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  1. Article ; Online: Medical students' perception of their 'distance travelled' in medical school applications.

    Ellsworth, Brandon L / Solano, Quintin P / Evans, Julie / Bidwell, Serena S / Byrnes, Mary / Sandhu, Gurjit

    Medical education

    2023  Volume 58, Issue 2, Page(s) 204–215

    Abstract: Introduction: Within medical school's holistic review of applicants includes a review of their distance travelled to get to this point in their education. The AAMC defines distance travelled (DT) as, 'any obstacles or hardships you've overcome to get to ...

    Abstract Introduction: Within medical school's holistic review of applicants includes a review of their distance travelled to get to this point in their education. The AAMC defines distance travelled (DT) as, 'any obstacles or hardships you've overcome to get to this point in your education or any life challenges you've faced and conquered'. What medical students consider as their distance travelled has not been explored. The authors sought to identify the factors medical students perceive are important for medical school admissions to consider when assessing someone's 'distance travelled' by asking current medical students to share their DT experiences along with the barriers and facilitators they encountered on their medical school journey.
    Methods: The authors conducted semi-structured interviews with US medical students through purposeful sampling methods. The social-ecological model framework was used to develop questions to elicit participants' experiences that contributed to their distance travelled. Interviews were conducted in 2021 and ranged from 60-75 minutes. Transcribed interviews were qualitatively analysed using interpretive description.
    Results: A total of 31 medical students from seven medical schools were included in the study. Overall, participants defined distance travelled as an applicant's hardships (e.g. being the primary caregiver for a family member) and privileges (e.g. having physician parents) they experienced. Three major themes were identified: (1) individual-level characteristics and factors, (2) interpersonal relationships and (3) aspects of the participants' community and society.
    Discussion: Our findings show that medical school applicants considered DT to be a valuable component of a holistic medical school admission process. Participants' experiences of DT were varied and complex. Our research suggests that admissions teams for medical schools should incorporate more comprehensive recruitment practices and inclusive methodological frameworks to accurately capture the diversity of identities and experiences of medical school applicants and to consider the factors that shape their journey to medical schools.
    MeSH term(s) Humans ; Education, Medical ; Perception ; School Admission Criteria ; Schools, Medical ; Students, Medical
    Language English
    Publishing date 2023-07-23
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 195274-2
    ISSN 1365-2923 ; 0308-0110
    ISSN (online) 1365-2923
    ISSN 0308-0110
    DOI 10.1111/medu.15167
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Role of Microvessels in Oxygen Supply to Tissue.

    Ellsworth, Mary L / Ellis, Christopher G / Popel, Aleksander S / Pittman, Roland N

    News in physiological sciences : an international journal of physiology produced jointly by the International Union of Physiological Sciences and the American Physiological Society

    2018  Volume 9, Issue 3, Page(s) 119–123

    Abstract: Since the early work of August Krogh in 1919, capillaries have been assumed to be the sole supplier of oxygen for tissue. Recent studies provide convincing evidence that other microvessels also contribute to tissue oxygenation and that capillaries play a ...

    Abstract Since the early work of August Krogh in 1919, capillaries have been assumed to be the sole supplier of oxygen for tissue. Recent studies provide convincing evidence that other microvessels also contribute to tissue oxygenation and that capillaries play a much more complex role than originally proposed by Krogh.
    Language English
    Publishing date 2018-01-31
    Publishing country United States
    Document type Journal Article
    ZDB-ID 632842-8
    ISSN 1522-161X ; 0886-1714
    ISSN (online) 1522-161X
    ISSN 0886-1714
    DOI 10.1152/physiologyonline.1994.9.3.119
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Regulation of blood flow distribution in skeletal muscle: role of erythrocyte-released ATP.

    Ellsworth, Mary L / Sprague, Randy S

    The Journal of physiology

    2012  Volume 590, Issue 20, Page(s) 4985–4991

    Abstract: The maintenance of adequate tissue O(2) levels in skeletal muscle is vital for normal physiology and requires a well regulated and appropriately distributed convective O(2) supply. Inherent in this fundamental physiological process is the requirement for ...

