‐associated secretory phenotype (SASP) in proliferating cells. In the current study, we wanted to investigate which cell type undergoes senescence in the brainstem in obesity. Neurons are post‐mitotic and do not undergo senescence, whereas glial cells can undergo senescence. Hence we hypothesized that obesity induces glial senescence in the brainstem. To address this hypothesis, 2‐month old C57BL/6J mice were fed with high fat diet (60% fat; n=5) and chow diet (10% fat; n=5) for 16 weeks. The animals were sacrificed at the end of the experiment, and their brains were collected for further processing. The freshly isolated brainstem was enzymatically digested (45 minutes, 37°C) and filtered through a 30μm mesh to form a cell suspension. Neuron isolation kit from Miltenyi Biotec was used to isolate glial and neuronal enriched cell population from the brainstem. RNA was extracted from these sorted cells and used for RT‐PCR analysis. Senescence was assessed using gene expression of cell cycle inhibitors and SASP factors. Data was analyzed by unpaired student’s t‐test and a p‐value less than 0.05 was considered statistically significant. We observed an increase in the gene expression of cell cycle inhibitors, p21 and p53 in the glial cell fraction isolated from the brainstem of obese mice compared to its lean counterparts. In addition, there was an increase in the mRNA levels of SASP factors such as the IL‐6 and MCP1 suggesting that obesity induces glial senescence in the brainstem. We were not able to obtain viable neurons for senescence analysis. Glial cells are known to play a supporting role in neuronal function through regulation of neurotransmission. Future studies will address glial cell specific mechanisms and understand how glia‐neuron crosstalk contributes to sympathetic nerve overactivity in obesity.Support or Funding InformationNIH‐HL148844 and RED account funds
Disruption of Metal Homeostasis and its Effect on Bacterial Growth and Antibiotic Resistance
Authors: Padyab Nika , Gallas Genna , Lozoya Maria , Veltri Charles , Hernandez Jose 
Published: April 2020

As effective as antibiotics have been since they were first discovered, antibiotic resistance proves to be a worldwide threat, endangering their efficacy. Over the years, there has been a significant decline in development of novel class antibiotics. These two factors have made once easily treated infections difficult to manage. Carbapenem‐resistant Enterobacteriaceae (CRE) are an emerging threat due to their high levels of antibiotic resistance. CRE have become resistant to almost all antibiotics, and cause 23,000 infections per year in the United States. Metals are a vital nutrient in all living organisms including bacteria and, have thus been targeted by antimicrobial agents. Bacteria, like all living organisms, must regulate their metal homeostasis in order to survive and replicate. Therefore, mechanisms able to diminish the availability of the metals to bacterial pathogens can be used to develop new therapeutic drugs.An example of a mechanism of bacterial resistance to antibiotics is the production of inactivating enzymes, such as carbapenemases, an example of which is seen in Klebsiella pneumoniae. Carbapenemases play an important role against b‐lactam antibiotics such as imipenem in Enterobacteriaceae. Carbapenemases are categorized based on their functional and molecular properties. Class B carbapenemases are metallo‐b‐lactamases (MBL) which require zinc in their active site, and are therefore considered metalloenzymes. MBL can hydrolyze all b‐lactams and are not inactivated by b‐lactamase inhibitors.In this study we analyzed antimicrobial susceptibility of K. pneumoniae isolates, KPC 2146, KPC 1705 and KPC 1706 which contain class B, class A and no carbapenemase, respectively. Metal homeostasis of isolates was disrupted by inducing zinc deficiency using TPEN, a metal chelator with high affinity for zinc, and preparing a zinc deficient minimal media. Carbapenemase activity was assessed using CARBA‐NP test and LC‐MS. Bacterial susceptibility of zinc‐deficient isolates to carbapenems was analyzed using spot plating, growth curve, minimum inhibitory concentration and ring of inhibition.Our findings demonstrate zinc dependency of class B carbapenemase in the KPC 2146 isolate, while class A carbapenemase in the KPC 1705 isolate was not affected. Spot plating and growth curve analyses demonstrated that zinc deficiency lowers bacterial growth in KPC 2146 in the presence of imipenem. Zinc deficiency via TPEN addition lowered imipenem, doripenem, ertapenem and meropenem MIC in KPC 2146. Ring of inhibition of KPC 2146 with imipenem was greatly affected by zinc chelation. In conclusion, we demonstrate that disrupting zinc homeostasis affects class B carbapenemase activity, which in turn increases bacterial susceptibility to carbapenems.Support or Funding InformationNika Padyab was supported by funds from the Biomedical Sciences Program at MWU. Drs. Veltri and Hernandez were supported by MWU intramural funds.
Rectovaginal septum and influencing factors in its morphology
Authors: Salinas-Alvarez Yolanda , Rodriguez-Abarca Maria Alejandra , Quiroga-Garza Alejandro , Guzman-Lopez Santos , Elizondo-Omaña Rodrigo Enrique , Jacobo-Baca Guillermo , de la Fuente-Villarreal David , de la Garza-Castro Oscar 
Published: April 2020