    Abstract The maintenance of adequate tissue O(2) levels in skeletal muscle is vital for normal physiology and requires a well regulated and appropriately distributed convective O(2) supply. Inherent in this fundamental physiological process is the requirement for a mechanism which both senses tissue O(2) need and locally adjusts flow to appropriately meet that need. Over the past several years we and others have suggested that, in skeletal muscle, O(2) carrying erythrocytes participate in the regulation of total blood flow and its distribution by releasing ATP. Importantly, the release of this vasoactive molecule must be both rapid and well controlled if it is to serve an important physiological role. Here we provide insights into three distinct regulated signalling pathways within the erythrocyte that are activated by exposure to reduced O(2) tension or in response to binding of agonists to the prostacyclin or β-adrenergic receptors. Although much has been learned about the role of the erythrocyte in perfusion of skeletal muscle, much remains to be understood. However, what is clear is that the long established passive carrier of O(2) also contributes to the regulation of the distribution of microvascular perfusion in skeletal muscle by virtue of its capacity to release ATP.
    MeSH term(s) Adenosine Triphosphate/metabolism ; Animals ; Epoprostenol/metabolism ; Erythrocytes/metabolism ; Humans ; Muscle, Skeletal/blood supply ; Muscle, Skeletal/metabolism ; Oxygen/metabolism ; Regional Blood Flow/physiology
    Chemical Substances Adenosine Triphosphate (8L70Q75FXE) ; Epoprostenol (DCR9Z582X0) ; Oxygen (S88TT14065)
    Language English
    Publishing date 2012-05-14
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 3115-x
    ISSN 1469-7793 ; 0022-3751
    ISSN (online) 1469-7793
    ISSN 0022-3751
    DOI 10.1113/jphysiol.2012.233106
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Erythrocyte-derived ATP and perfusion distribution: role of intracellular and intercellular communication.

    Sprague, Randy S / Ellsworth, Mary L

    Microcirculation (New York, N.Y. : 1994)

    2012  Volume 19, Issue 5, Page(s) 430–439

    Abstract: In complex organisms, both intracellular and intercellular communication are critical for the appropriate regulation of the distribution of perfusion to assure optimal O(2) delivery and organ function. The mobile erythrocyte is in a unique position in ... ...

    Abstract In complex organisms, both intracellular and intercellular communication are critical for the appropriate regulation of the distribution of perfusion to assure optimal O(2) delivery and organ function. The mobile erythrocyte is in a unique position in the circulation as it both senses and responds to a reduction in O(2) tension in its environment. When erythrocytes enter a region of the microcirculation in which O(2) tension is reduced, they release both O(2) and the vasodilator, ATP, via activation of a specific and dedicated signaling pathway that requires increases in cAMP, which are regulated by PDE3B. The ATP released initiates a conducted vasodilation that results in alterations in the distribution of perfusion to meet the tissue's metabolic needs. This delivery mechanism is modulated by both positive and negative feedback regulators. Importantly, defects in low O(2) -induced ATP release from erythrocytes have been observed in several human disease states in which impaired vascular function is present. Understanding of the role of erythrocytes in controlling perfusion distribution and the signaling pathways that are responsible for ATP release from these cells makes the erythrocyte a novel therapeutic target for the development of new approaches for the treatment of vascular dysfunction.
    MeSH term(s) Adenosine Triphosphate/metabolism ; Animals ; Cyclic Nucleotide Phosphodiesterases, Type 3/metabolism ; Erythrocytes/metabolism ; Humans ; Oxygen/metabolism ; Signal Transduction ; Vascular Diseases/metabolism ; Vascular Diseases/physiopathology ; Vascular Diseases/therapy ; Vasodilation
    Chemical Substances Adenosine Triphosphate (8L70Q75FXE) ; Cyclic Nucleotide Phosphodiesterases, Type 3 (EC 3.1.4.17) ; PDE3B protein, human (EC 3.1.4.17) ; Oxygen (S88TT14065)
    Language English
    Publishing date 2012-07-06
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 1217758-1
    ISSN 1549-8719 ; 1073-9688
    ISSN (online) 1549-8719
    ISSN 1073-9688
    DOI 10.1111/j.1549-8719.2011.00158.x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Red blood cell-derived ATP as a regulator of skeletal muscle perfusion.

    Ellsworth, Mary L

    Medicine and science in sports and exercise

    2004  Volume 36, Issue 1, Page(s) 35–41

    Abstract: Blood flow to skeletal muscle is a complex process designed to provide adequate, yet not excessive, amounts of oxygen to meet the ever-changing metabolic needs of the tissue. To accomplish this goal, a mechanism must exist that couples the oxygen needs ... ...

    Abstract Blood flow to skeletal muscle is a complex process designed to provide adequate, yet not excessive, amounts of oxygen to meet the ever-changing metabolic needs of the tissue. To accomplish this goal, a mechanism must exist that couples the oxygen needs of the tissue with the oxygen delivery system. A number of mechanisms have been investigated that have focused primarily on the vessel or tissue supplied. However, because none of these was able to adequately explain the precision inherent in oxygen supply, we began to investigate the potential role of the mobile oxygen carrier itself, the red blood cell. This review will provide evidence in support of the idea that the red blood cell is able to both sense oxygen need and evoke changes in blood flow to meet that need. In this scheme, as a red blood cell enters a region of increased metabolic demand relative to supply, the fall in hemoglobin oxygen saturation evokes the release of ATP, found within the red blood cell in mM amounts. The released ATP binds to purinergic receptors located on the vascular endothelium and induces a vasodilation that is conducted upstream increasing oxygen supply to the region of tissue supplied by the vessel. Although this mechanism is likely only one component of a complex system, which precisely regulates blood flow, we suggest that it plays a vital role in the regulation of perfusion distribution within tissue.
    MeSH term(s) Adenosine Triphosphate/blood ; Adenosine Triphosphate/pharmacology ; Adenosine Triphosphate/physiology ; Animals ; Erythrocytes/metabolism ; Humans ; Muscle, Skeletal/blood supply ; Muscle, Skeletal/metabolism ; Oxygen/blood ; Oxygen Consumption ; Partial Pressure ; Regional Blood Flow
    Chemical Substances Adenosine Triphosphate (8L70Q75FXE) ; Oxygen (S88TT14065)
    Language English
    Publishing date 2004-01
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, P.H.S. ; Review
    ZDB-ID 603994-7
    ISSN 1530-0315 ; 0195-9131 ; 0025-7990
    ISSN (online) 1530-0315
    ISSN 0195-9131 ; 0025-7990
    DOI 10.1249/01.MSS.0000106284.80300.B2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Vascular disease in pre-diabetes: new insights derived from systems biology.

    Sprague, Randy S / Ellsworth, Mary L

    Missouri medicine

    2010  Volume 107, Issue 4, Page(s) 265–269

    Abstract: In many cases vascular disease is present before the clinical onset of type 2 diabetes, that is, during the pre-diabetic period when insulin levels are markedly increased. In pre-diabetes, microvascular dysfunction correlates with plasma insulin levels ... ...

    Abstract In many cases vascular disease is present before the clinical onset of type 2 diabetes, that is, during the pre-diabetic period when insulin levels are markedly increased. In pre-diabetes, microvascular dysfunction correlates with plasma insulin levels and not blood glucose. Here we discuss the concept that insulin, at levels found in pre-diabetes, contributes to microvascular disease in skeletal muscle by inhibiting the release of the vasodilator, adenosine triphosphate (ATP), from erythrocytes.
    MeSH term(s) Adenosine Triphosphate/blood ; Diabetes Mellitus, Type 2/blood ; Diabetes Mellitus, Type 2/complications ; Diabetes Mellitus, Type 2/physiopathology ; Diabetic Angiopathies/blood ; Diabetic Angiopathies/physiopathology ; Endothelium, Vascular/metabolism ; Humans ; Insulin/blood ; Microvessels/physiopathology ; Oxygen/blood ; Prediabetic State/blood ; Prediabetic State/physiopathology ; Systems Biology ; Vascular Diseases/blood ; Vascular Diseases/physiopathology
    Chemical Substances Insulin ; Adenosine Triphosphate (8L70Q75FXE) ; Oxygen (S88TT14065)
    Language English
    Publishing date 2010-02-20
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 427362-x
    ISSN 0026-6620
    ISSN 0026-6620
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Synergistic effects of C-peptide and insulin on low O2-induced ATP release from human erythrocytes.

    Richards, Jennifer P / Stephenson, Alan H / Ellsworth, Mary L / Sprague, Randy S

    American journal of physiology. Regulatory, integrative and comparative physiology

    2013  Volume 305, Issue 11, Page(s) R1331–6

    Abstract: Erythrocytes participate in the matching of oxygen (O2) delivery with local need in skeletal muscle via the release of O2 and the vasodilator, ATP. It was reported that a concentration of insulin found in humans with insulin resistance inhibits low O2- ... ...