IntroductionThe rectovaginal septum (RVS) is a layer of dense fibro‐connective tissue, smooth muscle, and elastic and collagen fibers containing a neurovascular bundle of the inferior hypogastric plexus, providing support, innervation, and irrigation. It allows for mobility between the rectum and vagina and helps in limiting the spread of infections or tumors, as well as a guide for several types of surgeries. Any damage may predispose to rectocele, enterocele, fistula, constipation, incontinence, or sexual dysfunction.Currently, there is no consensus regarding the morphology (thickness or length). The objective of this study was to determine morphometric characteristics and variations in correlation to the number of pregnancies, method of delivery, parity and estrogenic exposure.Materials and methodsAn observational, cross‐sectional, retrospective, descriptive and comparative study was performed. Pelvic RMIs of Hispanic women from the northeast of México were obtained, with an age of 15 years and older. Those with gynecological pathology were excluded. Age, obstetrics and gynecology history was registered and the population was categorized by the number of pregnancies (nulligravida, 1–3 pregnancies, or ≥ 4 pregnancies), type of delivery (vaginal, cesarean section, or mixed), parity (primiparous or multiparous) and estrogen exposure (premenopause and postmenopause).ResultsA total of 102 RMIs were included, the mean age was 41.03 ± 15.23 years (range 15 to 77). A quarter (24.5%) of the patients were nulligravida, the rest (75.5%) being primi‐ or multigravida. Of those with previous pregnancies, vaginal delivery was the most common type (49.35%); 16.88% had a cesarean section, and 31.17% had a history of both types of delivery. Within the women who had a vaginal delivery, 19.6% were primipara and 41.2% were multipara; only 25.5% were postmenopause.The mean RVS length was 73.16 mm, with a thickness of 2.76, 2.24, and 2.53 mm for the upper, middle and lower thirds. In women with vaginal delivery, multiparous had a statistically significant longer RVS than primiparous (p 0.011), as well as a tendency of higher thickness, although the latter without statistical significance. Pre‐menopause women had statistically significant longer RVS (p 0.031) with a tendency to lose thickness towards post‐menopause.ConclusionThe morphology of RVS can be modified by different factors such as age, number of pregnancies, number of births and estrogenic exposure.
Factors That Limit Hispanic Representation in Medical Education: A Review of Hispanic Underrepresentation in Medical Education
Authors: Alaina Omar I. , Ynalvez Ruby A. , Ynalvez Marcus A. 
Published: April 2020

The underrepresentation of Hispanics in medical education poses a looming problem for the United States. The inability to produce a physician population that mirrors their patients leads to inadequate healthcare for individuals of all ethno‐racial backgrounds. By 2045, Hispanics are projected to make up the majority of the population. The U.S. is 30% Hispanic but only 4% of all current medical students are Hispanic. The objectives of this research were to: [1] analyze key academic, socioeconomic, and psychosocial factors that hinder Hispanics in entering medical schools, and [2] highlight the benefits of increasing Hispanic representation within medical education. A library research using electronic databases such as JSTOR, Proquest, and Medline was conducted. Fifty peer‐reviewed articles were selected, analyzed, and evaluated for their relevance. Relevancy was judged based on how well the articles addressed our objectives. The identification of key factors was done by surveying how often frequently these occurred in the literature.Our review identified multiple key factors. In terms of academics, Hispanics were limited by low GPA, MCAT scores, and gateway courses. In terms of socioeconomic factors, Hispanics were limited by household income and the high cost of obtaining a medical education. Lastly, key psychosocial‐related factors identified were a lack of Hispanic mentors, negative stereotype, stigmatization, micro aggression, and limited exposure to real life role models and to health careers. Our review shows that at any point in time, one or more of these factors play a limiting role in Hispanic students gaining admission into a medical school. To counter these hindrances, the following recommendations are in order: [1] create mentoring programs supported by medical schools for students in primary, secondary, and undergraduate levels; [2] devote resources to socially and economically disadvantaged areas by running summer internship programs, [3] create pipeline programs that are focused on URMs, and [4] encourage institutional change within medical education itself by seamlessly integrating cultural competency aspects into programs, curricula, courses, student orientation programs, and faculty training.Support or Funding InformationThis research was funded by the Texas A&M International University College of Arts and Sciences and ACT On IDEAS.