    Abstract Erythrocytes participate in the matching of oxygen (O2) delivery with local need in skeletal muscle via the release of O2 and the vasodilator, ATP. It was reported that a concentration of insulin found in humans with insulin resistance inhibits low O2-induced ATP release. However, in vivo, insulin is coreleased with connecting peptide (C-peptide) at equimolar concentrations, but because of the shorter insulin half-life, the peptides circulate at ratios of C-peptide to insulin ranging from 1:1 to 6:1. Here, we investigate the hypothesis that C-peptide and insulin work synergistically to maintain low O2-induced ATP release from human erythrocytes. Using a thin-film tonometer to alter O2 tension, we determined that either C-peptide or insulin alone inhibits low O2-induced ATP release in a concentration-dependent manner; however, coadministration of the peptides at a 1:1 ratio does not (n = 5; P < 0.05). Because this ratio of C-peptide to insulin is not present in vivo for extended periods, we also investigated the effect of additional physiological ratios on ATP release. In the presence of insulin concentrations that would be found in fasting humans (0.05 nM), C-peptide to insulin ratios of 4:1 and 6:1 did not adversely affect low O2-induced ATP release. However, at a concentration of insulin found in the peripheral circulation of humans under postprandial conditions (0.5 nM), a ratio of C-peptide to insulin of 6:1 inhibited low O2-induced ATP release (n = 5). These findings demonstrate a heretofore unrecognized synergism between C-peptide and insulin that could have physiological importance in the regulation of perfusion distribution in skeletal muscle.
    MeSH term(s) Adenosine Triphosphate/metabolism ; Adult ; Aged ; C-Peptide/pharmacology ; Cyclic AMP/blood ; Drug Synergism ; Erythrocytes/drug effects ; Erythrocytes/metabolism ; Female ; Humans ; Insulin/pharmacology ; Male ; Middle Aged ; Muscle, Skeletal/metabolism ; Oxygen/metabolism ; Young Adult
    Chemical Substances C-Peptide ; Insulin ; Adenosine Triphosphate (8L70Q75FXE) ; Cyclic AMP (E0399OZS9N) ; Oxygen (S88TT14065)
    Language English
    Publishing date 2013-10-02
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 603839-6
    ISSN 1522-1490 ; 0363-6119
    ISSN (online) 1522-1490
    ISSN 0363-6119
    DOI 10.1152/ajpregu.00341.2013
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Small prizes increased healthful school lunch selection in a Midwestern school district.

    Siegel, Robert / Lockhart, Mary Kate / Barnes, Allison S / Hiller, Elizabeth / Kipp, Roger / Robison, Debora L / Ellsworth, Samantha C / Hudgens, Michelle E

    Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme

    2016  Volume 41, Issue 4, Page(s) 370–374

    Abstract: As obesity has become a pressing health issue for American children, greater attention has been focused on how schools can be used to improve how students eat. Previously, we piloted the use of small prizes in an elementary school cafeteria to improve ... ...

    Abstract As obesity has become a pressing health issue for American children, greater attention has been focused on how schools can be used to improve how students eat. Previously, we piloted the use of small prizes in an elementary school cafeteria to improve healthful food selection. We hoped to increase healthful food selection in all the elementary schools of a small school district participating in the United States Department of Agriculture Lunch Program by offering prizes to children who selected a Power Plate (PP), which consisted of an entrée with whole grains, a fruit, a vegetable, and plain low-fat milk. In this study, the PP program was introduced to 3 schools sequentially over an academic year. During the kickoff week, green, smiley-faced emoticons were placed by preferred foods, and children were given a prize daily if they chose a PP on that day. After the first week, students were given a sticker or temporary tattoo 2 days a week if they selected a PP. Combining data from the 3 schools in the program, students increased PP selection from 4.5% at baseline to 49.4% (p < 0.0001) during an intervention period of 2.5 school weeks. The school with the longest intervention period, 6 months, showed a PP selection increase of from 3.9% to 26.4% (p < 0.0001). In conclusion, giving small prizes as rewards dramatically improves short-term healthful food selection in elementary school children.
    MeSH term(s) Animals ; Child ; Choice Behavior ; Female ; Food Preferences ; Food Services ; Fruit ; Health Behavior ; Healthy Diet ; Humans ; Lunch ; Male ; Milk ; Reward ; Schools ; Socioeconomic Factors ; Students ; United States ; Vegetables ; Whole Grains
    Language English
    Publishing date 2016-04
    Publishing country Canada
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2236708-1
    ISSN 1715-5320 ; 1715-5312
    ISSN (online) 1715-5320
    ISSN 1715-5312
    DOI 10.1139/apnm-2015-0535
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Towards a multiscale description of microvascular flow regulation

    DanielGoldman / MaryL.Ellsworth

    Frontiers in Physiology, Vol

    O2-dependent release of ATP from human erythrocytes and the distribution of ATP in capillary networks

    2012  Volume 3

    Abstract: Integration of the numerous mechanisms that have been suggested to contribute to optimization of O2 supply to meet O2 need in skeletal muscle requires a systems biology approach which permits quantification of these physiological processes over a wide ... ...

    Abstract Integration of the numerous mechanisms that have been suggested to contribute to optimization of O2 supply to meet O2 need in skeletal muscle requires a systems biology approach which permits quantification of these physiological processes over a wide range of length scales. Here we describe two individual computational models based on in vivo and in vitro studies which, when incorporated into a single robust multiscale model, will provide information on the role of erythrocyte-released ATP in perfusion distribution in skeletal muscle under both physiological and pathophysiological conditions. Healthy human erythrocytes exposed to low O2 tension release ATP via a well characterized signaling pathway requiring activation of the G-protein, Gi, and adenylyl cyclase leading to increases in cAMP. This cAMP then activates PKA and subsequently CFTR culminating in ATP release via pannexin 1. A critical control point in this pathway is the level of cAMP which is regulated by pathway-specific phosphodiesterases. Using time constants (~100ms) that are consistent with measured erythrocyte ATP release, we have constructed a dynamic model of this pathway. The model predicts levels of ATP release consistent with measurements obtained over a wide range of hemoglobin O2 saturations (sO2). The model further predicts how insulin, at concentrations found in prediabetes, enhances the activity of PDE3 and reduces intracellular cAMP levels leading to decreased low O2-induced ATP release from erythrocytes. The second model, which couples O2 and ATP transport in capillary networks, shows how intravascular ATP and the resulting conducted vasodilation are affected by local sO2, convection and ATP degradation. This model also predicts network-level effects of decreased ATP release resulting from elevated insulin levels. Taken together, these models lay the groundwork for investigating the systems biology of the regulation of microvascular perfusion distribution by erythrocyte-derived ATP.
    Keywords ATP transport model ; O2 transport model ; oxygen supply regulation ; signal pathway modeling ; capillary networks ; Physiology ; QP1-981 ; Science ; Q
    Subject code 570
    Language English
    Publishing date 2012-07-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: Liposomal delivery of a phosphodiesterase 3 inhibitor rescues low oxygen-induced ATP release from erythrocytes of humans with type 2 diabetes.

    Dergunov, Sergey A / Bowles, Elizabeth A / Gordon, Weston / Green, Michael / Bierman, August / Ellsworth, Mary L / Pinkhassik, Eugene / Sprague, Randy S

    Biochemistry and biophysics reports

    2015  Volume 2, Page(s) 137–142

    Abstract: ATP release from erythrocytes in response to low oxygen tension requires an increase in cAMP, the level of which is regulated by phosphodiesterase 3 (PDE3). Such release is defective in erythrocytes of humans with type 2 diabetes (DM2). This study tested ...

    Abstract ATP release from erythrocytes in response to low oxygen tension requires an increase in cAMP, the level of which is regulated by phosphodiesterase 3 (PDE3). Such release is defective in erythrocytes of humans with type 2 diabetes (DM2). This study tested a hypothesis that direct delivery of the clinically useful PDE3 inhibitor, cilostazol, to erythrocytes of humans with type 2 diabetes using liposomes would restore low-oxygen tension-induced ATP release. Cilostazol was incorporated into liposomes prepared from dimyristoylphosphatidylcholine (DMPC). Liposome-delivery of cilostazol restored ATP release from DM2 erythrocytes to levels which were not different from that released from non-cilostazol treated healthy erythrocytes under the same conditions. There were no observed adverse effects of the liposomes on either healthy or DM2 erythrocytes. The directed liposomal delivery of PDE inhibitors to erythrocytes may help prevent or slow the development of peripheral vascular disease in individuals with DM2 by restoring an important physiological controller of microvascular perfusion while minimizing side effects associated with systemic delivery of some of these inhibitors.
    Language English
    Publishing date 2015-05-30
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 2831046-9
    ISSN 2405-5808 ; 2405-5808
    ISSN (online) 2405-5808
    ISSN 2405-5808
    DOI 10.1016/j.bbrep.2015.05.011
    Database MEDical Literature Analysis and Retrieval System OnLINE

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